Metabolic syndrome

During digestion, the sugar (glucose) in the food you eat is absorbed into your blood stream. Insulin from your pancreas escorts glucose into your cells, where it provides energy for your body. Excess glucose is store in your liver.

Definition

Metabolic syndrome is a cluster of conditions that occur together, increasing your risk of heart disease, stroke and diabetes.

Having just one of these conditions — increased blood pressure, elevated insulin levels, excess body fat around the waist or abnormal cholesterol levels — isn't diagnosed as metabolic syndrome, but it does contribute to your risk of serious disease. If more than one of these conditions occur in combination, your risk is even greater.

If you have metabolic syndrome or any of the components of metabolic syndrome, you have the opportunity to make aggressive lifestyle changes. Making these changes can delay or derail the development of serious diseases that may result from metabolic syndrome.


Symptoms

Having metabolic syndrome means you have several disorders related to your metabolism at the same time, including:

* Obesity, particularly around your waist (having an "apple shape")
* Elevated blood pressure
* An elevated level of the blood fat called triglycerides and a low level of high-density lipoprotein (HDL) cholesterol — the "good" cholesterol
* Resistance to insulin, a hormone that helps to regulate the amount of sugar in your body

Having one component of metabolic syndrome means you're more likely to have others. And the more components you have, the greater are the risks to your health.


Causes
Normal metabolism
Type 2 diabetes

Research into the complex underlying process linking the group of conditions involved in metabolic syndrome is ongoing. As the name suggests, metabolic syndrome is tied to your body's metabolism, possibly to a condition called insulin resistance. Insulin is a hormone made by your pancreas that helps control the amount of sugar in your bloodstream.

Normally, your digestive system breaks down some of the foods you eat into sugar (glucose). Your blood carries the glucose to your body's tissues, where the cells use it as fuel. Glucose enters your cells with the help of insulin. In people with insulin resistance, cells don't respond normally to insulin, and glucose can't enter the cells as easily. Your body reacts by churning out more and more insulin to help glucose get into your cells. The result is higher than normal levels of both insulin and glucose in your blood.

Although perhaps not high enough to qualify as diabetes, an elevated glucose level still interferes with your body processes. Increased insulin raises your triglyceride level and other blood fat levels. It also interferes with how your kidneys work, leading to higher blood pressure. These combined effects of insulin resistance put you at risk of heart disease, stroke, diabetes and other conditions.


Combination of factors

Researchers are still learning what causes insulin resistance. It probably involves a variety of genetic and environmental factors. They think some people are genetically prone to insulin resistance, inheriting the tendency from their parents. But being overweight and inactive are major contributors.

Disagreement among experts

Not all experts agree on the definition of metabolic syndrome or whether it even exists as a distinct medical condition. Doctors have talked about this constellation of risk factors for years and have called it many names, including syndrome X and insulin resistance syndrome. Whatever it's called, and however it's precisely defined, this collection of risk factors is apparently becoming more prevalent.



Type 2 diabetes develops when your pancreas doesn't produce enough insulin or your cells becomes resistant to insulin.


Risk factors

The following factors increase your chances of having metabolic syndrome:

Age.
The prevalence of metabolic syndrome increases with age, affecting less than 10 percent of people in their 20s and 40 percent of people in their 60s. However, some research shows that about one in eight schoolchildren has three or more components of metabolic syndrome. And, other research has identified an association between childhood metabolic syndrome and adult cardiovascular disease decades later.

Race.
Hispanics and Asians seem to be at greater risk of metabolic syndrome than other races are.

Obesity.
A body mass index (BMI) — a measure of your percentage of body fat based on height and weight — greater than 25 increases your risk of metabolic syndrome. So does abdominal obesity — having an apple shape rather than a pear shape.

History of diabetes.
You're more likely to have metabolic syndrome if you have a family history of type 2 diabetes or a history of diabetes during pregnancy (gestational diabetes).

Other diseases.
A diagnosis of high blood pressure, cardiovascular disease or polycystic ovary syndrome — a similar type of metabolic problem that affects a woman's hormones and reproductive system — also increases your risk of metabolic syndrome.


When to seek medical advice

If you know you have at least one aspect of metabolic syndrome — such as high blood pressure, high cholesterol or an apple-shaped body — you may have the others and not know it. It's worth checking with your doctor. Ask whether you need testing for other components of the syndrome and what you can do to avoid serious diseases.


Tests and diagnosis

Although your doctor is not typically looking for "metabolic syndrome," the label may apply if you have three or more of the traits associated with this condition.

Several organizations have criteria for diagnosing metabolic syndrome. These guidelines were created by the National Cholesterol Education Program (NCEP) with modifications by the American Heart Association. According to these guidelines, you have metabolic syndrome if you have three or more of these traits:

Elevated waist circumference, greater than 35 inches for women and 40 inches for men. Certain genetic risk factors, such as having a family history of diabetes or being of Asian descent — which increases your risk of insulin resistance — lower the waist circumference limit. If you have one of these genetic risk factors, waist circumference limits are 31 to 35 inches for women and 37 to 39 inches for men.

Elevated level of triglycerides of 150 milligrams per deciliter (mg/dL) or higher, or you're receiving treatment for high triglycerides.
Reduced HDL (less than 40 mg/dL in men or less than 50 mg/dL in women) or you're receiving treatment for low HDL.

Elevated blood pressure of 130 millimeters of mercury (mm Hg) systolic (the top number) or higher or 85 mm Hg diastolic (the bottom number) or higher, or you're receiving treatment for high blood pressure.

Elevated fasting blood sugar (blood glucose) of 100 mg/dL or higher, or you're receiving treatment for high blood sugar.


Treatments and drugs

Tackling one of the risk factors of metabolic syndrome is tough — taking on all of them might seem overwhelming. But aggressive lifestyle changes and, in some cases, medication can improve all of the metabolic syndrome components. Getting more physical activity, losing weight and quitting smoking help reduce blood pressure and improve cholesterol and blood sugar levels. These changes are key to reducing your risk.

Exercise. Doctors recommend getting 30 to 60 minutes of moderate intensity exercise, such as brisk walking, every day.

Lose weight. Losing as little as 5 percent to 10 percent of your body weight can reduce insulin levels and blood pressure and decrease your risk of diabetes.

Eat healthy. The Dietary Approaches to Stop Hypertension (DASH) diet and the Mediterranean Diet, like many healthy-eating plans, limit unhealthy fats and emphasize fruits, vegetables, fish and whole grains. Both of these dietary approaches have been found to offer important health benefits - in addition to weight loss - for people who have components of metabolic syndrome. Ask your doctor for guidance before starting a new eating plan.

Stop smoking. Smoking cigarettes increases insulin resistance and worsens the health consequences of metabolic syndrome. Talk to your doctor if you need help kicking the cigarette habit.

Work with your doctor to monitor your weight and your blood glucose, cholesterol and blood pressure levels to ensure that lifestyle modifications are working. If you're not able to achieve your goals with lifestyle changes, your doctor may also prescribe medications to lower blood pressure, control cholesterol or help you lose weight. Insulin sensitizers may be prescribed to help your body use insulin more effectively. Aspirin therapy may help reduce your risk of heart attack and stroke.


Prevention
Mayo Clinic Healthy Weight Pyramid


The Mayo Clinic Healthy Weight Pyramid is a tool to help you lose weight or maintain your weight. It focuses on nutritious foods that contacin a small number of calories in a large amount of food - such as fruits, begetables, legumes, poultry, fish or whole grains. Fruits and vegetables, allowed in unlimited amounts, form the foundation of the pyramid. This pyramid also recommends healthy food choices within each food group. Candy and other processed sweets are acceptable, but in moderation - up tp 75 calories daily.


Whether you have one, two or none of the components of metabolic syndrome, the following lifestyle changes will reduce your risk of heart disease, diabetes and stroke:

Commit to a healthy diet. Eat plenty of fruits and vegetables. Choose lean cuts of white meat or fish over red meat. Avoid processed or deep-fried foods. Eliminate table salt and experiment with other herbs and spices.

Get moving. Get plenty of regular, moderately strenuous physical activity.

Schedule regular checkups. Check your blood pressure, cholesterol and blood sugar levels on a regular basis. Make additional lifestyle modifications if the numbers are going the wrong.


Lifestyle and home remedies

You can do something about your risk of metabolic syndrome and its complications — diabetes, stroke and heart disease. You can begin to curb your insulin resistance by making these lifestyle changes:

Lose weight. Losing as little as 5 percent to 10 percent of your body weight can reduce insulin levels and blood pressure, and decrease your risk of diabetes.

Exercise. Doctors recommend getting 30 to 60 minutes of moderate-intensity exercise, such as brisk walking, every day.

Stop smoking. Smoking cigarettes increases insulin resistance and worsens the health consequences of metabolic syndrome. Talk to your doctor if you need help kicking the cigarette habit.

Eat fiber-rich foods. Make sure you include whole grains, beans, fruits and vegetables in your grocery cart. These items are packed with dietary fiber, which can lower your insulin levels.

Polycystic Ovary Syndrome from Mayo Clinic

PCOS is a disorder involving irregular menstrual periods and excess androgen level. The ovaries develop cysts (above right) and may failed to release eggs.


Definition

Polycystic ovary syndrome (PCOS) is a common condition characterized by irregular menstrual periods, excess hair growth and obesity, though it can affect women in a variety of ways.

The exact cause of polycystic ovary syndrome is unknown, but the condition stems from a disruption in the monthly reproductive cycle. The name polycystic ovary syndrome comes from the appearance of the ovaries in some women with the disorder — large and studded with numerous cysts (polycystic).

Polycystic ovary syndrome affects about one in 10 women in the United States and is the leading cause of infertility in women. Early diagnosis and treatment of polycystic ovary syndrome can help reduce the risk of long-term complications, which include diabetes and heart disease.


Symptoms
Polycystic ovary syndrome

Women with polycystic ovary syndrome usually have at least several of the many signs and symptoms associated with PCOS, including:


Irregular or no menstruation.

This is the most common characteristic. Irregular menstruation means having menstrual cycles that occur at intervals longer than 35 days or fewer than eight times a year. The condition may begin in adolescence with the onset of menstruation, or it may appear later after a weight gain.


Signs of excess androgen.

Elevated levels of male hormones may result in physical signs, such as long, coarse hair on your face, chest, lower abdomen, back, upper arms or upper legs (hirsutism); acne; and male-pattern baldness (alopecia). However, not all women who have polycystic ovary syndrome have physical signs of androgen excess.


Enlarged ovaries with multiple cysts.

Your doctor may detect ovarian cysts by ultrasound. However, you may have ovaries with multiple cysts but still not have polycystic ovary syndrome. And you may have PCOS but have ovaries that appear normal.


Infertility.

Polycystic ovary syndrome is the most common cause of female infertility in the United States.


Obesity.

It's estimated that about half of women with polycystic ovary syndrome are obese.


Skin tags.

These small, excess growths of skin that are usually found on your neck or in your armpit are common in women with PCOS.


Prediabetes or type 2 diabetes.

The ability to use insulin effectively is impaired in PCOS and can result in high blood sugar levels and diabetes. Prediabetes is also called impaired glucose tolerance.


Acanthosis nigricans.

This is the medical term for darkened, velvety skin on the nape of your neck, armpits, inner thighs, vulva or under your breasts.

Additionally, the following are more likely to occur in women with PCOS:
* High blood pressure
* High blood cholesterol
* Elevated levels of C-reactive protein, which may be associated with cardiovascular problems
* Nonalcoholic steatohepatitis, a liver disease
* Sleep apnea


Causes

The intricate process of a woman's reproductive cycle is regulated by fluctuating levels of hormones produced by the pituitary gland in your brain, including luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and by your ovaries.

The ovaries secrete the female hormones estrogen and progesterone and also produce some androgens, the so-called male hormones. Androgens include testosterone, androstenedione and dehydroepiandrosterone (DHEA).

In polycystic ovary syndrome, your body produces an excess of androgens, and your ratio of LH to FSH is often abnormally high. The process of ovaries releasing eggs (ovulation) occurs less frequently than normal (oligo-ovulation), or the ovaries don't release eggs at all (anovulation). In the absence of ovulation, the menstrual cycle is irregular or absent.

Doctors don't know the cause of polycystic ovary syndrome, but research suggests a link to excess insulin, the hormone produced in the pancreas that allows cells to use sugar (glucose), your body's primary energy supply. By several mechanisms, excess insulin is thought to boost androgen production by your ovaries. Studies also indicate that genetic factors may play a role in PCOS.


When to seek medical advice

Early diagnosis and treatment of polycystic ovary syndrome may help reduce your risk of long-term complications, such as diabetes and heart disease.

Talk with your doctor if you have irregular, scant or no menstrual periods, are overweight, and have acne or excess facial hair growth. Your doctor may refer you to a doctor who specializes in hormonal disorders (endocrinologist).


Tests and diagnosis
Pelvic examination


As part f the pelvic examination, your doctor will insert two gloved fingers inside your vagina. While simultaneously pressing down on your abdomen, he or she can examine your uterus, ovaries and other organs.

There's no specific test to definitively diagnose polycystic ovary syndrome. The diagnosis is one of exclusion, which means your doctor considers all of your signs and symptoms and then rules out other possible disorders.

Besides a complete physical examination, including a pelvic examination, other tests you may have include:

Blood tests.

Your blood may be drawn for laboratory tests to measure levels of several hormones. These may include testosterone, DHEA sulfate, luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17-hydroxy progesterone, prolactin, and thyroid-stimulating hormone (TSH), which triggers the release of thyroid hormone from the thyroid gland. Additional blood testing may include fasting glucose, cholesterol and triglyceride levels.

Ultrasound.

Your doctor may request a pelvic ultrasound to check your ovaries and the thickness of the lining of your uterus. Ultrasound exams are painless. While you relax on a bed or examining table, a wand-like device (transducer) is placed on your body or in your vagina (transvaginal ultrasound). It emits inaudible sound waves that are translated into images on a computer.

Complications

Having polycystic ovary syndrome puts you at increased risk of:

* Type 2 diabetes
* High blood pressure
* Increased triglycerides
* Decreased high-density lipoprotein (HDL) cholesterol, the so-called "good" cholesterol
* Cardiovascular disease
* Metabolic syndrome, a cluster of signs and symptoms that indicate a significantly increased risk of cardiovascular disease

Because PCOS disrupts the reproductive cycle and exposes the uterus to a constant supply of estrogen, women with PCOS are at risk of:

*Abnormal uterine bleeding
* Cancer of the uterine lining (endometrial cancer)

Pregnancy concerns
You may need treatment with fertility medications to become pregnant if you have polycystic ovary syndrome. During pregnancy, you may be at increased risk of gestational diabetes and pregnancy-induced high blood


Treatments and drugs

Polycystic ovary syndrome treatment generally focuses on management of your individual main concerns, such as infertility, hirsutism, acne or obesity.

Long term, the most important aspect of treatment is managing cardiovascular risks, such as obesity, high blood cholesterol, diabetes and high blood pressure. To help guide ongoing treatment decisions, your doctor will likely want to see you for regular visits to perform a physical examination, measure your blood pressure and obtain fasting glucose and lipid levels.

You may benefit from counseling about healthy-eating choices and regular exercise. This is particularly important if you're overweight. Obesity makes insulin resistance worse. Weight loss can reduce both insulin and androgen levels, and may restore ovulation. Ask your doctor to recommend a weight-control program, and meet regularly with a dietitian.

Your doctor may prescribe one or more medications to help manage the symptoms and risks associated with PCOS.

Medications for regulating your menstrual cycle
If you're not trying to become pregnant, your doctor may prescribe low-dose oral contraceptives that combine synthetic estrogen and progesterone. They decrease androgen production and give your body a break from the effects of continuous estrogen. This decreases your risk of endometrial cancer and corrects abnormal bleeding.

An alternative approach is taking progesterone for seven to 10 days each month. This regulates your menstrual cycle and offers protection against endometrial cancer, but it doesn't improve androgen levels.

Your doctor also may prescribe metformin (Glucophage, Glucophage XR), an oral medication for type 2 diabetes that treats insulin resistance. This drug is still being studied as a treatment for polycystic ovary syndrome, but research has demonstrated that it improves ovulation and may reduce androgen levels. However, doctors don't yet know if metformin offers the same protection against endometrial cancer as does treatment with oral contraceptives or with progesterone alone.

Medications for reducing excessive hair growth
Your doctor may add a medication specifically targeted at countering the effects of excess androgen. Spironolactone (Aldactone) blocks the effects of androgen and reduces new androgen production. For those reasons, the drug isn't recommended if you're pregnant or planning to become pregnant. Spironolactone is also a diuretic and may cause you to urinate more frequently.

Your doctor might also prescribe eflornithine (Vaniqa), a prescription cream that slows facial hair growth in women. This medication is effective for about one-third of the women who use it. Avoid using this medication during pregnancy.

Medications for achieving pregnancy
To become pregnant, you may need a medication to trigger ovulation. Clomiphene (Clomid, Serophene) is an oral anti-estrogen medication that you take in the first part of your menstrual cycle. If clomiphene alone isn't effective, your doctor may add metformin to help trigger ovulation.

A study published in the New England Journal of Medicine compared the use of clomiphene and metformin, as well as a combination of the two medications, for achieving pregnancy. The study found that clomiphene was significantly more effective at helping women conceive than was metformin alone. About 80 percent of women are able to conceive using clomiphene, and it's estimated that 50 percent of women taking clomiphene have a baby.

If you don't become pregnant using clomiphene and metformin, your doctor may recommend using gonadotropins — follicle-stimulating hormone (FSH) and luteinizing hormone (LH) medications that are administered by injection. Because many women with PCOS have elevated levels of LH, your doctor may recommend treatment with FSH alone.

With clomiphene or gonadotropins, the risk of multiple births — twins or more — is increased.

Surgery
If medications don't help you become pregnant, your doctor rarely may recommend an outpatient surgery called laparoscopic ovarian drilling.

In this procedure, a surgeon makes a small incision in your abdomen and inserts a tube attached to a tiny camera (laparoscope). The camera provides the surgeon with detailed images of your ovaries and neighboring pelvic organs. The surgeon then inserts surgical instruments through other small incisions and uses electrical or laser energy to burn holes in enlarged follicles on the surface of the ovaries. The goal is to stimulate ovulation by reducing levels of LH and androgen hormones.

Hair removal
Several options besides prescription medications exist for hair removal. They include shaving, plucking and over-the-counter remedies such as waxes, gels, creams and lotions (depilatories). However, depilatories may irritate your skin, so follow package directions and on first use, apply the product to an inconspicuous area to determine if it's suitable for you. The results may last several weeks, then you must repeat treatment.

Options for longer lasting hair removal include:

Electrolysis.
To permanently remove excess hair, some women undergo electrolysis in addition to medical therapy. A fine needle is inserted into the hair follicle and electric current is applied to kill the follicle. Because only one follicle can be treated at a time, this method isn't useful for large areas of the body. Several treatments are usually necessary. Scarring or, rarely, skin infections may occur. Home electrolysis kits usually are ineffective because the hair follicle is deep in the skin, so seek care with an experienced, certified electrologist.

Laser therapy.
Laser hair removal systems use laser light — an intense, pulsating beam of light — to remove unwanted hair. Laser hair removal is effective on short, visible hair. Before the procedure, you shave the area to be treated, and allow it to grow to a stubble. Your doctor may use multiple treatments to target the affected areas. After several months, laser procedures permanently reduce one-third or more of the hair in the targeted area. Even after multiple treatments, however, you may experience some hair regrowth, although the new hair may be finer and lighter in color.


Lifestyle and home remedies

You may hear conflicting advice from media, support groups and health care professionals on the role of diet in weight management. Much of the disagreement focuses on carbohydrates.

Carbohydrates are long chains of glucose, a type of sugar. Your digestive system splits these chains into small sugar molecules that enter your bloodstream and trigger the release of insulin.

Low-fat, high-carbohydrate diets that have been popular in recent years may increase insulin levels, so some health and nutrition advocates advise women with polycystic ovary syndrome to follow a low-carbohydrate diet. However, a diet that calls for increased protein to compensate for decreased carbohydrates may spike your intake of saturated fats, elevating your blood cholesterol levels and increasing your risk of cardiovascular disease. Research hasn't demonstrated that a diet high in protein offers more benefit to women with PCOS than does a diet high in carbohydrates.

Choose complex carbohydrates
Carbohydrates provide many important nutrients, so don't severely restrict them. Instead, choose complex carbohydrates, which are high in fiber. The more fiber in a food, the more slowly it's digested and the more slowly your blood sugar levels rise. High-fiber carbohydrates include whole-grain breads and cereals, whole-wheat pasta, bulgur, barley, brown rice and beans. Limit less healthy, simple carbohydrates such as soda, excess fruit juice, cake, candy, ice cream, pies, cookies and doughnuts.

Additional research may determine which specific dietary approach is best, but it's clear that losing weight by reducing total calorie intake benefits the overall health of women with polycystic ovary syndrome. Work with your doctor and registered dietitian to determine the best dietary plan for you.

Get your exercise
Exercise helps lower your blood sugar levels. For women with polycystic ovary syndrome, an increase in daily physical activity and participation in a regular exercise regimen are essential for treating or preventing insulin resistance and for helping weight-control efforts.

Irregular Periods

Irregular or infrequent periods (oligomenorrhoea)
Reviewed by Dr Philip Owen, consultant obstetrician and gynaecologist

It's common for periods to be light and widely spaced when you first start having periods.

Periods also become more irregular as you get older and near the menopause.

This is normal because you won't produce an egg every month as you start and end fertility.


What if it isn't down to puberty or menopause?

Many women experience widely spaced periods, typically having one or two periods every six months. This may concern you, but it is very unlikely that there is a serious underlying cause.

If you are worried about the frequency of your periods, you should see your GP.


What else can cause irregular periods?

The commonest cause of infrequent periods is a condition called polycystic ovaries (PCOS).

Women with PCOS have a large number of very small (less than 1cm) cysts on their ovaries and a hormone imbalance. The cysts interfere with regular ovulation and so periods are infrequent.

PCOS is a common condition that affects as many as 10 per cent of women.


How is a diagnosis made?

The diagnosis of polycystic ovaries is made on the basis of one or more blood tests to measure hormone levels, often with a pelvic ultrasound scan of the ovaries.


What about treatment?

Treatment is only necessary if:

* you are concerned about the irregularity of your periods
* you are having difficulty becoming pregnant.


Based on a text by Dr Erik Fangel Poulsen, specialist
Last updated 16.02.2005

Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS)
Written by Dr David Cahill, consultant senior lecturer on obstetrics and gynaecology

What is polycystic ovary syndrome?

Polycystic (literally, many cysts) ovary syndrome (PCOS or PCO) is a complex condition that affects the ovaries (the organs in a woman's body that produce eggs).

In PCOS, the ovaries are bigger than average, and the outer surface of the ovary has an abnormally large number of small follicles (the sac of fluid that grows around the egg under the influence of stimulating hormones from the brain).

In PCOS, these follicles remain immature, never growing to full development or ovulating to produce an egg capable of being fertilised. For the woman this means that she rarely ovulates (releases an egg) and so is less fertile. In addition, she does not have regular periods and may go for many weeks without a period. Other features of the condition are excess weight and excess body hair.

The condition is relatively common among infertile women and particularly common among women with ovulation problems (an incidence of about 75 per cent). In the general population, around 25 per cent of women will have polycystic ovaries seen on ultrasound examination but most have no other symptoms or signs of PCOS and are perfectly healthy. The ultrasound appearance is also found in up to 14 per cent of women on the contraceptive pill.


What causes PCOS?

While it is not known if women are born with this condition, PCOS seems to run in families. This means that something that induces the condition is inheritable, and thus influenced by one or more genes.

Interestingly, when PCOS is passed down the man's side of the family, the men are not infertile, but they do have a tendency to become bald early in life, before the age of 30. Ongoing research is trying to clarify whether there is a clearly identifiable gene for PCOS. It seems likely that in the future one or two genes will be identified that play a fundamental role in determining a woman's likelihood of developing this condition.

Even if PCOS has a genetic basis, it is likely that not all women with the gene or genes will develop the condition. It is more likely to develop if there is a family history of diabetes (especially Type 2, the less severe type usually controlled by tablets), or if there is early baldness in the men in the family.

Women are also more at risk if they are overweight. Maintaining weight or body mass index (BMI) below a critical threshold is probably very important to determine whether some women develop the symptoms and physical features of the condition. Just how much weight (or what level of BMI) is difficult to say because it will be different for each individual. Certainly, for patients who are considered obese (with BMI greater than 30) or overweight (BMI 25 to 30), weight loss improves the hormonal abnormalities and improves the likelihood of ovulation and thus pregnancy.


Can PCOS be prevented?

If there is a genetic influence, then some people are more likely to get PCOS than others. However, it seems likely that you cannot alter your predisposition to PCOS. There is no current proof of any benefit of preventative weight loss, but the best advice for overall health is to maintain a normal weight or BMI, especially if you have strong indicators that PCOS could affect you. These indicators are:
a tendency in the family towards non-insulin dependent (Type 2) diabetes.
a tendency towards early baldness in the men in the family (before 30 years of age).
the knowledge that a close relative already has PCOS.


What are the symptoms?

The ways in which PCOS shows itself include:

* absent or infrequent periods (oligomenorrhoea): a common symptom of PCOS. Periods can be as frequent as every five to six weeks, but might only occur once or twice a year, if at all.

* increased facial and body hair (hirsutism): usually found under the chin, on the upper lip, forearms, lower legs and on the abdomen (usually a vertical line of hair up to the umbilicus).

* acne: usually found only on the face.

* infertility: infrequent or absent periods are linked with very occasional ovulation, which significantly reduces the likelihood of conceiving.

* overweight/obesity: a common finding in women with PCOS because their body cells are resistant to the sugar-control hormone insulin. This insulin resistance prevents cells using sugar in the blood normally and the sugar is stored as fat instead.

* miscarriage (sometimes recurrent): one of the hormonal abnormalities in PCOS, a raised level of luteinising hormone (LH - a hormone produced by the brain that affects ovary function), seems to be linked with miscarriage. Women with raised LH have a higher miscarriage rate (65 per cent of pregnancies end in miscarriage) compared with those who have normal LH values (around 12 per cent miscarriage rate).

These symptoms are related to several internal changes.

* Hormonal abnormalities, including:
raised luteinising hormone (LH) in the early part of the menstrual cycle.
raised androgens (male hormones usually found in women in tiny amounts).
lower amounts of the blood protein that carries all sex hormones (sex-hormone-binding globulin). a small increase in the amount of insulin and cellular resistance to its actions.

* Characteristic changes in the appearance of the ovaries on ultrasound scan. The ovaries are polycystic, with many small follicles scattered under the surface of the ovary (usually more than 10 or 15 in each ovary) and almost none in the middle of the ovary. These follicles are all small and immature, generally do not exceed 10mm in size and rarely, if ever, grow to maturity and ovulate.

Most women with PCOS will have the ultrasound findings, whereas the menstrual cycle abnormalities are found in around 66 per cent of women and obesity is found in 40 per cent. The increase in hair and acne are found in up to 70 per cent whereas the hormone abnormalities are found in up to 50 per cent of women.

It is likely that there are different stages of the disease throughout life. Younger women tend to have substantial difficulties with their periods, whereas older women have other problems such as diabetes and hypertension (high blood pressure), though their period patterns tend to become more regular.

Women with PCOS also have an increased risk of strokes and heart attacks, but their death rate from these conditions is not increased (Wild et al, 2000).

Women with PCOS may also have an increased risk of endometrial cancer (cancer of the lining of the womb), particularly if they have infrequent or absent periods.


How is PCOS diagnosed?

The diagnosis is based on the patient's symptoms and physical appearance. If the diagnosis seems likely because the patient's history contains many of the symptoms described already, certain investigations are done to provide confirmatory evidence or to indicate another cause for the symptoms.

These include:

* blood tests such as:
female sex hormones (at a certain point in the cycle if possible)
male sex hormones
sex-hormone-binding globulin
glucose
thyroid function tests
other hormones, eg prolactin.

*ultrasound examination.

Your own GP can do the initial blood investigations, ensuring they are carried out at the correct time of the cycle if appropriate. Your GP may be able to arrange an ultrasound scan.

Once the diagnosis is made, nothing more needs to be done for some women, eg if their fertility is not an issue, if their weight is within normal limits, and if they do not have excess body hair.

If any of the symptoms are an issue, then further advice and treatment, and possibly specialist referral is needed.


What else could it be?

The other conditions likely to cause abnormal periods include raised levels of prolactin and of thyroid stimulating hormone (TSH). Both these hormones are produced from a particular part of the brain, the anterior pituitary.

Raised prolactin levels can occur together with headaches and some disturbances of vision whereas raised TSH levels indicate low thyroid hormones (hypothyroidism). Both these conditions lead to suppressed ovulation and infertility.

Increased hair and acne reflect an increase in male hormones (androgens) in the blood. Other conditions can cause such an increase.

Rarely, adrenal disorders or tumours cause increased androgens. In these conditions, hirsutism usually develops quite rapidly; previously normal periods may also stop and, occasionally, muscle weakness occurs.

Loss of, or changes in, female aspects of body shape and appearance (secondary sexual characteristics), especially reduction in breast size, may also occur. As the androgen excess progresses, the voice can deepen and the clitoris can increase in size (clitoromegaly). If these serious medical disorders are present, the male hormone levels will be considerably increased, way above those found in PCOS, and specialist treatment should be arranged.


What can you do for PCOS?

There are several things that an individual can do if they have a tendency towards developing some or all of the elements of PCOS. Much of this involves lifestyle changes to ensure that your weight is kept within normal limits (BMI between 19 and 25).

In addition, because there is a likelihood of developing diabetes in later life and a slightly higher risk of heart disease, low-fat and low-sugar options should be considered when making choices about what to eat or to drink.

Weight loss, or maintaining weight below a certain level, will have the short-term benefit of increasing the likelihood of successful treatment and the long-term benefits of reducing the risk of diabetes and heart disease (Galtier-Dereure et al, 1997).


What can your doctor do?

Your family doctor will be able to provide many of the drug treatments available (although these are probably best taken in consultation with a specialist). Treatments aim to improve several aspects of PCOS, including:

* fertility, via the stimulation of ovulation
* reduction of the insulin resistance
* reduction of the increased hair.


Treatments

The range of treatments available and their application are listed in Tables 1 and 2.

Table 1 deals with the treatments for improving fertility in women with PCOS (Homberg, 1998; Pirwany et al, 1999; Farquhar et al, 2000; Hughes et al, 2000a; Hughes et al, 2000b; Hughes et al, 2000c).

Table 2 deals with the treatments for other features of PCOS including hirsutism, irregular or absent periods and obesity. The evidence in favour of using of these medications to improve symptoms is not strong (Lee et al, 2000).

Table 1: Treatments to improve fertility in women with polycystic ovary syndrome
Drug & Mode of Action : Clomifene (eg Clomid): mild stimulant of ovarian function (Hughes et al, 2000a).
Benefits : Effective method to achieve ovulation.
Risks :
1. Very low risk of ovarian hyperstimulation syndrome.
2. Possible risk of multiple pregnancy if several mature follicles develop.
3. Increased risk of ovarian tumours in women having more than 12 cycles of treatment.

Effects on life quality
1. Simple easy method of treatment with tablets to be taken by mouth, for five days each month. 2. Minimal effects while taking tablets, though some develop headaches.
3. Obvious benefit if pregnancy ensues (pregnancy also lowers the increased risk of ovarian tumour back to that of the normal population).


Drug & Mode of Action :
Gonadotrophin injections: direct stimulation of the ovarian follicles to grow.

Benefits : Ovulation rates of over 90 per cent in most women and pregnancy rates of 20-25 per cent per cycle.

Risks :
1. Ovarian hyperstimulation syndrome.
2. Multiple pregnancy if many mature follicles develop.

Effects on life quality
1. Require daily injections of hMG or FSH derived from urine or recombinant FSH (Hughes et al, 2000c).
2. Several studies suggest the benefits of taking a second drug in conjunction. This should suppress LH and improves the chances of an ongoing pregnancy.


Drug & Mode of Action :
Metformin (eg Glucophage): many actions - eg reduction of male steroid production by the ovaries.

Benefits : Improves the uptake of sugars into cells by insulin. Ovulation rates up to 90 per cent of cycles (Pirwany et al, 1999, Galtier-Dereure et al, 1997).

Risks :
No significant associated risk.

Effects on life quality
Considerable gastrointestinal upset reported - particularly diarrhoea - which is somewhat improved by reducing the daily dose.


Drug & Mode of Action :
Gonadotrophin releasing hormone agonists: stimulate the release of natural sex hormones from the brain.

Benefits :
Lowers LH concentrations and reduces the likelihood of miscarriage (Homberg, 1998, Hughes et al, 2000b).

Risks :
Needs to be used in conjunction with FSH injections and therefore all the above risks also are present. GnRH agonists themselves have little risk in short-term use.


Table 2: Treatments for other features of polycystic ovary syndrome

PCOS Feature : Raised androgen (male sex hormone) level
Available Treatment : Metformin (eg Glucophage)
Comments :
1. Metformin reduces the abnormal findings of raised androgens and decreased sex-hormone binding protein in the blood, but it can cause considerable gastrointestinal upset - particularly diarrhoea - which is somewhat improved by reducing the daily dose. It is less effective in women of normal weight and does not improve hirsutism.

PCOS Feature : Irregular periods
Available Treatment : Metformin
Comments :
1. Return of periods in 90-95 per cent of women.

PCOS Feature : Obesity
Available Treatment : Metformin
Comments:
1. Several studies have examined the effect on weight loss; the majority support its effectiveness.

PCOS Feature : Hirsutism
Available Treatment : Combined oral contraceptives, especially containing the anti-androgen cyproterone acetate (eg Dianette).
Comments :
1. These increase the levels of the sex hormone carrier in the blood, leaving less androgen free to cause hirsutism.
2. It may take six months before any noticeable improvement occurs and two to three years to achieve the maximum benefit from anti-androgens because of the length of the growth-cycle of hair.

PCOS Feature : Hirsutism
Available Treatment : Finasteride
Comments :
1. Finasteride reduces the amount of hair by preventing androgen getting into cells. It can cause headache and depression, and contraception is essential to avoid accidental exposure to a foetus. It is useful as a second-line drug for the treatment of excess hair but is not licensed for this purpose, and some pharmacies have made inappropriate comments to my patients when filling prescriptions, affecting their likelihood of taking the treatment.

PCOS Feature : Endometrial cancer (cancer of the womb lining)
Available Treatment : Progestogens, medroxyprogesterone acetate.
Comments :
1. Stops endometrium (womb lining) from developing, and counteracts any tendency towards cell abnormalities and cancer. Occasional bloating and fluid retention occur.


The increased risk of endometrial cancer is thought to be due to certain hormonal abnormalities that result in continuous stimulation of the lining of the womb by oestrogen. However, the mild increase in insulin found in these women may also have negative effects.

It does seem sensible to advise women with absent or very infrequent periods to take occasional progestogen therapy to 'oppose' the oestrogen and minimise the risk of endometrial cancer.


Non-drug treatments

Ovarian diathermy (surgery that uses heat to alter ovarian function) is thought to reduce the amount of androgen secreting tissue in the ovaries, leading to resumption of ovulation in up to 80 per cent of women. The risks include those of having a laparoscopy and a theoretical risk of ovarian damage from the diathermy. The benefits include resumption of ovulation in a simple manner, with effects lasting six to nine months (Farquhar et al, 2000; Homberg, 1998).

There is a range of non-drug treatments available for hirsutism. Once a serious increase in male hormone levels has been excluded, then local cosmetic options can safely be considered. These include:

* bleaching
* depilatory preparations
* waxing
* plucking
* laser hair removal
* electrolysis
* shaving.

Each is usually effective but expert advice should be taken, because each method has its own problems.

Bleaching and depilatory preparations can occasionally cause a local allergic reaction.

Waxing and plucking often break the hair shaft rather than actually remove it from the hair follicle and, therefore, should be considered to be little more effective than shaving.

Electrolysis and laser hair removal usually give the most prolonged action but both are expensive and cannot tackle large areas of the skin. Electrolysis is painful and laser removal may not be permanent.

Damage to skin or follicles can also occur with either. Waxing, plucking and shaving can lead to inflammation and infection of hair follicles, requiring topical antibiotic creams.

Sugaring is less likely to provoke this result than waxing. Best results will be obtained from shaving if hypoallergenic shaving soaps and razors are used. There is no evidence that plucking, waxing or shaving will encourage increased hair growth.


What is the outlook?

Living with PCOS means different things for different women. This is because women experience the condition in different ways and have more or less severe symptoms depending on their situation. In addition, as women get older, some symptoms change with age; hirsutism become less as hair distribution patterns change with advancing age and as the male hormones in the blood revert to more normal levels (Winters et al, 2000).

Women with PCOS are more prone to some serious conditions. These include an increase in the likelihood of developing diabetes (usually Type 2 diabetes (non-insulin dependent diabetes) and of developing cancer of the womb lining (endometrial cancer).

They also are more at risk of hypertension (high blood pressure) and high cholesterol, though if weight is controlled, high blood pressure is less likely to occur (Wild et al, 2000). Therefore, it makes sense to watch for symptoms suggestive of these conditions and to see your doctor should any suspicious symptoms be present.

For endometrial cancer, these include irregular spotting or bleeding in the 40 to 50 year age group or any bleeding after themenopause. For diabetes, these include unusual thirst requiring large amounts of fluids, tiredness, and passage of increased amounts of urine, particularly at night.


References

Farquhar C, Vanderkerckhove P et al (2000). Laparoscopic "drilling" by diathermy or laser for ovulation induction in anovulatory polycystic ovary syndrome (Cochrane Review). Cochrane Database Syst Rev 2000; (2): CD001122.

Galtier-Dereure F, Pujol P et al (1997). "Choice of stimulation in polycystic ovarian syndrome: the influence of obesity. Hum Reprod 1997; 12 (Suppl 1): 88-96.

Homberg R (1998). Adverse effects of luteinizing hormone on fertility. London: Balliere Tindall, 1998.

Hughes E, Collins J et al (2000a). Clomiphene citrate for ovulation induction in women with oligo-amenorrhoea (Cochrane Review). Cochrane Database Syst Rev 2000; (2): CD000056.

Hughes E, Collins J et al (2000b). Gonadotrophin-releasing hormone analogue as an adjunct to gonadotropin therapy for clomiphene-resistant polycystic ovarian syndrome (Cochrane Review). Cochrane Database Syst Rev 2000; (2): CD000097.

Hughes E, Collins J et al (2000c). Ovulation induction with urinary follicle stimulating hormone versus human menopausal gonadotropin for clomiphene-resistant polycystic ovary syndrome (Cochrane Review). Cochrane Database Syst Rev 2000: (2): CD000092.

Lee O, Farquhar C et al (2000). Spironolactone versus placebo or in combination with steroids for hirsutism and/or acne (Cochrane Review). Cochrane Database Syst Rev 2000; (2): CD000194.

Pirwany IR, Yates RW et al (1999). Effects of the insulin sensitizing drug metformin on ovarian function, follicular growth and ovulation rate in obese women with oligomenorrhoea. Hum Reprod 1999; 14(12): 2963-68.

Wild S, Pierpoint T et al (2000). Long-term consequences of polycystic ovary syndrome: results of a 31 year follow-up study. Human Fertility 2000; 3(2): 101-05.

Wild S, Pierpoint T et al (2000). Cardiovascular disease in women with polycystic ovary syndrome at long-term follow-up: a retrospective cohort study. Clin Endocrinol (Oxf) 2000; 52(5): 595-600.

Winters SJ, Talbott E et al (2000). Serum testosterone levels decrease in middle age in women with the polycystic ovary syndrome. Fertil Steril 2000; 73(4): 724-29.
Last updated 15.09.2005


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Endocrine disease

Wikepedia's Source, URL here

Among the hundreds of endocrine diseases (or endocrinological diseases) are:

Adrenal disorders:
Adrenal insufficiency
Addison's disease
Congenital adrenal hyperplasia (adrenogenital syndrome)
Mineralocorticoid deficiency
Conn's syndrome
Cushing's syndrome
Pheochromocytoma
Adrenocortical carcinoma

Glucose homeostasis disorders:
Diabetes mellitus
Hypoglycemia
Idiopathic hypoglycemia
Insulinoma

Metabolic bone disease:
Osteoporosis
Osteitis deformans (Paget's disease of bone)
Rickets and osteomalacia

Pituitary gland disorders:
Diabetes insipidus
Hypopituitarism (or Panhypopituitarism)
Pituitary tumors
Pituitary adenomas
Prolactinoma (or Hyperprolactinemia)
Acromegaly, gigantism
Cushing's disease

Parathyroid gland disorders:
Primary hyperparathyroidism
Secondary hyperparathyroidism
Tertiary hyperparathyroidism
Hypoparathyroidism
Pseudohypoparathyroidism

Sex hormone disorders:
Disorders of sex development or intersex disorders
Hermaphroditism
Gonadal dysgenesis
Androgen insensitivity syndromes
Hypogonadism
Gonadotropin deficiency
Kallmann syndrome
Klinefelter syndrome
Ovarian failure
Testicular failure
Turner syndrome
Disorders of Gender
Gender identity disorder
Disorders of Puberty
Delayed puberty
Precocious puberty
Menstrual function or fertility disorders
Amenorrhea
Polycystic ovary syndrome

Thyroid disorders:
Hyperthyroidism and Graves-Basedow disease
Hypothyroidism
Thyroidities
Thyroid cancer

Tumours of the endocrine glands not mentioned elsewhere
Multiple endocrine neoplasia
MEN type 1
MEN type 2a
MEN type 2b

See also separate organs
Autoimmune polyendocrine syndromes
Incidentaloma - an unexpected finding on diagnostic imaging, often of endocrine glands

[edit] See also
Endocrinology
Wikipedia:MeSH C19
ICD-10 Chapter IV: Endocrine, nutritional and metabolic diseases
List of ICD-9 codes 240-279: Endocrine, nutritional and metabolic diseases, and immunity disorders

[edit] External links
MeSH Endocrine+system+diseases
MedlinePlus Overview endocrinediseases
Overview at Merck Manual of Diagnosis and Therapy
Endotext

Endocrinology

Major endocrine glands : MALE (left), FEMALE (right)
1. Pineal Gland
2. Pituitary Gand
3. Thyroid Gland
4. Thymus
5. Adrenal Gland
6. Pancreas
7. Ovaries
8. Testes



Wikipedia's info, URL is HERE

Endocrinology (from Greek ἔνδον, endon, "within"; κρῑνω, krīnō, "to separate"; and -λογία, -logia) is a branch of medicine dealing with disorder of the endocrine system and its specific secretions called hormones.


Contents[hide]
1 Function of endocrine organs, hormones and receptors
2 Chemical classes of hormones
2.1 Amines
2.2 Peptide and protein
2.3 Steroid
3 History and key discoveries of endocrinology
4 Endocrinology as a profession
4.1 Work
4.2 Training
4.3 Professional organizations
5 Patient education
6 Diseases
7 Endocrinologist in Popular Culture
8 See also
9 References
10 External links
10.1 Societies and associations


Function of endocrine organs, hormones and receptors

Hormones are molecules that act as signals from one type of cells to another. Most hormones reach their targets via the blood.

All multicellular organisms need coordinating systems to regulate and integrate the function of cells. Two mechanisms perform this function in higher animals: the nervous system and the endocrine system. The endocrine system acts through the release (generally into the blood) of chemical agents and is vital to the proper development and function of organisms. As Hadley notes,[1] the integration of developmental events such as proliferation, growth, and differentiation (including histogenesis and organogenesis) and the coordination of metabolism, respiration, excretion, movement, reproduction, and sensory perception depend on chemical cues, substances synthesised and secreted by specialised cells.

Endocrinology is concerned with the study of the biosynthesis, storage, chemistry, and physiological function of hormones and with the cells of the endocrine glands and tissues that secrete them.

The endocrine system consists of several glands, in different parts of the body, that secrete hormones directly into the blood rather than into a duct system. Hormones have many different functions and modes of action; one hormone may have several effects on different target organs, and, conversely, one target organ may be affected by more than one hormone.

In the original 1902 definition by Bayliss and Starling (see below), they specified that, to be classified as a hormone, a chemical must be produced by an organ, be released (in small amounts) into the blood, and be transported by the blood to a distant organ to exert its specific function. This definition holds for most "classical" hormones, but there are also paracrine mechanisms (chemical communication between cells within a tissue or organ), autocrine signals (a chemical that acts on the same cell), and intracrine signals (a chemical that acts within the same cell).[2] A neuroendocrine signal is a "classical" hormone that is released into the blood by a neurosecretory neuron (see article on Neuroendocrinology).

Hormones act by binding to specific receptors in the target organ. As Baulieu notes, a receptor has at least two basic constituents:

a recognition site, to which the hormone binds
an effector site, which precipitates the modification of cellular function.[3]
Between these is a "transduction mechanism" in which hormone binding induces allosteric modification that, in turn, produces the appropriate response.

Chemical classes of hormones

Amine hormones: norepinephrine and triiodothryonine

Steroid hormones: cortisol and vitamin D3
Griffin and Ojeda identify three different classes of hormone based on their chemical composition:[4]

[edit] Amines
Amines, such as norepinephrine, epinephrine, and dopamine, are derived from single amino acids, in this case tyrosine. Thyroid hormones such as 3,5,3’-triiodothyronine (T3) and 3,5,3’,5’-tetraiodothyronine (thyroxine, T4) make up a subset of this class because they derive from the combination of two iodinated tyrosine amino acid residues.

Peptide and protein
Peptide hormones and protein hormones consist of three (in the case of thyrotropin-releasing hormone) to more than 200 (in the case of follicle-stimulating hormone) amino acid residues and can have molecular weights as large as 30,000. All hormones secreted by the pituitary gland are peptide hormones, as are leptin from adipocytes, ghrelin from the stomach, and insulin from the pancreas.

Steroid
Steroid hormones are converted from their parent compound, cholesterol. Mammalian steroid hormones can be grouped into five groups by the receptors to which they bind: glucocorticoids, mineralocorticoids, androgens, estrogens, and progestagens.


History and key discoveries of endocrinology

The study of endocrinology began in China. The Chinese were isolating sex and pituitary hormones from human urine and using them for medicinal purposes by 200 BC[5]. They used many complex methods, such as sublimation. [6] Eventually, when Berthold noted that castrated cockerels did not develop combs and wattles or exhibit overtly male behaviour, European endocrinology began (however, it should be noted that the Chinese anticipated the science by over 1500 years.) [7] He found that replacement of testes back into the abdominal cavity of the same bird or another castrated bird resulted in normal behavioural and morphological development, and he concluded (erroneously) that the testes secreted a substance that "conditioned" the blood that, in turn, acted on the body of the cockerel. In fact, one of two other things could have been true: that the testes modified or activated a constituent of the blood or that the testes removed an inhibitory factor from the blood. It was not proven that the testes released a substance that engenders male characteristics until it was shown that the extract of testes could replace their function in castrated animals. Pure, crystalline testosterone was isolated in 1935.[8]

Although most of the relevant tissues and endocrine glands had been identified by early anatomists, a more humoral approach to understanding biological function and disease was favoured by classical thinkers such as Aristotle, Hippocrates, Lucretius, Celsus, and Galen, according to Freeman et al,[9] and these theories held sway until the advent of germ theory, physiology, and organ basis of pathology in the 19th century.

In medieval Persia, Avicenna (980-1037) provided a detailed account on diabetes mellitus in The Canon of Medicine (c. 1025), "describing the abnormal appetite and the collapse of sexual functions and he documented the sweet taste of diabetic urine." Like Aretaeus of Cappadocia before him, Avicenna recognized a primary and secondary diabetes. He also described diabetic gangrene, and treated diabetes using a mixture of lupine, trigonella (fenugreek), and zedoary seed, which produces a considerable reduction in the excretion of sugar, a treatment which is still prescribed in modern times. Avicenna also "described diabetes insipidus very precisely for the first time", though it was later Johann Peter Frank (1745-1821) who first differentiated between diabetes mellitus and diabetes insipidus.[10]

In the 12th century, al-Jurjani, another Persian physician, provided the first description of Graves' disease after noting the association of goitre and exophthalmos in his Thesaurus of the Shah of Khwarazm, the major medical dictionary of its time.[11][12] Al-Jurjani also established an association between goitre and palpitation.[10] The disease was later named after Irish doctor Robert James Graves,[13] who described a case of goiter with exophthalmos in 1835. The German Karl Adolph von Basedow also independently reported the same constellation of symptoms in 1840, while earlier reports of the disease were also published by the Italians Giuseppe Flajani and Antonio Giuseppe Testa, in 1802 and 1810 respectively,[14] and by the English physician Caleb Hillier Parry (a friend of Edward Jenner) in the late 18th century.[15]

In 1902 Bayliss and Starling performed an experiment in which they observed that acid instilled into the duodenum caused the pancreas to begin secretion, even after they had removed all nervous connections between the two.[16] The same response could be produced by injecting extract of jejunum mucosa into jugular vein, showing that some factor in the mucosa was responsible. They named this substance "secretin" and coined the term hormone for chemicals that act in this way.

Von Mering and Minkowski made the observation in 1889 that removing the pancreas surgically led to an increase in blood sugar, followed by a coma and eventual death—symptoms of diabetes mellitus. In 1922, Banting and Best realized that homogenizing the pancreas and injecting the derived extract reversed this condition.[17] The hormone responsible, insulin, was not discovered until Frederick Sanger sequenced it in 1953.

Neurohormones were first identified by Otto Loewi in 1921.[18] He incubated a frog's heart (innervated with its vagus nerve attached) in a saline bath, and left in the solution for some time. The solution was then used to bathe a non-innervated second heart. If the vagus nerve on the first heart was stimulated, negative inotropic (beat amplitude) and chronotropic (beat rate) activity were seen in both hearts. This did not occur in either heart if the vagus nerve was stimulated. The vagus nerve was adding something to the saline solution. The effect could be blocked using atropine, a known inhibitor to heart vagal nerve stimulation. Clearly, something was being secreted by the vagus nerve and affecting the heart. The "vagusstuff" (as Loewi called it) causing the myotropic effects was later identified to be acetylcholine and norepinephrine. Loewi won the Nobel Prize for his discovery.

Recent work in endocrinology focuses on the molecular mechanisms responsible for triggering the effects of hormones. The first example of such work being done was in 1962 by Earl Sutherland. Sutherland investigated whether hormones enter cells to evoke action, or stayed outside of cells. He studied norepinephrine, which acts on the liver to convert glycogen into glucose via the activation of the phosphorylase enzyme. He homogenized the liver into a membrane fraction and soluble fraction (phosphorylase is soluble), added norepinephrine to the membrane fraction, extracted its soluble products, and added them to the first soluble fraction. Phosphorylase activated, indicating that norepinephrine's target receptor was on the cell membrane, not located intracellularly. He later identified the compound as cyclic AMP (cAMP) and with his discovery created the concept of second-messenger-mediated pathways. He, like Loewi, won the Nobel Prize for his groundbreaking work in endocrinology.[19]


Endocrinology as a profession

Although every organ system secretes and responds to hormones (including the brain, lungs, heart, intestine, skin, and the kidney), the clinical specialty of endocrinology focuses primarily on the endocrine organs, meaning the organs whose primary function is hormone secretion. These organs include the pituitary, thyroid, adrenals, ovaries, testes, and pancreas.

An endocrinologist is a doctor who specializes in treating disorders of the endocrine system, such as diabetes, hyperthyroidism, and many others (see list of diseases below).

[edit] Work
The medical specialty of endocrinology involves the diagnostic evaluation of a wide variety of symptoms and variations and the long-term management of disorders of deficiency or excess of one or more hormones.

The diagnosis and treatment of endocrine diseases are guided by laboratory tests to a greater extent than for most specialties. Many diseases are investigated through excitation/stimulation or inhibition/suppression testing. This might involve injection with a stimulating agent to test the function of an endocrine organ. Blood is then sampled to assess the changes of the relevant hormones or metabolites. An endocrinologist needs extensive knowledge of clinical chemistry and biochemistry to understand the uses and limitations of the investigations.

A second important aspect of the practice of endocrinology is distinguishing human variation from disease. Atypical patterns of physical development and abnormal test results must be assessed as indicative of disease or not. Diagnostic imaging of endocrine organs may reveal incidental findings called incidentalomas, which may or may not represent disease.

Endocrinology involves caring for the person as well as the disease. Most endocrine disorders are chronic diseases that need life-long care. Some of the most common endocrine diseases include diabetes mellitus, hypothyroidism and the metabolic syndrome. Care of diabetes, obesity and other chronic diseases necessitates understanding the patient at the personal and social level as well as the molecular, and the physician–patient relationship can be an important therapeutic process.

Apart from treating patients, many endocrinologists are involved in clinical science and medical research, teaching, and hospital management.

[edit] Training
There are roughly 70,000 to 80,000 endocrinologists in the United States. Endocrinologists are specialists of internal medicine or pediatrics. Reproductive endocrinologists deal primarily with problems of fertility and menstrual function—often training first in obstetrics. Most qualify as an internist, pediatrician, or gynecologist for a few years before specializing, depending on the local training system. In the U.S. and Canada, training for board certification in internal medicine, pediatrics, or gynecology after medical school is called residency. Further formal training to subspecialize in adult, pediatric, or reproductive endocrinology is called a fellowship. Typical training for a North American endocrinologist involves 4 years of college, 4 years of medical school, 3 years of residency, and 3 years of fellowship. Adult endocrinologists are board certified by the American Board of Internal Medicine (ABIM) in Endocrinology, Diabetes and Metabolism.

[edit] Professional organizations
In North America the principal professional organizations of endocrinologists include The Endocrine Society,[20] the American Association of Clinical Endocrinologists,[21] the American Diabetes Association,[22] the Lawson Wilkins Pediatric Endocrine Society,[23] and the American Thyroid Association.[24]

In the United Kingdom, the Society for Endocrinology[25] and the British Society for Paediatric Endocrinology and Diabetes[26] are the main professional organisations. The European Society for Paediatric Endocrinology[27] is the largest international professional association dedicated solely to paediatric endocrinology. There are numerous similar associations around the world.

[edit] Patient education
Because endocrinology encompasses so many conditions and diseases, there are many organizations that provide education to patients and the public. The Hormone Foundation is the public education affiliate of The Endocrine Society and provides information on all endocrine-related conditions. Other educational organizations that focus on one or more endocrine-related conditions include the American Diabetes Association, National Osteoporosis Foundation, Human Growth Foundation, American Menopause Foundation, Inc., and Thyroid Foundation of America.

[edit] Diseases
See main article at Endocrine diseases
A disease due to a disorder of the endocrine system is often called a "hormone imbalance", but is technically known as an endocrinopathy or endocrinosis.

[edit] Endocrinologist in Popular Culture
Dr. Lisa Cuddy , a character on the television show House M.D..
Elliot Reid becomes an expert in the field in the Scrubs episode My Way Home.

[edit] See also
Pediatric endocrinology
Neuroendocrinology
Reproductive endocrinology
hormone

[edit] References
^ Hadley, Mac E. (2000). Endocrinology, 5th ed., Englewood Cliffs, N.J: Prentice Hall. ISBN 0-13-080356-1.
^ Nussey S, Whitehead S (2001). Endocrinology: An Integrated Approach. ISBN 1-85996-252-1.
^ Kelly, Paul; Baulieu, Etienne-Emile (1990). Hormones: from molecules to disease. Paris: Hermann. ISBN 2-7056-6030-5.
^ Ojeda, Sergio R.; Griffin, James Bennett (2000). Textbook of endocrine physiology, 4th ed., Oxford [Oxfordshire]: Oxford University Press. ISBN 0-19-513541-5.
^ Temple, Robert. The Genius of China.pp. 141, 142. ISBN 9781594772177.
^ Temple, Robert. The Genius of China.p. 142. ISBN 9781594772177
^ Berthold AA. Transplantation der Hoden Arch. Anat. Phsiol. Wiss. Med. 1849;16:42-6.
^ David K, Dingemanse E, Freud J et al. Uber krystallinisches mannliches Hormon aus Hoden (Testosteron) wirksamer als aus harn oder aus Cholesterin bereitetes Androsteron. Hoppe Seylers Z Physiol Chem 1935;233:281.
^ Freeman ER, Bloom DA, McGuire EJ (2001). "A brief history of testosterone". J. Urol. 165 (2): 371–3. doi:10.1097/00005392-200102000-00004. PMID 11176375.
^ a b Nabipour, I. (2003), "Clinical Endocrinology in the Islamic Civilization in Iran", International Journal of Endocrinology and Metabolism 1: 43–45 [44–5]
^ Basedow's syndrome or disease at Who Named It - the history and naming of the disease
^ Ljunggren, J. G. (August 10, 1983), "Who was the man behind the syndrome: Ismail al-Jurjani, Testa, Flagani, Parry, Graves or Basedow? Use the term hyperthyreosis instead", Lakartidningen 80 (32-33): 2902, PMID 6355710
^ Robert James Graves at Who Named It
^ Giuseppe Flajani at Who Named It
^ Hull G (1998). "Caleb Hillier Parry 1755-1822: a notable provincial physician". Journal of the Royal Society of Medicine 91 (6): 335–8. PMID 9771526.
^ Bayliss WM, Starling EH. The mechanism of pancreatic secretion. J Physiol 1902;28:325–352.
^ Bliss M (1989). "J. J. R. Macleod and the discovery of insulin". Q J Exp Physiol 74 (2): 87–96. PMID 2657840.
^ Loewi, O. Uebertragbarkeit der Herznervenwirkung. Pfluger's Arch. ges Physiol. 1921;189:239-42.
^ Sutherland EW (1972). "Studies on the mechanism of hormone action". Science 177 (47): 401–8. PMID 4339614, http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=4339614.
^ Endo-society.org
^ AACE.com
^ Diabetes.org
^ lwpes.org
^ Thyroid.org
^ endocrinology.org
^ bsped.org.uk
^ Eurospe.org

[edit] External links
Endocrinology (British online textbook)
Endotext (American online textbook)
Useful Endocrinology Resources for Residents
Endocrinology journals from Elsevier
Endocrinology news updates from Elsevier
MeSH Endocrinology
The Hormone Foundation
Endocrinology Center medical in Thailand

[edit] Societies and associations
Endocrine Society
American Association of Clinical Endocrinologists
American Diabetes Association
Lawson Wilkins Pediatric Endocrine Society
Society for Endocrinology
Society for Behavioral Neuroendocrinology
British Society for Paediatric Endocrinology & Diabetes