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Polycystic ovary syndrome (PCOS, also known clinically as Stein-Leventhal syndrome), is an endocrine disorder that affects 5–10% of women. It occurs amongst all races and nationalities, is the most common hormonal disorder among women of reproductive age, and is a leading cause of infertility. The symptoms and severity of the syndrome vary greatly between women. While the causes are unknown, insulin resistance (often secondary to obesity) is heavily correlated with PCOS.

Nomenclature

Other names for this disorder include
  • Polycystic ovary disease (although this is not correct because PCOS is characterized as a syndrome rather than a disease)
  • Functional ovarian hyperandrogenism
  • Hyperandrogenic chronic anovulation
  • Ovarian dysmetabolic syndrome

Definition

Two definitions are commonly used:
  1. In 1990 a consensus workshop sponsored by the NIH/NICHD suggested that a patient has PCOS if she has (1) signs of androgen excess (clinical or biochemical), (2) oligoovulation, and (3) other entities are excluded that would cause polycystic ovaries.
  2. In 2003 a consensus workshop sponsored by ESHRE/ASRM in Rotterdam indicated PCOS to be present if 2 out of 3 criteria are met: (1) oligoovulation and/or anovulation, (2) excess androgen activity, (3) polycystic ovaries (by gynecologic ultrasonography), and other causes of PCOS are excluded.

The Rotterdam definition is wider, including many more patients, notably patients without androgen excess, whereas in the NIH/NICHD definition androgen excess is a prerequisite. Critics maintain that findings obtained from the study of patients with androgen excess cannot necessarily be extrapolated to patients without androgen excess.

Signs and symptoms

Common symptoms of PCOS include

Signs are:

  • Multiple cysts on the ovaries. Sonographically they may look like a string of pearls.
  • Enlarged ovaries, generally 1.5 to 3 times larger than normal, resulting from multiple cysts
  • Thickened, smooth, pearl-white outer surface of ovary
  • Chronic pelvic pain, possibly due to pelvic crowding from enlarged ovaries; however, the actual cause is not yet known
  • The ratio of LH (Luteinizing hormone) to FSH (Follicle stimulating hormone) is greater than 1:1, as tested on Day 3 of the menstrual cycle.
  • High levels of testosterone.
  • Low levels of sex hormone binding globulin.
  • Hyperinsulinemia.

Risks

Women with PCOS are at risk for the following:

Some data suggest that women with PCOS have a higher risk of miscarriage. Also, many women with PCOS have a difficult time conceiving because of their irregular cycles and lack of ovulation. However, it is possible for these women to have normal pregnancies with the aid of medication and diet.

Diagnosis

It is vital to note that not all women with PCOS have polycystic ovaries, nor do all women with ovarian cysts have PCOS; although a pelvic ultrasound is a major diagnostic tool, it is not the only one. Diagnosis can be difficult, particularly because of the wide range of symptoms and the variability in presentation (which is why this disorder is characterized as a syndrome rather than a disease). There is a lot of controversy about the appropriate testing:
  • gynecologic ultrasonography
  • testosterone: free more sensitive than total
  • Fasting biochemical screen and lipid profile
  • 2-hour oral glucose tolerance test (GTT) in patients with risk factors (obesity, family history, history of gestational diabetes) and may indicate impaired glucose tolerance (insulin resistance) in 15-30% of women with PCOS. Frank diabetes can be seen in 6-8% of women with this condition. Insulin resistance can be observed in both normal weight and overweight patients.
  • For exclusion purpose:

The role of other tests is more controversial, including

  • fasting insulin level or GTT with insulin levels (also called IGTT). Elevated insulin levels have been helpful to predict response to medication and may indicate women who will need higher dosages of metformin or the use of a second medication to significantly lower insulin levels. Elevated blood sugar and insulin values do not predict who responds to an insulin-lowering medication, low-glycemic diet, and exercise. Many women with normal levels may benefit from combination therapy. A hypoglycemic response in which the two-hour insulin level is higher and the blood sugar lower than fasting is consistent with insulin resistance.
  • LH:FSH ratio
  • DHEAS
  • SHBG
  • Androstenedione

Differential diagnosis

Other causes of irregular or absent menstruation and hirsutism, such as congenital adrenal hyperplasia, Cushing's syndrome, hyperprolactinemia, and other pituitary or adrenal disorders, should be investigated.

Pathogenesis

PCOS develops when the ovaries are stimulated to produce excessive amounts of male hormones (androgens), particularly testosterone, either through the release of excessive luteinizing hormone (LH) by the pituitary gland or through high levels of insulin in the blood (hyperinsulinaemia) in women whose ovaries are sensitive to this stimulus.

This syndrome acquired its most widely used name because a common symptom is multiple (poly) ovarian cysts. These form where egg follicles matured but were never released from the ovary because of abnormal hormone levels. These generally take on a 'string of pearls' appearance. The condition was first described in 1935 by Dr. Stein and Dr. Leventhal, hence its original name of Stein-Leventhal syndrome.

PCOS is characterized by a complex set of symptoms, and the cause cannot be determined for all patients. However, research to date suggests that insulin resistance could be a leading cause. PCOS may also have a genetic predisposition, and further research into this possibility is taking place. No specific gene has been identified, and it is thought that many genes could contribute to the development of PCOS.

A majority of patients with PCOS - some investigators say all - have insulin resistance. Their elevated insulin levels contribute to or cause the abnormalities seen in the hypothalamic-pituitary-ovarian axis that lead to PCOS. Specifically, hyperinsulinemia increases GnRH pulse frequency, LH over FSH dominance, increased ovarian androgen production, decreased follicular maturation, and decreased SHBG binding; all these steps lead to the development of PCOS. Insulin resistance is a common finding among both normal weight and over weight PCOS patients.

Treatment

Medical treatment of PCOS is tailored depending on the patient's goals. If restoration of ovulation and fertility are desired, then metformin and or clomiphene citrate are indicated. In cases of clomiphene resistance, injections of follicle stimulating hormone may be used. If hirsutism is a primary concern, then oral contraceptives and either cyproterone acetate or spironolactone (a blocker of androgen receptors) are indicated. If the goal is to prevent the unopposed estrogen effect of anovulation, which can lead to endometrial hyperplasia and endometrial cancer, then oral contraceptives or cyclic progestins are indicated.

Low-carbohydrate diets and sustained regular exercise are also beneficial. More recently doctors and nutritional experts are recommending a low-GI diet in which a significant part of the total carbohydrates are obtained from fruit, vegetables and wholegrain sources. These diets help women with PCOS to maintain steady blood sugar and insulin levels and may assist in weight loss. A diet composed of mainly low-GI foods combined with regular exercise will also help to combat the effects of insulin resistance.

Many women find insulin-lowering medications such as metformin hydrochloride (Glucophage®), pioglitazone hydrochloride (Actos®), and rosiglitazone maleate (Avandia®) helpful, and ovulation may resume when they use these agents. Many women report that metformin use is associated with upset stomach, diarrhea, and weight-loss. Such side effects usually resolve within 2-3 weeks. Both symptoms and weight loss appear to be less with the extended release versions. Most published studies use either generic metformin or the regular, non-extended release version. Starting with a lower dosage and gradually increasing the dosage over 2-3 weeks and taking the medication toward the end of a meal may reduce side effects. The use of basal body temperature or BBT charts is an effective way to follow progress. It may take up to six months to see results, but when combined with exercise and a low-glycemic diet up to 85% will improve menstrual cycle regularity and ovulation.

Ian Stoakes, a UK based scientist has recently found some success in treating PCOS through tailored diets. Stoakes believes that there is a strong link between PCOS, Diabetes etc and Inflamation caused by the failure of the blood to absorb specific foods. Blood samples are taken and then tested to see how they react to different food types. The patient is then provided with a list of foods they can eat and foods to avoid. A number of people have claimed success in losing weight, alleviating symptoms and successful pregnancies as a result of this approach. It however remains a controversial approach.

Initial research also suggests that the risk of miscarriage is significantly reduced when Metformin is taken throughout pregnancy (9% as opposed to as much as 45%); however, further research is needed in this area.

For patients who do not respond to insulin-sensitizing medications and who wish to achieve pregnancy, there are many options available including, clomiphene citrate to induce ovulation or ART procedures such as controlled ovarian hyperstimulation and IVF.

Though surgery is usually the treatment option of last resort, the polycystic ovaries can be treated with surgical procedures such as

  • laparoscopy electrocauterization or laser cauterization
  • ovarian wedge resection (rarely done now because it is more invasive and has a 30% risk of adhesions, sometimes very severe, which can impair fertility)
  • ovarian drilling

References

  • Ehrmann DA. Polycystic ovary syndrome. N Engl J Med 2005;352:1223-36. PMID 15788499.
  • (UK)

External links

Overviews

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Endocrinology | Gynecology | Medical conditions related to obesity

PCOS | Syndrome de Stein-Leventhal | 多嚢胞性卵巣症候群 | Síndrome do Ovário Policístico | PCOS | Polikistik Over

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Polycystic ovary syndrome".

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