New Hope for Women Suffering from Polycystic Ovary Syndrome
 

by Dr. Sue Evans


e will hear a lot about polycystic ovary syndrome (PCOS) in the new millennium. In the past it quietly languished as a gynaecologic obscurity, often under-diagnosed. This is despite the fact that at least 5 per cent of women of reproductive age have it. Now new evidence is emerging about its link with diabetes and the so-called 'lifestyle diseases' associated with obesity and sedentary living. Combine that with increasing public awareness of the issues of infertility and cosmetic health and you have a problem that is attracting a lot of interest.

What is PCOS? For most women it is a disorder that gives them irregular or no periods, infertility, acne and excessive facial and body hair growing in a male-type pattern. They are typically overweight. On pelvic ultrasound their ovaries will have clusters of small, immature cysts. None of these will mature into an ovulating follicle. They will probably also have mild biochemical abnormalities. Their androgen levels, the so-called male hormones, may be slightly raised. In particular their gonadotropins, the hormones that stimulate the ovaries in a normal cycle will he present in abnormal amounts.

What causes this complex range of signs and symptoms? Several theories have previously suggested the fault lies in the ovaries themselves or in the pituitary gland, which releases gonadotropins.

Recently however it has been appreciated that excessive insulin secretion can account for all the features of PCOS and probably causes it. The body is secreting large amounts of insulin in order to overcome an inherent resistance to insulin in the body tissues. This is the same mechanism also that accounts for most cases of maturity onset diabetes. This explains why women with PCOS have a much higher incidence of diabetes than normal.

Insulin of course is a hormone essential to life. It allows glucose to be taken by the cells of the body and used as energy. In cases of insulin resistance however not only is there an excess of glucose in the bloodstream (because the insulin is not able to do its job) but the excess insulin leads to a variety of harmful effects. In woman insulin acts directly on the ovaries to produce large amounts of androgens unchecked by the normal hormonal restraints, Hence menstrual cycle control is lost and fertility is impaired. The excess androgens also give rise to the typical PCO features of acne and excessive hair. Insulin also causes weight gain, which in itself can perpetuate the whole PCO picture.

As disturbing as these symptoms may be in the short-term, excessive insulin secretion also has unfortunate downstream effects. In the liver it leads to increases in circulating fat level and decreases in the enzyme, which inhibits hardening of the arteries. Over time this leads to the woman having an appreciably increased risk of heart disease. In fact women with coronary disease have disproportionately high rates of PCOS.

So, clearly this is more than just a. gynaecological problem. If unrecognized it has the potential to lead to significant metabolic problems in later life. In the past physicians have concentrated on treating only the gynaecological and cosmetic symptoms as they present. So menstrual irregularity was treated with the oral contraceptive pill, infertility with ovulation-inducing agents, acne and excess hair with anti-androgen agents and so on. Many of these treatments had undesirable side effects and none of them addressed all the symptoms at once.

However, now that our understanding of the mechanism of PCOS has improved, so have our hopes that a single agent may attack the root cause of the problem, i.e. high levels of insulin. We already have a drug, metformin, long used in the treatment of diabetes, which has so far proved promising in clinical trials. Provisional evidence suggests that on metformin, most women can lose weight and resume normal cycle control and fertility. By lowering levels of circulating androgens, acne and hair growth also improve. Importantly, by lowering blood sugar levels and reducing the risk factors for hardened arteries metformin may offer long term cardiovascular benefit.