Association of insulin resistance with hyperandrogenia in women

In humans, the skin is a target tissue for androgen action; hair growth and sebum secretion are under active androgen control. An increased production or metabolism of testosterone, the main active androgen, shows up clinically in dermatological symptoms such as hirsutism, hyperseborrheic acne and alopecia. Polycystic ovary syndrome (PCOS) is the most frequent androgen disorder of ovarian function. PCOS patients have amenorrhea or severe oligomenorrhea, increased testosterone levels and most often enlarged polycystic ovaries on ultrasound examination. In addition, many PCOS patients have a tendency to accumulate abdominal fat and/or to develop obesity. Some also display a particular metabolic pattern including an atherogenic lipid profile, glucose intolerance and an increased fasting insulin level, which is known to be closely linked with an insulin resistant state. Several studies have now reported that PCOS patients show increased incidence of type 2 diabetes and cardiovascular disease. In addition to being a target for androgens the skin has abundant insulin receptors on the keratinocyte surface membrane and acanthosis nigricans is a common symptom of severe insulin resistance among patients with insulin receptor disorders. However, acanthosis nigricans could also be present in PCOS women given evidence of the intensity of their insulin resistance. This presentation will review the mutual relationship between hyperandrogenia and insulin resistance, with particular attention paid to: (1) insulin secretion and insulin sensitivity in PCOS; (2) the complexity of the molecular mechanisms involved in insulin resistance; (3) the paradoxical relationship between insulin resistance and hyperandrogenia; (4) the current genetic studies; and (5) new avenues for long-term treatment of PCOS women.