[How to explore... hyperandrogenism associated with insulin resistance ? An example based on the HAIR-AN syndrome.]

HAIR-AN, a syndrome associating hyperandrogenism, insulin resistance and acanthosis nigricans, is currently considered as a severe form of polycystic ovary syndrome. The physiopathology of this syndrome relies on the insulin resistance which is the basis of a vicious circle : the resulting hyperinsulinism leads to an excessive production of androgens. The latter increases abdominal fat deposition which in turn worsens the insulin resistance. Hyperinsulinism is also responsible for the acanthosis nigricans by stimulating the IGF-1 receptors on keratinocytes and fibroblasts. Hyperandrogenism is clinically translated into hirsutism that can be severe. Frequently, menstrual irregularity and obesity are part of the syndrome. HAIR-AN syndrome begins soon after puberty and is currently under-diagnosed. Treatment relies on an improvement in insulin-resistance by a loss of body weight and the use of insulin sensitizers. Moreover, anti-androgenic drugs will help improving hirsutism. Although more invasive, bariatric surgery has shown a great efficacy in this syndrome : by permitting a substantial loss of weight, it often normalizes insulin-sensitivity, allowing for improvements in hyperandrogenism and acanthosis nigricans.