Metformin is quite an old
drug, but it is optimal for the control of glycemia in
Type 2 diabetes. It was reported, 15 years ago, that
insulin resistance was abnormally high in most
polycystic ovary syndrome (PCOS) patients. Starting from that moment, increasing numbers of studies were performed to demonstrate the efficacy of
metformin in controlling and/or modulating several aspects of PCOS, which is the most common cause of
menstrual irregularity, inesthetisms and
infertility.
Metformin induces higher
glucose uptake, thus inducing a lower synthesis/secretion of
insulin. Such an effect permits the possible restoration of the normal
biological functions that are severely affected by the
compensatory hyperinsulinemia reactive to the increased peripheral
insulin resistance. These are the basis of the many positive effects of this
drug, such as the restoration of menstrual cyclicity, ovulatory cycles and fertility, because abnormal
insulin levels affect the hypothalamus-pituitary-ovarian function, as well as the use of
glucose in peripheral tissues.
Metformin improves the impairments typically observed in hyperinsulinemic PCOS patients, reducing the possible evolution towards
metabolic syndrome and
Type 2 diabetes; and when pregnancy occurs, it consistently reduces the risk of
gestational diabetes,
eclampsia and
hypertension. PCOS seems to be the perfect physiopathological condition that might have higher benefits from
metformin administration, obviously after
Type 2 diabetes. This review focuses on the many aspects of PCOS and on the possible issues of this disease for which
metformin might be a putative optimal treatment.