Polycystic ovarian syndrome (PCOS) is universally recognised as the commonest endocrinopathy of women. The definition and the aetiological hypotheses of PCOS are continuously evolving to accommodate expanding knowledge on the syndrome, which is now known to be more complex than purely a reproductive disorder. Increased androgen synthesis, disrupted folliculogenesis and insulin resistance lie at the pathophysiological core of PCOS. An intriguing concept involves the perpetuation of a vicious circle with endocrine/reproductive and metabolic components. An unfavourable metabolic environment may unmask genetic traits of ovarian dysfunction, and the unfolding endocrine derangement could further aggravate the metabolic disarray. This article reviews the molecular mechanisms known to underlie the ovarian and metabolic abnormalities characterising PCOS. The putative interdependence between reproductive and metabolic aspects of PCOS, and therapeutic implications for the management of PCOS, are also discussed.

BACKGROUND: Women with polycystic ovary syndrome (PCOS) have an increased prevalence of insulin resistance (IR) and related disorders. Elevated serum levels of cellular adhesion molecules (CAMs) reflect low-grade chronic inflammation and have been associated with several insulin-resistant states. The objective of this study is to investigate whether soluble inflammatory markers [soluble intercellular adhesion molecule-1 (sICAM-1), soluble endothelial leukocyte adhesion molecule-1 (sE-selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1) and C-reactive protein (CRP)] are altered in PCOS and to further elucidate the effect of metformin treatment on their levels. METHODS: Two young populations were studied [62 women with PCOS and 45 normal women of similar age, BMI and waist-to-hip ratio (WHR)]. Plasma levels of sICAM-1, sVCAM-1, sE-selectin and high-sensitivity CRP (hsCRP) were measured in both groups. Additionally, the effect of metformin on these molecules was investigated in 22 women with PCOS who accepted to metformin protocol (1700 mg daily for a 6-month period). RESULTS: In the total population studied, plasma levels of hsCRP (mg/l), sICAM-1 (ng/ml) and sE-selectin (ng/ml) were higher in the PCOS group compared with those in controls (hsCRP 1.31 ± 0.22 versus 0.92 ± 0.27, P = 0.014, sICAM-1 301.21 ± 24.80 versus 209.86 ± 17.05, P = 0.025, sE-selectin 57.37 ± 4.08 versus 45.67 ± 4.62, P = 0.045, respectively). sVCAM-1 (ng/ml) did not differ statistically among the two groups (P = 0.896). A significant reduction in hsCRP and sVCAM-1 was achieved after 6 months of metformin administration: PCOS pretreatment hsCRP 1.92 ± 0.60 versus PCOS post-treatment hsCRP 0.52 ± 0.26, P = 0.005; PCOS pretreatment sVCAM-1 668.09 ± 98.38 versus PCOS post-treatment sVCAM-1 365.82 ± 99.77, P = 0.039. CONCLUSION: These findings imply the presence of chronic inflammation in women with PCOS. Metformin decreases the levels of plasma inflammatory indices. Further investigation is required to determine whether these findings may prove to be of clinical significance for PCOS patients.

Polycystic ovary syndrome (PCOS) is now recognized to be the most common endocrinopathy in women of reproductive age with a prevalence of 6.6–6.8%. PCOS, a syndrome of unknown etiology, was initially regarded as a reproductive disorder. However, in the last 15 years the role of insulin resistance (IR) has been identified as a significant contributor to the pathogenesis of PCOS, and the metabolic and cardiovascular sequelae of the syndrome have been increasingly appreciated. The coexistence and interaction of reproductive and cardiometabolic abnormalities in the context of PCOS have created a need for a modified therapeutic management of affected women.Insulin sensitizers, particularly metformin, have been introduced as a pharmaceutical option targeting not only IR, but several other aspects of the syndrome, including reproductive abnormalities. The landscape of the multifaceted actions of metformin evolves to broaden the therapeutic implications of this old drug in a new fashion for patients with PCOS. Most recently, the spectrum of metformin's targets has been expanded, and molecular studies have explored the tissue-specific mechanisms of metformin in the liver, the muscle, the endothelium, and the ovary. The use of metformin in pregnant women with PCOS comprises another scarcely explored, but promising area of research. This review attempts to cover the spectrum of metformin's cellular actions in different tissues and to summarize the current literature regarding the potential medical value of this medication in PCOS. Even if many of these actions are individually modest, they seem to be collectively sufficient to confer therapeutic benefits not only in cardiometabolic aspects but also in reproductive aspects of PCOS.