Indices of low-grade chronic inflammation in polycystic ovary syndrome and the beneficial effect of metformin

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.