Hyperreninemia Characterizing Women with Polycystic Ovary Syndrome Improves after Metformin Therapy

Background: Polycystic ovary syndrome (PCOS) is characterized by chronic anovulation, hyperandrogenemia and insulin resistance. Hyperreninemia is observed in insulin resistance and hyperandrogenemic states. Aims: To investigate the levels of total plasma renin and their possible relationship with insulin resistance and hyperandrogenemia and to explore the effect of metformin on these parameters in PCOS women. Methods: 48 PCOS women who were age-and body mass index (BMI)-matched with 21 healthy women were studied. Total renin, aldosterone levels, glucose and insulin levels were measured at basal state and during an oral glucose tolerance test in all subjects. A subgroup of women with PCOS was evaluated 6 months after metformin administration. Results: Total renin levels were significantly higher in PCOS women compared to controls. PCOS women compared to controls displayed higher areas under the curve for glucose, insulin and total renin (AUCREN). Mean AUCREN was correlated significantly with insulin resistance indices and positively with free testosterone levels. Total renin, aldosterone, androgen levels and insulin sensitivity indices were significantly improved after 6 months on metformin treatment. Conclusions: PCOS women demonstrated an insulin resistance and hyperandogenemia-related increase in serum total renin levels. Metformin treatment was shown to significantly reduce total renin levels. Copyright (C) 2009 S. Karger AG, Basel