Serum osteoprotegerin concentrations are decreased in women with the polycystic ovary syndrome.

Objective: Osteoprotegerin (OPG), an inhibitor of osteoclastic bone resorption, has a variety of functions including anti-inflammatory effects and a possible cardiovascular protective role. Both low-grade chronic inflammation and cardiovascular risk are increased in women with the polycystic ovary syndrome (PCOS). We aimed to study serum OPG concentrations in PCOS patients.

Design: Case-control study including 40 PCOS patients matched with 40 non-hyperandrogenic women for age and body mass index.

Methods: Basal serum sampling and standard oral glucose tolerance test, and measurement of serum OPG concentrations by commercial ELISA.

Results: Serum OPG concentrations were lower in women with PCOS compared with those of controls (304+/-120 vs 363+/-105 pg/ml respectively; F=7.641, P=0.007) independently of obesity. No differences were observed in serum receptor activator of nuclear factor-kappaB ligand (RANKL) levels and in the RANKL/OPG molar ratio. A multivariate linear regression model (R(2)=0.208, F=6.579, P=0.001) showed that PCOS (beta=-0.281, P=0.008), obesity (beta=-0.245, P=0.022) and age (beta=0.296, P=0.006) were predictive of serum OPG concentrations.

Conclusions: Serum OPG concentrations are reduced in PCOS patients independently of obesity. Considering the anti-inflammatory effects of OPG, its reduced serum concentrations might contribute to the proinflammatory state and cardiovascular risk of PCOS patients.