The association of bone mineral density with insulin resistance in patients with polycystic ovary syndrome

Abstract

Objective: The aim of the study was to compare the bone mineral density (BMD) measurements between the patients with polycystic ovary syndrome (PCOS) and age and the body mass index (BMI) matched healthy controls, and to examine whether insulin resistance was associated with BMD. Study design: Twenty-nine consecutive patients with PCOS and seventeen, age and BMI matched healthy control women were included in the study. Blood samples were obtained for follicle stimulating hormone, luteinizing hormone, estradiol, dehydroepiandrosterone-sulfate, 17 hydroxy-progesterone, free testosterone, sex hormone binding globulin, insulin, and glucose levels and BMD measurements were performed for total body, lumbar spine (L2–L4), and femoral neck for each participant. Insulin resistance was estimated by fasting insulin level, fasting glucose/insulin ratio and 75 g of glucose tolerance test for 2 h. Differences between the groups were analyzed by Student’s t-test and Mann–Whitney U-test where appropriate. Correlation analysis between the parameters concerning insulin resistance and BMD measurements were performed in patients with PCOS using Pearson’s correlation coefficient ( r). Correlation analysis was also performed between serum hormone levels and BMD measurements in the PCOS group. Partial correlation coefficients were calculated for these parameters, using age and BMI as covariates. Results: Free testosterone and 17 hydroxy-progesterone levels were significantly high in patients with PCOS compared to the control women ( P=0.001 and 0.04, respectively). Fasting insulin was significantly higher and fasting glucose/insulin ratio was significantly lower in the PCOS group compared to the controls ( P=0.021 and 0.008, respectively). BMD measurements did not differ between the groups ( P>0.05). There were significant correlations between fasting insulin and total BMD ( r=0.424, P<0.05) and fasting glucose/insulin ratio and L2–L4 BMD ( r=−0.401, P<0.05) after controlling for age and BMI. Conclusion: BMD measurements are not different between the patients with polycystic ovary syndrome and healthy control women and hyperinsulinemia, and insulin resistance might play a role in the preserved BMD.