Altered Vitamin D Status and Bone Mineral Density in Obese and Non-obese Patients With Polycystic Ovary Syndrome: A Cross-Sectional Study in Turkey.

Background  Polycystic ovary syndrome (PCOS) is the most common endocrinological disease in women of reproductive age. In addition to providing the basis for comorbidities such as metabolic and cardiovascular diseases, it also affects bone metabolism. This study aimed to determine whether there is a relationship between bone mineral density (BMD), vitamin D status, insulin resistance, sex hormones, and calcium metabolism disorders in women with PCOS. Methodology Fifty-six non-obese women with PCOS, 67 obese women with PCOS, and 45 normal weight controls participated in the study. Circulating levels of gonadotropins, estradiol, prolactin, dehydroepiandrosterone sulfate, total testosterone, thyroid stimulating hormone, sex hormone-binding globulin, insulin, glucose, and calcium metabolism parameters were assessed. We used the Homeostatic Model Assessment-Insulin Resistance Index to detect insulin resistance. BMD values in the various body regions were measured by dual X-ray absorptiometry. Results Women with PCOS had significantly lower vitamin D values and lumbar spine BMD than controls (p <0.001 and p <0.05, respectively). Among the patients with PCOS subgroups, vitamin D deficiency (VDD) was more frequent in obese PCOS patients (67.1%) than in non-obese patients (58.9%). We found significantly lower BMD at all sites only in the subgroup of the non-obese PCOS women than in controls (p <0.001). Conclusions VDD is prevalent in PCOS women in those with obesity and hyperandrogenemia. Non-obese PCOS women have significantly lower BMD measurements than healthy controls, but obese PCOS women have BMD values comparable with normal-weight eumenorrheic controls. Body mass index is the most important factor determining BMD in women with PCOS.