Influence of gene variants related to calcium homeostasis on biochemical parameters of women with polycystic ovary syndrome

Purpose The purpose of this study was to evaluate the associations between polymorphisms in vitamin D receptor (VDR), parathyroid hormone (PTH), calcium sensing receptor (CASR), insulin receptor (INSR), and adiponectin (ADIPOQ) genes and biochemical characteristics of women with polycystic ovary syndrome (PCOS). Methods Serum levels of LH, FSH, estradiol, testosterone, prolactin, SHBG, glucose, IGF-1, IGFBP-1, calcium, phosphorus, PTH, 25(OH) D, and 1,25(OH)(2) D were measured in 56 women with PCOS. Furthermore, genotyping five, one, one, two, and two polymorphisms of the VDR, PTH, CASR, INSR, and ADIPOQ genes, respectively, were performed. Results The VDR TaqI "CC" genotype was associated with elevated serum levels of LH (p=0.011). There were significant associations between decreased levels of SHBG and both VDR BsmI "GG" (p=0.009) and ADIPOQ BsmI "CC" (p=0.016) genotypes. Furthermore, patients with CaSR Hin1I "TG" genotype showed higher HoMA-IR (p=0.008). All these associations remained significant after Bonferroni correction. In addition, phosphorus correlated negatively with estradiol (r=-0.298, P=0.026) and positively with glucose (r=0.287, P=0.032). Conclusions These data indicated for the first time that it is possible that the VDR and CASR gene variants through their effects on LH and SHBG levels, and insulin resistance are involved in pathogenesis of PCOS.