Bone Abstracts

Introduction: Osteocalcin (OC) is a marker of bone formation but also seems to play a hormonal role in the regulation of glucose and energy metabolism. Recently, an association of BMI with a haplotype composed of three single nucleotide polymorphisms (SNPs) in the gene for OC, located on chromosome 1q22, was observed in ethnically homogeneous European pedigrees.

Aim: The aim of the study was to test the association of these three polymorphisms in the gene of OC with BMI in a cohort of women with polycystic ovary syndrome (PCOS). Moreover, as these women show an adverse metabolic profile, we aimed to evaluate a possible association with parameters of glucose and lipid metabolism: AUCinsulin, AUCglucose, Matsuda, QUICKI (indices for insulin sensitivity), HOMA-IR (index for insulin resistance), levels of triglycerides, total cholesterol, HDL and LDL.

Methods: Genotypes of SNPs in the OC gene were successfully determined in 680 PCOS women by 5′-exonuclease assay. Metabolic and anthropometric characterization as well as oral glucose tolerance tests were performed according to standard measurements and biochemical analysis.

Results: As for one G>C polymorphism, CC genotype carriers had a significantly higher BMI (25.2 kg/cm² (IQR 22.1–31.1)) compared to CG genotype carriers (23.5 kg/cm² (IQR 20.7–28.9), P=0.007), but not compared to women carrying the GG genotype (23.7 kg/cm² (IQR 20.7–28.0), P=0.083). None of the investigated genetic variants was associated with any of the parameters of glucose and lipid metabolism analyzed.

Discussion: We confirm the association of one G>C polymorphism with BMI in a cohort of PCOS women. However, all three OC SNPs did not show any association with parameters of glucose and lipid metabolism in this cohort of PCOS women with an adverse metabolic profile.