Endocrine Abstracts

Introduction: Accumulating evidence suggests an association of vitamin D with insulin resistance (IR) in women with polycystic ovary syndrome (PCOS). The role of PTH in insulin metabolism is less clear. We aim to study the association of PTH and 25-hydroxyvitamin D (25(OH)D) levels with metabolic and endocrine parameters in a cohort of PCOS women.

Methods: We measured PTH and 25(OH)D levels in 544 PCOS and 139 healthy control women within the same age range. Metabolic, endocrine, and anthropometric measurements and oral glucose tolerance tests were performed.

Results: PCOS women had higher PTH levels than controls in age-adjusted analysis (P=0.018), but results were attenuated after adjustment for BMI (P=0.073). PCOS women with higher PTH levels were significantly older, had higher BMI, waist-to-hip ratio (WHR), systolic and diastolic blood pressure, fasting and stimulated insulin levels, homeostatic model assessment-IR (HOMA-IR), CRP levels, and Ferriman–Gallwey-scores and significantly lower 25(OH)D, SHBG, quantitative insulin sensitivity check index (QUICKI), serum calcium, and phosphorus (P<0.05 for all). In linear regression analysis, BMI (P<0.001), age (P<0.001), and PTH (P=0.016) were independent predictors of AUCinsulin, whereas 25(OH)D was not. In linear regression analysis using the same covariates, BMI (P<0.001) and PTH (P=0.006) independently predicted HOMA-IR, whereas age and 25(OH)D did not. Likewise, in linear regression analysis, BMI (P<0.001) and PTH (P=0.037) independently predicted insulin sensitivity assessed by QUICKI, whereas age and 25(OH)D were not related to insulin sensitivity.

Discussion: We present evidence that PTH levels are independently associated with IR and insulin sensitivity in a large cohort of PCOS women.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.