Affiliation:
1. Division of Endocrinology and Human Reproduction, Second Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Thessaloniki, Greece
2. Laboratory of Nuclear Medicine, AHEPA University Hospital of Thessaloniki, Thessaloniki, Greece
3. Endocrine Section of the First Department of Internal Medicine, Athens University School of Medicine, Athens, Greece
Abstract
Abstract
Background: The present study was designed to investigate the effects of polycystic ovary syndrome (PCOS) and of obesity on serum parathyroid hormone (ΡΤΗ), 25-hydroxyvitamin D (25-OH-vitamin D), and 1,25-dihydroxyvitamin D [1,25-(OH)2-vitamin D] concentrations and the possible associations of the above calciotropic hormones with the hormonal and metabolic characteristics of the syndrome.
Methods: We studied 58 obese [body mass index (BMI) >30 kg/m2] women with PCOS, 64 overweight (ΒΜI, 25–30 kg/m2) women with the syndrome, 169 normal-weight (BMI <25 kg/m2) women with PCOS, 29 obese controls (ovulatory women without clinical or biochemical hyperandrogenemia), 14 overweight controls, and 70 normal-weight controls. Blood samples were collected (at 0900 after an overnight fast) between the 3rd and 6th days of a menstrual cycle in the control groups and during a spontaneous bleeding episode in the PCOS groups. Circulating concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), testosterone, Δ4-androstenedione, 17α-hydroxyprogesterone, sex-hormone–binding globulin (SHBG), insulin, glucose, PTH, 25-OH-vitamin D, and 1,25-(OH)2-vitamin D were measured.
Results: Both PCOS and increased body weight had a significant positive effect on serum PTH values. PTH concentrations were significantly correlated with age, BMI, glucose, PRL, SHBG, and testosterone. Only the correlations with testosterone and PRL were BMI-independent. The effect of PCOS on PTH concentrations remained significant after adjustment for BMI, but not after adjustment for testosterone concentration. Increased body weight also had a significant negative effect on 25-OH- and 1,25-(OH)2-vitamin D concentrations, but no association with the syndrome was observed.
Conclusions: The results of the present study are in agreement with previous data supporting an association of increased PTH and decreased vitamin D metabolite concentrations with obesity. Moreover, the present findings indicate, for the first time, that PTH probably is also linked to PCOS-associated hyperandrogenism.
Publisher
Oxford University Press (OUP)
Subject
Biochemistry, medical,Clinical Biochemistry