Endocrine Abstracts

Introduction: It has been demonstrated that there are differences in the effect of body mass index (BMI) on the serum 25-hydroxyvitamin D levels (25-OH D); differences appeared stronger in subjects with higher BMI. In this study we aimed to assess the association between 25-OH D status and body fat distribution and caratid intima medai thickness.

Methods: 86 obese premenapousal women (aged 17–55 years) and 56 women with normal BMI took part in this study. Antropometric measurements including waist circumferences (WC) were done. Serum concentrations of fasting blood glucose, insulin, calcium, PTH, 25-OH D were measured. Body fat distrubution was evaluated by ultarsonography. Body fat thickness in four regions and carotid intima media thickness (CIMT) were measured. Total fat and fat ratio were also measured by Bioelectrical Impedance Analysis (BIA).

Results: Visceral (VFT), subcutaneous (SFT), preperitoneal fat thickness (PFT) and the CIMT were significantly higher in obese subjects (P < 0.01). 25-OH D were similar and low in both groups. (13.38 ng/ml in obese and 13.99 ng/ml in controls). 25-OH D were correlated negatively with waist circumference (P=0.025, R=−0.263) and VFT (P=0.002, R=−0.366). Whereas PTH levels were positively correlated with WC (P=0.042, R=+0.241). There wasn’t any correlation with 25-OH D and SFT and PFT. Total fat mass measured by BIA was also negatively correlated wtih 25-OH D. CIMT was negatively correlated with 25-OH D (P=0.028, R=−0.269) and positively correlated with PTH (P=0.018, R=+0.291).

Conclusion: There are several studies investigated the relation between vitamin D and adiposity. They have different results concerning the relation between Vitamin D and BMI,waist circumference and fat distribution measured by different methods. Ethnicity, gender, and age may play a role in mediating this relation. This study showed that in premenopausal Turkish obese women, vitamin D may have a contributing factor on fat distribution so on cardiovascular risks in obesity.