July - September 2018, Volume 14, Issue 3

Nikolova MG, Boyanov MA, Tsakova AD

Correlations of Serum Vitamin D with Metabolic Parameters in Adult Outpatients with Different Degrees of Overweight / Obesity Coming from an Urban Community

Acta Endo (Buc) 2018, 14 (3): 375-383
doi: 10.4183/aeb.2018.375

Objective. To describe the correlations between serum 25(OH) vitamin D and anthropometric and metabolic parameters in adult outpatients of both sexes with different BMI coming from an urban community. Subjects and Methods. 264 subjects referred for obesity assessment participated – 109 men and 155 women (20-60 years). Body weight and height, waist circumference (WC), blood pressure were recorded. Body composition was assessed by bioelectrical impedance (BIA) on a Tanita BC 420 MA analyzer (Tanita Inc., Japan). Serum 25(OH)D Total, Insulin, High-sensitivity C-reactive protein, blood glucose, total, HDL-cholesterol and triglycerides were measured. The insulin resistance index was calculated (HOMA-IR). Participants with BMI>25.0 kg/m2 underwent standard 75 g OGTT. Statistical analysis was performed on an IBM SPSS Statistics 19.0 for Windows platform (Chicago, IL). Results. Normal weight was found in 27.2 % of the participants, 24.6 % had overweight, 29.2 % -class I obesity, and 18.9 % – class II or III. Vitamin D was weakly and inversely correlated to different variables in the whole group – such as weight, WC, WC/Height, % body fat and HOMA-IR index (r=-0.231, -0.283, -0.307, -0.339, -0.328 respectively, all p<0.001). Building subgroups based on BMI led to loss of significance. Backward analysis revealed Total-C/LDL-C ratio, and LDL-C/HDL-C ratio as strongest predictors of serum vitamin D (p=0.001; R2=0.204). Conclusion. The association of vitamin D with blood pressure, plasma lipids, glucose and insulin is very weak on an individual level. However, several obesity indices (WC, WC/height ratio, % Body fat from BIA) might be used as a screening tool for subjects at risk for vitamin D deficiency.

Keywords: body composition, obesity, metabolism parameters, vitamin D

Correspondence: Prof. Mihail A. Boyanov, “Aleksandrovska” University Hospital, Clinic of Endocrinology and Metabolism, 1 G. Sofiyski str., Sofia, 1431, Bulgaria, E-mail: mihailboyanov@yahoo.com