Abstrakt

Evaluation of the relationship between vitamin D levels and metabolic syndrome components

Leyla Ipek Rudvan Al, Meliha Cagla Sonmezer, Ayse Gokce CVicek, Muge Keskin, Fatma Kaplan Efe, Ibrahim Mustafa Cimen

Objective: Metabolic Syndrome (MS) is a metabolic disorder with several cardiovascular risk factors such as insulin resistance, impaired glucose tolerance, Diabetes Mellitus (DM), obesity, abdominal fat accumulation, dyslipidemia and hypertension (HT). Recently, excessive emphasis has been put on the relationship between Vitamin D (Vit D) deficiency and MS. However, studies are limited. The aim of this study is to investigate the prevalence of vitamin D deficiency and its association with metabolic syndrome and its components in Turkish women.

Methods: This cross-sectional study was conducted at Ankara Training and Research Hospital Internal Diseases Polyclinic between February 2012 and August 2012. Patients were questioned about the use of medication for HT, DM and dyslipidemia as well as Calcium-Vit D. Blood pressure and anthropometric measurements (height, body weight, waist circumference, and hip circumference) were evaluated. Biochemical parameters related to Metabolic Syndrome such as the levels of fasting plasma glucose (mg/ dl), 2-h postprandial blood glucose (mg/dl), fasting insulin, glycated hemoglobin (HbA1c) and 25 (OH) Vit D were studied. Levels of insulin and 25 (OH) Vit D were measured using DRG Diagnostics (DRG Instruments GmbH, Germany) ELISA kits and Tandem MassSpectrometer (Tandem-MS), respectively. Patients were assessed for MS according to the IDF (International Diabetes Foundation) criteria. Insulin sensitivity was assessed using the HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) method. The data were analyzed using SPSS for Windows 11.5 software package. p<0.05 was considered statistically significant for the results.

Results: The study included 191 adult female cases among patients presenting at the Internal Diseases Polyclinic, who met the inclusion criteria. The mean age of the patients was 47.1 ± 9.8 (22-73) y. There was no statistically significant difference in Vit D levels between the women with and without MS diagnosis based on IDF criteria (p>0.05). The results from the analysis of correlation between fasting blood glucose and Vit D levels were similar (p=0.447, p=0.255). There was a statistically significant correlation between fasting insulin levels, HOMA-IR and HDL (p<0.05).The group with insulin resistance had statistically significantly higher levels of Vit D compared to those without insulin resistance (p=0.036). However, there was not any statistically significant correlation between DM status and Vit D levels (p>0.05). The correlation between TG levels and Vit D levels were similar (p:0.299). Components of the MS that were not associated with serum Vit D levels including waist circumference and blood pressure (p:0.259; p:0.621).

Conclusions: Vitamin D deficiency is prevalent in this Turkish women population. Presence of metabolic syndrome was not associated with presence of vitamin D deficiency. We concluded that long-term and detailed studies with broad case series are required to investigate the relationship between Vit D deficiency and MS components.