The effect of obesity on vitamin D levels in male patients with TYPE 2 diabetes mellitus

Objectives Type 2 Diabetes Mellitus (DM) is a chronic disease with many complications and its prevalence is increasing worldwide. Although the role of obesity in the etiopathogenesis of Type 2 DM is known, it is reported that 25(OH) vitamin D deficiency may be effective in the etiopathogenesis. Moreover, the relationship between 25(OH) vitamin D deficiency and obesity has been the subject of many studies in recent years. Most of the patients admitted to our clinics have 25(OH) vitamin D deficiency. In the literature, it is common to examine the differences in 25(OH) vitamin D levels and 25(OH) vitamin D and insulin resistance, obesity and diabetes in female and male patients. However, there are few studies on the relationship between 25(OH) vitamin D and metabolic diseases in male diabetic patients. We aimed to investigate the effect of obesity on 25(OH) vitamin D levels in male patients with Type 2 DM who presented to our clinic. Materials and Methods The study included 66 male patients with Type 2 DM and 42 healthy individuals without a chronic disease. Height, weight and waist circumference measurements of all patients were performed at the time of admission and the body mass index (BMI) was calculated. Demographic and laboratory data were recorded. The diabetic patients and the control group were divided into two groups as BMI ≥30 and BMI <30. According to the World Health Organization (WHO) classification, individuals with BMI ≥30 were considered obese and BMI <30 were considered nonobese. Blood samples were taken from all patients, including 25(OH) vitamin D, hemoglobin (Hb), platelet (plt), mean erythrocyte volume (MCV), mean platelet volume (MPV), fasting blood glucose, HbA1c, creatinine, AST, ALT, total cholesterol, LDL, HDL, triglyceride levels were evaluated. In addition, all subjects were grouped as obese and non-obese and 25(OH) vitamin D levels were compared between the two groups. Results The mean value of 25(OH) vitamin D in our study was statistically significantly different between diabetic group and control group (p<0.001). When all the subjects included in the study were grouped as obese and non-obese, the mean 25(OH) vitamin D was similar between the two groups (p=0.472). When only the diabetic group was grouped as obese and nonobese, the mean of 25(OH) vitamin D was 26.2 ± 4.2 nmol / l in the obese group and 29.3 ± 6.5 nmol / l in the nonobese group (p=0.029). 25(OH) vitamin D were significantly lower in the obese diabetic group than the nonobese group (p=0.029). Linear regression analysis was performed to compare the 25(OH) vitamin D levels between groups. In the linear regression analysis, when the effect of variables on 25(OH) vitamin D is purified, 25(OH) vitamin D was 3.846 units lower in obese diabetic subjects compared to non-obese diabetic subjects (p=0.08). In the same model, ALT was statistically significantly higher in the obese group than in the non-obese group, independent of the other variables (p=0.005). In the diabetic group, 25(OH) vitamin D was negatively correlated with height (p=0.039), hemoglobin (p=0.0006), hematocrit (p= 0.006), total cholesterol (p=0.010) and triglyceride (p=0.042) levels and positively correlated with MPV (p=0.023), ALT (p=0.016) and AST (p=0.006). Conclusion Our study showed that obesity was effective on 25(OH) vitamin D levels in obese patients with Type 2 DM and obese individuals had lower 25(OH) vitamin D levels compared to nonobese individuals. This result can be interpreted as the risk of vitamin D deficiency in Type 2 diabetic individuals with a body mass index over 30. Therefore, considering the long-term results of 25(OH) vitamin D deficiency, obese diabetic individuals should be evaluated with regular follow-up in terms of plasma 25(OH) vitamin D levels and treatment with appropriate approaches in cases where insufficiency or deficiency is determined.