Low Serum Levels of 25-Hydroxyvitamin D in Association with Type 2 Diabetes in Indian Patients

Objective: Vitamin D deficiency is a common disorder worldwide and is indicated by low serum 25-hydroxyvitamin D levels. Recent studies have suggested an association of 25-hydroxyvitamin D deficiency with diabetes mellitus. The objective of this study is to investigate the relationship between 25-hydroxyvitamin D concentration and type 2 diabetes in South Indian patients. Materials and Methods: In a cross sectional study, we recruited 150 patients with type 2 diabetes and 150 age and sex matched controls, Yashoda hospital, Hyderabad, India, from December 2011 to November 2013. All cases and controls were evaluated for fasting serum glucose, fasting insulin, serum cholesterol, calcium, phosphorus, alkaline phosphatase, C-reactive protein (CRP), glycosylated hemoglobin (HbA1c) and 25-hydroxyvitamin D levels. Results: In both 150 cases and 150 controls, mean age was 51.5 years and 70% participants were men. Deficiency of 25-hydroxyvitamin D (42.6%) (P<0.0001) and CRP positivity (48%) (P<0.0001) were significantly more common and mean alkaline phosphatase (143±3.4) (P<0.0001), mean HbA1c (8.3±1.8) (P<0.0001) and mean HOMA IR (3.80 +1.45) (P<0.0001) were higher in cases compared to controls. In type 2 diabetes, 25-hydroxyvitamin D deficiency was significantly associated with elevated longer mean duration of diabetes 15.1±4.3 years (P<0.0001), positive CRP (0.02), increased HOMA –IR (<0.0001), neuropathy 19 (29.6%) (P=0.03), and retinopathy 11(15.6%) (P=0.04).After adjustment using multiple logistic regression analysis, deficiency of 25-hydroxyvitamin D was independently associated with type 2 diabetes (odds: 2.8 95% CI: 1.80 - 8.09). Conclusion: Our study showed a 42.6% prevalence of 25-hydroxyvitamin D deficiency in type 2 diabetes and was independently associated with type 2 diabetes in Indian adults.