Association of Serum Vitamin D, IL-4 Levels and Vitamin D Receptor Gene Polymorphism in Coronary Artery Disease with and Without Type 2 Diabetes Mellitus

The aim of this study was to investigate the association of serum vitamin D, IL-4 levels and vitamin D receptor gene polymorphism in coronary artery disease with and without type 2 diabetes mellitus. Methods: The study was conducted in Department of Medicine and Department of Biochemistry, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi. It involved two groups of patients suffering from CAD with type 2 diabetes mellitus (n =40) and CAD without type 2 diabetes mellitus (n =40). Blood sample was collected from all subjects using all aseptic precautions. The levels of serum 25-hydroxy Vitamin D were measured by Electrochemiluminescence Immunoassay. Expected normal serum values considered was 14-80ng/ml. Serum IL-4 had been measured by using commercially available ELISA kit provided by GEN- PROBE Diaclone, France. Expected normal serum value considered was < 98pg/ml. Results: The mean age of patients in different study groups were CAD with DM, 59.15± 9.31 years and CAD without DM, 58.1±9.51 years. Mean vitamin D levels were 18.6±8.3 ng/ml in CAD with DM and 23.4±9 ng/ml in CAD without DM. Mean IL-4 levels were 1.31±0.27pg/ml in CAD with DM group, 1.21±0.29pg/ml in CAD without DM group. The FF genotype of vitamin D receptor gene was present in 47.5 % of CAD with DM patients and 35 % of CAD without DM patients. The Ff genotype was present in 37.5 % of CAD with DM patients and 52.5 % of CAD without DM patients. The ff genotype was reported in 15 % of CAD with DM patients and 12.5 % of CAD without DM patients. Allele F of Vitamin D receptor gene constituted 66 % of total gene pool in CAD with DM patients and 61 % in CAD without DM patients. No significant association was observed with respect to the VDR FokI genotypes and cardiovascular outcomes. Conclusion: Serum Vitamin D levels were decreased in both groups of patients, more significantly decreased in the presence of DM in CAD patients. Serum IL-4 levels were significantly higher in CAD with DM group as compared to CAD without DM group. No associations could be found between Vitamin D receptor gene FokI polymorphism and risk of CAD in diabetic and non-diabetic individuals. No significant correlation was found between vitamin D and IL-4 levels in the patients of both groups. The association between VDR FokI polymorphism, vitamin D and inflammatory markers needs to be further explored in diabetic CAD patients.