Association of vitamin D binding protein genotype IF-IF with vitamin D levels in male Pakistani population

Objective/ Introduction: As it is widely known that low levels of vitamin D [25(OH)D] are a risk factor in a number of communicable and non-communicable diseases, we wanted to evaluate its role in patients suffering from acute myocardial infarction and healthy controls. We also wanted to investigate the association of vitamin D binding protein (VDBP) genotypes with serum levels of 25(OH)D in this cohort. Methods: We recruited 265 adult males (119 healthy individuals, 146 patients) with the age range of 19-64 years from the National Institute of Cardiovascular Diseases and personnel of the Aga Khan University. DNA was extracted from EDTA blood by salting out method. Gc genotyping was performed by PCR-RFLP (Polymerase Chain Reaction- Restriction Fragment Length Polymorphism). 25(OH)D, alkaline phosphatase, calcium and phosphate levels were analyzed by biochemical kits. All statistical analyses were carried out on SPSS version 19. Results: The mean 25 (OH)D level was 13.95 ± 13.72 ng/ml. Overall vitamin D deficiency (25(OH) D levels \u3c 20 ng/ml) among males was 75.4%, while sufficiency (25(OH) D levels \u3e 30 ng/ml) was only 9.5%. Linear regression analysis revealed that the males with Gc1F-1F genotype have on the average 14.14 ng/ml higher 25(OH)D levels compared to males with 1S-1S genotype after adjusting for age (r2= 0.085, p \u3c0.0005). Age, alkaline phosphatase and calcium were not correlated with 25(OH)D levels (p \u3e0.20 ). However, we found that phosphate levels were positively correlated with vitamin D levels (r= 0.195, p = 0.002). Conclusion: There is a high prevalence of vitamin D deficiency in a Pakistani male population of AMI patients and healthy controls. A positive association of Gc wild type genotype (IF-IF) with 25 (OH)D levels indicates that regulation of 25(OH)D levels in adult males is influenced by variation in VDBP gene. Keywords: Myocardial Infarction, vitamin D, Vitamin D binding protein, Gc genotyp