The 27-bp repeat polymorphism in intron 4 (27 bp-VNTR) of endothelial nitric oxide synthase (eNOS) gene is associated with albumin to creatinine ratio in Mexican Americans

The T-786C, Glu298Asp, and 27 bp variable number of tandem repeats (27 bp-VNTR-a/b) polymorphsims of the endothelial nitric oxide synthase (eNOS) gene are thought to alter nitric oxide production and contribute to the development of vascular and renal disease risk. The objective of this study is to investigate whether these three polymorphisms examined previously by others are associated with cardiovascular and renal disease risk in Mexican Americans. Study participants (N = 848; 21 families) were genotyped for T-786C, Glu298Asp, and 27 bp-VNTR-a/b polymorphisms by PCR followed by restriction digestion. Association analyses were performed by a measured genotype approach implemented in the program SOLAR. Of the phenotypes (type 2 diabetes, hypertension, body mass index, waist circumference, total cholesterol, high density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure, albumin to creatinine ratio (ACR), and estimated glomerular filtration rate) examined for association, the 27 bp-VNTR-a/b variant exhibited statistically significant association with ACR (P = 0.047) after accounting for the trait specific covariate effects. In addition, the promoter variant (T-786C) showed a significant association with triglycerides (P = 0.034) after accounting for covariate influences. In conclusion, the present study adds evidence to the role of eNOS candidate gene polymorphisms in modulating the risk factors related to cardiovascular-renal disease in Mexican Americans although the magnitude of the genetic effect is small.