Interaction of the C-344T polymorphism of CYP11b2 gene with body mass index and waist circumference affecting diastolic blood pressure in Chinese Mongolian population

Abstract

Background. The relationship between the C-344T polymorphism of CYP11b2 gene and blood pressure (BP) is controversial. The present study aimed to investigate whether it was affected by environmental determinants in Chinese Mongolian population. Methods. A cross-sectional study was conducted between 2003 and 2004 in Tongliao City of Inner Mongolia, China. Epidemiological and clinical data and blood samples were obtained from subjects. Multiple linear regression models were used to estimate the associations between the CYP11b2 genotype and BP. Results. In univariate model, the CYP11b2 genotype was associated with diastolic BP. When stratified by the body mass index (BMI) tertile, the estimated association was significant in the highest tertile of the BMI group with adjustment for age and gender (TT:β=3.3, p=0.042), but was not significant in the other tertiles. After multivariate adjustment, the estimated association was still significant only in highest tertile of BMI group (TC:β=3.7, p=0.030; TT:β=3.7, p=0.023). A similar pattern emerged in analyses stratified by the waist circumference (WC) tertile. Conclusion. In this study, the association between the CYP11b2 genotype and diastolic BP was modified by BMI and WC, suggesting an interaction of the C-344T polymorphism of CYP11b2 with BMI and WC in a Chinese Mongolian population.