Influence of CRP, IL6, and TNFA gene polymorphisms on circulating levels of C-reactive protein in Mexican adolescents.

ABSTRACT

BACKGROUND AND AIMS: Obesity correlates with a chronic and low-grade inflammation status. C-reactive protein (CRP) measurement has been used as an independent risk marker for future cardiovascular events. CRP level shows interindividual variability due to environmental and genetic factors. The aim of this study was to assess the association of functional polymorphisms on CRP, IL6, and TNFA genes with serum CRP levels in Mexican mestizo adolescents. METHODS: Body mass index (BMI), serum high-sensitivity C-reactive protein (hsCRP) levels, and genotypes for CRP+1444C>T, IL6-174G>C, and TNFA-308G>A polymorphisms were obtained from 418 unrelated Mexican adolescents. Genetic association with hsCRP levels was evaluated by means of a dominant genetic model with uni- and multivariate analysis. RESULTS: Genotype frequencies for all three polymorphisms were according to Hardy-Weinberg equilibrium (HWE). CRP+1444T, TNFA-308A, and IL6-174C allele frequencies were 37, 7, and 10%, respectively. CRP+1444T was associated with higher mean CRP levels independent of age, gender and BMI (ß = 0.21; 95% confidence interval [95% CI] = 0.02-0.39); p = 0.030). IL6-174C was associated with low CRP levels in the overweight group (p = 0.005). IL6-174G>C and TNFA-308G>A allele frequencies observed from this Mexican sample were similar to data for other Mexican populations. CONCLUSIONS: The CRP+1444C>T polymorphism was associated with CRP levels in Mexican adolescents and could be used as a genetic marker for the early detection of individuals at risk for developing obesity-related conditions such as cardiovascular disease or type 2 diabetes mellitus in early adulthood.