Associations between CLCNKA_B tag SNPs with essential hypertension and interactions between genetic and environmental factors in an island population in China.

OBJECTIVE

Essential hypertension (EH) is known as the result from the interaction of environmental and genetic factors. We selected tag SNPs of CLCNKA_B genes as gene markers, to elucidate the relationship between CLCNKA_B and EH, and to determine the possible interaction among tag SNPs and dietary factors in island of China.

METHODS

A case-control study was conducted in Changshan islands of China, blood samples of 806 participants were genotyped, and the general characteristics and dietary habits of them were collected. Unconditional logistic regression (ULR) was used to assess the effects of CLCNKA_B tag SNPs and dietary factors on EH. Generalized multifactor dimensionality reduction (GMDR) was used to test gene-environment interaction for EH risk.

RESULTS

Four SNPs were identified as the tag SNPs of CLCNKA_B. Recessive model for rs5253 and rs2275166 were marginal associated with the decrease risk of EH (OR = 0.36, 95% CI = 0.12-1.07 for rs5253; OR = 0.40, 95% CI = 0.16-1.05 for rs2275166). In GMDR, the five-factor interaction model of rs1010069, salt, marine products, meat and edible oil consumption was the best model, with a maximum CVC of 10/10 and a TBA of 0.638 (p = 0.001). In ULR, compared with subjects carried wild genotypes and null dietary risk factor, those with three or more dietary risk factors and mutation genotypes had 5.90-fold EH risk (95% CI:2.24-15.53).

CONCLUSION

Though the single loci of tag SNPs of CLCNKA_B are not enough to significantly increase the EH susceptibility, the combination of CLCNKA tag SNP, salt, marine products, meat and edible oil consumption is associated with elevated risk.