The interactions between alcohol consumption and DNA methylation of the ADD1 gene promoter modulate essential hypertension susceptibility in a population-based, case-control study

The potential effects of the interactions between DNA methylation (CpG1 and CpG2-5 methylation levels) of the alpha-adducin (ADD1) gene promoter and ADD1 tagSNPs (tag single-nucleotide polymorphisms) or the environmental factors on essential hypertension (EH) risk have not been clarified. Thus, we performed an age-and gender-matched case-control study to investigate the association between ADD1 tagSNPs and EH. A total of 1020 subjects with EH and 1020 normotensive subjects were genotyped by melting temperature shift technology. Logistic regression was used to assess the associations of ADD1 tagSNPs, environmental factors and EH. The generalized multifactor dimensionality reduction (GMDR) method was applied to explore the potential interactions. Under additive, dominant and recessive models, no significant associations were evidenced between EH and rs3755885, rs2071694, rs4963 or rs3775067 with the complete data set or the gender-stratified analysis after adjusting for triglycerides, body mass index and alcohol consumption. However, we observed a significant association between rs4961 and EH under the dominant model after Bonferroni correction when adjusting for confounding factors in the entire sample (odds ratio (OR)= 0.64, 95% confidence interval (CI)= 0.50-0.83, P= 0.001). In GMDR, the two-factor interaction model of alcohol consumption and DNA methylation (CpG1 methylation) was the best model, with a maximum cross-validation consistency of 9/10 and testing balance accuracy of 0.63 (P= 0.01). Our results indicate that the SNP rs4961 has a protective role in the development of EH. In conclusion, the interactions between alcohol consumption and DNA methylation (CpG1 methylation) of the ADD1 gene promoter have a significant role in modifying EH susceptibility.