Association of AGTR1 and ACE2 gene polymorphisms with structural atrial fibrillation in a Chinese Han population

The renin-angiotensin system (RAS) is thought to play an important role in atrial fibrillation (AF). The RAS contains the ACE/Angll/AGTR1 axis and the ACE2/Ang(1-7)/MAS axis, which restrict each other via mutual antagonism and regulate myocardial hypertrophy, fibrosis and remodelling. The aim of our study was to investigate the association between single nucleotide polymorphisms (SNPs) in angiotensin-II type-1 receptor (AGTR1) and angiotensin-converting enzyme 2 (ACE2) and structural AF in a Chinese Han population. The SNPs (rs1492100, rs1492099, rs1492097, rs3772616) in AGTR1 and the SNP rs6632677 in ACE2 were compared in 300 structural AF patients (67.61 +/- 12.56 years) and 300 controls (66.08 +/- 12.47 years). The genotype frequencies of SNP rs1492099 in AGTR1 in the structural AF cohort vs controls were as follows: GG, 72.7 vs 83.0%; AG 26.0 vs 16.3%; AA 1.3 vs 0.7% (P=0.009). The frequency of the minor allele of SNP rs1492099 in AGTR1 was 14.2% in the structural AF group compared with 8.8% in the controls (t=0.004; odds ratio [OR], 1.727; 95% confidence interval [CI]: 1.154-2.487). In addition, the genotype frequencies of SNP rs6632677 in ACE2 in the structural AF male patients vs male controls were as follows: GG, 70.5 vs 83.1%; CG 26.3 vs 15.6%; and CC 3.2 vs 1.3% (P=0.029). The frequency of the minor allele of SNP rs6632677 in ACE2 was 16.3% in structural AF male patients compared with 9.1% in male controls (P=0.008; OR, 1.954; 95%Cl: 1.196-3.192). Furthermore, we found an interaction between the SNP rs6632677 in ACE2 and the SNPs (rs1492100/rs1492099 / rs3772616) in AGTR1 in structural AF patients by the multifactor dimensionality reduction (MDR) method. The results indicate that polymorphism rs1492099 in the AGTR1 gene is associated with structural AF in a Chinese Han population. It was hypothesized that the ACE2 gene, which maps to the X chromosome, may be correlated with the risk of structural AF in a Chinese Han male population. Furthermore, we found an interaction between ACE2 and AGTR1 in structural AF patients in a Chinese Han population.