Impact of interaction between CYP1A1 genetic polymorphisms and smoking on coronary artery disease in the Han of China

Aims: To investigate the association of CYP1A1 genotype and additional gene–smoking interaction with coronary artery disease (CAD) risk based on a Chinese case-control study. Methods: A total of 1862 participants (1134 men, 728 women) were selected, including 620 CAD patients and 1242 normal controls. Logistic regression was performed to investigate association of CYP1A1 genotype, gene–gene, and gene–smoking interaction with CAD. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best gene–gene and gene–smoking interaction combination, cross-validation consistency, the testing balanced accuracy, and the sign test, to assess if each selected interaction was calculated. Results: The carriers of homozygous mutant of rs4886605 polymorphism and heterozygous of rs4646903 are associated with increased CAD risk than those with wild-type homozygotes; OR (95% CI) was 1.98 (1.53–2.61) and 1.58 (1.24–1.96), respectively. The carriers of homozygous mutant of rs1048943 polymorphism is associated with decreased CAD risk than those with wild-type homozygotes, OR (95% CI) = 0.75 (0.60–0.93). GMDR model indicated a potential gene–gene interaction between rs4886605 and rs4646903 and a potential gene–smoking interaction between rs4886605 and smoking. Participants with rs4886605-CT or TT and rs4646903-TC or CC genotype have the highest CAD risk, compared to participants with rs4886605-CC and rs4646903-TT genotype; OR (95% CI) was 2.72 (2.03–3.61). In addition, we also found that smokers with rs4886605-CT or TT genotype have the highest CAD risk, compared to nonsmokers with rs4886605-CC genotype; OR (95% CI) was 3.07 (2.23–3.96). Conclusions: rs4886605 and rs4646903 are associated with increased CAD risk, but rs1048943 is associated with decreased CAD risk; we also found gene–gene interaction between rs4886605 and rs4646903 and gene–environment interaction between rs4886605 and smoking.