Purpose: This study investigated whether the association between passive smoking exposure and primary dysmenorrhea is modified by two susceptibility genes, cytochrome P450 1A1 (CYP1A1)MspI and CYP1A1HincII.
Methods: We recruited 1645 female textile workers from 1997 to 2000 in Anqing, China, collecting information about passive smoking and status of primary dysmenorrhea and taking blood samples. We analyzed the association of CYP1A1 gene polymorphisms and passive smoking exposure with primary dysmenorrhea using multiple logistic regression.
Results: In the passive smoking group, women who had the C/C6235 genotype (odds ratio [OR] = 1.8; 95% confidence intervals [CI] = 1.0-3.3) in CYP1A1MspI and Ile/Ile462 genotype (OR = 2.9; 95% CI = 1.1-7.7) in CYP1A1HincII had increased risk of dysmenorrhea. When stratified by genotype, the adjusted OR of dysmenorrhea was 1.6 (95% CI = 1.2-2.1) for the passive smoking group with the Ile/Ile462 genotype and 1.5 (95% CI = 1.0-2.1) with the C/C6235 genotype, compared with the nonpassive smoking group. The data further showed that there was a significant combined effect between passive smoking and the CYP1A1MspI C/C6235 and HincII Ile/Ile462 genotypes (OR = 2.4; 95% CI = 1.2-4.9).
Conclusions: CYP1A1MspI and HincII genotypes modified the association between passive smoking and primary dysmenorrhea.