CYP1A1 Gene Polymorphisms in Modifying the Association Between Passive Smoking and Primary Dysmenorrhea

Purpose This study investigated whether the association between passive smoking exposure and primary dysmenorrhea is modified by two susceptibility genes, cytochrome P450 1A1 ( CYP1A1 ) Msp I and CYP1A1Hin cII. 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 CYP1A1Msp I and Ile/Ile462 genotype (OR = 2.9; 95% CI = 1.1–7.7) in CYP1A1Hin cII 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 CYP1A1Msp I C/C6235 and Hin cII Ile/Ile462 genotypes (OR = 2.4; 95% CI = 1.2–4.9). Conclusions CYP1A1Msp I and Hin cII genotypes modified the association between passive smoking and primary dysmenorrhea.