Relationship between ischemic stroke and both gene polymorphisms of methylenetetrahydrofolate reductase and cigarette smoking

Objective To study the relationship between ischemic stroke (IS) and both gene polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and cigarette smoking. Methods Four hundred and fifty-four patients with IS and 334 controls were recruited in our study; their gene polymorphisms of MTHFR were detected by PCR and denaturing high performance liquid chromatogram (DHPLC). The patients were further divided into different subgroups based on TOAST criteria and scores of neurological impairments and the distribution of MTHFR genotypes were analyzed accordingly. The relationships between IS and both cigarette smoking and these genotypes were measured by odds ratios (ORs) and 95％ confidence intervals (95％CIs). The ORs and 95％ Cls were calculated by unconditional logistic regression. Results TT genotype and T allele were associated with LAA type and CE type,moderate type and severe type of IS. OR of TT genotype and T allele in smoking patients with IS were 4.393 and 2.359, respectively; but the OR ofCC genotype in smoking patients with IS was 0.353. On the other hand, the OR of all genotypes and alleles in non-smoking patients with IS were not significantly different as compared with those in controls. Conclusion Cigarette smokers with T alleles are likely to suffer IS, but those cigarette smokers with C alleles are not; and there exist interactions between cigarette smoking and MTHFR gene in the pathogenesis of IS. Key words: Ischemic stroke;  Methylenetetrahydrofolate reductase;  Gene polymorphism; Genetic predisposition to disease;  Cigarette smoking