Interaction between longevity-associated mitochondrial DNA 5178 C/A polymorphism and cigarette smoking on...

Mitochondrial DNA 5178 C/A (mt5178 C/A), namely NADH dehydrogenase subunit 2 237 Leu/Met, polymorphism is as reported in literature associated with longevity and susceptibility to ischemic heart disease or cerebrovascular disorders in the Japanese population. Previous reports suggested that mt5178A genotype exerts antiatherogenic effects. The aim of this study was to investigate whether mt5178 C/A polymorphism is associated with hematological parameters, such as thrombogenic risk factors for myocardial infarction and stroke, in 321 healthy Japanese men. No significant differences were observed between mt5178 C/A genotypes, but in subjects with body mass index (BMI) of < or = 23, this polymorphism influenced the effects of habitual smoking on hematological parameters. Red blood cell (RBC) counts were significantly lower and mean corpuscular hemoglobin (MCH) levels were significantly higher in smokers with mt5178A than nonsmokers with mt5178A. Platelet counts were significantly higher in smokers with mt5178C than nonsmokers with mt5178C. Cigarette consumption was strongly associated with RBC counts, mean corpuscular volume levels, and MCH levels for men with mt5178A, and was associated with platelet counts for those with mt5178C. Moreover, BMI was significantly positively associated with RBC counts and platelet counts only in men with mt5178A, age was significantly negatively associated with RBC counts only in men with mt5178C. These data suggest that mt5178 C/A polymorphism may influence the effects of cigarette smoking on hematological parameters in healthy BMI < or = 23 Japanese men.