Longevity-associated mitochondrial DNA 5178 A/C polymorphism influences effects of cigarette smoking on serum protein fraction levels in Japanese men

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is reportedly associated with longevity and susceptibility to age-related diseases in Japanese individuals. We previously reported an association between mt5178 A/C polymorphism and serum protein fraction levels in healthy Japanese women. An association between habitual smoking and serum protein fraction levels has also been reported previously. The aim of this study was to examine whether mt5178 A/C polymorphism influenced the effects of habitual smoking on serum protein fraction levels in 321 healthy Japanese men. In mt5178C genotype men, alpha-1 and alpha-2 globulin levels were higher in smokers than in nonsmokers (P<0.001, and P=0.002, respectively). The influence of smoking on these globulin levels depended on cigarette consumption. However, in mt5178A genotype men, no significant difference was observed in alpha-1 or alpha-2 globulin levels between smokers and nonsmokers. These results suggest that longevity-associated mt5178 A/C polymorphism may influence the effects of cigarette smoking on serum protein fraction levels in healthy Japanese men.