Apolipoprotein E polymorphism and the relationships of physical fitness to plasma lipoprotein-lipid levels in men and women.
PURPOSE: A high level of cardiovascular fitness is generally associated with a plasma lipoprotein-lipid profile predictive of a low cardiovascular disease risk. We have investigated whether apolipoprotein (apo) E polymorphism could alter the relationships of physical fitness to plasma lipoprotein-lipid levels in a sample of healthy untrained subjects (64 premenopausal women and 65 men). METHODS: Subjects were grouped according to gender and apo E phenotype determined by isoelectric focusing electrophoresis. RESULTS: In both genders, VO2max expressed in mL x kg(-1) x min(-1) was negatively correlated with plasma triglyceride levels in apo E2 carriers and apo E3 homozygotes (-0.55< or =r< or =0.31; P<0.05), whereas these associations were not found in apo E4 groups. Plasma low-density lipoprotein (LDL)-C levels were negatively associated with VO2max (r = -0.39; P<0.05) only in women homozygotes for apo E3 whereas VO2max was positively correlated with plasma high-density lipoprotein (HDL)2-C levels only in men (r = 0.51; P<0.001) and women (r = 0.65; P<0.001) who were apo E3 homozygotes. A control for concomitant association with body fat mass and glucose intolerance performed by partial correlation analyses revealed that, with the exception of the plasma HDL2-C levels in the apo E3 homozygotes, most of the significant associations between VO2max (mL x kg(-1) x min(-1)) and plasma lipoprotein-lipid levels were mediated by concomitant variation in body fatness and glucose tolerance. CONCLUSIONS: These results suggest that the magnitude of the relationships between VO2max and plasma lipoprotein-lipid levels is influenced by the apo E polymorphism. Thus, apo E2 carriers may be particularly responsive to improved fitness, thereby preventing the development of hypertriglyceridemia and type III dyslipoproteinemia.