Obesity and alcohol modulate the effect of apolipoprotein E polymorphism on lipids and insulin

OBJECTIVE: To assess the interaction between apolipoprotein (apo) E polymorphism, alcohol consumption, and BMI on insulin, lipid, and lipoprotein levels in men. RESEARCH METHODS AND PROCEDURES: Cross-sectional study of 266 healthy men without hypolipidemic or antidiabetic drug treatment. BMI, apo E polymorphisms, insulin, and lipid and lipoprotein levels were assessed. Alcohol consumption was assessed by questionnaire. epsilon2/epsilon4 carriers were excluded from the analysis. RESULTS: On bivariate analysis, epsilon2 carriers had lower levels of total and low-density lipoprotein cholesterol and higher levels of apo E and lipoparticle B:E than epsilon3 carriers, the opposite being found for epsilon4 carriers compared with epsilon3 carriers; epsilon4 carriers also had significantly higher insulin levels. On multivariate analysis, significant interactions (p < 0.04) between apo E alleles and increased BMI were found for total and low-density lipoprotein cholesterol and insulin levels, the increase in those parameters with BMI being stronger among epsilon4 carriers than among epsilon3 or epsilon2 carriers. Significant interactions (p < 0.02) between apo E alleles and alcohol consumption were also found for apo B levels, which increased in epsilon2 carriers but remained relatively stable in epsilon3 and tended to decrease in epsilon4 carriers. DISCUSSION: These data suggest that effects of apo E alleles on lipids and insulin levels are partly dependent on environmental variables such as BMI and alcohol intake. These findings highlight the importance of gene x environment interactions on the deleterious effect of obesity on cardiovascular risk factors.