Effect of apolipoprotein E polymorphism on the serum lipid and insulin response to whole grain consumption in coronary artery disease patients

Whether apo E polymorphism influenced serum lipids and insulin response to the isocalorical replacement of refined rice with whole grains was investigated in coronary artery disease (CAD) men with a low-fat diet. CAD men (n=110) were switched from their basal diet (61% carbohydrate and 19% fat) to isoenergetic diet containing 70g whole grain powder (220kcal), as a carbohydrate source of breakfast for 16 weeks. Apo E2 group (n=11) showed higher baseline serum triglyceride than apo E3 group (n=82). Baseline serum concentrations of total and LDL cholesterol and apo B were highest in apo E4 group (n=16), intermediate in apo E3 and lowest in apo E2. Apo E3 groups showed significantly decreases of triglyceride, total and LDL cholesterol and apo B by 12%, 5%, 8% and 8% after 16 weeks, respectively. In apo E4 group, similar decrease of LDL cholesterol and apo B was observed. HDL cholesterol significantly increased by 8% and 15% in apo E3 and E4 groups, respectively. Apo E3 group showed about 9% decrease in fasting insulin and glucose. Apo E genotype modified the serum lipids and insulin response to the isocalorical replacement of refined rice with whole grains in CAD men with a low-fat diet; apo E2 subjects were non-responders, while apo E3 subjects were favorable responders.