Relevance of apolipoprotein E polymorphism for coronary artery disease in the Saudi population

Background.--The apolipoprotein E alleles epsilon 2 and epsilon 4 have been reported as independent risk factors for coronary artery disease (CAD) and as predictors for the development of atherosclerosis. Methods and Results.--We determined by polymerase chain reaction the distribution of apolipoprotein E polymorphism in 320 Saudi blood donors (BD), 96 CAD patients, and 40 control subjects who had undergone angiography. Compared to controls, only epsilon 4 was elevated in CAD patients. More than 61% (P < .0001) of the patients had angina, and 52.1% (P < .05) were diabetic; both of these factors were strongly associated with the presence of allele epsilon 2. The epsilon 2 allele was also associated with hypertension, elevated serum triglycerides, and total cholesterol. On the other hand, the allele epsilon 4 appeared to be associated with increased risk of CAD and was also associated with hypertension, 3-vessel disease, and restenosis. Conclusions.--Accordingly, epsilon 4 may be associated with increased risk of CAD, whereas epsilon 2 appears to be a predictor of several risk factors for atherosclerosis.