ASSOCIATION OF APO-E POLYMORPHISM WITH PLASMA-LIPID LEVELS IN A MULTIETHNIC ELDERLY POPULATION

Apolipoprotein E polymorphisms are important determinants of blood lip id levels and have been associated with longevity and atherosclerosis. However, information is limited on the effects of apo E variation on the lipids of nonwhite and elderly individuals. We rested the hypothes is that apo E polymorphisms are associated with plasma lipid levels in an elderly. multiethnic population, Cross-sectional data from 1068 no ninstitutionalized individuals from northern Manhattan over the age of 64 who were not on a lipid-lowering diet or drug were analyzed. The e thnic distribution was 34% African-Americans, 47% Hispanics, and 19% n on-Hispanic Caucasians. In the entire group. the most prevalent apo E allele was epsilon 3 (76%), followed by epsilon 4 (16%) and epsilon 2 (8%); epsilon 4 was more prevalent in African-Americans (21%) than in non-Hispanic Caucasians (12%) or Hispanics (14%). The apo epsilon 2 al lele was the most important correlate of plasma lipids, but this assoc iation varied across ethnoracial groups. After being adjusted for age. sex, obesity, diabetes mellitus. and alcohol intake, LDL cholesterol levels declined with each apo epsilon 2 allele by 8.8 mg/dL in Hispani cs and by 25.6 and 18.1 mg/dL in non-Hispanic Caucasians and African-A mericans. respectively (P<.001). No significant independent effect was noted for any apo E genotype on HDL cholesterol. Overall, there was a reduction in the total/HDL cholesterol ratio, per apo epsilon 2 allel e, of 0.82 in non-Hispanic Caucasians and 0.43 and 0.48 in African-Ame rican and Hispanic individuals, respectively (P<.05). In a multivariat e model, apo epsilon 4 did not significantly affect plasma lipid level s. Plasma triglyceride levels were inversely correlated with the numbe r of apo epsilon 4 alleles (175, 159. and 143 mg/dL with 0, 1, and 2 a lleles, respectively; P =.002), and this effect increased with age. Th us, in an elderly, multiethnic population. apolipoprotein E polymorphi sms were important determinants of blood lipids, with differing effect s depending on ethnicity. The presence of apo epsilon 2 was associated with lower LDL cholesterol levels and total/HDL cholesterol ratio, al though apo epsilon genotype did not influence HDL cholesterol levels. Prospective studies are needed to test whether apo epsilon 2 protects against incident cardiovascular disease in the elderly.