Cholesterol fractions and apolipoproteins as risk factors for heart disease mortality in older men

Abstract

Background: The relevance of blood lipid levels as risk factors for ischemic heart disease (IHD) in older people is uncertain; hence, cholesterol-lowering therapy is not routinely prescribed in older populations.

Methods: We assessed IHD mortality associations with plasma levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein B, and apolipoprotein A(1) measured in older men. Ischemic heart disease was assessed in a 7-year follow-up of a cohort of 5344 men (mean age, 76.9 years), including 74.3% without cardiovascular disease (CVD) or statin use and 25.6% with CVD or statin use. Hazard ratios (HRs) for 447 deaths from IHD were estimated for a 2-SD difference in usual plasma lipid levels.

Results: Ischemic heart disease mortality was not significantly associated with total cholesterol levels in all men (HR, 1.05), but a significant positive association in men without CVD and a slight nonsignificant inverse association in men with CVD were observed (HR, 1.47 vs 0.84). The patterns were similar for low-density lipoprotein cholesterol levels (HR, 1.50 vs 0.98) and for apolipoprotein B levels (HR, 1.68 vs 0.93). Ischemic heart disease risks were inversely associated with high-density lipoprotein cholesterol levels and with apolipoprotein A(1) levels in men with and without CVD. Ischemic heart disease risks were strongly associated with total/high-density [corrected] lipoprotein cholesterol levels (HR, 1.57) and apolipoprotein B/apolipoprotien [corrected] A(1) levels (HR, 1.54), and remained strongly related at all ages.

Conclusions: Blood lipid levels other than total cholesterol levels were associated with IHD in older men. Differences in lipid levels that are achievable by statin use were associated with about a one-third lower risk of IHD, irrespective of age.