Cholesterol fractions and apolipoproteins as risk factors for heart disease mortality in older men.
Clarke R., Emberson JR., Parish S., Palmer A., Shipley M., Linksted P., Sherliker P., Clark S., Armitage J., Fletcher A., Collins R.
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.