Hypercholesterolemia and the ageing subject.

Iversen et al. have recently dealt in this Journal, with the effects of total cholesterol (TC) levels on cardiovascular risk according to age in a healthy population from the Copenhagen City Heart Study. They conclude that the association between high TC and incident coronary heart disease (CHD) event rate declines progressively with advancing age and is no more valid above 80 years [1]. This thorough survey considers more than 10,000 men and women before statin introduction in Denmark; its conclusions are in agreement with other cohort investigations but rely simply on total cholesterol and not on other useful lipid parameters. On the other hand data from a recent meta-analysis (61 prospective observational studies), consisting of almost 900,000 adults without previous disease, disclose that 1 mmol/L lower TC was associated with a statistically significant hazard ratio of 0.72, 0.82 and 0.85 lower CHD mortality in both sexes at ages 60–69, 70–79 and 80–89 years, respectively, and that HDL-cholesterol (HDL-C) and TC to HDL-C ratio are more informative parameter than total cholesterol alone [2]. We agree with the latter conclusions, pointing out that the EPESE Study related the apparent adverse effects associated with low TC levels in very old patients (average baseline age of 79) to comorbidity and frailty, and that adjusting for potential confounders (among which HDL-C) restored the direct relationship between TC and CHD in this population characterized by a heterogeneous health state [3]. Also the experience matured by our study-group suggests a prominent effect related to HDL-C [4], showing that free-living healthy octo-nonagenarians (free from CHD and stroke) are not characterized by high HDL-C or low LDL-C levels, but by a very low prevalence of low HDL-C (3.9%) [5], while HDL-C levels associate also with functional status [6]. Besides, while we could not exclude that dyslipoproteinemic high-cholesterol value in old people is under-represented since abated by premature death in affected individuals, we maintain that also small increases in relative CHD risk in elderly individuals associate with a striking increase in absolute risk, given the high prevalence of CHD with advancing age. This suggests that excluding older persons from cholesterol screening may be inappropriate, but that a comprehensive lipid profile and clinical judgment is essential for deciding if pharmacological treatment is needed.