A high total serum cholesterol level does not carry a risk of cardiovascular mortality among people 85 years and older and is related to decreased all-cause mortality. At this old age, there are few data on fractionated lipoprotein levels in the determination of cardiovascular disease risk. The aim of this study was to evaluate the relationships between low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol levels and mortality from specific causes among people in the oldest age categories.
Between September 1, 1997, and September 1, 1999, a total of 705 inhabitants in the community of Leiden, the Netherlands, reached the age of 85 years. Among these old people, we initiated a prospective follow-up study to investigate determinants of successful aging. A total of 599 subjects participated (response rate, 87%) and all were followed up to September 2001. Serum levels of total, LDL, and HDL cholesterol were assessed at baseline along with detailed information on comorbid conditions. The main outcome measure was all-cause and specific mortality risk.
During 4 years of follow-up, 152 subjects died. The leading cause of death was cardiovascular disease, with similar mortality risks in all tertiles of LDL cholesterol level. In contrast, low HDL cholesterol level was associated with a 2.0-fold higher risk of fatal cardiovascular disease (95% confidence interval [CI], 1.2-3.2). The mortality risk of coronary artery disease was 2.0 (95% CI, 1.0-3.9) and for stroke it was 2.6 (95% CI, 1.0-6.6). Both low LDL cholesterol and low HDL cholesterol concentrations were associated with an increased mortality risk of infection: 2.7 (95% CI, 1.2-6.2) and 2.4 (95% CI, 1.1-5.6), respectively. The risks were unaffected by comorbidity.
In contrast to high LDL cholesterol level, low HDL cholesterol level is a risk factor for mortality from coronary artery disease and stroke in old age.