Several studies have shown that high levels of total cholesterol and low-density lipoprotein (LDL) cholesterol increase a middle-aged man’s risk for coronary heart disease (CHD). However, similar findings have been less consistent in older patients. Curb and associates examined the relationship between cholesterol levels and cardiovascular disease in older men.
The long-term, prospective study included healthy Japanese-American men 45 to 68 years of age. Exclusion criteria were a history of CHD and use of lipid-lowering medications. The authors noted baseline risk factors (e.g., body mass index, hypertension, total cholesterol, high-density lipoprotein cholesterol, LDL cholesterol, triglyceride levels, smoking history, and diabetes). The apolipoprotein E (ApoE) genotype was identified through blood tests.
At the 6-year follow-up, 145 of the 2,424 participants had suffered a coronary event. Participants with total cholesterol levels between 200 and 219 mg per dL (5.20 to 5.65 mmol per L), and LDL cholesterol levels between 120 to 129 mg per dL (3.10 to 3.30 mmol per L) had the fewest incidences of CHD, but the risk increased in patients whose cholesterol concentrations declined and increased beyond these ranges, creating a U-shaped curve. The results did not change after adjusting for age and baseline risk factors. The ApoE genotype had no significant effect on CHD risk.
The authors conclude that the study demonstrated a nonlinear relationship between cholesterol levels and cardiovascular disease in older men. Although the cause of this association is unclear, the authors state that low total cholesterol levels may be a marker for frailty and other age-related health problems. The authors suggest that physicians treat elevated cholesterol in the older patients, because trials have shown that older persons benefit from lipid-lowering treatments. They state that further studies are needed to determine the benefit of excessively lowering older patients’ cholesterol levels.