Objectives: To examine the relationship of total cholesterol and high-density lipoprotein cholesterol (HDL-C) with coronary heart disease (CHD) mortality and with occurrence of new CHD events in persons aged 71 years and older.
Design: Prospective cohort study with a median of 4.4 years of follow-up.
Setting: East Boston, Mass; New Haven, Conn; and Iowa and Washington counties, Iowa.
Participants: A total of 2527 women and 1377 men who completed an interview, had serum lipid determinations, and survived at least 1 year. New CHD events were evaluated in persons with no CHD history or hospitalization.
Main outcome measures: Death due to CHD (ICD-9 codes 410 through 414 as underlying cause of death); new occurrence of CHD events (fatal CHD or hospitalization with CHD [ICD-9 codes 410 through 414]).
Results: After adjustment for established CHD risk factors, the relative risk (RR) of death due to CHD for those with low HDL-C (< 0.90 mmol/L [< 35 mg/dL]) compared with the reference group (HDL-C > or = 1.55 mmol/L [> or = 60 mg/dL]) was 2.5 (95% confidence interval [CI], 1.6 to 4.0). Elevated risk was present in subgroups aged 71 through 80 years (RR, 4.1; 95% CI, 1.9 to 8.8) and over 80 years (RR, 1.8; 95% CI, 0.99 to 3.4), and in men and women. Low HDL-C predicted an increased risk of occurrence of new CHD events (RR, 1.4; 95% CI, 1.1 to 2.0), with similar but nonsignificant results in subgroups of men and women. Total cholesterol was less consistently associated with CHD mortality than HDL-C. When we compared individuals with total cholesterol of at least 6.20 mmol/L (240 mg/dL) with the reference group with total cholesterol of 4.16 to 5.19 mmol/L (161 to 199 mg/dL), a significant risk of CHD mortality was seen for women (RR 1.8; 95% CI, 1.03 to 3.0) but not for men (RR, 1.0; 95% CI, 0.5 to 2.0). In the total population, for each 1-unit increase in the total cholesterol/HDL-C ratio there was a 17% increase in the risk of CHD death that was statistically significant.
Conclusions: Low HDL-C predicts CHD mortality and occurrence of new CHD events in persons older than 70 years. Elevated total cholesterol was not found to be associated with CHD mortality in older men, but may be a risk factor for CHD in older women.