Elevated plasma lipoprotein(a) and coronary heart disease in men aged 55 years and younger. A prospective study

Abstract

Objective: To establish whether elevated lipoprotein(a) [Lp(a)], detected as a sinking pre-beta-lipoprotein band on electrophoresis of fresh plasma, is an independent risk factor for the development of premature coronary heart disease (CHD) in men.

Design and setting: Prospective study of the Framingham offspring cohort.

Participants: A total of 2191 men aged 20 to 54 years old who were free of cardiovascular disease when they were examined between 1971 and 1975.

Main outcome measures: Incident CHD (myocardial infarction, coronary insufficiency, angina pectoris, or sudden cardiac death) occurring by age 55 years.

Results: After a median follow-up of 15.4 years, there were 129 CHD events. The relative risk (RR) estimates (with 95% confidence intervals [CIs]) for premature CHD derived from a proportional hazards model that included age, body mass index, and the dichotomized risk factor covariables elevated plasma Lp(a) level, total cholesterol level of 6.2 mmol/L (240 mg/dL) or more, high-density lipoprotein (HDL) level less than 0.9 mmol/L (35 mg/dL), smoking, glucose intolerance, and hypertension were as follows: elevated Lp(a) level, RR, 1.9 (95% CI, 1.2-2.9), prevalence, 11.3%; total cholesterol level of 6.2 mmol/L or more, RR, 1.8 (95% CI, 1.2-2.7), prevalence, 14.3%; HDL level of less than 0.9 mmol/L, RR, 1.8 (95% CI, 1.2-2.6), prevalence 19.2%; smoking, RR 3.6 (95% CI, 2.2-5.5), prevalence, 46.7%; glucose intolerance, RR, 2.7 (95% CI, 1.4-5.3), prevalence, 2.6%; hypertension, RR, 1.2 (95% CI, 0.8-1.8), prevalence, 26.3%.

Conclusions: Elevated plasma Lp(a) is an independent risk factor for the development of premature CHD in men, comparable in magnitude and prevalence (ie, attributable risk) to a total cholesterol level of 6.2 mmol/L (240 mg/dL) or more, or an HDL level less than 0.9 mmol/L (35 mg/dL).