Clinical utility of different lipid measures for prediction of coronary heart disease in men and women.

CONTEXT

Evidence is conflicting regarding the performance of apolipoproteins vs traditional lipids for predicting coronary heart disease (CHD) risk.

OBJECTIVES

To compare performance of different lipid measures for CHD prediction using discrimination and calibration characteristics and reclassification of risk categories; to assess incremental utility of apolipoproteins over traditional lipids for CHD prediction.

DESIGN, SETTING, AND PARTICIPANTS: Population-based, prospective cohort from, Framingham, Massachusetts. We evaluated serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, apolipoprotein (apo) A-I and apo B, and 3 lipid ratios (total cholesterol:HDL-C, LDL-C:HDL-C, and apo B:apo A-I) in 3322 middle-aged white participants who attended the fourth offspring examination cycle (1987-1991) and were without cardiovascular disease. Fifty-three percent of the participants were women.

MAIN OUTCOME MEASURE

Incidence of first CHD event (recognized or unrecognized myocardial infarction, angina pectoris, coronary insufficiency, or coronary heart disease death).

RESULTS

After a median follow-up of 15.0 years, 291 participants, 198 of whom were men, developed CHD. In multivariate models adjusting for nonlipid risk factors, the apo B:apo A-I ratio predicted CHD (hazard ratio [HR] per SD increment, 1.39; 95% confidence interval [CI], 1.23-1.58 in men and HR, 1.40; 95% CI, 1.16-1.67 in women), but risk ratios were similar for total cholesterol:HDL-C (HR, 1.39; 95% CI, 1.22-1.58 in men and HR, 1.39; 95% CI, 1.17-1.66 in women) and for LDL-C:HDL-C (HR, 1.35; 95% CI, 1.18-1.54 in men and HR, 1.36; 95% CI 1.14-1.63 in women). In both sexes, models using the apo B:apo A-I ratio demonstrated performance characteristics comparable with but not better than that for other lipid ratios. The apo B:apo A-I ratio did not predict CHD risk in a model containing all components of the Framingham risk score including total cholesterol:HDL-C (P = .12 in men; P = .58 in women).

CONCLUSIONS

In this large, population-based cohort, the overall performance of apo B:apo A-I ratio for prediction of CHD was comparable with that of traditional lipid ratios but did not offer incremental utility over total cholesterol:HDL-C. These data do not support measurement of apo B or apo A-I in clinical practice when total cholesterol and HDL-C measurements are available.