Non-HDL cholesterol, apolipoproteins A-I and B100, standard lipid measures, lipid ratios, and CRP as risk factors for cardiovascular disease in women

Abstract

Context: Current guidelines for cardiovascular risk detection are controversial with regard to the clinical utility of different lipid measures, non-high-density lipoprotein cholesterol (non-HDL-C), lipid ratios, apolipoproteins, and C-reactive protein (CRP).

Objective: To directly compare the clinical utility of total cholesterol, low-density lipoprotein cholesterol (LDL-C), HDL-C, non-HDL-C, apolipoproteins A-I and B(100), high-sensitivity CRP, and the ratios of total cholesterol to HDL-C, LDL-C to HDL-C, apolipoprotein B(100) to apolipoprotein A-I, and apolipoprotein B(100) to HDL-C as predictors of future cardiovascular events in women.

Design, setting, and participants: Prospective cohort study of 15,632 initially healthy US women aged 45 years or older (interquartile range, 48-59 years) who were enrolled between November 1992 and July 1995. All participants were followed up over a 10-year period for the occurrence of future cardiovascular events.

Main outcome measure: Hazard ratios (HRs) and 95% confidence intervals (CIs) for first-ever major cardiovascular events (N = 464) according to baseline levels of each biomarker.

Results: After adjustment for age, smoking status, blood pressure, diabetes, and body mass index, the HRs for future cardiovascular events for those in the extreme quintiles were 1.62 (95% CI, 1.17-2.25) for LDL-C, 1.75 (95% CI, 1.30-2.38) for apolipoprotein A-I, 2.08 (95% CI, 1.45-2.97) for total cholesterol, 2.32 (95% CI, 1.64-3.33) for HDL-C, 2.50 (95% CI, 1.68-3.72) for apolipoprotein B(100), 2.51 (95% CI, 1.69-3.72) for non-HDL-C, and 2.98 (95% CI, 1.90-4.67) for high-sensitivity CRP (P<.001 for trend across all quintiles). The HRs for the lipid ratios were 3.01 (95% CI, 2.01-4.50) for apolipoprotein B(100) to apolipoprotein A-I, 3.18 (95% CI, 2.12-4.75) for LDL-C to HDL-C, 3.56 (95% CI, 2.31-5.47) for apolipoprotein B(100) to HDL-C, and 3.81 (95% CI, 2.47-5.86) for the total cholesterol to HDL-C (P<.001 for trend across all quintiles). The correlation coefficients between high-sensitivity CRP and the lipid parameters ranged from -0.33 to 0.15, and the clinical cut points for CRP of less than 1, 1 to 3, and higher than 3 mg/L provided prognostic information on risk across increasing levels of each lipid measure and lipid ratio.

Conclusions: Non-HDL-C and the ratio of total cholesterol to HDL-C were as good as or better than apolipoprotein fractions in the prediction of future cardiovascular events. After adjustment for age, blood pressure, smoking, diabetes, and obesity, high-sensitivity CRP added prognostic information beyond that conveyed by all lipid measures.