Importance of assessing HDL cholesterol in primary care setting

Subjects with elevated levels of high-density lipoprotein (HDL) cholesterol at baseline had a significantly lower risk of coronary events, according to results from a retrospective primary care cohort study.1 These data provide support for a therapeutic strategy targeting HDL cholesterol for cardiovascular risk reduction in the primary care setting.

Researchers identified a cohort of 6,928 patients attending an urban primary care practice who had two or more lipid measurements between January 1985 and December 1997 (mean interval between assessments 2.6 years). During a mean follow-up period of 5.1 years after the second lipid measurement 2,167 patients (31%) had an acute coronary event (i.e. hospitalisation for myocardial infarction or acute coronary syndrome, ECG or cardiac enzyme measurement indicative of acute myocardial infarction or coronary artery intervention).

Multivariable proportional hazards analysis identified baseline HDL cholesterol as the only significant lipid predictor of subsequent coronary events. Every 10 mg/dL (0.26 mmol/L) increase in baseline HDL cholesterol was associated with an 11% decrease (95% CI 7% to 14%) in the risk of future coronary events. Additionally, raising HDL cholesterol levels by 10 mg/dL (0.26 mmol/L) was associated with a 7% lower risk of subsequent events (95%CI 3% to 10%).

The results of this study indicate that primary care clinicians should pay more attention to HDL cholesterol as a predictor of cardiovascular disease and target for lipid-modifying interventions.

Reference

1. Koro CE, Bowlin SJ, Stump TE et al. The independent correlation between high-density lipoprotein cholesterol and subsequent major adverse coronary events. Am Heart J 2006;151:755.e1-755.e6.

Commentary

The outcomes of population studies have shown that the level of cardiovascular risk is inversely related to HDL levels, and that this relationship is independent of LDL levels. This study provides further evidence of the benefit of high HDL levels by showing that HDL cholesterol levels are strong predictors of major coronary events in a primary care cohort. Limitations of this particular study relate to whether the results are a true representation of the general population. Other issues relate to the fact that lipid levels were not measured routinely in the cohort, and that only patients who had had their lipid levels measured twice were included in the analysis. This raises the possibility that the analysis is biased towards high risk individuals.