Predicted coronary risk for adults with coronary heart disease and low HDL-C: an analysis from the US National Health and Nutrition Examination Survey.

PURPOSE: To assess the national prevalence of low levels of high-density lipoprotein cholesterol (HDL-C) among adults with coronary heart disease (CHD) and the relationship between low HDL-C and predicted rates of recurrent CHD events.

METHODS: This study used data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) to examine the prevalence of risk factors for recurrent CHD events among survey respondents with existing CHD. The predicted probability of recurrent CHD events in the next 10 years was estimated using published Framingham Heart Study equations for secondary CHD prevention. All data analyses were weighted to produce national estimates using the NHANES sampling weights.

RESULTS: This study included 1291 survey participants aged > or =40 years who self-reported having coronary heart disease, angina, or heart attack. Of the study subjects with available HDL-C data, the percentage of respondents who had low HDL-C (<40 mg/dL), intermediate HDL-C (40 to <60 mg/dL), and high HDL-C (> or =60 mg/dL) was 29%, 50%, and 21%, respectively, based on the national weighted population estimate. For respondents with low HDL-C, the prevalence of diabetes in men and the prevalence of smoking in women were significantly higher than those with high HDL-C (p<0.05). The predicted 10-year coronary risk for subjects with low HDL-C was considerably higher than for subjects with intermediate and high HDL-C. Although subjects with low HDL-C comprised only 29% of the population, they contributed approximately 38% of the subjects with predicted CHD events.

LIMITATIONS: The assessment of certain CHD risk factors and the existence of CHD in the NHANES surveys relied on self-reports, which are subject to recall bias.

CONCLUSIONS: Study results showed that US adults with CHD and low HDL-C will likely contribute a disproportionately high percentage to total CHD events in the next 10 years, suggesting the need for greater awareness of the consequences of low HDL-C.