Trends in high levels of low-density lipoprotein cholesterol in the United States, 1999-2006

Abstract

Context: Studies show that a large proportion of adults with high levels of low-density lipoprotein cholesterol (LDL-C) remain untreated or undertreated despite growing use of lipid-lowering medications.

Objective: To investigate trends in screening prevalence, use of cholesterol-lowering medications, and LDL-C levels across 4 study cycles (1999-2000, 2001-2002, 2003-2004, and 2005-2006).

Design, setting, and participants: The National Health and Nutrition Examination Survey (NHANES) is a cross-sectional, stratified, multistage probability sample survey of the US civilian, noninstitutionalized population. After we restricted the study sample to fasting participants aged 20 years or older (n = 8018) and excluded pregnant women (n = 464) and participants with missing data (n = 510), our study sample consisted of 7044 participants.

Main outcome measure: High LDL-C levels, defined as levels above the specific goal for each risk category outlined in guidelines from the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III). All presented results are weighted and age-standardized to 2000 standard population estimates.

Results: Prevalence of high LDL-C levels among persons aged 20 years or older decreased from 31.5% in 1999-2000 to 21.2% in 2005-2006 (P < .001 for linear trend) but varied by risk category. By the 2005-2006 study cycle, prevalence of high LDL-C was 58.9%, 30.2%, and 11.0% for high-, intermediate-, and low-risk categories, respectively. Self-reported use of lipid-lowering medications increased from 8.0% to 13.4% (P < .001 for linear trend), but screening rates did not change significantly, remaining less than 70% (P = .16 for linear trend) during the study periods.

Conclusions: Among the NHANES population aged 20 years or older, the prevalence of high LDL-C levels decreased from 1999-2000 to 2005-2006. In the most recent period, the prevalence was 21.2%.