Prevalence of high cholesterol level by sociodemographic subgroups in a nationally representative sample of the United States

Background: High cholesterol level is a known risk factor for cardiovascular diseases (CVD). Differences in high cholesterol level by gender, race/ethnicity, marital status, education, and poverty levels are evaluated.

Methods: Secondary data analysis using the National Health and Nutrition Examination Survey (NHANES) 1999-2012 cycle (n=35,438) was performed accounting for the complex sampling design. Analysis was restricted to adults 20 years and older. High cholesterol was defined as having any of the following: total cholesterol ≥240mg/dL, HDL <40mg/dL, LDL ≥130mg/dL, or self-report of having been diagnosed by a physician. All variables were dichotomized (e.g., high cholesterol level yes vs. no). Weighted frequencies were calculated and a multivariable logistic regression model for having high cholesterol was fitted to estimate adjusted odds ratios (AOR) and 95% confidence intervals (95%CI) using SAS v9.3.  

Results: Proportion of high cholesterol level increased from 8.6% (1999) to 10.2% (2012). High cholesterol prevalence was higher among males (69% vs. 61.8% females), Whites (67.5% vs. 55.9% non-Hispanic Blacks), widowed/divorced/separated (71.2% vs. 47.7% never married), people with less than high school education (67.4% vs. 64.0% college), and above national poverty level (66.2% vs. 59.8% below).  Majority of sample with diabetes (79.2%) and high-blood-pressure (72.9%) also have high cholesterol level. In the adjusted model (2^ndgroup being a referent), significant differences in gender (male vs. female [AOR=1.35]:95%CI:1.26-1.44), ethnicity (Whites vs. non-Hispanic Blacks [1.59]:1.38-1.83), marital status (married/living with partner vs. never married [1.35]:1.23-1.48), diabetes ([1.16]:1.05-1.28) and high-blood-pressure ([1.32]:1.24-1.41) were found.

Conclusions: Prevalence of total cholesterol level varies between sociodemographic subgroups in the US population. Cholesterol screening and monitoring efforts should focus on these high risk subgroups in the future.