Investigating the association between lipid profile and coronary heart disease by race

By Pooja Toshniwal PahariaFeb 8 2023Reviewed by Aimee Molineux

In a recent study published in the Journal of the American College of Cardiology, researchers investigated the use of serological high-density lipoprotein cholesterol (HDL-C) values to estimate the risk of coronary heart disease (CHD) among adult Black and White individuals.

Background

Coronary heart disease (CHD) has caused considerable morbidity and mortality in the United States (US). Risk factors for CHD include hypertension, dyslipidemia, diabetes mellitus, obesity, smoking, and lack of exercise, and their association with CHD may vary by race among American Black individuals. The inverse association between serological HDL-C levels and the risk of CHD, observed among European White individuals, might inaccurately estimate CHD risks among Black populations and therefore, reduce the efficacy of strategies aimed at preventing and managing cardiovascular diseases for Black individuals.

About the study

In the present study, researchers evaluated the association between serum lipid profile and the risk of coronary heart disease by race.

For the study, 30,239 White and Black US residents aged ≥45.0 years, were recruited from the REGARDS (REasons for Geographic and Racial Differences in Stroke) study, identified through telephonic conversations and mail. The team excluded individuals of any race except Black or White, individuals who received therapy for anti-cancer therapy in the prior year, individuals with chronic medical disorders precluding study participation, individuals with cognitive impairments, individuals residing in nursing homes, or those who could not speak English.

In addition, the team excluded individuals with a previous history of CHD. Telephonic surveys were conducted initially to survey individuals and establish eligibility. The team obtained data on demographic parameters and medical conditions through computer-aided telephonic interviews. The participants self-documented their race. At-home examinations were conducted for anthropometric measurements (such as blood pressure). The team performed follow-up telephonic assessments semi-annually to identify probable cardiac events.

Baseline serological samples were obtained, and the levels of HDL-C, cholesterol, glucose, and triglycerides were determined using colorimetric reflectance spectrophotometry. Cox regression modeling was performed, adjusting for behavioral and clinical risk factors, estimating the association between the levels of lipids and CHD risk by age, and hazard ratios (HR) were calculated.

Results

The sample population comprised 21.0% of individuals from counties situated on the coast of South Carolina, Georgia, and North Carolina), and 35.0% from the remaining south-eastern regions of the US (including Alabama, Tennessee, Arkansas, Louisiana, and Mississippi), and 44.0% from other regions of the US.

Out of 29,290 individuals followed-up in the REGARDS study, 5,389 CHD patients were excluded. The remaining 23,901 individuals were considered for the final analysis, among which 58% were White and 58% were female, with an average age of 64.0 years. Over 11 years (median) of follow-up, 1,615 individuals were diagnosed with CHD, of which 664 (41%) and 951 (46%) patients were adult Black and White individuals, respectively.

Serum triglycerides and low-density lipoprotein-cholesterol levels were related to elevated CHD risks among Black and White individuals. Lower high-density lipoprotein-cholesterol values were related to greater CHD risks among White (HR 1.2) but not among Black (HR 0.9) individuals. Higher high-density lipoprotein-cholesterol values did not protect against CHD in both races, with HR values for White and Black populations being 0.96 and 0.91, respectively.

Black females showed greater incident CHD rates than White females, and CHD fatality was greater among Black individuals than White individuals. In unadjusted-type analyses, every 1.0 standard deviation (SD) elevation in serum triglyceride (82.0 mg per dL) and LDL-C (34.0 mg per dL) levels was related to modest elevation in the risk of CHD (HR values of 1.1 and 1.1, respectively), and similar findings were obtained in the adjusted analyses.

Lower serum high-density lipoprotein-cholesterol values were related to lower rates of coronary heart disease-free living among White but not among Black individuals. Higher serum high-density lipoprotein-cholesterol values were related to favorable rates of coronary heart disease-free living among White but not among Black individuals. Lower serum high-density lipoprotein-cholesterol levels were related to an elevated risk of CHD risk among White (HR 1.3) but not among Black individuals (HR 0.97).

The study findings showed that serum triglyceride and low-density lipoprotein-cholesterol levels modestly estimated the risk of CHD among adult Black and White individuals. Lower high-density lipoprotein-cholesterol values were related to higher CHD risk among White but not among Black participants, and higher serum HDL-C values did not confer protection against CHD in both races. The findings showed that currently used high-density lipoprotein-cholesterol-based estimations of the risk of CHD could inaccurately assess the risk among adult Black individuals.