Association of Serum Lipids and Coronary Heart Disease in Contemporary Observational Studies
Background—The use of statins increased among US adults with high coronary heart disease (CHD) risk following publication of the 2001 cholesterol treatment guidelines.
Methods and Results—We analyzed the association between lipids and CHD among 9,578 REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants and 346,595 Kaiser Permanente Southern California (KPSC) members with baseline lipid measurements in 2003-2007. We performed the same analyses among 14,590 Atherosclerosis Risk In Communities (ARIC) study participants with lipid measurements in 1987-1989. Analyses were restricted to blacks and whites 45-64 years of age, without CHD, who were not taking statins at baseline. Total cholesterol, high-density lipoprotein cholesterol (HDL-C) and triglycerides were measured at baseline. Low-density lipoprotein cholesterol (LDL-C), non-HDL-C, total-to-HDL-C and triglycerides-to-HDL-C ratios were calculated. The prevalence of diabetes, history of stroke and antihypertensive medication use increased at higher LDL-C in ARIC but not in REGARDS or KPSC. Over 8.9 years of follow-up, 225 CHD events occurred in REGARDS, 6,547 events in KPSC and 583 events in ARIC. After multivariable adjustment, less favorable lipid levels were associated with higher hazard ratios (HR) for CHD in ARIC. These associations were attenuated in REGARDS and KPSC. For example, the HR (95%CI) associated with the highest versus lowest quartile of LDL-C (≥146 mg/dL versus ≤102 mg/dL) was 1.89 (1.42-2.51) in ARIC, and 1.25 (0.81-1.92) in REGARDS and 1.49 (1.38-1.61) in KPSC.
Conclusions—The association between lipids and CHD in contemporary studies may be attenuated due to preferential use of statins by high risk individuals.
- Received August 18, 2015.
- Revision received October 28, 2015.
- Accepted November 11, 2015.