Impact of optimal cholesterol levels on subclinical atherosclerosis in the absence of risk factors in young adults.

BACKGROUND AND AIMS

We aimed to assess the association of blood lipids with the prevalence, incidence, and progression of subclinical atherosclerosis among young individuals without dyslipidemia and other traditional cardiovascular risk factors (CVRFs).

METHODS

A total of 1270 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study aged 32-46 years free of cardiovascular disease, diabetes, hypertension, current smoking, and dyslipidemia (total cholesterol [TC] ≥ 240 mg/dL, triglycerides [TG] ≥ 150 mg/dL, low-density lipoprotein cholesterol [LDL-C] ≥ 160 mg/dL, high-density lipoprotein cholesterol [HDL-C] < 40 mg/dL, or taking lipid-lowering medications) were included. A subgroup with optimal lipids within the low-CVRF group was defined with TC < 200 mg/dL, LDL-C < 100 mg/dL, non-HDL-C < 130 mg/dL, and women with HDL-C ≥ 50 mg/dL.

RESULTS

1-SD higher TC (25.9 mg/dL), LDL-C (24.7 mg/dL), and non-HDL-C (26.6 mg/dL) were associated with a greater risk of presence (hazard ratios: 1.30-1.36), incidence (1.30-1.32), and progression (1.31-1.35) of coronary artery calcium (CAC) and a 42-44% greater odds of composite mean carotid intima-media thickness (CIMT) ≥ 75th percentile [780 μm] (p < 0.05). Repeating the analyses in a subset of participants with a CAC score of zero did not alter the association of TC, LDL-C, and non-HDL-C with CIMT. In the subgroup with optimal lipids, these lipid indices remained associated with an increased risk of presence and incidence of CAC and greater CIMT measures.

CONCLUSIONS

Among adults aged 32-46 years, in the absence of traditional CVRFs, elevated cholesterol levels, even within what is considered optimal, are associated with atherosclerosis and arteriopathy.