Al Rifai M, et al. - Researchers looked at how cardiovascular risk factors are associated with subclinical atherosclerosis among individuals with untreated low-density lipoprotein cholesterol (LDL-C) <70 mg/dL. A moderately common prevalence of subclinical atherosclerosis was noted among middle-aged to older individuals with untreated LDL-C <70 mg/dL. In these subjects, subclinical atherosclerosis was found to be related to cigarette smoking.

Methods

• Participants from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Brazilian Longitudinal Study of Adult Health (ELSA-Brazil) cohorts were included.
• The validated Martin/Hopkins equation that uses an adjustable factor for the ratio of triglycerides to very low-density lipoprotein cholesterol was used to calculate LDL-C in order to optimize accuracy.
• Subclinical atherosclerosis was defined as a coronary artery calcium (CAC) score >0 in the combined cohort or common carotid intima media thickness (cIMT) in the 4th quartile, using cohort-specific cIMT distributions at baseline.
• The cross-sectional associations of cardiovascular risk factors and subclinical atherosclerosis were studied using logistic regression models.

Results

• A total of 9,411 participants not on lipid lowering therapy were included; LDL-C <70 mg/dL was detected in 263 of them (3%) (MESA: 206, ELSA: 57).
• Mean age was 58 (SD 12) years, with 43% men, and 41% black.
• Researchers found that the prevalence of CAC >0 in those with untreated LDL-C<70 mg/dL was 30%, and 18% were in 4th quartile of cIMT.
• They noted that only ever smoking showed significant association with both CAC and cIMT in demographically adjusted models.
• Risk factor-adjusted models revealed similar results (smoking: OR, 2.29; 95% CI, 1.10–4.80 and OR, 3.44; 95% CI, 1.41–8.37 for CAC and cIMT, respectively).