Abstract P176: The Prevalence and Correlates of Advanced Atherosclerosis Among Those With Optimal Low-Density Lipoprotein Cholesterol Levels: The Multi-Ethnic Study of Atherosclerosis (MESA)
Introduction: The prevalence of atherosclerosis and relative importance of traditional non-lipid risk factors when low-density lipoprotein cholesterol (LDL-C) is optimal remains unclear. Indeed, some have argued that these risk factors only induce atherogenesis when LDL-C is elevated, but this has not been conclusively demonstrated. Therefore, we examined the association between non-lipid risk factors and advanced subclinical atherosclerosis in individuals with optimal untreated LDL-C (<70 mg/dL) within the Multi-Ethnic Study of Atherosclerosis (MESA).
Hypothesis: We hypothesized that at optimal LDL-C, 1) advanced atherosclerosis is common, 2) is associated with traditional non-lipid risk factors, and 3) that this association is not modified by LDL-C.
Methods: Of 5,565 MESA participants not on lipid lowering therapy, 245 had optimal LDL-C of 100, 4th quartile of common carotid intima media thickness (CIMT) adjusted for age and gender, or increased burden of carotid plaque by ultrasound. Within the entire untreated MESA cohort, multiplicative interaction terms were created between each risk factor and 1 unit standard deviation increase in LDL-C.
Results: The mean age was 62 years (±11), 45% were male, 33% were white, 8% Chinese, 39% black and 20% Hispanic. The age- and gender-adjusted prevalence of CAC >100, 4th quartile of CIMT, and increased burden of carotid plaque was 16%, 20%, and 21%, respectively for LDL-C 160 mg/dL. At optimal LDL-C, the strongest correlates of advanced atherosclerosis were advanced age, male sex, current or former smoking [OR= 1.08 (1.01-1.15), 4.83 (1.43-16.38), 4.13 (1.37-12.43), and 5.12 (1.26-20.89) respectively]. Weaker correlation was observed for systolic and diastolic blood pressure. Family history of CHD was not associated with any atherosclerotic outcome and in sensitivity analysis neither was low HDL-C (<40 mg/dL in men or <50 mg/dL in women). There was no interaction between risk factors and increasing LDL-C for the association with any measure of atherosclerosis.
Conclusion: In conclusion, in the presence of optimal LDL-C advanced atherosclerosis is not uncommon and is associated with familiar traditional risk factors. There is no interaction between traditional risk factors and LDL-C, suggesting that traditional risk factors have the same atherogenic potential in patients with optimal LDL-C. Patients with LDL-C <70 mg/dL can develop atherosclerosis if other risk factors such as smoking are present.
Author Disclosures: M.S. Al Rifai: None. R. Blankstein: None. S.S. Martin: None. J.W. McEvoy: None. M.J. Blaha: None. R. Blumenthal: None. P. Ouyang: H. Other; Significant; Society of Women's Health Research NIH Astra-Zeneca Cordex System Inc. K. Nasir: None. J. Yeboah: None. S.J. Shea: B. Research Grant; Significant; NIH research funding. J.F. Polak: None. M. Miedema: None.
- © 2015 by American Heart Association, Inc.