Abstract 3911: Aortic Calcium and Systemic Atherosclerosis in the Multiethnic Study of Atherosclerosis
Background: Atherosclerosis often occurs in multiple vascular beds. The relation of abdominal aortic calcium (AAC) with other measures of atherosclerosis, namely carotid intimal media thicknesses (CIMT), coronary artery calcium (CAC), and ankle-brachial index (ABI) has not been widely examined.
Methods: The co-occurrence of AAC, CIMT, CAC, and ABI was examined in 1906 subjects (mean age 62.0 years, 49% female) in the Multiethnic Study of Atherosclerosis (MESA), an epidemiological study of African-American, Asian, Caucasian, and Hispanic adults aged 45–84 initially free of cardiovascular disease. CAC presence assessed by cardiac CT, common and internal CIMT ≥ 1 mm, and ABI <0.9 at baseline were examined in relation to AAC measured by abdominal CT an average of 2.4 years later. Relative risk (RR) regression, adjusted for age, gender, race, and risk factors (RF) compared the association of CIMT, CAC, and ABI with AAC in a single model. The prevalence of (and associated RF for) systemic atherosclerosis (≥3 sites) was also examined.
Results: AAC was present in 70% of females and 73% of males and was strongly associated with other atherosclerotic measures (Table⇓). RR regression showed internal CIMT ≥1mm and any CAC (but not low ABI) to be independently associated with a 7.8% and 17% greater probability, respectively, of any AAC (both p<0.001). Atherosclerosis among 0, 1, 2, 3, or all 4 locations (CAC>0, AAC>0, CIMT ≥1mm, and/or ABI<0.9) was present in 24%, 29%, 28%, 18%, and 2% of females and 16%, 25%, 30%, 27%, and 3% of males, respectively. Age, male gender, Caucasian race, LDL-C, current or former smoking, systolic blood pressure, diabetes, family history, and low HDL-C were independently associated (p≤0.01) with atherosclerosis in ≥3 sites.
Conclusions: Increased CAC and CIMT are independently associated with AAC. One-fifth of women, one-third of men, and those with multiple RF have atherosclerosis in ≥3 sites; the prognostic significance of this should be investigated.