Abstract MP66: Skeletal Muscle Adipose Tissue is Associated with Coronary Artery Calcification: The CARDIA Study
Ectopic fat within skeletal muscles, liver, and around the heart may play a role in cardiovascular disease (CVD) risk. It is unclear if associations of ectopic adipose tissues with CVD risk are independent of abdominal visceral adiposity. We tested the hypothesis that adipose tissue deposited within the lumbar paraspinous muscles is associated with coronary artery calcification (CAC), a measure of subclinical atherosclerosis, after accounting for traditional CVD risk factors and visceral adiposity (VAT).
Methods—Total muscle, lean, and fat volumes (cm3) of the left and right side paraspinous muscles were quantified at the level of the 3rd and 4th lumbar disk space (L3/L4) using computed tomography (CT) in 3,172 Coronary Artery Risk Development in Young Adults (CARDIA) participants in 2010-11 (year 25 exam). VAT was measured at L4/L5. Both muscle and VAT used a 1 cm thick set of CT slices. Abdominal muscles, VAT, and CAC were assessed in the same scanning session. Associations of CAC prevalence (0 versus >0) and Agatston score with paraspinous muscle adipose tissue volume were modeled using multivariable logistic and generalized log-linear regression (gamma distribution, log link), respectively.
Results—The unadjusted mean (SD) of the left and right side paraspinous muscle volumes was 33.0 (7.3) cm3. Mean intermuscular (IM) adipose tissue was 3.7(2.6) cm3 and lean tissue volume was 29.1(6.9) cm3, representing 11.2% and 88.2% of the total muscle volume, respectively. IM adipose, lean, and total muscle volumes differed significantly by sex (each p<.0001) and race (p=0.021, p<.0001, and p<.0001, respectively) after accounting for age and field center. Paraspinous adipose tissue volume was directly associated with CAC prevalence and Agatston score in models including CVD risk factors and VAT (see table).
Conclusions—Greater IM adipose tissue within the paraspinous muscles was associated with greater prevalence and severity of CAC independent of CVD risk factors and VAT in this cross-sectional study.
- © 2013 by American Heart Association, Inc.