Objective: To determine the association between body composition dynamics and low-attenuation coronary plaque (LAP) burden.
Subjects/Methods: 89 participants (40% women, 60±7.7 years) of the Dietary Intervention to Stop Coronary Atherosclerosis in Computed Tomography (DISCO-CT) study with nonobstructive atherosclerosis confirmed in computed tomography angiography (CCTA), a randomized (1:1), single-center study were included into the analysis.
Interventions/Methods: Patients were randomly assigned to either experimental arm [intensive diet and lifestyle intervention atop optimal medical therapy (OMT)] or OMT alone over 66.8±13.7 weeks. Changes (∆) in body mass (BM) and body composition parameters, including total body fat (TBF), skeletal muscle mass (SMM), and fat-to-muscle ratio (FMR) were compared with CCTA-measured ∆LAP.
Results: BM reduction was significantly higher in the experimental (∆BM=-3.6±4.9 kg) vs. control arm (∆BM=-1.4±2.9 kg; p=0.015). In the experimental arm, TBF and FMR decreased [∆TBF=-3.4±4.8%; ∆FMR=-12.9 (-21.2,-4.3)%] and SMM increased (∆SMM=1.9±2.8%). Opposite changes were observed in the control arm [∆TBF=1.1±5.5%; ∆FMR=3.1(-5.3,10.7)%; ∆SMM=-0.7±3.2%; all interarm p<0.001]. ∆LAP was positively correlated with ∆BM, ∆TBF, and ∆FMR (r=0.45, p<0.001; r=0.300, p=0.004; r=0.233, p=0.028; respectively), and negatively with ∆SMM (r=-0.285, p=0.007). Multivariate linear regression analysis revealed the association of ∆LAP with ∆TBF and ∆FMR.
Conclusions: The study intervention resulted in BM reduction characterized by fat loss and skeletal muscle gain. This weight loss pattern may lead to reduction of high-risk coronary plaque.