Background: Despite extensive research on body weight and cardiovascular risk, the
mechanistic relationship between weight loss and coronary plaque modification has
not been adequately addressed. This study aimed to determine the association between
body composition dynamics and low-attenuation coronary plaque (LAP) burden. Methods:
Eighty-nine participants (40% women, 60 +/- 7.7 years) of the Dietary Intervention
to Stop Coronary Atherosclerosis in Computed Tomography (DISCO-CT) study with non-obstructive
atherosclerosis with nonobstructive atherosclerosis confirmed in computed tomography
angiography (CCTA), a randomized (1:1), prospective, single-center study were included
into the analysis. Patients were randomly assigned to either experimental arm (intensive
diet and lifestyle intervention atop optimal medical therapy, n = 45) or control arm
(optimal medical therapy alone, n = 44) over 66.8 +/- 13.7 weeks. Changes (triangle)
in body mass (BM) and body composition parameters, including total body fat (TBF),
skeletal muscle mass (SMM), and fat-to-muscle ratio (FMR), measured with bioimpedance
analyzer were compared with CCTA-measured triangle LAP. Coronary plaque analysis was
performed using the 2 x 192 dual-energy scanner (Somatom Force, Siemens, Germany),
while quantitative coronary plaque measurements were performed using a semi-automated
plaque analysis software system (QAngioCT v3.1.3.13, Medis Medical Imaging Systems,
Leiden, The Netherlands). Results: Significant intergroup differences were found for
triangle BM (-3.6 +/- 4.9 kg in the experimental vs. -1.4 +/- 2.9 kg in the control
group, p = 0.015), triangle TBF (-3.4 +/- 4.8% in the experimental vs. 1.1 +/- 5.5%
in the control arm, p < 0.001), triangle SMM (1.9 +/- 2.8% in the experimental vs.
-0.7 +/- 3.2% in the control arm, p < 0.001), and FMR [-12.9 (-21.2; -4.3)% in the
experimental vs. 3.1 (-5.3; 10.7)% in the control arm, p < 0.001]. triangle LAP did
not differ significantly between the study arms; however, in the whole study population,
triangle LAP was positively correlated with triangle BM, triangle TBF, and triangle
FMR (r = 0.45, p < 0.001; r = 0.300, p = 0.004; r = 0.233, p = 0.028, respectively),
and negatively with triangle SMM (r = -0.285, p = 0.007). Multivariate linear regression
analysis revealed the association of triangle LAP with triangle BM, triangle TBF,
and triangle FMR. Conclusions: The study intervention resulted in BM reduction characterized
by fat loss, skeletal muscle gain, and increased FMR. This weight loss pattern may
lead to a reduction in high-risk coronary plaque. Compared to a simple weight control,
tracking body composition changes over time can provide valuable information on adverse
coronary plaque modification.
