Low Skeletal Muscle Mass Is Associated With the Presence, Incidence, and Progression of Coronary Artery Calcification.

Background: Low skeletal muscle mass (SMM) is an emerging risk factor of cardiovascular disease (CVD). We investigated the association between SMM and coronary artery calcification (CAC).

Methods: We enrolled 19,728 adults free of CVD who underwent computed tomographic estimation of Agatston CAC scores for cross-sectional analysis. Among them, 5,401 subjects who had at least 2 follow-up CAC scores were included in longitudinal analysis. Relative SMM is presented as the skeletal muscle mass index [SMI (%) = total appendicular muscle mass (kg)/body weight (kg) × 100]. CAC presence and incidence were defined as CAC score > 0, and CAC progression was defined as √CAC score (follow-up) - √CAC score (baseline) > 2.5.

Results: Among all of the subjects (mean age 53.4 years, 80.8% male), the prevalence of CAC was 36.7%. The incidence of CAC was 17.4% during a mean of 3.6 years, and the progression of CAC was 49.9% during a mean of 2.3 years. The lowest SMI quartile was significantly associated with an increased risk of CAC presence (adjusted odds ratio 2.75, 95% confidence interval [CI] 2.45-3.05; P < 0.001), incidence (adjusted hazard ratio [AHR] 1.99, 95% CI 1.36-2.91; P < 0.001), and progression (AHR 1.48, 95% CI 1.25-1.77; P < 0.001) compared with the highest quartile. SMI as a continuous value was also significantly inversely associated with CAC. SMI was the best parameter to be related to CAC among other quantitative indices such as height or body mass index adjusted.

Conclusions: Low SMM is significantly associated with an elevated risk of CAC, independently of other cardiometabolic parameters.