Objective
We aimed to investigate the interaction of reduced skeletal muscle mass and abdominal obesity on coronary artery calcification (CAC).
Design and methods
A total of 19,728 adults free of cardiovascular disease (CVD) who contemporaneously underwent cardiac tomography and bioelectrical impedance analysis were enrolled in a cross-sectional and longitudinal cohort. Skeletal muscle mass index (SMI) was calculated the following formula: SMI (%) = total appendicular muscle mass (kg)/body weight (kg) x 100 according to sex. CAC presence or incidence was defined as CAC score>0, and CAC progression was defined as √CAC score (follow-up) − √CAC score (baseline)>2.5. Pre-sarcopenia was defined as SMI ≤ –1.0 standard deviation of the sex-specific mean of a young reference group. Abdominal obesity was defined as waist circumference ≥90cm for men and ≥85cm for women. All individuals were further classified into four groups: normal, abdominal obesity alone, pre-sarcopenia alone, and pre-sarcopenic obesity.
Results
Individuals with pre-sarcopenic obesity showed the highest adjusted odds ratio (AOR) for CAC presence (AOR 2.16, 95% confidence interval [CI]: 1.98–2.36, P<0.001) as well as total CAC incidence and progression (adjusted hazard ratio 1.54, 95% CI: 1.37–1.75, P<0.001), compared with normal individuals. Pre-sarcopenic obesity significantly increased CAC incidence and progression compared to either pre-sarcopenia or abdominal obesity alone.
Conclusion
Pre-sarcopenia and abdominal obesity together were significantly associated with a higher CAC presence and increased risk of CAC incidence and progression, independent of traditional CVD risk factors.