Higher total abdominal muscle fraction (TAM-Fraction) on CT was significantly associated with a lower risk of incident cardiovascular disease events (HR 0.73 per 1-SD increase) after adjustment for traditional obesity measures.
Cohort (n=3,016)
No
Does total abdominal muscle mass fraction on CT predict incident cardiometabolic risk factors and CVD events in a primary prevention cohort?
TAM-Fraction on a single abdominal CT slice is a novel body composition marker that improves cardiometabolic risk prediction beyond traditional obesity measures.
Hazard Ratio: 0.73 (95% CI 0.57–0.92)
p-value: p=0.0094
OBJECTIVES: To provide a standard for total abdominal muscle mass (TAM) quantification on computed tomography (CT) and investigate its association with cardiovascular risk in a primary prevention setting. METHODS: We included 3016 Framingham Heart Study participants free of cardiovascular disease (CVD) who underwent abdominal CT between 2002 and 2005. On a single CT slice at the level of L3/L4, we segmented (1) TAM-Area, (2) TAM-Index (= TAM-Area/height) and, (3) TAM-Fraction (= TAM-Area/total cross-sectional CT-area). We tested the association of these muscle mass measures with prevalent and incident cardiometabolic risk factors and incident CVD events during a follow-up of 11.0 ± 2.7 years. RESULTS: In this community-based sample (49% women, mean age: 50.0 ± 10.0 years), all muscle quantity measures were significantly associated with prevalent and incident cardiometabolic risk factors and CVD events. However, only TAM-Fraction remained significantly associated with key outcomes (e.g., adj. OR 0.68 0.55, 0.84 and HR 0.73 0.57, 0.92 for incident hypertension and CVD events, respectively) after adjustment for age, sex, body mass index, and waist circumference. Moreover, only higher TAM-Fraction was associated with a lower risk (e.g., adj. OR: 0.56 0.36-0.89 for incident diabetes versus TAM-Area: adj. OR 1.26 0.79-2.01 and TAM-Index: 1.09 0.75-1.58). CONCLUSION: TAM-Fraction on a single CT slice at L3/L4 is a novel body composition marker of cardiometabolic risk in a primary prevention setting that has the potential to improve risk stratification beyond traditional measures of obesity. KEY POINTS: • In this analysis of the Framingham Heart Study (n = 3016), TAM-F on a single slice CT was more closely associated with prevalent and incident cardiometabolic risk factors as compared to TAM alone or TAM indexed to body surface area. • TAM-F on a single abdominal CT slice at the level of L3/L4 could serve as a standard measure of muscle mass and improve risk prediction.
Kammerlander et al. (Sat,) conducted a cohort in Primary prevention of cardiovascular disease (n=3,016). Total abdominal muscle fraction (TAM-Fraction) vs. Lower TAM-Fraction was evaluated on Incident CVD events (HR 0.73, 95% CI 0.57-0.92, p=0.0094). Higher total abdominal muscle fraction (TAM-Fraction) on CT was significantly associated with a lower risk of incident cardiovascular disease events (HR 0.73 per 1-SD increase) after adjustment for traditional obesity measures.