Abstract
OBJECTIVES: Assessment of the progression of abdominal aortic calcification (AAC) may be a surrogate marker of the impact of physical function on cardiovascular risk. Our aim was to assess the risk of rapid AAC progression in older men with low relative appendicular lean mass (RALM) and poor physical function. DESIGN: Prospective cohort study. SETTING: Community-dwelling older men. PARTICIPANTS: 621 men aged 50-85 followed prospectively (baseline, 3 and 7.5 years). MEASUREMENTS: Body composition was assessed by DXA. Poor physical function was defined as incapacity to perform ≥1 of 5 clinical tests (balance, muscle strength). AAC was assessed using Kauppila's semiquantitative score. Reclassification improvement was assessed by comparing the areas under the curve (AUC) using DeLong's method. RESULTS: Rapid AAC progression (>0.6 point/year) was found in 168 men (27.1%). After adjustment for confounders including baseline AAC, the risk of rapid AAC progression increased with lower RALM (OR=1.42/SD, 95%CI: 1.09-1.86, p<0.01) and was higher in the lowest (<7.5kg/m2) vs. highest (>8.6kg/m2) quartile (OR=2.15, 95%CI: 1.17-3.95, p<0.01). Poor physical performance was associated with rapid AAC progression (OR=2.76, 95%CI: 1.48-5.91, p<0.005). Low RALM (<7.84kg/m2 defined using Youden's index) and poor physical function contributed to the risk of rapid AAC progression jointly. Men who had low RALM and poor physical function had higher risk of rapid AAC progression vs. men without these traits (OR=4.66, 95%CI: 1.72-12.62, p<0.05). RALM and physical function improved the identification of men with rapid AAC progression (DAUC=0.026, 95%CI: 0.005-0.046, p<0.05) after adjustment for confounders including baseline AAC score. CONCLUSIONS: Low RALM and poor physical function are associated with higher risk of rapid AAC progression and possibly represent another measure of cardiovascular risk.