Introduction: Little is known about the impact of low muscle mass (MM) assessed by calf circumference (CC), arm circumference (AC), arm muscle circumference (AMC), and corrected arm muscle circumference (CAMC)-on mortality risk later in life. We aimed to investigate the impact of low MM assessed by CC, AC, AMC and, CAMC on all-cause, cardiovascular, and cancer mortality risk.
Methods: Data came from 418 older adults who participated in a 10-year follow-up prospective cohort study. Low MM was defined as a CC < 33 cm for women and < 34 cm for men and by the lowest tertile of AC, AMC, and CAMC stratified by sex. The log rank test, Kaplan-Meier curves, and Cox regression were used.
Results: There were 147 deaths: 49 related to CVD and 22 to cancer. A small CC (HR = 1.57, 95% CI, 1.12-2.20), AMC (HR = 1.61, 95% CI, 1.13-2.30) and CAMC (HR = 1.45, 95% CI, 1.03-2.04) were associated with all-cause mortality. A small CAMC was a protective factor for CVD mortality (HR = 0.46, 95% CI, 0.22-0.98). In the Kaplan-Meier analysis, older adults with LMM presented low all-cause mortality survival, with AC (p < 0.05), AMC (p < 0.005), CAMC (p < 0.002), and CC (p < 0.001). Cancer mortality was associated with low CAMC (p < 0.020).
Conclusions: Low MM assessed by anthropometric measures (AC, AMC, CAMC and CC) increased the all-cause mortality risk. A small CAMC decreased the CVD mortality.