Xin Liu, Zhaoxin Jiang, Pan Liu, Shenghong Chen, Yumei Wu, Jiahao Meng, Shuguang Gao
Seventeen RCTs were included. Compared with NS alone, the combined intervention improved lower limb strength (SMD 0.35; 95% CI, 0.18-0.52; P < 0.0001) but did not improve upper limb strength (handgrip) (SMD 0.15; 95% CI, -0.01 to 0.30; P = 0.07). Muscle mass (SMD 0.65; 95% CI, -0.23 to 1.54; P = 0.15) and lean body mass (LBM) (SMD 0.27; 95% CI, -0.12 to 0.66; P = 0.18) were not significantly different. A small standardized improvement in usual walking speed (UWS) was detected with the combined intervention (SMD 0.38; 95% CI, 0.10-0.66; P = 0.008). When expressed in absolute units, the pooled UWS improvement was 0.07 m/s (95% CI, 0.03-0.12; P = 0.001). Timed Up and Go (TUG) performance favored exercise plus NS but did not reach significance (SMD -0.33; 95% CI, -0.74 to 0.08; P = 0.11). Serum 25(OH)D did not differ between groups. Accordingly, GRADE certainty was moderate for lower limb strength, but low for upper limb strength and UWS, and very low for muscle mass and TUG, indicating that confidence is highest for the lower-limb strength benefit, while effects on mobility and body composition remain more uncertain.
PURPOSE: This meta-analysis sought to evaluate whether the addition of exercise to nutritional support (NS) improves physical function compared with NS alone in older adults diagnosed with malnutrition retrospectively verified as compatible with the updated Global Leadership Initiative on Malnutrition (GLIM) 2025 phenotypic-etiologic framework.
METHODS: A comprehensive search was conducted in PubMed, Embase, Web of Science, and the Cochrane Library to identify randomized controlled trials (RCTs) comparing combined exercise and NS versus NS alone in malnourished older adults. Studies were included if participants met GLIM-defined malnutrition criteria and the trial reported relevant physical function or nutritional outcomes. Predefining upper and lower limb strength as distinct endpoints, data were analyzed using a random-effects model, with results expressed as standardized mean differences (SMDs) and 95% confidence intervals (CIs). To facilitate interpretation, a positive SMD denotes an effect favoring the combined intervention, except for TUG, where a negative value is favorable.
FINDINGS: Seventeen RCTs were included. Compared with NS alone, the combined intervention improved lower limb strength (SMD 0.35; 95% CI, 0.18-0.52; P < 0.0001) but did not improve upper limb strength (handgrip) (SMD 0.15; 95% CI, -0.01 to 0.30; P = 0.07). Muscle mass (SMD 0.65; 95% CI, -0.23 to 1.54; P = 0.15) and lean body mass (LBM) (SMD 0.27; 95% CI, -0.12 to 0.66; P = 0.18) were not significantly different. A small standardized improvement in usual walking speed (UWS) was detected with the combined intervention (SMD 0.38; 95% CI, 0.10-0.66; P = 0.008). When expressed in absolute units, the pooled UWS improvement was 0.07 m/s (95% CI, 0.03-0.12; P = 0.001). Timed Up and Go (TUG) performance favored exercise plus NS but did not reach significance (SMD -0.33; 95% CI, -0.74 to 0.08; P = 0.11). Serum 25(OH)D did not differ between groups. Accordingly, GRADE certainty was moderate for lower limb strength, but low for upper limb strength and UWS, and very low for muscle mass and TUG, indicating that confidence is highest for the lower-limb strength benefit, while effects on mobility and body composition remain more uncertain.
IMPLICATIONS: Adding exercise to nutritional support was associated with small but statistically significant improvements in lower limb strength and UWS in malnourished older adults. While this combined approach optimizes specific functional outcomes, current evidence does not demonstrate added benefits for overall body composition or upper limb strength.