Table 2. Characteristics of studies included in the systematic review and meta-analysis.
| Author(Year) | Studytype | Comparison | Duration ofIntervention | Numberof cases | MeanAge (year) | Sex(Male %) | Mean BMI(kg/m2) | Lean bodymass (kg) | Muscle strength(kg), double leg press | Muscle strength (kg),leg extension | |||
| Before | After | Before | After | Before | After | ||||||||
| Dalyet al [27] | RCT | Protein vsControl | 4 months | 53 vs 47 | 72 vs 74 | 0 v. 0 | 28 vs 28 | 0.6 (0.3, 0.8)* vs 0.1 (−0.4, 1.1)* | NA | NA | 28 (18, 39)* vs 10 (−1, 21)* | ||
| Vermeerenet al [28] | RCT | Protein vsControl | mean 9 days | 23 vs 24 | 66 vs 65 | 61 vs 75 | 20 vs 21 | Mean change from baseline: –0.5±2.6 vs –0.4±2.7 | NA | NA | Mean change from baseline: 3±8 vs 2±9 | ||
| Chaleet al [8] | RCT | Protein vsControl | 6 months | 42 vs 38 | 78 vs 77.3 | 40 vs 42 | 27 vs 26.9 | 46.7±8.6 vs 46.4±8.4 | 47.3±8.6 vs 46.7±8.4 | 125±39 vs 128±47 | 151±58 vs 149±54 | NA | NA |
| Alemán-Mateoet al [29] | RCT | Protein vsControl | 3 months | 20 vs 20 | 75 vs 77 | 40 vs 45 | 27 vs 26 | 37.1±6.3 vs 36.8±6.4 | 37.9±6.5 vs 37.6±6.4 | NA | NA | NA | NA |
| Tielandet al [20] | RCT | Protein vsControl | 24 weeks | 34 vs 31 | 78 vs 81 | 41.2 vs 48.9 | 27 vs 26.2 | 45.8±9.9 vs 46.7±9.5 | 45.8±9.9 vs 46.6±9.5 | 118±47 vs 124±50 | 136±47 vs 139±50 | 57±29 vs 57±28 | 68±29 vs 63±28 |
| Tielandet al [26] | RCT | Protein vsControl | 24 weeks | 31 vs 31 | 78 vs 79 | 35 vs 32 | 28.7 vs 28.2 | 47.2±9.6 vs 45.7±8.9 | 48.5±9.4 vs 45.4±8.9 | 124±39 vs 116±36 | 169±39 vs 162±41 | 56±17 vs 58±17 | 77±18 vs 79±18 |
| Leenderset al [19] | RCT | Leucine vsControl | 24 weeks | 39 vs 28 | 71 vs 71 | 100 vs 100 | 27.4 vs 27.2 | 61.9±6.9 vs 62.2±6.9 | 62.0±6.2 vs 62.2±6.9 | 202±44 vs 205±37 | 217±50 vs 218±42 | 80±12 vs 88±16 | 84±19 vs 94±21 |
| Ferrandoet al [18] | RCT | Amino acidvsControl | 10 days | 10 vs 11 | 71 vs 68 | 10 vs 50 | NA | 43.0±0.6 vs 46.8±1.0 | 42.1±0.6 vs 45.3±1.0 | NA | NA | NA | NA |
| Verhoevenet al [17] | RCT | Leucine vsControl | 12 weeks | 15 vs 14 | NA | 100 vs 100 | 25.9 vs 26.3 | 54.6±5.8 vs 55.8±3.4 | 55.0±5.8 vs 56.2±4.1 | 170±8 vs172±6 | NA | 85±3 vs85±3 | NA |
NA, not available; RCT: randomized controlled trial.
*values are within-group mean absolutes of the change from baseline with 95% confidence intervals in parentheses.