Protein supplementation combined with low-intensity resistance training in geriatric medical patients during and after hospitalisation: a randomised, double-blind, multicentre trial

Sarcopenia (loss of muscle mass/strength) burdens many older adults - hospitalised older adults being particularly vulnerable. Treating the condition, protein supplementation (PrS) and resistance training (RT) may act synergistically. Therefore, this block-randomised, double-blind, multicentre intervention study, recruiting geriatric patients > 70 years from three medical departments, investigated the effect of PrS combined with RT during hospitalisation and 12 weeks after discharge. Participants were randomly allocated (1:1) to receive PrS (totally 27·5 g whey protein/d, about 2000 kJ/d) or isoenergetic placebo-products (< 1·5 g protein/d) divided into two servings per d to supplement the habitual diet. Both groups were engaged in a standardised, progressive low-intensity RT programme for the lower extremities (hospital: supervised daily/after discharge: self-training 4×/week). From April 2016 to September 2017, 2351 patients were screened, 462 were eligible, and 165 included. Fourteen were excluded and ten dropped out, leaving 141 participants in the intention-to-treat analysis. The average total protein intake during hospitalisation/after discharge was 1·0 (interquartile range (IQR) 0·8, 1·3)/1·1 (IQR 0·9, 1·3) g/kg per d (protein-group) and 0·6 (IQR 0·5, 0·8)/0·9 (IQR 0·6, 1·0) g/kg per d (placebo group). Both groups improved significantly for the primary and secondary endpoints of muscle mass/strength, functional measurements and quality of life, but no additional effect of PrS was seen for the primary endpoint (30-s chair stand test, repetitions, median changes from baseline: (standard test: 0 (IQR 0, 5) (protein group) v. 2 (IQR 0, 6) (placebo group) and modified test: 2 (IQR 0, 5) (protein group) v. 2 (IQR -1, 5) (placebo group)) or any secondary endpoints (Mann-Whitney U tests, P > 0·05). In conclusion, PrS increasing the total protein intake by 0·4 and 0·2 g/kg per d during hospitalisation and after discharge, respectively, does not seem to increase the adaptive response to low-intensity RT in geriatric medical patients.