We evaluated the efficacy of muscle-targeted nutritional support on the functional outcomes of multidisciplinary intensive rehabilitation treatment (MIRT) in patients with Parkinson disease (PD) or parkinsonism.
We conducted a pragmatic, bicentric, randomized (1:1), assessor-blind controlled trial (Protein, Leucine and Vitamin D Enhancing Rehabilitation [PRO-LEADER]; April 2017 to January 2018) in cognitively intact patients with PD or parkinsonism and undergoing a 30-day MIRT. Patients (n = 150) received a standard hospital diet with or without a whey protein–based nutritional supplement enriched with leucine and vitamin D twice daily. The primary efficacy endpoint was the increase in the distance walked during a 6-minute walking test (6MWT). Secondary endpoints were changes in 4-meter walking speed, Timed Up and Go test (TUG), Berg balance scale, handgrip strength, Self-assessment Parkinson’s Disease Disability Scale, body weight, and skeletal muscle mass (SMM).
Nutritional support resulted in greater increase in the distance walked during 6MWT (mean 69.6 meters [95% confidence interval (CI) 60.7–78.6]) than no support (51.8 meters [95% CI 37.0–66.7]): center-adjusted mean difference, 18.1 meters (95% CI 0.9–35.3) (p = 0.039). Further adjustment for changes in dopaminergic therapy and SMM yielded consistent results: mean difference, 18.0 meters (95% CI 0.7–35.2) (p = 0.043). A meaningful effect was also found for the following secondary endpoints: 4-meter walking speed (p = 0.032), TUG (p = 0.046), SMM, and SMM index (p = 0.029). Six patients discontinued the nutritional therapy due to mild side effects.
The consumption of a whey protein–based nutritional formula enriched with leucine and vitamin D with MIRT improved lower extremity function and preserved muscle mass in patients with PD or parkinsonism.
Classification of evidence
This study provides Class I evidence that for patients with parkinsonism undergoing intensive rehabilitation, a whey protein–based nutritional formula enriched with leucine and vitamin D increased distance walked on the 6MWT.