Hydrolyzed casein and whey protein meals comparably stimulate net whole-body protein synthesis in COPD patients with nutritional depletion without an additional effect of leucine co-ingestion

Clin Nutr. 2014 Apr;33(2):211-20. doi: 10.1016/j.clnu.2013.06.014. Epub 2013 Jul 1.


Background & aims: Muscle wasting commonly occurs in COPD, negatively affecting outcome. The aim was to examine the net whole-body protein synthesis response to two milk protein meals with comparable absorption rates (hydrolyzed casein (hCAS) vs. hydrolyzed whey (hWHEY)) and the effects of co-ingesting leucine.

Methods: Twelve COPD patients (GOLD stage II-IV) with nutritional depletion, were studied following intake of a 15 g hCAS or hWHEY protein meal with or without leucine-co-ingestion, according to a double-blind randomized cross-over design. The isotopic tracers L-[ring-(2)H5]-Phenylalanine, L-[ring-(2)H2]-Tyrosine, L-[(2)H3]-3-Methylhistidine (given via continuous intravenous infusion), and L-[(15)N]-Phenylalanine (added to the protein meals) were used to measure endogenous whole-body protein breakdown (WbPB), whole-body protein synthesis (WbPS), net protein synthesis (NetPS), splanchnic extraction and myofibrillar protein breakdown (MPB). Analyses were done in arterialized-venous plasma by LC/MS/MS.

Results: WbPS was greater after intake of the hCAS protein meal (P < 0.05) whereas the hWHEY protein meal reduced WbPB more (P < 0.01). NetPS was stimulated comparably, with a protein conversion rate greater than 70%. Addition of leucine did not modify the insulin, WbPB, WbPS or MPB response.

Conclusions: Hydrolyzed casein and whey protein meals comparably and efficiently stimulate whole-body protein anabolism in COPD patients with nutritional depletion without an additional effect of leucine co-ingestion. This trial was registered at clinicaltrials.gov as NCT01154400.

Keywords: Chronic obstructive pulmonary disease; Hydrolyzed casein protein; Hydrolyzed whey protein; Leucine; Nutritionally depleted; Whole-body protein kinetics.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Absorption
  • Adult
  • Aged
  • Amino Acids / blood
  • Anthropometry
  • Body Composition
  • Caseins / administration & dosage
  • Caseins / pharmacokinetics*
  • Chromatography, Liquid
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Insulin / blood
  • Leucine / administration & dosage*
  • Male
  • Malnutrition / complications
  • Malnutrition / drug therapy
  • Meals
  • Middle Aged
  • Milk Proteins / administration & dosage
  • Milk Proteins / pharmacokinetics*
  • Muscle Proteins / drug effects
  • Muscle Proteins / metabolism
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / metabolism
  • Protein Biosynthesis
  • Pulmonary Disease, Chronic Obstructive / complications
  • Pulmonary Disease, Chronic Obstructive / drug therapy*
  • Tandem Mass Spectrometry
  • Whey Proteins


  • Amino Acids
  • Caseins
  • Insulin
  • Milk Proteins
  • Muscle Proteins
  • Whey Proteins
  • Leucine

Associated data

  • ClinicalTrials.gov/NCT01154400