title: High anabolic potential of essential amino acid mixtures in advanced nonsmall cell lung cancer.
abstract: BACKGROUND
  Conventional nutritional supplements are not or only partly successful in inducing protein accretion in advanced cancer, suggesting an attenuated anabolic response. To prevent muscle wasting and its deleterious consequences, generating an anabolic response is crucial. Dietary essential amino acids (EAA) have anabolic properties in other wasting diseases; however, data in advanced cancer are lacking.
  
  
  METHODS
  In 13 patients with advanced nonsmall-cell lung cancer (NSCLC) (stage III and IV) and 11 healthy age-matched subjects, we measured protein synthesis and breakdown of the whole body, and net protein anabolism (difference between protein synthesis and breakdown) after intake of 14 g of free EAA with high leucine levels (EAA/leucine) versus a balanced amino acid mixture containing both EAA and non-EAA as present in whey protein, according to a randomized, double-blind, crossover design.
  
  
  RESULTS
  Protein synthesis and net protein anabolism were higher after intake of the EAA/leucine than the balanced amino acid mixture (P < 0.001), independent of presence of cancer. A highly significant linear relationship between net protein anabolism and the amount of EAA available in the systemic circulation (R(2): 0.85, P < 0.001) was found in both groups. The presence of muscle or recent weight loss, systemic inflammatory response, or length of survival did not influence this relationship. High leucine levels in the EAA/leucine mixture was of no anabolic benefit.
  
  
  CONCLUSIONS
  There is no anabolic resistance or attenuated anabolic potential to intake of 14 g of EAA/leucine or balanced amino acid mixture in advanced (mainly stage III) NSCLC. The high anabolic potential of dietary EAA in cancer patients is independent of their nutritional status, systemic inflammatory response or disease trajectory, suggesting a key role of EAA in new nutritional approaches to prevent muscle loss, thereby improving outcome of patients with advanced cancer.
  NCT01172314.
authors.affiliation: Department of Health and Kinesiology, Center for Translational Research in Aging and Longevity, Texas A&M University, College Station; Department of Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, USA. Electronic address: mpkj.engelen@ctral.org.
authors.forename: M P K J
authors.initials: MPKJ
authors.lastname: Engelen
authors.affiliation: Department of Hematology and Oncology, University of Arkansas for Medical Sciences, Little Rock, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Safar
authors.affiliation: Department of Pulmonary and Critical Care Medicine, University of Arkansas for Medical Sciences, Little Rock, USA.
authors.forename: T
authors.initials: T
authors.lastname: Bartter
authors.affiliation: Department of Health and Kinesiology, Center for Translational Research in Aging and Longevity, Texas A&M University, College Station; Department of Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, USA.
authors.forename: F
authors.initials: F
authors.lastname: Koeman
authors.affiliation: Department of Health and Kinesiology, Center for Translational Research in Aging and Longevity, Texas A&M University, College Station; Department of Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, USA.
authors.forename: N E P
authors.initials: NEP
authors.lastname: Deutz
mesh_terms: D000368:Aged; D000601:Amino Acids, Essential / Q000627:therapeutic use*; D045930:Anabolic Agents / Q000627:therapeutic use*; D002100:Cachexia / Q000188:drug therapy / Q000517:prevention & control*; D002289:Carcinoma, Non-Small-Cell Lung; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D008175:Lung Neoplasms; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology; D009133:Muscular Atrophy / Q000188:drug therapy / Q000517:prevention & control*; D014176:Protein Biosynthesis / Q000502:physiology; D059748:Proteolysis / Q000187:drug effects; D000067816:Whey Proteins / Q000627:therapeutic use
chemical_list: D000601:Amino Acids, Essential; D045930:Anabolic Agents; D000067816:Whey Proteins
keywords: cachexia; dietary essential amino acids; nonsmall-cell lung cancer; protein anabolism; stable isotopes; translational research