title: Is glutamine deficiency the link between inflammation, malnutrition, and fatigue in cancer patients?
abstract: OBJECTIVE
  Evaluation of potential associations between plasma glutamine levels and the incidence of cancer related fatigue, physical performance, poor nutritional status, and inflammation in patients with solid tumors.
  
  
  METHODS
  Mono-center cross-sectional study recruiting 100 (34 women) consecutive patients (September 2009-March 2011; ≥18 y) with solid tumors and causal tumor therapy.
  
  
  METHODS
  Fasting venous blood was harvested for routine clinical chemistry, amino acid (HPLC) and inflammation marker analyses. Clinical assessments included global, physical, affective and cognitive fatigue (questionnaire) and Karnofsky performance status. Nutritional status was evaluated using bioelectrical impedance analysis, the Prognostic Inflammatory and Nutritional Index and plasma protein levels. Regression analyses were performed to correlate continuous variables with plasma glutamine (95% confidence intervals).
  
  
  RESULTS
  Nutritional status was impaired in 19% of the patients. Average plasma glutamine concentration (574.0 ± 189.6 μmol/L) was within normal range but decreased with impaired physical function. Plasma glutamine was linked to the ratio extracellular to body cell mass (p < 0.044), CRP (p < 0.001), physical (p = 0.014), affective (p = 0.041), and global fatigue (p = 0.030). Markers of inflammation increased with low physical performance.
  
  
  CONCLUSIONS
  The data support our working hypothesis that in cancer patients systemic inflammation maintains a catabolic situation leading to malnutrition symptoms and glutamine deprivation, the latter being associated with cancer related fatigue.
authors.affiliation: Department of Internal Medicine III, Ludwig-Maximilians-University-Großhadern, Munich, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Schlemmer
authors.affiliation: Fresenius Kabi-Deutschland, GmbH, Bad Homburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Suchner
authors.affiliation: Schön Klinik, Bad Aibling, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Schäpers
authors.affiliation: Department of Internal Medicine III, Ludwig-Maximilians-University-Großhadern, Munich, Germany.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Duerr
authors.affiliation: Department of Nutrition and Food Sciences - Nutritional Physiology, University of Bonn, Bonn, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Alteheld
authors.affiliation: Estimate, Augsburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zwingers
authors.affiliation: Department of Nutrition and Food Sciences - Nutritional Physiology, University of Bonn, Bonn, Germany. Electronic address: pstehle@uni-bonn.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Stehle
authors.affiliation: Carl-Ludwig-Institute of Physiology, University of Leipzig, Germany.
authors.forename: Heinz-Gerd
authors.initials: HG
authors.lastname: Zimmer
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005221:Fatigue / Q000097:blood* / Q000150:complications; D005260:Female; D005973:Glutamine / Q000097:blood* / Q000172:deficiency; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D008297:Male; D044342:Malnutrition / Q000097:blood* / Q000150:complications; D008875:Middle Aged; D009043:Motor Activity; D009369:Neoplasms / Q000097:blood* / Q000150:complications; D015596:Nutrition Assessment; D009752:Nutritional Status; D011379:Prognosis; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D005973:Glutamine
keywords: Cancer related fatigue; Glutamine; Inflammation; Malnutrition; Solid tumors