title: Impact of Plasma Kynurenine Level on Functional Capacity and Outcome in Heart Failure　- Results From Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF).
abstract: Kynurenine is a circulating metabolite from the essential amino acid tryptophan. Accelerated degradation of kynurenine in skeletal muscle has been reported to provide an anti-inflammatory effect. The aim of this study was to investigate the association between blood kynurenine and muscle mass/function in patients with heart failure (HF), in whom diseased muscle mass/function plays a pathophysiological role.
  
  
  
  Plasma kynurenine was assessed in 249 patients with HF (67±11 years, 21% women) and in 45 controls from the SICA-HF study. Kynurenine was higher in 173 HF patients with reduced ejection fraction (EF) and in 76 patients with preserved EF than controls (3.5±1.5, 3.4±1.3, and 2.4±1.1 μmol/L, P<0.001). In HF patients, kynurenine had an inverse association with handgrip strength (r=-0.26, P<0.01), peak oxygen consumption (r=-0.29, P<0.01), 6-min walk distance (r=-0.23, P<0.01), and had a positive association with kidney and liver function parameters. No correlation was observed between kynurenine and lean mass. On multivariable linear regression analysis, a significant association was noted between kynurenine and peak oxygen consumption even after adjustment for age, gender, BMI, and hemoglobin (β=-0.23, P<0.001). Patients with higher kynurenine were at higher risk of death (adjusted HR, 1.46 per 1 μmol/L, P<0.01).
  
  
  
  In stable HF patients, plasma kynurenine was inversely correlated with muscle strength and functional capacity as well as with liver and kidney function.
authors.affiliation: Innovative Clinical Trials, Department of Cardiology and Pneumology, University of Göttingen Medical School.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Nicole
authors.initials: N
authors.lastname: Ebner
authors.forename: Jochen
authors.initials: J
authors.lastname: Springer
authors.forename: Joerg C
authors.initials: JC
authors.lastname: Schefold
authors.forename: Wolfram
authors.initials: W
authors.lastname: Doehner
authors.forename: Thomas Bernd
authors.initials: TB
authors.lastname: Dschietzig
authors.forename: Stefan D
authors.initials: SD
authors.lastname: Anker
authors.forename: Stephan
authors.initials: S
authors.lastname: von Haehling
mesh_terms: D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D018572:Disease-Free Survival; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000401:mortality*; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007737:Kynurenine / Q000097:blood*; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D015996:Survival Rate
chemical_list: D007737:Kynurenine