title: Circulating follistatin in patients with chronic kidney disease: implications for muscle strength, bone mineral density, inflammation, and survival.
abstract: OBJECTIVE
  Follistatin mediates muscle growth and bone mineralization. At present, it is unknown whether circulating follistatin levels are altered in chronic kidney disease (CKD) or links to CKD risk factors and outcomes.
  
  
  METHODS
  Plasma follistatin levels were cross-sectionally analyzed in relation to protein-energy wasting (PEW), handgrip strength (HGS), bone mineral density (BMD), and inflammatory markers in 280 CKD stage 5 patients, 32 CKD stage 4 patients, 16 CKD stage 3 patients, and 32 control subjects. In CKD stage 5 patients survival was prospectively investigated during a follow-up period of up to 5 years.
  
  
  RESULTS
  The plasma follistatin concentration was not higher in CKD stage 5 patients than in other CKD stages or controls. In CKD stage 5 patients, circulating follistatin positively correlated with age, high-sensitivity C-reactive protein (hsCRP), and IL-6; negatively correlated with HGS, serum creatinine, and BMD; and was increased in patients with PEW. In a multivariate logistic regression model, lower HGS, lower BMD, and higher hsCRP independently correlated with higher follistatin levels. In a Cox regression model, follistatin levels were not associated with all-cause mortality.
  
  
  CONCLUSIONS
  Circulating follistatin levels were neither elevated nor predicted outcome in patients with CKD. However, increased follistatin levels occurred together with increased inflammation, reduced muscle strength, and low BMD, suggesting an involvement of a mechanism including follistatin in the uremic wasting process.
authors.affiliation: Division of Baxter Novum, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Carrero
authors.forename: Abdul Rashid
authors.initials: AR
authors.lastname: Qureshi
authors.forename: Björn
authors.initials: B
authors.lastname: Anderstam
authors.forename: Olof
authors.initials: O
authors.lastname: Heimbürger
authors.forename: Peter
authors.initials: P
authors.lastname: Bárány
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
authors.forename: Peter
authors.initials: P
authors.lastname: Stenvinkel
mesh_terms: D000368:Aged; D015519:Bone Density / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D038681:Follistatin / Q000097:blood* / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000401:mortality / Q000503:physiopathology; D012307:Risk Factors; D014511:Uremia / Q000097:blood / Q000401:mortality / Q000503:physiopathology
chemical_list: C503233:FST protein, human; D038681:Follistatin