title: Low Serum Creatine Kinase Level Predicts Mortality in Patients with a Chronic Kidney Disease.
abstract: BACKGROUND
  Serum creatine kinase (sCK) reflects CK activity from striated skeletal muscle. Muscle wasting is a risk factor for mortality in patients with chronic kidney disease (CKD). The aim of this study is to evaluate whether sCK is a predictor of mortality and end-stage renal disease (ESRD) in a CKD population.
  
  
  METHODS
  We included 1801 non-dialysis-dependent CKD patients from the NephroTest cohort. We used time-fixed and time-dependent cause-specific Cox models to estimate hazard ratios (HRs) for the risk of death and for the risk of ESRD associated with gender-specific sCK tertiles.
  
  
  RESULTS
  Higher sCK level at baseline was associated with a lower age, a higher body mass index, and a higher level of 24 h urinary creatinine excretion, serum albumin and prealbumin (p<0.001). Men, patients of sub-Saharan ancestry, smokers and statin users also experienced a higher level of sCK. In a time-fixed Cox survival model (median follow-up 6.0 years), the lowest gender-specific sCK tertile was associated with a higher risk of death before and after adjustment for confounders (Crude model: hazard ratio (HR) 1.77 (95% CI: 1.34-2.32) compared to the highest tertile; fully-adjusted model: HR 1.37 (95% CI: 1.02-1.86)). Similar results were obtained with a time-dependent Cox model. The sCK level was not associated with the risk of ESRD.
  
  
  CONCLUSIONS
  A low level of sCK is associated with an increased risk of death in a CKD population. sCK levels might reflect muscle mass and nutritional status.
authors.affiliation: Service de néphrologie, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris (AP-HP), Paris, France.|College de France, Laboratory of Central Neuropeptides in the Regulation of Body Fluid Homeostasis and Cardiovascular Functions, Center for Interdisciplinary Research in Biology (CIRB), INSERM U1050, Paris, France.
authors.forename: Adrien
authors.identifier: http://orcid.org/0000-0003-4632-6332
authors.initials: A
authors.lastname: Flahault
authors.affiliation: INSERM UMRS-1018, CESP Team 5 (Renal and Cardiovascular Epidemiology), Villejuif, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Metzger
authors.affiliation: Paris Descartes University, Paris, France, Sorbonne Paris Cité, Paris, France.|Clinical chemistry, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Chassé
authors.affiliation: Université Pierre et Marie Curie, INSERM U702, Paris, France.|Hôpital Tenon, AP-HP, Service d'Explorations Fonctionnelles, Paris, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Haymann
authors.affiliation: Hôpital Tenon, AP-HP, Service de Néphrologie, Paris, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Boffa
authors.affiliation: Hôpital Bichat, AP-HP, Service de Physiologie, Paris, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Flamant
authors.affiliation: Hôpital Bichat, AP-HP, Service de Néphrologie, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Vrtovsnik
authors.affiliation: Hôpital Européen Georges Pompidou, AP-HP, Service d'Explorations Fonctionnelles, Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Houillier
authors.affiliation: INSERM UMRS-1018, CESP Team 5 (Renal and Cardiovascular Epidemiology), Villejuif, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Stengel
authors.affiliation: Service de néphrologie, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris (AP-HP), Paris, France.|Paris Descartes University, Paris, France, Sorbonne Paris Cité, Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Thervet
authors.affiliation: Paris Descartes University, Paris, France, Sorbonne Paris Cité, Paris, France.|Clinical chemistry, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pallet
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000201:enzymology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models
chemical_list: D003402:Creatine Kinase