title: Cortisol levels are associated with mortality risk in hemodialysis patients.
abstract: BACKGROUND
  End-stage renal disease (ESRD) conveys high mortality risk by complex mechanisms not fully elucidated but possibly linked to hormonal abnormalities, including cortisol. Whereas a high serum cortisol level has recently been linked with increased mortality in the general population, there is scarce information on the clinical associates and prognostic value of cortisol levels in ESRD.
  
  
  METHODS
  Prospective study of prevalent hemodialysis patients (n = 75), mostly non-diabetic (76%), where cortisol levels were assessed and patients were afterwards followed for a median of 20 (interquartile range (IQR) 8 - 31) months.
  
  
  RESULTS
  Cortisol levels were negatively correlated with plasma sodium (Rho = -0.26. p < 0.025) and positively correlated with C-reactive protein (CRP; Rho = 0.26, p = 0.027). The association with CRP remained independent of multiple confounders. Baseline cortisol levels of those who died were higher than of those who survived (19.8 ± 6.9 vs. 15.3 ± 5.7 mcg/dL, p = 0.0083). Kaplan-Meier analysis showed that patients with cortisol levels within the highest tertile (≥ 18 mcg/dL) were at increased risk of death. Cortisol was associated with risk of death both in crude and adjusted Cox proportional hazards models (HR 1.09 (1.021 - 1.167) p = 0.011; and 1.16 (1.027 - 1.309), p = 0.01, respectively)).
  
  
  CONCLUSIONS
  High serum concentrations of cortisol were associated with a state of inflammation and independently identified a subgroup of chronic hemodialysis patients at a high mortality risk.
authors.affiliation: Renal Medicine, IIS-Fundación Jiménez Díaz University Hospital, Madrid, Instituto Reina Sofia de Investigaciones Nefrologicas (IRSIN-FRIAT), Madrid, Universidad Autonoma de Madrid, Madrid, Spain, and Baxter Novum and Renal Medicine, CLINTEC, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Carolina
authors.initials: C
authors.lastname: Gracia-Iguacel
authors.forename: Emilio
authors.initials: E
authors.lastname: González-Parra
authors.forename: Jesús
authors.initials: J
authors.lastname: Egido
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
authors.forename: Ignacio
authors.initials: I
authors.lastname: Mahillo
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Carrero
authors.forename: Alberto
authors.initials: A
authors.lastname: Ortiz
mesh_terms: D000367:Age Factors; D000368:Aged; D001823:Body Composition; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000150:complications; D002423:Cause of Death; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007249:Inflammation; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000097:blood / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis / Q000401:mortality*; D012307:Risk Factors; D012964:Sodium / Q000097:blood; D015996:Survival Rate
chemical_list: D010281:Parathyroid Hormone; D002097:C-Reactive Protein; D012964:Sodium; D003404:Creatinine; D006854:Hydrocortisone