title: Serum Potassium, End-Stage Renal Disease and Mortality in Chronic Kidney Disease.
abstract: OBJECTIVE
  Hypokalemia and hyperkalemia are often noted in chronic kidney disease (CKD) patients, but their impact on mortality and end-stage renal disease (ESRD) is less well understood. We aimed at studying the associations between potassium disorders, and mortality and progression to ESRD in a CKD population.
  
  
  METHODS
  Using our electronic health record-based CKD registry, 36,359 patients with eGFR <60 ml/min/1.73 m(2) and potassium levels measured from January 1, 2005 to September 15, 2009 were identified. We examined factors associated with hypokalemia (<3.5 mmol/l) and hyperkalemia (>5.0 mmol/l) using logistic regression models and associations between serum potassium levels (both as continuous and categorical variables) and all-cause mortality or ESRD using Cox-proportional hazards models.
  
  
  RESULTS
  Serum potassium <3.5 mmol/l was noted among 3% and >5.0 mmol/l among 11% of the study population. In the multivariable logistic regression analysis, lower eGFR, diabetes and use of ACE inhibitors or Angiotensin-Receptor Blockers were associated with higher odds of having hyperkalemia. Heart failure and African American race were factors associated with higher odds of hypokalemia. After adjustment for covariates including kidney function, serum potassium <4.0 and >5.0 mmol/l were significantly associated with increased mortality risk, but there was no increased risk for progression to ESRD. Time-dependent repeated measures analysis confirmed these findings. When potassium was examined as a continuous variable, there was a U-shaped association between serum potassium levels and mortality.
  
  
  CONCLUSIONS
  In patients with stage 3-4 CKD, serum potassium levels <4.0 and >5.0 mmol/l are associated with higher mortality but not with ESRD.
authors.affiliation: Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Georges N
authors.initials: GN
authors.lastname: Nakhoul
authors.forename: Haiquan
authors.initials: H
authors.lastname: Huang
authors.forename: Susana
authors.initials: S
authors.lastname: Arrigain
authors.forename: Stacey E
authors.initials: SE
authors.lastname: Jolly
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Schold
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Nally
authors.forename: Sankar D
authors.initials: SD
authors.lastname: Navaneethan
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D057911:Angiotensin Receptor Antagonists / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D003920:Diabetes Mellitus / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006947:Hyperkalemia / Q000097:blood / Q000453:epidemiology*; D007008:Hypokalemia / Q000097:blood / Q000453:epidemiology* / Q000208:ethnology; D007676:Kidney Failure, Chronic / Q000097:blood / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012042:Registries; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000401:mortality*; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
chemical_list: D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D011188:Potassium