title: The impact of serum potassium concentration on mortality after liver transplantation: a cohort multicenter study.
abstract: BACKGROUND
  Potassium plays a key role in human metabolism in both health and disease. The impact of recipient serum potassium concentration [K] on mortality after liver transplantation has not been described previously.
  
  
  METHODS
  We assessed the effect of recipient [K] on the survival of adult first single-organ liver transplant recipients in the United Kingdom and Ireland between March 1, 1994, and February 28, 2007 (n=5942), adjusting for recipient, donor, and graft characteristics.
  
  
  RESULTS
  The overall risk-adjusted mortality significantly varied by [K], being higher among hyperkalemic ([K]>5.0 mmol/L) recipients (n=424, hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.01-1.88) and those with [K] of 4.5-5.0 mmol/L (n=1154, HR 1.47, 95% CI 1.13-1.91), compared with hypokalemic ([K]<3.5 mmol/L) recipients (n=360). However, the excess mortality was confined to the first posttransplant year among hyperkalemic recipients (HR 1.61, 95% CI 1.10-2.35) with no significant difference thereafter (HR 1.03, 95% CI 0.62-1.73). This was also true for recipients with [K] of 4.5 to 5.0 mmol/L (< or =1 year: HR 1.70, 95% CI 1.22-2.38; >1 year: HR 1.09, 95% CI 0.71-1.66). In contrast, those with [K] of 3.5 to 3.9 mmol/L (n=1518) and [K] of 4.0-4.4 mmol/L (n=2091) had similar risk-adjusted mortality at the above time points. When [K] was used as a continuous variable in the multivariable analysis, a mmol increase in [K] was associated with an increased adjusted risk of mortality of 27% (95% CI 12%-44%) at 1 year and 19% (95% CI 7%-31%) at 5 years.
  
  
  CONCLUSIONS
  Recipient [K] is an independent predictor of death after liver transplantation. This finding could be of clinical utility in the management, risk stratification, selection, and prioritization of appropriate candidates for transplantation among patients with end-stage liver disease.
authors: Liver Transplant Unit, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Hills Road, Cambridge, United Kingdom. drdawwas@gmail.com
authors: Muhammad F
authors: MF
authors: Dawwas
authors: James D
authors: JD
authors: Lewsey
authors: Christopher J
authors: CJ
authors: Watson
authors: Alexander E
authors: AE
authors: Gimson
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000097:blood / Q000209:etiology / Q000401:mortality*; D007008:Hypokalemia / Q000097:blood / Q000209:etiology / Q000401:mortality*; D007494:Ireland / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D016031:Liver Transplantation / Q000009:adverse effects / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D011188:Potassium