title: Hypokalemia is associated with increased mortality rate in chronic hemodialysis patients.
abstract: BACKGROUND
  Both hypokalemia (hypoK) and hyperkalemia (hyperK) are life-threatening to hemodialysis (HD) patients. This study was conducted to compare their clinical characteristics and long-term survival.
  
  
  METHODS
  Patients were divided into three groups according to the last mid-week predialysis serum potassium concentrations: hypoK (<3.5 mEq/l), normoK (between 3.5 and 5.5 mEq/l), and hyperK (>5.5 mEq/l). The maximal duration of the follow-up period was 54 months.
  
  
  RESULTS
  Compared with the hyperK group,patients in the hypoK group were older (p <0.05), had a higher incidence of comorbidity factors, less body weight gain prior to HD (p < 0.05), lower body mass index (BMI, p < 0.05), and higher BUN to creatinine ratio and hs-CRP (p < 0.05). The serum albumin and prealbumin concentrations were also lowest in the hypoK group, compared with the normoK and hyperK groups, respectively (all p < 0.001). A similar finding was also obtained for the normalized protein catabolism rate (nPCR, p < 0.001) among the three groups. Positive linear correlations between serum albumin and potassium concentration were only found in the hypoK and normoK groups (p < 0.001). Multiple logistic regression analysis showed that hypoalbuminemia, low BUN, and phosphate concentrations were significantly correlated with hypoK. HypoK patients also had a lower cumulative survival rate than hyperK patients.
  
  
  CONCLUSIONS
  HypoK HD patients, with lower serum levels of albumin, prealbumin, nPCR, and BMI, but higher level of hs-CRP, showed a malnutritional and inflammatory status, and caused increased mortality rate.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan, ROC.
authors.forename: Jyh-Chang
authors.initials: JC
authors.lastname: Hwang
authors.forename: Charn-Ting
authors.initials: CT
authors.lastname: Wang
authors.forename: Chien-An
authors.initials: CA
authors.lastname: Chen
authors.forename: Hung-Chun
authors.initials: HC
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D005260:Female; D006801:Humans; D007008:Hypokalemia / Q000150:complications*; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D006435:Renal Dialysis; D012189:Retrospective Studies; D012709:Serum Albumin / Q000032:analysis; D016019:Survival Analysis; D013997:Time Factors; D055815:Young Adult
chemical_list: D012709:Serum Albumin; D011188:Potassium