Hypokalemia in Chinese peritoneal dialysis patients: prevalence and prognostic implication.
BACKGROUND
Abnormal potassium metabolism may contribute to the increased cardiac morbidity and mortality seen in dialysis patients. We studied the pattern of serum potassium levels in a cohort of Chinese peritoneal dialysis (PD) patients.


METHODS
We studied serum potassium levels of 266 PD patients during 3 consecutive clinic visits. Dialysis adequacy, residual renal function, and nutritional status also were assessed. Patients were followed up for 33.7 +/- 20.7 months.


RESULTS
Mean serum potassium level was 3.9 +/- 0.5 mEq/L (mmol/L). Five patients (1.9%) had an average serum potassium level less than 3 mEq/L (mmol/L), whereas 54 patients (20.3%) had a serum potassium level less than 3.5 mEq/L (mmol/L). Serum potassium levels correlated with overall Subjective Global Assessment score (r = 0.276; P < 0.001) and serum albumin level (r = 0.173; P = 0.005) and inversely with Charlson comorbidity score (r = -0.155; P = 0.011). There was no correlation between serum potassium level and daily PD exchange volume, total Kt/V, urine volume, or residual glomerular filtration rate. By means of multivariate analysis with Cox proportional hazard model to adjust for confounders, serum potassium level was an independent predictor of actuarial patient survival. PD patients with hypokalemia (serum potassium < 3.5 mEq/L [mmol/L]) had significantly worse actuarial survival (hazard ratio, 1.79; 95% confidence interval, 1.12 to 2.85; P = 0.015) than those without hypokalemia after adjusting for confounding factors.


CONCLUSIONS
Hypokalemia is common in Chinese PD patients. Serum potassium level was associated with nutritional status and severity of coexisting comorbid condition. Furthermore, hypokalemia was an independent predictor of survival in PD patients. Additional studies may be needed to investigate the benefit of potassium supplementation for PD patients with hypokalemia.
Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China. ccszeto@cuhk.edu.hk
Cheuk-Chun
CC
Szeto
Kai-Ming
KM
Chow
Bonnie Ching-Ha
BC
Kwan
Chi-Bon
CB
Leung
Kwok-Yi
KY
Chung
Man-Ching
MC
Law
Philip Kam-Tao
PK
Li
D000328:Adult; D000368:Aged; D002423:Cause of Death; D002681:China / Q000453:epidemiology; D015314:Dialysis Solutions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007008:Hypokalemia / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000401:mortality / Q000628:therapy; D015993:Life Tables; D008297:Male; D044342:Malnutrition / Q000097:blood / Q000150:complications; D008875:Middle Aged; D009026:Mortality; D009752:Nutritional Status; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D017419:Potassium, Dietary; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis
D015314:Dialysis Solutions; D017419:Potassium, Dietary