title: Evaluating Hyponatremia in Non-Diabetic Uremic Patients on Peritoneal Dialysis.
abstract: ♦
  
  
  BACKGROUND
  An approach to hyponatremia in uremic patients on peritoneal dialysis (PD) necessitates the assessment of intracellular fluid volume (ICV) and extracellular volume (ECV). The aim of the study was to evaluate the association of plasma sodium (Na(+)) concentration and body fluid composition and identify the causes of hyponatremia in non-diabetic PD patients. ♦
  
  
  METHODS
  Sixty non-diabetic uremic patients on PD were enrolled. Baseline body fluid composition, biochemistry, hand-grip test, peritoneal membrane characteristics, dialysis adequacy, Na(+) and water balance, and residual renal function (RRF) were measured. These parameters were reevaluated for those who developed hyponatremia, defined as serum Na(+) concentration < 132 mmol/L and a decline in serum Na(+) > 7 mmol/L, during monthly visits for 1 year. Body fluid composition was determined by multi-frequency bioelectrical impedance (BIA). ♦
  
  
  RESULTS
  There was no significant correlation between serum Na(+) concentrations and any other parameters except a negative correction with overnight ultrafiltration (UF) amount (p = 0.02). The ICV/ECV ratio was positively correlated with serum albumin (p < 0.005) and hand grip strength (p < 0.05). Over 1 year, 9 patients (M:F = 3:6, aged 35 - 77) with 4 different etiologies of hyponatremia were identified. Hyponatremic patients with a body weight (BW) loss had either an increased ICV/ECV ratio associated with primarily a negative Na(+) balance (n = 2) or a reduced ratio of ICV/ECV associated with malnutrition (n = 2). In contrast, hyponatremic patients with a BW gain had either a reduced ICV/ECV ratio associated with a rapid loss of RRF and a higher peritoneal permeability (n = 2) or a normal to increased ICV/ECV ratio associated with high water intake (n = 3). ♦
  
  
  CONCLUSIONS
  Besides BW change and ultrafiltration rate, the assessment of ICV/ECV ratio is valuable in identifying the etiologies of hyponatremia in PD and provides a guide for optimal therapy.
authors.affiliation: Division of Nephrology, Department of Medicine, Cathay General Hospital, School of Medicine, Fu-Jen Catholic University, Taipei, Taiwan National Defense Medical Center, Taipei, Taiwan.
authors.forename: Ming-Tso
authors.initials: MT
authors.lastname: Yan
authors.affiliation: Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Cheng
authors.affiliation: Department of Nutrition, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Hsiu-Yuan
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Division of Nephrology, Department of Medicine, Cathay General Hospital, School of Medicine, Fu-Jen Catholic University, Taipei, Taiwan.
authors.forename: Chwei-Shiun
authors.initials: CS
authors.lastname: Yang
authors.affiliation: Division of Nephrology, Department of Medicine, Cathay General Hospital, School of Medicine, Fu-Jen Catholic University, Taipei, Taiwan.
authors.forename: Sheng-Jeng
authors.initials: SJ
authors.lastname: Peng
authors.affiliation: Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan l521116@ndmctsgh.edu.tw.
authors.forename: Shih-Hua
authors.initials: SH
authors.lastname: Lin
mesh_terms: D000328:Adult; D001823:Body Composition; D001826:Body Fluids; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000378:metabolism*; D011446:Prospective Studies; D012964:Sodium / Q000097:blood*; D014462:Ultrafiltration; D014511:Uremia / Q000503:physiopathology*; D014882:Water-Electrolyte Balance
chemical_list: D012964:Sodium
keywords: Bio-impedance; hyponatremia; non-diabetes; nutrition; peritoneal dialysis; residual renal function