title: Extracellular volume expansion in peritoneal dialysis patients.
abstract: BACKGROUND
  Cardiovascular mortality remains high among peritoneal dialysis (PD) patients. Several small studies have suggested that PD patients are volume expanded, and as such this could be a cardiovascular risk factor. We therefore wished to investigate factors which could lead to extracellular water (ECW) expansion.
  
  
  METHODS
  Retrospective cross-sectional audit of 600 prevalent, adult PD patients attending two tertiary university PD centers, with corresponding assessments of PD adequacy, transport status, and multifrequency bioimpedance measurements of extracellular water to total body water (ECW/TBW).
  
  
  RESULTS
  600 PD patients, median age 57.5 (46.9-67.9) years, 54% male, 31% diabetic, 47.6% Caucasoid, median PD vintage 16 (3.7-38) months, (64% prescribed icodextrin, 34% hypertonic glucose dialysates, and 74% antihypertensive medications). Mean ECW 15.1±0.2 L, ICW 20±0.2 L, ECW/TBW ratio 0.437±0.007. On multivariate analysis %ECW/TBW was associated with age (F=13.1 ß=0.045 p=0.000), number of antihypertensive medications (F=10.3 ß=0.43 p=0.001), log CRP (F=12.9 ß=1.3 p=0.000), and negatively with serum albumin (F=25 ß=-0.22 p=0.000), and residual renal function (urine volume mL F=9.96 ß=-0.001 p=0.002) (weekly Kt/Vurine F=8.82 ß=-2.05, p=0.003).
  
  
  CONCLUSIONS
  Overhydration as assessed by ECW/TBW is prevalent in adult PD patients, and is associated with loss of residual renal function, inflammation, malnutrition and hypertension - as assessed by antihypertensive medications. As this was a retrospective cross-sectional audit, whether loss of residual renal function, inflammation, and protein energy wasting lead to volume expansion remains to be determined in prospective longitudinal studies.
authors.affiliation: Department of Nephrology, Barts and the London NHS trust Royal London Hospital, London - UK.
authors.forename: Stanley
authors.initials: S
authors.lastname: Fan
authors.forename: Rabya H
authors.initials: RH
authors.lastname: Sayed
authors.forename: Andrew
authors.initials: A
authors.lastname: Davenport
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000378:metabolism / Q000401:mortality / Q000503:physiopathology; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000378:metabolism*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D007674:Kidney Diseases / Q000150:complications / Q000378:metabolism / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D016014:Linear Models; D016015:Logistic Models; D008131:London; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D015999:Multivariate Analysis; D010530:Peritoneal Dialysis / Q000009:adverse effects / Q000401:mortality; D010953:Plasma Volume; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014882:Water-Electrolyte Balance
chemical_list: D000959:Antihypertensive Agents