title: [Extracellular hydration status and residual urinary sodium excretion in chronic hemodialysis patients: a cross-sectional multicenter study].
abstract: BACKGROUND
  In dialysis patients, a misevaluation of dry weight may lead to an increased morbidity and mortality. The aim of this cross-sectional multicenter study was to evaluate the association between residual urinary sodium excretion and extracellular volume status in chronically treated hemodialysis patients.
  
  
  METHODS
  Dry weight was determined clinically and by whole-body bioimpedance spectroscopy (Body Composition Monitor, Fresenius Medical Care) prior to a mid-week session in 40 chronic hemodialysis patients with significant residual diuresis (more than 250 mL per day) and receiving treatment in four dialysis centers. Regarding their hydration status assessed by the Body Composition Monitor and in comparison to a healthy reference population, patients were assigned to 1 of the 3 categories: overhydrated, normohydrated and dehydrated. Urine output, urinary sodium excretion and residual renal function were measured for all patients within 30 days before dry weight assessment.
  
  
  RESULTS
  The median post-HD session FO was of-0.40 L (IQR: from-1.95 to+0.90) and the median residual urinary sodium excretion was of 64 mmol/L (IQR: 46-79). Among these patients, 16 were normohydated, 16 were dehydrated and 8 were overhydrated. There was a linear relationship between the hydration status after HD session and the urinary sodium excretion (estimate: 5.6±1.5; p<0.001). Compared with normohydrated patients, overhydrated patients had a higher residual urinary sodium excretion (estimate: 26±10; p<0.01).
  
  
  CONCLUSIONS
  In this study, urinary sodium excretion is associated with the hydration status evaluated by whole-body bioimpedance spectroscopy.
authors: Service de néphrologie, centre hospitalier universitaire de Rennes, hôpital Pontchaillou, 2, rue Henri-Le-Guilloux, 35033 Rennes cedex 9, France.
authors: Romain
authors: R
authors: Crochette
authors: Service de néphrologie, centre hospitalier universitaire de Caen, hôpital Clémenceau, boulevard Georges-Clémenceau, CS 30001, 14033 Caen cedex 9, France.
authors: Thierry
authors: T
authors: Lobbedez
authors: Service de néphrologie hémodialyse, hôpital Bois-Guillaume, 147, avenue du Maréchal-Juin, 76230 Bois-Guillaume, France.
authors: Mélanie
authors: M
authors: Hanoy
authors: Service de néphrologie hémodialyse, hôpital Bois-Guillaume, 147, avenue du Maréchal-Juin, 76230 Bois-Guillaume, France.
authors: Frank
authors: F
authors: Le Roy
authors: Service de néphrologie hémodialyse, centre hospitalier du Cotentin, BP 208, 50102 Cherbourg-Octeville cedex, France.
authors: Jacky
authors: J
authors: Potier
authors: Service d'hémodialyse, centre hospitalier Mémorial, 715, rue Dunant, 50000 Saint-Lô, France.
authors: Thibault
authors: T
authors: Besselièvre
authors: Service d'hémodialyse, centre hospitalier, 25, rue Fresnay, 61000 Alençon, France.
authors: Éric
authors: É
authors: Cardineau
authors: Service de néphrologie hémodialyse, centre hospitalier Robert-Bisson, 4, rue Aini, 14100 Lisieux, France.
authors: Isabelle
authors: I
authors: Landru
authors: Service de néphrologie, centre hospitalier universitaire de Caen, hôpital Clémenceau, boulevard Georges-Clémenceau, CS 30001, 14033 Caen cedex 9, France.
authors: Maxence
authors: M
authors: Ficheux
authors: Service de néphrologie, centre hospitalier universitaire de Caen, hôpital Clémenceau, boulevard Georges-Clémenceau, CS 30001, 14033 Caen cedex 9, France.
authors: Jean-Philippe
authors: JP
authors: Ryckelynck
authors: Service de néphrologie, centre hospitalier universitaire de Caen, hôpital Clémenceau, boulevard Georges-Clémenceau, CS 30001, 14033 Caen cedex 9, France. Electronic address: henri-p@chu-caen.fr.
authors: Patrick
authors: P
authors: Henri
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000652:urine; D001834:Body Water / Q000378:metabolism*; D001835:Body Weight; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000378:metabolism*; D005260:Female; D005602:France; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000378:metabolism* / Q000628:therapy* / Q000652:urine; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis; D012680:Sensitivity and Specificity; D012964:Sodium / Q000652:urine*; D014882:Water-Electrolyte Balance
chemical_list: D015415:Biomarkers; D012964:Sodium
keywords: Dry weight; Hemodialysis; Hémodialyse chronique; Natriurèse; Poids sec; Urinary sodium excretion