title: Renal function can improve at any stage of chronic kidney disease.
abstract: BACKGROUND
  Even though renal function decline is considered relentless in chronic kidney disease (CKD), improvement has been shown in patients with hypertensive nephropathy. Whether this can occur in any type of nephropathy and at any stage is unknown as are the features of patients who improve.
  
  
  METHODS
  We identified 406 patients in the NephroTest cohort with glomerular filtration rates (mGFR) measured by (51)Cr-EDTA clearance at least 3 times during at least 2 years of follow-up. Individual examination of mGFR trajectories by 4 independent nephrologists classified patients as improvers, defined as those showing a sustained mGFR increase, or nonimprovers. Twelve patients with erratic trajectories were excluded. Baseline data were compared between improvers and nonimprovers, as was the number of recommended therapeutic targets achieved over time (specifically, for systolic and diastolic blood pressure, proteinuria, and use of renin angiotensin system blockers).
  
  
  RESULTS
  Measured GFR improved over time in 62 patients (15.3%). Their median mGFR slope was +1.88[IQR 1.38, 3.55] ml/min/year; it was -2.23[-3.9, -0.91] for the 332 nonimprovers. Improvers had various nephropathies, but not diabetic glomerulopathy or polycystic kidney disease. They did not differ from nonimprovers for age, sex, cardiovascular history, or CKD stage, but their urinary albumin excretion rate was lower. Improvers achieved significantly more recommended therapeutic targets (2.74±0.87) than nonimprovers (2.44±0.80, p<0.01). They also had fewer CKD-related metabolic complications and a lower prevalence of 25OH-vitamin-D deficiency.
  
  
  CONCLUSIONS
  GFR improvement is possible in CKD patients at any CKD stage through stage 4-5. It is noteworthy that this GFR improvement is associated with a decrease in the number of metabolic complications over time.
authors.affiliation: Department of Nephrology, AP-HP, Hôpital Tenon, Paris, France.
authors.forename: Lise
authors.initials: L
authors.lastname: Weis
authors.affiliation: Research Centre in Epidemiology and Population Health, Inserm Unit 1018, CESP, Villejuif, France ; UMRS 1018, Univ Paris-Sud, Villejuif, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Metzger
authors.affiliation: Department of Physiology, AP-HP, Hôpital Tenon, Paris, France ; INSERM UNIT 702, Paris, France ; UMR S 702, Univ Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Haymann
authors.affiliation: Department of Nephrology, AP-HP, Hôpital Européen Georges Pompidou, Paris, France ; UMR S 775, Univ Paris Descartes, Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Thervet
authors.affiliation: Department of Physiology, AP-HP, Hôpital Bichat, Paris, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Flamant
authors.affiliation: Department of Nephrology, AP-HP, Hôpital Bichat, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Vrtovsnik
authors.affiliation: Department Physiology, AP-HP, Hôpital Européen Georges Pompidou, Paris, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Gauci
authors.affiliation: UMR S 775, Univ Paris Descartes, Paris, France ; Department Physiology, AP-HP, Hôpital Européen Georges Pompidou, Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Houillier
authors.affiliation: Research Centre in Epidemiology and Population Health, Inserm Unit 1018, CESP, Villejuif, France ; UMR S 775, Univ Paris Descartes, Paris, France ; Department Physiology, AP-HP, Hôpital Européen Georges Pompidou, Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Froissart
authors.affiliation: Department of Physiology, AP-HP, Hôpital Tenon, Paris, France ; INSERM UNIT 702, Paris, France ; UMR S 702, Univ Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Letavernier
authors.affiliation: Research Centre in Epidemiology and Population Health, Inserm Unit 1018, CESP, Villejuif, France ; UMRS 1018, Univ Paris-Sud, Villejuif, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Stengel
authors.affiliation: Department of Nephrology, AP-HP, Hôpital Tenon, Paris, France ; INSERM UNIT 702, Paris, France ; UMR S 702, Univ Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Boffa
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001794:Blood Pressure; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D006977:Hypertension, Renal / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D007668:Kidney; D008297:Male; D008875:Middle Aged; D009393:Nephritis / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D012084:Renin-Angiotensin System / Q000187:drug effects; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014808:Vitamin D Deficiency / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors