title: A comparison of measured and estimated glomerular filtration rate in successfully treated HIV-patients with preserved renal function.
abstract: BACKGROUND
  Monitoring of renal function becomes increasingly important in the aging population of HIV-1 infected patients. We compared Cockroft & Gault (C&G), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD), Cystatin C- and 24 h urine-based estimated GFR (eGFR) with the gold standard, measured GFR (mGFR) using [125I]-iothalamate.
  
  
  METHODS
  Substudy within a randomized, multinational trial comparing continuing zidovudine/ lamivudine with switching to tenofovir/ emtricitabine in patients with suppressed HIV-1 infection. Accuracy (defined as the mean difference between eGFR and mGFR) and precision (defined as standard deviation (SD) of the mean difference between eGFR and mGFR) of the eGFRs were calculated using linear regression and Bland & Altman analysis.
  
  
  RESULTS
  We included 19 patients, 18 men, 15 Caucasian, mean (SD) age 46.0 y (± 8.9) and BMI 23.9 kg/m2 (± 3.0). Mean (SD) mGFR was 102 ml/min/1.73 m2 (± 19), 4 patients had mild renal dysfunction. All eGFRs tended to underestimate true GFR, with best accuracy for C&G (-1 ml/min/1.73 m2), CKD-EPI (-1 ml/min/1.73 m2), 24 hcreatinine clearance (-2 ml/min/1.73 m2) and MDRD-6 (0 ml/min/1.73 m2), and worst for cystatin C-based (-9 ml/min/1.73 m2) and MDRD-4 estimations (-10 ml/min/1.73 m2). Accuracy worsened at higher mGFR, but was not significantly influenced by age. C&G tended to overestimate at higher BMI. Precision was comparable for all GFR estimations.
  
  
  CONCLUSIONS
  In this limited number of patients with preserved renal function and suppressed HIV-infection C&G and CKD-EPI appeared to be the best reflection of real GFR and most practical tool for monitoring GFR.
authors.affiliation: Amsterdam Institute for Global Health and Development, Academic Medical Center, Amsterdam, the Netherlands. s.m.vrouenraets@amc.uva.nl
authors.forename: Saskia M E
authors.initials: SM
authors.lastname: Vrouenraets
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Fux
authors.forename: Ferdinand W N M
authors.initials: FW
authors.lastname: Wit
authors.forename: Evian Fernandez
authors.initials: EF
authors.lastname: Garcia
authors.forename: Kees
authors.initials: K
authors.lastname: Brinkman
authors.forename: Frans J
authors.initials: FJ
authors.lastname: Hoek
authors.forename: Jan P
authors.initials: JP
authors.lastname: van Straalen
authors.forename: Hansjakob
authors.initials: H
authors.lastname: Furrer
authors.forename: Ray T
authors.initials: RT
authors.lastname: Krediet
authors.forename: Peter
authors.initials: P
authors.lastname: Reiss
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000627:therapeutic use; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D015992:Body Mass Index; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D000068679:Emtricitabine; D005260:Female; D005919:Glomerular Filtration Rate; D015658:HIV Infections / Q000188:drug therapy* / Q000503:physiopathology*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D063065:Organophosphonates / Q000627:therapeutic use; D010865:Pilot Projects; D012107:Research Design; D018709:Statistics, Nonparametric; D000068698:Tenofovir; D016896:Treatment Outcome; D015215:Zidovudine / Q000627:therapeutic use
chemical_list: D019380:Anti-HIV Agents; D063065:Organophosphonates; D003841:Deoxycytidine; D019259:Lamivudine; D015215:Zidovudine; D000068698:Tenofovir; D000068679:Emtricitabine; D000225:Adenine