title: Association of mGFR of the Remaining Kidney Divided by Its Volume before Donation with Functional Gain in mGFR among Living Kidney Donors.
abstract: The predictors of long-term renal function in living kidney donors are currently discussed. Our objectives were to describe the predictors of functional gain of the remaining kidney after kidney donation. We hypothesized that GFR of the remaining kidney divided by volume of this kidney (rk-GFR/vol) would reflect the density of functional nephrons and be inversely associated with functional gain of the remaining kidney.
  
  
  
  We conducted a prospective monocentric study including 63 living donors (26 men; 50.3±11.8 years old) who had been evaluated for (51)Cr-EDTA and measured GFR, split renal function by scintigraphy before donation (between 2004 and 2009), and measured GFR at 5.7±0.5 years after donation. For 52 donors, volume of the remaining kidney (measured and estimated with the ellipsoid formula using renal computed tomography scannography) was determined before donation. We tested our hypothesis in an external validation cohort of 39 living donors (13 men; 51.0±9.4 years old) from another single center during the same time period.
  
  
  
  For the main cohort, the mean measured GFR was 97.6±13.0 ml/min per 1.73 m(2) before donation and 63.8±9.4 ml/min per 1.73 m(2) at 5 years. Functional gain averaged 16.2±7.2 ml/min per 1.73 m(2) (+35.3%±16.7%). Multivariate analysis showed that age, body mass index, and rk-GFR/vol at donation were negatively correlated with functional gain and had strong predictive power of the 5-year functional gain (adjusted 5-year functional gain for age: -0.4 [95% confidence interval (95% CI), -0.5 to -0.1]; body mass index: -0.3 [95% CI, -0.6 to -0.1]; rk-GFR/vol: -55.1 [95% CI, -92.3 to -17.9]). We tested this model in the external validation cohort (adjusted 5-year functional gain for age: -0.1 [95% CI, -0.5 to 0.3]; body mass index: -0.9 [95% CI, -1.8 to -0.1]; rk-GFR/vol: -97.6 [95% CI, -137.5 to -57.6]) and confirmed that rk-GFR/vol was inversely associated with 5-year functional gain.
  
  
  
  For given age and body mass index, the long-term functional gain of the remaining kidney is inversely associated with the new variable rk-GFR/vol at donation.
authors.affiliation: Due to the number of contributing authors, the affiliations are provided in the Supplemental Material .
authors.forename: Marie
authors.initials: M
authors.lastname: Courbebaisse
authors.forename: François
authors.initials: F
authors.lastname: Gaillard
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Tissier
authors.forename: Catherine
authors.initials: C
authors.lastname: Fournier
authors.forename: Alexis
authors.initials: A
authors.lastname: Le Nestour
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Corréas
authors.forename: Hind
authors.initials: H
authors.lastname: Slimani-Thevenet
authors.forename: Frank
authors.initials: F
authors.lastname: Martinez
authors.forename: Carine
authors.initials: C
authors.lastname: Léon
authors.forename: Dominique
authors.initials: D
authors.lastname: Eladari
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Timsit
authors.forename: Philippe
authors.initials: P
authors.lastname: Otal
authors.forename: Chantal
authors.initials: C
authors.lastname: Hignette
authors.forename: Gérard
authors.initials: G
authors.lastname: Friedlander
authors.forename: Arnaud
authors.initials: A
authors.lastname: Méjean
authors.forename: Pascal
authors.initials: P
authors.lastname: Houillier
authors.forename: Nassim
authors.initials: N
authors.lastname: Kamar
authors.forename: Christophe
authors.initials: C
authors.lastname: Legendre
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D009399:Nephrons / Q000033:anatomy & histology / Q000502:physiology; D009929:Organ Size; D011237:Predictive Value of Tests; D011446:Prospective Studies; D009927:Tissue and Organ Procurement; D014057:Tomography, X-Ray Computed
keywords: Humans; Living Donors; albuminuria; blood pressure; chronic renal disease; glomerular filtration rate; kidney; kidney donation; kidney volume; renal function decline