Age-adapted percentiles of measured glomerular filtration in healthy individuals: extrapolation to living kidney donors over 65 years.
OBJECTIVES
Most data on glomerular filtration rate (GFR) originate from subjects <65 years old, complicating decision-making in elderly living kidney donors. In this retrospective multi-center study, we calculated percentiles of measured GFR (mGFR) in donors <65 years old and extrapolated these to donors ≥65 years old.


METHODS
mGFR percentiles were calculated from a development cohort of French/Belgian living kidney donors <65 years (n=1,983), using quantiles modeled as cubic splines (two linear parts joining at 40 years). Percentiles were extrapolated and validated in an internal cohort of donors ≥65 years (n=147, France) and external cohort of donors and healthy subjects ≥65 years (n=329, Germany, Sweden, Norway, France, The Netherlands) by calculating percentages within the extrapolated 5th-95th percentile (P5-P95).


RESULTS
Individuals in the development cohort had a higher mGFR (99.9 ± 16.4 vs. 86.4 ± 14 and 82.7 ± 15.5 mL/min/1.73 m2) compared to the individuals in the validation cohorts. In the internal validation cohort, none (0%) had mGFR below the extrapolated P5, 12 (8.2%) above P95 and 135 (91.8%) between P5-P95. In the external validation cohort, five subjects had mGFR below the extrapolated P5 (1.5%), 25 above P95 (7.6%) and 299 (90.9%) between P5-P95.


CONCLUSIONS
We demonstrate that extrapolation of mGFR from younger donors is possible and might aid with decision-making in elderly donors.
['Delanaye|Pierre|P|', 'Gaillard|François|F|', 'van der Weijden|Jessica|J|', 'Mjøen|Geir|G|', 'Ferhman-Ekholm|Ingela|I|', 'Dubourg|Laurence|L|', 'Ebert|Natalie|N|', 'Schaeffner|Elke|E|', 'Åkerfeldt|Torbjörn|T|', 'Goffin|Karolien|K|', 'Couzi|Lionel|L|', 'Garrouste|Cyril|C|', 'Rostaing|Lionel|L|', 'Courbebaisse|Marie|M|', 'Legendre|Christophe|C|', 'Hourmant|Maryvonne|M|', 'Kamar|Nassim|N|', 'Cavalier|Etienne|E|https://orcid.org/0000-0003-0947-2226', 'Weekers|Laurent|L|', 'Bouquegneau|Antoine|A|', 'de Borst|Martin H|MH|', 'Mariat|Christophe|C|', 'Pottel|Hans|H|', 'van Londen|Marco|M|']
living kidney donors glomerular filtration rate elderly