Age-adapted percentiles of measured glomerular filtration in healthy individuals: extrapolation to living kidney donors over 65 years

• Published in: Clinical chemistry and laboratory medicine Vol. 60; no. 3; pp. 401 - 407
• Main Authors: Delanaye, Pierre, Gaillard, François, van der Weijden, Jessica, Mjøen, Geir, Ferhman-Ekholm, Ingela, Dubourg, Laurence, Ebert, Natalie, Schaeffner, Elke, Åkerfeldt, Torbjörn, Goffin, Karolien, Couzi, Lionel, Garrouste, Cyril, Rostaing, Lionel, Courbebaisse, Marie, Legendre, Christophe, Hourmant, Maryvonne, Kamar, Nassim, Cavalier, Etienne, Weekers, Laurent, Bouquegneau, Antoine, de Borst, Martin H., Mariat, Christophe, Pottel, Hans, van Londen, Marco
• Format: Journal Article
• Language: English
• Published: Germany De Gruyter 23.02.2022; Walter De Gruyter & Company
• Subjects: Aged; Creatinine; Decision making; elderly; Extrapolation; Glomerular Filtration Rate; Human health and pathology; Humans; Immunology; Kidney; Kidney Transplantation; Kidneys; Life Sciences; Living Donors; living kidney donors; Older people; Organ donors; Quantiles; Retrospective Studies; Urology and Nephrology; France; glomerular filtration rate; living kidney donors; elderly
• ISSN: 1434-6621; 1437-4331; 1437-4331
• DOI: 10.1515/cclm-2021-1011

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. 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). 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 m ) 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. We demonstrate that extrapolation of mGFR from younger donors is possible and might aid with decision-making in elderly donors.