Water intake and progression of chronic kidney disease: the CKD-REIN cohort study Sandra Wagner 1 , Thomas Merkling 1 , Marie Metzger 2 , Lise Bankir 3 , Maurice Laville 4 , Luc Frimat 5,6 , Christian Combe 7,8 , Christian Jacquelinet 2,9 , Denis Fouque 4 , Ziad A. Massy 2,10 and Be ´ne ´dicte Stengel 2 ; for the CKD-REIN study group* 1 Universite ´ de Lorraine, INSERM CIC 1433, Nancy CHRU, Inserm U1116, FCRIN INI-CRCT, Nancy, France, 2 Centre de recherche en Epide ´miologie et Sante ´ des Populations (CESP), INSERM U1018, Universite ´ Paris-Saclay, Universite ´ Versailles Saint Quentin, Villejuif, France, 3 Sorbonne Universite ´, INSERM, Centre de Recherche des Cordeliers, Paris, France, 4 De ´partement de Ne ´phrologie, Centre Hospitalier Lyon-Sud, Universite ´ de Lyon, UCBL, Carmen, Pierre-Be ´nite, France, 5 EA4360 Apemac, Universite ´ de Lorraine, Universite ´ Paris-Descartes, Nancy, France, 6 De ´partement de Ne ´phrologie, CHU de Nancy, Vandoeuvre-le `s-Nancy, France, 7 Service de Ne ´phrologie-Transplantation-Dialyse-Aphe ´re `se, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France, 8 INSERM, U1026, Universite ´ Bordeaux Segalen, Bordeaux, France, 9 Agence de Biome ´decine, Saint Denis la Plaine, France 10 Service de Ne ´phrologie, Ho ˆpital Ambroise Pare ´, AP-HP, Paris, France *The list of members of the CKD-REIN study group are provided in the Acknowledgements. Correspondence to: Be ´ne ´dicte Stengel; E-mail: benedicte.stengel@inserm.fr GRAPHICAL ABSTRACT Conclusion Wagner, S. et al. NDT (2021) @NDTSocial In patients with CKD, the relationship between plain water intake and progression to kidney failure appears to be U-shaped. Both low and high intake may not be beneficial in CKD Background General population studies suggest that higher water intake may reduce CKD prevalence and kidney function decline Cohort studies in CKD are inconclusive, but some suggest that higher fluid intake may not be appropriate Prospective cohort study Water intake and progression of chronic kidney disease (CKD): the CKD-REIN cohort study Methods Results Multi-centre study (n=40) CKD-REIN cohort (France) Adult patients with CKD 3–4 (eGFR 15–60 ml/min/1.73 m 2 ) Urine volume and osmolarity by 24 h urine collection Interview to evaluate total and plain water intake Outcomes: • eGFR slope • Progression to kidney failure N=1265 with water intake and 24 h urine collection Plain water intake (litres/day) > 2 1–1.5 < 0.5 Kidney failure hazard ratio eGFR slope (ml/min/1.73 m 2 /year) 1.55 (95% CI 1.03–2.32) 1.59 (95% CI 1.06–2.38) Ref 1.88 (95% CI 1.02–3.47) –2.48 (95% CI –3.15 to –1.81) –2.12 (95% CI –2.61 to –1.62) –1.79 (95% CI –2.16 to –1.42) –2.34 (95% CI –2.76 to –1.93) –1.43 (95% CI –2.14 to –0.71) ? 0.5–1 1.76 (95% CI 0.95–3.24) 1.5–2 V C The Author(s) 2021. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. ORIGINAL ARTICLE Nephrol Dial Transplant (2022) – doi: 10.1093/ndt/gfab036 Advance Access publication 12 February 2021 the 37: 730 739 Downloaded from https://academic.oup.com/ndt/article/37/4/730/6134139 by guest on 16 June 2022