PMID- 25805215 OWN - NLM STAT- MEDLINE DCOM- 20151201 LR - 20150625 IS - 1460-2385 (Electronic) IS - 0931-0509 (Linking) VI - 30 IP - 7 DP - 2015 Jul TI - Population-based dose-response curve of glomerular filtration rate to dietary protein intake. PG - 1156-62 LID - 10.1093/ndt/gfv026 [doi] AB - BACKGROUND: Kidney function measured as estimated glomerular filtration rate (eGFR) is a risk factor for mortality and severe diseases. Protein intake up-regulates kidney function. The dose-response curve of eGFR over protein intake is unknown. Urinary urea nitrogen is an objective index of protein intake. METHODS: The study cross-sectionally analysed the relation between overnight urinary urea nitrogen ((on)U-ureaN) and eGFR with and without control for other variables in 4106 adults of the Gubbio population. Analyses were done for serum creatinine (S-cr) also to investigate the independency of results from eGFR calculation. RESULTS: Higher (on)U-ureaN associated with higher eGFR, and lower S-cr independently of sex and age (simple and partial correlation coefficients >0.100, P < 0.001). Analyses by (on)U-ureaN decile indicated sigmoid curves of eGFR and S-cr over (on)U-ureaN with trend to flatness in the lowest 20% and the highest 20% of (on)U-ureaN (<5.19 and >10.12 mg/h, respectively). Multi-variable spline regression indicated that the relation of eGFR over (on)U-ureaN was non-significant for (on)U-ureaN <5.19 mg/h (coefficient = +0.27, 95% CI = -0.31/+0.84, P = 0.364), positive for (on)U-ureaN in the range 5.19-10.12 mg/h (coefficients = 1.35-1.64, lower 95% CI >/= +0.48, P 10.12 mg/h (coefficient = +0.05, 95% CI = -0.06/ +0.16, P = 0.394). eGFR differed by approximately 8 mL/min x 1.73 m(2) between the lowest and highest 20% of (on)U-ureaN distribution. CONCLUSIONS: Higher protein intake relates to higher eGFR. The relation is sigmoid with eGFR up-regulation for (on)U-ureaN >5.19 mg/h, a threshold approximately corresponding to the recommended daily allowance for protein intake (0.8 g/day per kg of ideal weight). CI - (c) The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. FAU - Cirillo, Massimo AU - Cirillo M AD - Department of Medicine and Surgery, University of Salerno, Baronissi, Italy. FAU - Zingone, Fabiana AU - Zingone F AD - Department of Medicine and Surgery, University of Salerno, Baronissi, Italy. FAU - Lombardi, Cinzia AU - Lombardi C AD - Department of Maternity and Pediatrics, Hospital of Benevento, Benevento, Italy. FAU - Cavallo, Pierpaolo AU - Cavallo P AD - Department of Physics, University of Salerno, Baronissi, Italy. FAU - Zanchetti, Alberto AU - Zanchetti A AD - Istituto Auxologico Italiano, University of Milan, Milan, Italy. FAU - Bilancio, Giancarlo AU - Bilancio G AD - Department of Medicine and Surgery, University of Salerno, Baronissi, Italy. LA - eng PT - Journal Article DEP - 20150323 PL - England TA - Nephrol Dial Transplant JT - Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association JID - 8706402 RN - 0 (Dietary Proteins) RN - 8W8T17847W (Urea) RN - AYI8EX34EU (Creatinine) SB - IM MH - Adult MH - Aged MH - Cohort Studies MH - Creatinine/*blood MH - Cross-Sectional Studies MH - Dietary Proteins/*administration & dosage/*metabolism MH - Female MH - *Glomerular Filtration Rate MH - Humans MH - Kidney/*physiopathology MH - Kidney Function Tests MH - Male MH - Middle Aged MH - Multivariate Analysis MH - Risk Factors MH - Urea/*urine OTO - NOTNLM OT - creatinine OT - dietary protein OT - eGFR OT - kidney function OT - urea EDAT- 2015/03/26 06:00 MHDA- 2015/12/15 06:00 CRDT- 2015/03/26 06:00 PHST- 2014/12/03 00:00 [received] PHST- 2015/01/15 00:00 [accepted] PHST- 2015/03/26 06:00 [entrez] PHST- 2015/03/26 06:00 [pubmed] PHST- 2015/12/15 06:00 [medline] AID - gfv026 [pii] AID - 10.1093/ndt/gfv026 [doi] PST - ppublish SO - Nephrol Dial Transplant. 2015 Jul;30(7):1156-62. doi: 10.1093/ndt/gfv026. Epub 2015 Mar 23.