Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Nov;6(11):2634-41.
doi: 10.2215/CJN.01990211. Epub 2011 Sep 1.

Urine volume and change in estimated GFR in a community-based cohort study

William F Clark  1 , Jessica M Sontrop, Jennifer J Macnab, Rita S Suri, Louise Moist, Marina Salvadori, Amit X Garg
Affiliations

Urine volume and change in estimated GFR in a community-based cohort study

William F Clark et al. Clin J Am Soc Nephrol. 2011 Nov.

Abstract

Background and objectives: The effect of increased fluid intake on kidney function is unclear. This study evaluates the relationship between urine volume and renal decline over 6 years in a large community-based cohort.

Design, setting, participants, & measurements: This prospective cohort study was undertaken in Canada from 2002 to 2008. We obtained 24-hour urine samples from adult participants with an estimated GFR (eGFR) ≥60 ml/min per 1.73 m(2) at study entry. Percentage annual change in eGFR from baseline was categorized as average decline <1% per year, between 1% and 4.9% (mild-to-moderate decline) or ≥5% (rapid decline).

Results: 2148 participants provided valid 24-hour urine samples, grouped as <1 L/d (14.5%); 1 to 1.9 L/d (51.5%); 2 to 2.9 L/d (26.3%); and ≥3 L/d (7.7%). Baseline eGFR for each category of urine volume was 90, 88, 84, and 87 ml/min per 1.73 m(2), respectively. Overall, eGFR declined by 1% per year, with 10% demonstrating rapid decline and 40% demonstrating mild-to-moderate decline. An inverse, graded relationship was evident between urine volume and eGFR decline: For each increasing category of 24-hour urine volume, percentage annual eGFR decline was progressively slower, from 1.3%, 1.0%, 0.8%, to 0.5%, respectively; P = 0.02. Compared with those with urine volume 1 to 1.9 L/d, those with urine volume ≥3 L/d were significantly less likely to demonstrate mild-to-moderate decline (adjusted odds ratio 0.66; 95% confidence interval 0.46 to 0.94) or rapid decline (adjusted odds ratio 0.46; 95% confidence interval 0.23 to 0.92); adjusted for age, gender, baseline eGFR, medication use for hypertension (including diuretics), proteinuria, diabetes, and cardiovascular disease.

Conclusions: In this community-based cohort, decline in kidney function was significantly slower in those with higher versus lower urine volume.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Flow of participants from recruitment to analysis.
Figure 2.
Figure 2.
Decline in kidney function between first and last assessment over 5.7 years (n = 2148). eGFR, estimated GFR.
Figure 3.
Figure 3.
Urine volume and risk for renal decline in the general population (n = 2148). eGFR, estimated GFR; OR, odds ratio; CI, confidence interval.
See this image and copyright information in PMC

Comment in

References

    1. Vreeman RC, Carroll AE: Medical myths. BMJ 335: 1288–1289, 2007 - PMC - PubMed
    1. Wenzel UO, Hebert LA, Stahl RA, Krenz I: My doctor said I should drink a lot! Recommendations for fluid intake in patients with chronic kidney disease. Clin J Am Soc Nephrol 1: 344–346, 2006 - PubMed
    1. Valtin H: “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8 x 8”? Am J Physiol Regul Integr Comp Physiol 283: R993–R1004, 2002 - PubMed
    1. Negoianu D, Goldfarb S: Just add water. J Am Soc Nephrol 19: 1041–1043, 2008 - PubMed
    1. Lette F, Dwyer JP: The fluid craze. Lancet 372: 782, 2008 - PubMed

Publication types

MeSH terms