Helmholtz Gemeinschaft

Search
Browse
Statistics
Feeds

Increased salt consumption induces body water conservation and decreases fluid intake

[thumbnail of original article]
Preview
PDF (original article) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
1MB
[thumbnail of Supplemental Material]
Preview
PDF (Supplemental Material) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
9MB

Item Type:Article
Title:Increased salt consumption induces body water conservation and decreases fluid intake
Creators Name:Rakova, N., Kitada, K., Lerchl, K., Dahlmann, A., Birukov, A., Daub, S., Kopp, C., Pedchenko, T., Zhang, Y., Beck, L., Johannes, B., Marton, A., Müller, D.N., Rauh, M., Luft, F.C. and Titze, J.
Abstract:BACKGROUND: The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions. METHODS: Over the course of 2 separate space flight simulation studies of 105 and 205 days' duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance. RESULTS:A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion. CONCLUSION: Humans regulate osmolyte and water balance by rhythmical mineralocorticoid and glucocorticoid release, endogenous accrual of surplus body water, and precise surplus excretion. FUNDING: Federal Ministry for Economics and Technology/DLR; the Interdisciplinary Centre for Clinical Research; the NIH; the American Heart Association (AHA); the Renal Research Institute; and the TOYOBO Biotechnology Foundation. Food products were donated by APETITO, Coppenrath und Wiese, ENERVIT, HIPP, Katadyn, Kellogg, Molda, and Unilever.
Keywords:Dietary Sodium Chloride, Glucocorticoids, Mineralocorticoids, Space Flight, Water, Water-Electrolyte Balance
Source:Journal of Clinical Investigation
ISSN:0021-9738
Publisher:American Society for Clinical Investigation
Volume:127
Number:5
Page Range:1932-1943
Date:1 May 2017
Additional Information:Copyright © 2017, American Society for Clinical Investigation
Official Publication:https://doi.org/10.1172/JCI88530
External Fulltext:View full text on PubMed Central
PubMed:View item in PubMed

Repository Staff Only: item control page

Downloads

Downloads per month over past year

Open Access
MDC Library