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Title: High water turnover, hydration status, and heat stress among Daasanach pastoralists in a hot, semi-arid climate
Abstract Background and objectivesWater is essential for proper physiological function. As temperatures increase, populations may struggle to meet water needs despite adaptations or acclimation; chronic dehydration can cause kidney damage. We evaluate how daily water requirements are associated with ambient temperature (ambT), wet bulb globe temperature (WBGT), urine specific gravity (USG; marker of hydration status), and albumin:creatinine ratio (ACR; kidney function biomarker) among Daasanach pastoralists living in a hot, dry northern Kenyan climate. MethodologyWater turnover (WT), USG, and ACR were measured using deuterium depletion (WT), refractometry (USG), and urine dipstick (ACR) for 76 participants aged 5–68 years in June 2022–23. Relationships between WT, ambT, WBGT, USG, and ACR were evaluated using linear and generalized linear models. ResultsAdult WT was higher than mean values worldwide, peaking around 7 l/day. Water demands increase from childhood through middle age before falling in later life. Adult WT was not correlated with ambT or WBGT. About 2/11 children’s and 7/36 adults’ USG indicated dehydration; USG was not correlated with child WT but was negatively correlated with adult WT when accounting for body size. WT was lower among adults with high (≥30 mg/g) ACR; high ACR was associated with higher USG. Conclusions and implicationsHigh Daasanach WT is likely driven by hot, semi-arid conditions, and lifestyle, rather than by compromised kidney function. Most participants were well-hydrated. Despite nonsignificant correlations between temperature and adult WT, high WT highlights the physiological demands of hot, dry climates. As climate change increases the global population exposed to hotter temperatures, global water needs will likely increase.  more » « less
Award ID(s):
1924322
PAR ID:
10661307
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Oxford
Date Published:
Journal Name:
Evolution, Medicine, and Public Health
Volume:
13
Issue:
1
ISSN:
2050-6201
Page Range / eLocation ID:
215 to 228
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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