Asher Y Rosinger1,2, Hilary J Bethancourt1,3, Zane S Swanson4, Kaylee Lopez1, W Larry Kenney5, Tomas Huanca6, Esther Conde6, Rosemary Nzunza7, Emmanuel Ndiema8, David R Braun9,10, Herman Pontzer4,11. 1. Department of Biobehavioral Health, Pennsylvania State University, University Park, Pennsylvania, USA. 2. Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania, USA. 3. Department of Anthropology, Northwestern University, Evanston, Illinois, USA. 4. Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, USA. 5. Department of Kinesiology, Pennsylvania State University, University Park, Pennsylvania, USA. 6. Centro Boliviano de Investigación y Desarrollo Socio Integral, San Borja, Bolivia. 7. Center for Virus Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya. 8. Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya. 9. Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, District of Columbia, USA. 10. Department of Human Evolution, Max Planck Institute of Evolutionary Anthropology, Leipzig, Germany. 11. Global Health Institute, Duke University, Durham, North Carolina, USA.
Abstract
OBJECTIVES: Thirst is an evolved central homeostatic feedback system that helps regulate body water for survival. Little research has examined how early development and exposure to extreme environments and water availability affect thirst perception, particularly outside Western settings. Therefore, we compared two indicators of perceived thirst (current thirst and pleasantness of drinking water) using visual scales among Tsimane' forager-horticulturalists in the hot-humid Bolivian Amazon and Daasanach agro-pastoralists in hot-arid Northern Kenya. METHODS: We examined how these measures of perceived thirst were associated with hydration status (urine specific gravity), ambient temperatures, birth season, age, and population-specific characteristics for 607 adults (n = 378 Tsimane', n = 229 Daasanach) aged 18+ using multi-level mixed-effect regressions. RESULTS: Tsimane' had higher perceived thirst than Daasanach. Across populations, hydration status was unrelated to both measures of thirst. There was a significant interaction between birth season and temperature on pleasantness of drinking water, driven by Kenya data. Daasanach born in the wet season (in utero during less water availability) had blunted pleasantness of drinking water at higher temperatures compared to those born in the dry season (in utero during greater water availability). CONCLUSIONS: Our findings suggest hydration status is not a reliable predictor of thirst perceptions in extreme-hot environments with ad libitum drinking. Rather, our findings, which require additional confirmation, point to the importance of water availability during gestation in affecting thirst sensitivity to heat and water feedback mechanisms, particularly in arid environments. Thirst regulation will be increasingly important to understand given climate change driven exposures to extreme heat and water insecurity.
OBJECTIVES: Thirst is an evolved central homeostatic feedback system that helps regulate body water for survival. Little research has examined how early development and exposure to extreme environments and water availability affect thirst perception, particularly outside Western settings. Therefore, we compared two indicators of perceived thirst (current thirst and pleasantness of drinking water) using visual scales among Tsimane' forager-horticulturalists in the hot-humid Bolivian Amazon and Daasanach agro-pastoralists in hot-arid Northern Kenya. METHODS: We examined how these measures of perceived thirst were associated with hydration status (urine specific gravity), ambient temperatures, birth season, age, and population-specific characteristics for 607 adults (n = 378 Tsimane', n = 229 Daasanach) aged 18+ using multi-level mixed-effect regressions. RESULTS: Tsimane' had higher perceived thirst than Daasanach. Across populations, hydration status was unrelated to both measures of thirst. There was a significant interaction between birth season and temperature on pleasantness of drinking water, driven by Kenya data. Daasanach born in the wet season (in utero during less water availability) had blunted pleasantness of drinking water at higher temperatures compared to those born in the dry season (in utero during greater water availability). CONCLUSIONS: Our findings suggest hydration status is not a reliable predictor of thirst perceptions in extreme-hot environments with ad libitum drinking. Rather, our findings, which require additional confirmation, point to the importance of water availability during gestation in affecting thirst sensitivity to heat and water feedback mechanisms, particularly in arid environments. Thirst regulation will be increasingly important to understand given climate change driven exposures to extreme heat and water insecurity.
Authors: Lauren Christopher; Felicia C Madimenos; Richard G Bribiescas; Samuel S Urlacher; James J Snodgrass; Lawrence S Sugiyama; Herman Pontzer Journal: Am J Hum Biol Date: 2019-02-23 Impact factor: 1.937
Authors: Asher Y Rosinger; Herman Pontzer; David A Raichlen; Brian M Wood; Susan N Tanner; Jeff M Sands Journal: Am J Phys Anthropol Date: 2019-01-31 Impact factor: 2.868
Authors: Sarah L White; Vlado Perkovic; Alan Cass; Choon Lan Chang; Neil R Poulter; Tim Spector; Leigh Haysom; Jonathan C Craig; Isa Al Salmi; Steven J Chadban; Rachel R Huxley Journal: Am J Kidney Dis Date: 2009-04-01 Impact factor: 8.860