The Effect of Acute Hypohydration on Indicators of Glycemic Regulation, Appetite, Metabolism and Stress: A Systematic Review and Meta-Analysis.

Mitchell E Zaplatosch,William M Adams

doi:10.3390/nu12092526

Abstract

Evidence synthesizing the effects of acute body water losses on various markers of glycemic regulation, appetite, metabolism, and stress is lacking. Thus, the purpose of this review was to summarize the response of various hormonal changes involved in these physiologic functions to dehydration. A comprehensive literature search for peer-reviewed research in the databases PubMed, Scopus, CINAHL, and SportDiscus was conducted. Studies were included if they contained samples of adults (>18 years) and experimentally induced dehydration as measured by acute body mass loss. Twenty-one articles were eligible for inclusion. Findings suggested cortisol is significantly elevated with hypohydration (standard mean difference [SMD] = 1.12, 95% CI [0.583, 1.67], p < 0.0001). Testosterone was significantly lower in studies where hypohydration was accompanied by caloric restriction (SMD= −1.04, 95% CI [−1.93, −0.14], p = 0.02), however, there were no changes in testosterone in studies examining hypohydration alone (SMD = −0.17, 95% CI [−0.51 0.16], p = 0.30). Insulin and ghrelin were unaffected by acute total body water losses. Acute hypohydration increases markers of catabolism but has a negligible effect on markers of glycemic regulation, appetite, anabolism and stress. Given the brevity of existing research, further research is needed to determine the impact of hydration on glucagon, leptin, peptide YY and the subsequent outcomes relevant to both health and performance.

Highlights

Maintaining an adequate state of hydration is vital for optimizing human health and performance.Previous literature assessing the role of hydration on exercise performance has demonstrated the detrimental impact of acute hypohydration on aerobic [1,2,3] and anaerobic [4,5,6,7] exercise performance, as well as cognitive function [8,9,10,11]
Forty-four full text articles were removed for methodological concerns including no body mass change measures (n = 17), allowing water or other fluids before trials (n = 18), participants primarily undergoing energy restriction rather than acute dehydration (n = 4), outside of age range (n = 1), case study (n = 1), arrived dehydrated (n = 1), microgravity (n = 1) as well as an inability to access two articles
The purpose of this systematic review and meta-analysis was to summarize the influence of dehydration as measured by acute review body mass on hormonal of glycemic regulation, The purpose of this systematic and loss meta‐analysis was indices to summarize the influence of appetite, metabolism, and by stress

Summary

Introduction

Previous literature assessing the role of hydration on exercise performance has demonstrated the detrimental impact of acute hypohydration on aerobic [1,2,3] and anaerobic [4,5,6,7] exercise performance, as well as cognitive function [8,9,10,11]. The focus has shifted from the short-term impact of hypohydration on exercise and cognitive performance to the role that inadequate fluid intake, termed underhydration [12], has on health-related outcomes such as obesity [3,13,14,15,16,17,18], diabetes [19,20,21], and chronic kidney disease [22,23]. Alterations in endocrine function, notably, changes in glycemic regulation, appetite control, metabolism, and stress, directly or indirectly influence several processes required for training adaptation [24,25] and can impact one’s health status [26,27]

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