Adequate Hydration and Health Outcomes

Study Summary

Cardiovascular diseases (CVD) are the leading cause of death in middle- and high-income countries, according to data from the World Health Organization (WHO). Epidemiological studies have associated low water intake and underhydration with diabetes, chronic kidney disease, and an increased risk of CVD. Similarly, the prevalence of chronic metabolic dysfunction is increasing dramatically worldwide, becoming both a significant public health concern and a global economic burden. Reports from the WHO indicate that the number of people with diabetes worldwide has risen from 108 million in 1980 to 422 million in 2014, representing 8.5% of adults. Therefore, there is an urgent need to identify modifiable risk factors that could help prevent metabolic dysfunction and mitigate the epidemic of type 2 diabetes (T2D). Evidence suggests that the hormone arginine vasopressin (AVP) may play a key role. AVP is the primary hormone responsible for regulating body fluid balance; however, increased AVP secretion, such as under conditions of low water intake, appears to be a risk factor for developing diabetes. Increasing water intake may represent a simple and cost-effective way to improve glucose regulation and cardiovascular health. However, many individuals do not prefer drinking plain water, and although beverages with high sugar content may promote greater fluid intake, they also contribute additional calories that can negatively impact body weight and overall health. Thus, the central research question of this study is whether improving hydration with non-sugar-sweetened beverages can provide equivalent benefits for hydration and health outcomes in adults. Aim 1: To explore the association between habitual fluid intake and fluid preferences (water and non-sugar-sweetened beverages), hydration biomarkers, and health outcomes in normal-weight and obese adults. Aim 2: To compare the impact of increased total water intake, provided as plain water or non-sugar-sweetened beverages,

Primary Outcome

Flow-mediated dilation (FMD) will be assessed as a non-invasive measure of endothelial function using brachial artery ultrasound. A high-resolution ultrasound probe will measure baseline artery diameter, then artery diameter after 5 minutes of forearm cuff occlusion, followed by rapid cuff deflation. FMD% will be calculated as a percent of \[(Maximum Post-Deflation Diameter - Baseline Diameter)/Baseline Diameter\]×100 This outcome provides the percent increase in brachial artery diameter relativ

Conditions Studied

Interventions

• OTHER Baseline - week 1
• OTHER Low Water Intake - week 2
• OTHER Moderate Water Intake - week 3
• OTHER Adequate Water Intake - week 4
• OTHER Washout - week 5

Study Locations (2)