About this trial
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, on hydration, cardiovascular health, and glucose regulation in normal-weight and obese adults.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
BMI 18.5-24.9 or 30.0-39.9 kg/m2
HbA1c ≤7%
Age 20-65 y
available for 8 consecutive weeks same day and time
Disqualifiers
Diabetes
HbA1c >7% BMI ≤18.5, BMI of 25 to <30, or ≥ 40 kg/m2
night shifting work
losing or gaining weight during the last 2 months (>5 lbs. fluctuation)
Trial design
Crossover
Treatments tested in this trial
Baseline - week 1
Other interventionHabitual fluid intake during week 1
Low Water Intake - week 2
Other interventionLow water intake as described by the protocol
Moderate Water Intake - week 3
Other interventionModerate Water Intake - Week 3
Adequate Water Intake - week 4
Other interventionAdequate Water Intake - week 4
Washout - week 5
Other interventionWashout - week 5
Low fluid intake with non caloric sweeteners - Week 6
Other interventionLow fluid intake with non caloric sweeteners - Week 6
Moderate fluid intake with non caloric sweeteners - Week 7
Other interventionModerate fluid intake with non caloric sweeteners - Week 7
Adequate fluid intake with non caloric sweeteners - Week 8
Other interventionAdequate fluid intake with non caloric sweeteners - Week 8
Treatment groups
8
Treatment groupsSee each treatment group below.
Trial outcomes
Primary outcomes
Flow-mediated dilation %
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 relative to baseline, reflecting endothelium-dependent vasodilation.
Area under the curve for glucose
The positive integer of the glucose levels during the 120 minutes post ingestion of 75 g of glucose
Insulin area under the curve
The positive integer of the insulin levels during the 120 minutes post ingestion of 75 g of glucose
glucagon area under the curve
The positive integer of the glucagon levels during the 120 minutes post ingestion of 75 g of glucose
Secondary outcomes
Confusion-bewilderment
Confusion-bewilderment assessment via the short version of Profile of Mood State Questionnaire. Score range 0-20 with higher score indicating negative mood descriptor
Depression-dejection
Depression-dejection assessment via the short version of Profile of Mood State Questionnaire. Score range 0-20 with higher score indicating negative mood descriptor
Fatigue-inertia
Fatigue-inertia assessment via the short version of the Profile of Mood State Questionnaire. Score range 0-20, with higher score indicating a negative mood descriptor
Vigour-activity
Vigour-activity assessment via the short version of Profile of Mood State Questionnaire. Score range 0-20 with higher score indicating positive mood descriptor
Sponsors and contacts
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