INDIGO-2: The Effect of High Water Intake on Glucose Regulation in Low-drinkers

Study Overview
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Brief Summary
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Previous studies have indicated increased vasopressin due to hypertonic saline infusion impairs glucose regulation. The current study will examine the effect of low water intake on glucose regulation. No currently published study has investigated the acute effect of low water intake on glucose regulation using continuous glucose monitoring over the course of a full day. The aim of the study is to observe the effect of low water intake on glucose regulation in low drinkers. The study will study the glycemic responses to standardized meals in adults during an 11-hour period in two conditions: a) high water intake and b) low water intake. It is hypothesized that the area under the glucose curve will be greater in the low water intake trial as compared to the high water intake trial

Official Title
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INDIGO-2: The Effect of High Water Intake on Glucose Regulation in Low-drinkers

Conditions
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Dehydration, Diabetes Mellitus, Type 2

Intervention / Treatment
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* Other: Water Intake


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy sedentary participants aged 30-55 years body mass 27.5-35.0 kg·m2 low water intake less than 1.5 L∙day-1 (male) or 1.0 L∙day-1 (female) 24 h urine osmolality greater than 800 mmol/kg Exclusion Criteria: diabetes HbA1c >6.5% impaired liver or kidney function cardiovascular disease weight change of more than 3 kg in the past month pregnancy previous surgery on digestive tract exercise >4 h/week

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Water intake<br>High water intake of 3.0 L/day in males and 2.0 L/day in females | Other: Water Intake<br>* Increased water intake during the 11 h protocol<br>|
| Active Comparator: Low Water Intake<br>Low water intake of 0.5 L/day in males and 0.4 L/day | Other: Water Intake<br>* Increased water intake during the 11 h protocol<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under the curve of Glucose at lunch |  | 2-hour window starting right before the lunch meal (12:00 pm - 2:00 pm) | 
| Area under the curve of Glucose at Dinner |  | 2-hour window starting right before dinner (4:00 pm - 6:00 pm) | 
| Area under the curve of Glucose for the entire experiment |  | 11-hour window starting right before breakfast till 2 hours after dinner (7:00 am - 6:00 pm) | 
| Area under the curve of Copeptin for the entire experiment |  | 11-hour window starting right before breakfast till 2 hours after dinner (7:00 am - 6:00 pm) | 
| Area under the curve of Glucagon at lunch |  | 2-hour window starting right before the lunch meal (12:00 pm - 2:00 pm) | 
| Area under the curve of Glucagon at dinner |  | 2-hour window starting right before dinner (4:00 pm - 6:00 pm) | 
| Urinary glucose excretion |  | Entire 11-hour protocol 7:00 am - 6:00 pm | 
| Area Under the Curve for Plasma osmolality |  | the entire 11-hour protocol 7:00 am - 6:00 pm | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under the curve of Insulin at lunch |  | 2-hour window starting right before the lunch meal (12:00 pm - 2:00 pm) | 
| Area under the curve of Insulin at dinner |  | 2-hour window starting right before dinner (4:00 pm - 6:00 pm) | 
| Area under the curve of Glucagon like peptide 1 at dinner |  | 2-hour window starting right before dinner (4:00 pm - 6:00 pm) | 
| Area under the curve of Glucagon like peptide 1at lunch |  | 2-hour window starting right before the lunch meal (12:00 pm - 2:00 pm) | 
| Area under the curve of plasma cortisol |  | the entire 11-hour protocol 7:00 am - 6:00 pm | 
| Area under the curve for Thirst rating | Thirst assessed by Visual analog scale | the entire 11-hour protocol 7:00 am - 6:00 pm | 
| Mood assessment with a questionnaire | Assessed by Profile of mood state questionnaire | single measurement at baseline before the beginning of breakfast at 7:00 am and 1-hour before dinner meal at 3:00 pm | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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dehydration, vasopressin, copeptin