ObesityNCT01224704
Water Deprivation Protocol
A study testing Hypertonic saline infusion and Water deprivation in people with Obesity, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
Trial summary
Background: One area in which obese and lean individuals may be different is how their bodies handle water balance and thirst. Studies done in animals suggest that individuals with greater body fat may tolerate periods without water better than lean animals. Read more about this study
- Who is it for?
- Ages 18 to 50 years, men only
- Conditions the study is for
- Obesity
- What is being tested?
- Hypertonic saline infusion and Water deprivation
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Oct 2010to 28 Mar 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Men only
- No healthy volunteers
- Adult
Who may be able to join
- Male.
- Age 18-50 yrs to minimize hormonal influences on thirst perception in aging men.
- BMI<25 kg/m^2 for the lean group and BMI >=35 kg/m^2 for obese group (but weigh less than 350 pounds to accommodate the DXA scanner) for the obese group.
- Healthy, as determined by medical history and physical examination, without the exclusions listed below:
Who cannot join
- History or Clinical Manifestation of:
- Currently smoking
- Any medications
- Weight <50kg (as the blood withdrawal limit would be exceeded)
- Hemoglobin concentration < 12mg/dl on screening labs
- Type 1 or type 2 diabetes (according to World Health Organization diagnostic criteria (59))
Show all 18Show fewer
- Endocrine disorders (Cushing's disease, pituitary diseases, hypo- or hyperthyroidism, diabetes insipidus, SIADH)
- Hypertension as diagnosed and treated by an outside physician or by sitting blood pressure measurement, using an appropriate cuff, >140/90 mmHg on two or more occasions
- Fasting triglyceride concentrations >= 500 mg/dl
- Cardiovascular disease, including coronary heart disease, heart failure, arrhythmias and peripheral arterial disease
- Liver disease, including cirrhosis, active hepatitis B or C and AST or ALT >= 3x normal
- Renal disease, as defined by serum creatinine concentrations >= 1.5 mg/dl and / or proteinuria >300 mg/day (200 (micro)g/min)
- Central nervous system disease, including previous history of cerebrovascular accidents, dementia, and neurodegenerative disorders
- Cancer requiring treatment in the past five years, except for non-melanoma skin cancers or cancers that have been clearly cured or, in the opinion of the investigator, carry an excellent prognosis
- Infectious diseases such as active tuberculosis, HIV (by self report), chronic coccidioidomycoses or other chronic infections
- Alcohol and/or current use of drugs (more than 2 drinks per day and regular use of drugs such as amphetamines, cocaine, heroin, or marijuana)
- Psychiatric conditions or behaviors that would be incompatible with safe and successful participation in this study, including claustrophobia and eating disorders such as anorexia or bulimia nervosa
- All subjects will be fully informed of the aim, nature, and risks of the study prior to giving written informed consent. Subjects will also be specifically advised that the results of testing for drug usage will be filed in the medical record and would, therefore, be available as part of this record.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessment of Thirst and Role of Water/Electrolytes Homeostasis During Water Deprivation in Obesity
Background:
- One area in which obese and lean individuals may be different is how their bodies handle water balance and thirst. Studies done in animals suggest that individuals with greater body fat may tolerate periods without water better than lean animals. Other research has found a link between the ability to tolerate periods without water and increased body weight. Researchers are interested in studying whether the ability to tolerate periods without water and ability to feel thirst might differ in lean versus obese individuals.
Read more
Objectives:
- To evaluate the effects of water deprivation and feelings of thirst in lean and obese individuals.
Eligibility:
- Healthy individuals at least 18 years of age who are either lean (body mass index less than 26 kg/m(2)) or obese (body mass index at least 35 kg/m(2)).
Design:
- Participants will be screened with a medical history, physical examination, and blood and urine tests.
- Participants will spend the entire study (13 days) as inpatients at the National Institutes of Health Clinical Center.
- Participants will have the following tests and procedures:
- Body composition assessment (using low-level x-rays) to determine the percentage of fat tissue in the body.
- Oral glucose tolerance test (similar to that often used to diagnose diabetes). Individuals who are suspected to have diabetes will not be allowed to continue with the study.
- High salt infusion test, in which an infusion of saline (salt water) will be given for 2 hours and participants will respond to questions about how hungry and thirsty they feel during the procedure.
- Water deprivation test, in which participants will go for 24 hours without water or food and respond to questions about how hungry and thirsty they feel.
- 24-hour stay in a metabolic chamber to determine how many calories participants burn in a day.
- A series of questionnaires about participants' eating habits, feelings about food, and personal feelings, as well as computer-based tests involving the performance of various tasks.
- Measurement of free-living energy using doubly-labeled water, in which participants will drink a sample of water with extra-heavy atoms of hydrogen and oxygen to evaluate the amount of water in the body.
- 24-hour urine collection.
- Frequent blood samples, urine collection, and fat tissue biopsies during the various study procedures.
- After the end of the 13-day study, participants will return after 1 week for a final urine collection.
Read the detailed description
Study Description:
The percentage of people with overweight / obesity in the United States has reached very high levels, with 65% of adults over the age of 20 being overweight. Recently, there have been a number of advances in our understanding of the underlying causes of obesity, including greater understanding of both the effects of the environment and effects that are hereditary (i.e., genetic).
One area in which obese versus lean individuals may be different is how their bodies handle water balance and thirst. Studies done in animals suggest that individuals with greater body fat may tolerate periods without water better than lean animals. Thus, at least in animals, others have found a link between ability to tolerate periods without water and increased body weight.
We are studying whether the ability to tolerate periods without water and ability to feel thirst might differ in lean versus obese individuals. To do so, we will ask lean and obese individuals to undergo tests that include a period of approximately 24 hours without drinking any water, and on a separate day a shorter period of an intravenous high salt solution infusion. We will be looking at how the ability to withstand thirst (dehydration), subsequent water intake (rehydration), changes in hormone levels during these periods, and behavioral and physiological responses to thirst and rehydration differ in lean versus obese individuals. We hope that the data gathered from this study will give us more information about important differences in how water balance is regulated in lean versus obese individuals. Understanding these questions may provide new insights into differences between lean and obese individuals.
Objectives:
Primary Objective: to determine if obese versus lean individuals differ in their response (as measured by objective measurement of water intake) to water deprivation and hyperosmolality (dehydration).
Secondary Objective: to determine if during these challenges there are differences in hormonal responses to dehydration and subsequent rehydration, and how these changes are related to adiposity and adipose tissue metabolism.
- Conditions
- Obesity
- Being tested
- Hypertonic saline infusion, Water deprivation
- Keywords
- Hypertonic Saline Infusion, Water Deprivation, Thirst, Water/Electrolytes Homeostasis, Obesity
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hypertonic saline infusionOther
Three percent saline (0.1ml/kg of the lean mass/min) will be infused for 120 minutes.
Water deprivationOther
24 hour water deprivation
| Study group | Role | What they receive |
|---|---|---|
| Lean: hypertonic first | Experimental | Lean: Hypertonic solution at day 6 and water deprivation at day 10 Receives: Other: Hypertonic saline infusion; Other: Water deprivation |
| Lean: water deprivation first | Experimental | Lean: Water deprivation at day 6 and hypertonic solution at day 10 Receives: Other: Hypertonic saline infusion; Other: Water deprivation |
| Obese: hypertonic first | Experimental | Obese: Hypertonic solution at day 6 and water deprivation at day 10 Receives: Other: Hypertonic saline infusion; Other: Water deprivation |
| Obese: water deprivation first | Experimental | Obese: Water deprivation at day 6 and hypertonic solution at day 10 Receives: Other: Hypertonic saline infusion; Other: Water deprivation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Water intake
Water intake (ml/kg body weight) over the first hour following water deprivation or saline infusion
Measured: End of 24 hour intervention
Secondary outcomes (2)
Hormonal response
Vasopressin, apelin, renin-angiotensis system, natriuretic peptides in blood
Measured: During and at the end of intervention
Thirst rating
Thirst is measured by questionnaire using a visual analog scale.
Measured: During and at the end of interventions
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Oct 2010 (estimated)
- Study start19 Oct 2010
- Primary completion9 Sep 2018
- Study completion28 Mar 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 75 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Marci E Gluck, Ph.D., Principal investigator, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01224704
- Sponsor's protocol ID
- 999911008
- Other IDs
- 11-DK-N008
- Status last verified
- 26 Aug 2026
- First submitted
- 19 Oct 2010
- Last updated
- 2 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999-2004. JAMA. 2006 Apr 5;295(13):1549-55. doi: 10.1001/jama.295.13.1549.
PubMed 16595758Esslinger KA, Jones PJ. Dietary sodium intake and mortality. Nutr Rev. 1998 Oct;56(10):311-3. doi: 10.1111/j.1753-4887.1998.tb01667.x.
PubMed 9810812Cohen HW, Hailpern SM, Fang J, Alderman MH. Sodium intake and mortality in the NHANES II follow-up study. Am J Med. 2006 Mar;119(3):275.e7-14. doi: 10.1016/j.amjmed.2005.10.042.
PubMed 16490476Stinson EJ, Graham AL, Thearle MS, Gluck ME, Krakoff J, Piaggi P. Cognitive dietary restraint, disinhibition, and hunger are associated with 24-h energy expenditure. Int J Obes (Lond). 2019 Jul;43(7):1456-1465. doi: 10.1038/s41366-018-0305-9. Epub 2019 Jan 16.
PubMed 30651576Stinson EJ, Krakoff J, Gluck ME. Depressive symptoms and poorer performance on the Stroop Task are associated with weight gain. Physiol Behav. 2018 Mar 15;186:25-30. doi: 10.1016/j.physbeh.2018.01.005. Epub 2018 Jan 9.
PubMed 29326031
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Thirst and Role of Water/Electrolytes Homeostasis During Water Deprivation in Obesity
- ClinicalTrials.gov ID
- NCT01224704
- Acronym / sponsor ID
- 999911008
- Conditions
- Obesity
- Keywords
- Hypertonic Saline Infusion, Water Deprivation, Thirst, Water/Electrolytes Homeostasis, Obesity
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 75 participants (actual)
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)US National Institutes of Health
- Study start
- 19 Oct 2010 (actual)
- Primary completion
- 9 Sep 2018 (actual)
- Study completion
- 28 Mar 2019 (actual)
- First posted
- 20 Oct 2010 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background:
- One area in which obese and lean individuals may be different is how their bodies handle water balance and thirst. Studies done in animals suggest that individuals with greater body fat may tolerate periods without water better than lean animals. Other research has found a link between the ability to tolerate periods without water and increased body weight. Researchers are interested in studying whether the ability to tolerate periods without water and ability to feel thirst might differ in lean versus obese individuals.
Objectives:
- To evaluate the effects of water deprivation and feelings of thirst in lean and obese individuals.
Eligibility:
- Healthy individuals at least 18 years of age who are either lean (body mass index less than 26 kg/m(2)) or obese (body mass index at least 35 kg/m(2)).
Design:
- Participants will be screened with a medical history, physical examination, and blood and urine tests.
- Participants will spend the entire study (13 days) as inpatients at the National Institutes of Health Clinical Center.
- Participants will have the following tests and procedures:
- Body composition assessment (using low-level x-rays) to determine the percentage of fat tissue in the body.
- Oral glucose tolerance test (similar to that often used to diagnose diabetes). Individuals who are suspected to have diabetes will not be allowed to continue with the study.
- High salt infusion test, in which an infusion of saline (salt water) will be given for 2 hours and participants will respond to questions about how hungry and thirsty they feel during the procedure.
- Water deprivation test, in which participants will go for 24 hours without water or food and respond to questions about how hungry and thirsty they feel.
- 24-hour stay in a metabolic chamber to determine how many calories participants burn in a day.
- A series of questionnaires about participants' eating habits, feelings about food, and personal feelings, as well as computer-based tests involving the performance of various tasks.
- Measurement of free-living energy using doubly-labeled water, in which participants will drink a sample of water with extra-heavy atoms of hydrogen and oxygen to evaluate the amount of water in the body.
- 24-hour urine collection.
- Frequent blood samples, urine collection, and fat tissue biopsies during the various study procedures.
- After the end of the 13-day study, participants will return after 1 week for a final urine collection.
Detailed description
Study Description:
The percentage of people with overweight / obesity in the United States has reached very high levels, with 65% of adults over the age of 20 being overweight. Recently, there have been a number of advances in our understanding of the underlying causes of obesity, including greater understanding of both the effects of the environment and effects that are hereditary (i.e., genetic).
One area in which obese versus lean individuals may be different is how their bodies handle water balance and thirst. Studies done in animals suggest that individuals with greater body fat may tolerate periods without water better than lean animals. Thus, at least in animals, others have found a link between ability to tolerate periods without water and increased body weight.
We are studying whether the ability to tolerate periods without water and ability to feel thirst might differ in lean versus obese individuals. To do so, we will ask lean and obese individuals to undergo tests that include a period of approximately 24 hours without drinking any water, and on a separate day a shorter period of an intravenous high salt solution infusion. We will be looking at how the ability to withstand thirst (dehydration), subsequent water intake (rehydration), changes in hormone levels during these periods, and behavioral and physiological responses to thirst and rehydration differ in lean versus obese individuals. We hope that the data gathered from this study will give us more information about important differences in how water balance is regulated in lean versus obese individuals. Understanding these questions may provide new insights into differences between lean and obese individuals.
Objectives:
Primary Objective: to determine if obese versus lean individuals differ in their response (as measured by objective measurement of water intake) to water deprivation and hyperosmolality (dehydration).
Secondary Objective: to determine if during these challenges there are differences in hormonal responses to dehydration and subsequent rehydration, and how these changes are related to adiposity and adipose tissue metabolism.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Lean: hypertonic first | Experimental | Other: Hypertonic saline infusion, Other: Water deprivationLean: Hypertonic solution at day 6 and water deprivation at day 10 |
| Lean: water deprivation first | Experimental | Other: Hypertonic saline infusion, Other: Water deprivationLean: Water deprivation at day 6 and hypertonic solution at day 10 |
| Obese: hypertonic first | Experimental | Other: Hypertonic saline infusion, Other: Water deprivationObese: Hypertonic solution at day 6 and water deprivation at day 10 |
| Obese: water deprivation first | Experimental | Other: Hypertonic saline infusion, Other: Water deprivationObese: Water deprivation at day 6 and hypertonic solution at day 10 |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Male.
- Age 18-50 yrs to minimize hormonal influences on thirst perception in aging men.
- BMI<25 kg/m^2 for the lean group and BMI >=35 kg/m^2 for obese group (but weigh less than 350 pounds to accommodate the DXA scanner) for the obese group.
- Healthy, as determined by medical history and physical examination, without the exclusions listed below:
Key exclusion criteria (18 listed)
- Currently smoking
- Any medications
- Weight <50kg (as the blood withdrawal limit would be exceeded)
- Hemoglobin concentration < 12mg/dl on screening labs
- Type 1 or type 2 diabetes (according to World Health Organization diagnostic criteria (59))
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hypertonic saline infusionThree percent saline (0.1ml/kg of the lean mass/min) will be infused for 120 minutes. | Other | Lean: hypertonic first, Lean: water deprivation first, Obese: hypertonic first, Obese: water deprivation first |
| Water deprivation24 hour water deprivation | Other | Lean: hypertonic first, Lean: water deprivation first, Obese: hypertonic first, Obese: water deprivation first |
Primary outcome
Water intake
Time frame: End of 24 hour intervention
Water intake (ml/kg body weight) over the first hour following water deprivation or saline infusion
2 secondary outcomes
Hormonal response
Time frame: During and at the end of intervention
Thirst rating
Time frame: During and at the end of interventions
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2026.
- Background: PubMed 16595758Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999-2004. JAMA. 2006 Apr 5;295(13):1549-55. doi: 10.1001/jama.295.13.1549.
- Background: PubMed 9810812Esslinger KA, Jones PJ. Dietary sodium intake and mortality. Nutr Rev. 1998 Oct;56(10):311-3. doi: 10.1111/j.1753-4887.1998.tb01667.x.
- Background: PubMed 16490476Cohen HW, Hailpern SM, Fang J, Alderman MH. Sodium intake and mortality in the NHANES II follow-up study. Am J Med. 2006 Mar;119(3):275.e7-14. doi: 10.1016/j.amjmed.2005.10.042.
- Derived from this study: PubMed 30651576Stinson EJ, Graham AL, Thearle MS, Gluck ME, Krakoff J, Piaggi P. Cognitive dietary restraint, disinhibition, and hunger are associated with 24-h energy expenditure. Int J Obes (Lond). 2019 Jul;43(7):1456-1465. doi: 10.1038/s41366-018-0305-9. Epub 2019 Jan 16.
- Derived from this study: PubMed 29326031Stinson EJ, Krakoff J, Gluck ME. Depressive symptoms and poorer performance on the Stroop Task are associated with weight gain. Physiol Behav. 2018 Mar 15;186:25-30. doi: 10.1016/j.physbeh.2018.01.005. Epub 2018 Jan 9.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Marci E Gluck, Ph.D. principal investigator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hypertonic saline infusion and Water deprivation in people with Obesity, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Water intake (time frame: End of 24 hour intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01224704, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2026; AzTrials last refreshed its copy on 2 Nov 2026.