Dehydrated, Water-Electrolyte Imbalance, MalnutritionDrinkAgeNCT07892742
Effects of Increased Water Intake on Hormonal Response, Hydration Status, and Physical Function in Low-drinking Older Adults
A study testing Water in people with Dehydrated, Water-Electrolyte Imbalance, Malnutrition and Dehydration (Physiology), run by Polytechnic University of Santarém.
Trial summary
DrinkAge is a randomized controlled trial investigating whether increasing daily water intake can improve hydration and health-related outcomes in adults aged 60 years or older who habitually drink relatively little water. The study will include 38 participants who habitually consume 35 mL/kg/day or less of water. Read more about this study
- Who is it for?
- Ages 60 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Dehydrated, Water-Electrolyte Imbalance, Malnutrition, Dehydration (Physiology)
- What is being tested?
- Water
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 38 participants
- Where
- No sites listed yet
- Study dates
- 1 Nov 2026to 31 Jul 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 60 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participants must meet all of the following criteria:
- Age ≥60 years.
- Habitual total water intake (WI) ≤35 mL·kg-¹·day-¹, including water from drinking water, beverages, and food moisture, as determined by dietary assessment.
- Community-dwelling.
- Able to ambulate independently without the use of assistive devices.
- Able to attend all study visits at the SPRINT laboratories.
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- Clinically stable during the three months preceding study inclusion.
- No cognitive impairment that would compromise the ability to provide informed consent or comply with study procedures.
- Willing and able to maintain habitual dietary patterns and physical activity levels throughout the study period, except for the prescribed modification in WI in the experimental group (EG).
- Able to comply with all study procedures, as determined by the investigators.
Who cannot join
- Clinically unstable cardiovascular disease.
- Clinically unstable renal disease.
- Clinically unstable metabolic or endocrine disease.
- Clinically unstable type 2 diabetes.
- Any medical condition requiring fluid restriction.
- Known history of recurrent hyponatremia.
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- Chronic use of medications known to substantially affect fluid and electrolyte balance, including:- Loop diuretics;
- Thiazide diuretics;
- Desmopressin;
- Sodium-glucose cotransporter-2 (SGLT2) inhibitors.
- Cognitive impairment preventing the provision of informed consent.
- Musculoskeletal or neurological conditions that preclude participation in physical performance assessments.
- Major surgery within the previous six months.
- Current alcohol or substance abuse.
- Participation in another clinical trial within the previous three months.
- Any other condition considered by the investigators to compromise participant safety, study compliance, or interpretation of the study results.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: DrinkAge Study: Effects of Increased Water Intake on Hormonal Response, Hydration Status, and Physical Function in Low-drinking Older Adults - a Randomized Controlled Trial
DrinkAge is a randomized controlled trial investigating whether increasing daily water intake can improve hydration and health-related outcomes in adults aged 60 years or older who habitually drink relatively little water.
The study will include 38 participants who habitually consume 35 mL/kg/day or less of water. Participants will be randomly assigned to either increase their daily water intake to at least 45 mL/kg/day or maintain their usual water intake for 7 days.
Read more
Before and after the 7-day intervention, participants will undergo assessments of hydration, blood and urine markers, hormone levels, body water distribution, body composition, muscle and physical function, mood, physical activity, and health-related quality of life.
The main purpose of the study is to determine whether increasing habitual water intake changes levels of arginine vasopressin, a hormone involved in the regulation of body water balance. The study will also investigate whether increasing water intake is associated with changes in hydration status, cardiovascular and kidney-related markers, stress-related hormones, body water distribution, physical performance, mood, and quality of life.
The results may help clarify whether increasing habitual water intake is a feasible strategy to improve hydration and support healthy ageing in older adults who habitually drink relatively little water.
Read the detailed description
The DrinkAge study is a 7-day randomized controlled trial designed to investigate the effects of increasing habitual water intake on hormonal regulation of water balance, hydration status, body water distribution, cardiometabolic and renal biomarkers, neuromuscular function, physical performance, mood, physical activity, and health-related quality of life in community-dwelling older adults who habitually consume relatively low amounts of water.
Older adults may be particularly susceptible to low habitual water intake because of age-related reductions in thirst perception and changes in renal water conservation, as well as medication use, mobility limitations, and other factors that may make adequate fluid consumption more difficult. Individuals who habitually consume relatively little water can maintain total body water and plasma osmolality through physiological mechanisms that conserve water. One of these mechanisms is increased secretion of arginine vasopressin (AVP), a hormone involved in the regulation of water balance and kidney water conservation. Although this response helps maintain water homeostasis, persistent activation of AVP has been associated with several metabolic, renal, cardiovascular, and stress-related outcomes.
Previous intervention studies in younger and middle-aged adults have reported that increasing habitual water intake can reduce copeptin, a validated surrogate marker of AVP secretion, and may improve some hydration and metabolic markers. However, evidence from randomized intervention studies in older adults remains limited. In addition, it is not well established whether increasing habitual water intake affects body water distribution, muscle function, functional capacity, mood, or quality of life in older adults who habitually drink relatively little water.
The primary aim of the DrinkAge study is to determine whether increasing habitual water intake for 7 days changes circulating plasma AVP concentration in low-drinking older adults. The study will also investigate whether the intervention changes objective and subjective markers of hydration, cardiometabolic and renal biomarkers, cortisol, body water compartments, bioelectrical impedance parameters, neuromuscular function, functional capacity, mood, physical activity, and health-related quality of life.
A total of 38 adults aged 65 years or older will be recruited from the community of Rio Maior, Santarém, Portugal. Participants must have a habitual total water intake of 35 mL/kg/day or less, including water obtained from beverages and foods. Participants must be community-dwelling, able to attend the study visits at the research laboratories, and able to walk independently without assistive devices. Participants must have a stable clinical condition and be able to provide informed consent and comply with the study procedures.
Potential participants will undergo a screening process to confirm eligibility. The screening process will include collection of demographic and clinical information, assessment of body mass and height, dietary and fluid-intake assessment, and evaluation of hydration biomarkers. Habitual total water intake will be assessed using a three-day food and fluid diary, including one weekend day. Participants with a habitual total water intake of 35 mL/kg/day or less will be classified as low drinkers and will proceed with the remaining eligibility assessment.
Participants who meet all eligibility criteria will be randomly assigned in a 1:1 ratio to either an experimental group or a control group. Randomization will be performed using a computer-generated allocation scheme by a member of the research team who is not involved in data collection or intervention delivery. Permuted blocks and stratification by sex will be used.
Participants assigned to the experimental group will increase their total daily water intake to at least 45 mL/kg/day for 7 days. The prescribed intake will be individualized according to body mass and the estimated contribution of food to total water intake. The intervention will consist of increasing fluid intake while participants maintain their habitual dietary patterns. The additional fluid provided during the intervention will be Vimeiro Original natural mineral water. Participants will receive pre-measured water bottles corresponding to their individualized daily prescription. The bottles will include graduated time markers to encourage the gradual distribution of water intake throughout the day.
Participants in the experimental group will also receive a hydration scorecard to record beverage type, volume, and time of consumption. Daily reminders will be provided during the intervention period to support adherence.
Participants assigned to the control group will be instructed to maintain their habitual water and fluid intake and usual dietary habits throughout the 7-day study period. Control participants will not receive the hydration tools or behavioral support provided to the experimental group.
Participants in both groups will be instructed to maintain their habitual dietary patterns, physical activity levels, caffeine consumption, and alcohol intake throughout the intervention. Any changes in medication, illness, unusual physical activity, or environmental conditions that could affect hydration status will be recorded.
Adherence to the intervention will be assessed using daily food and fluid records completed throughout the 7-day intervention. These records will be reviewed by a registered dietitian to estimate total daily water intake and determine whether participants achieved the prescribed water-intake target. Participants may also be asked to provide daily confirmations or photographs of beverage containers when necessary to improve the accuracy of intake reporting.
Assessments will be performed at baseline and immediately after the 7-day intervention under standardized laboratory conditions. Participants will undergo anthropometric, biochemical, hydration, body composition, neuromuscular, functional, psychological, and quality-of-life assessments.
The primary outcome is plasma arginine vasopressin concentration, measured at baseline and post-intervention.
Hydration status will be assessed using multiple physiological, biochemical, and perceptual measures. These will include serum, urine, and saliva osmolality; urine-specific gravity; urine color; and subjective measures of thirst and mouth dryness. Urine samples will be collected in the morning, and osmolality measurements will be performed using a freezing-point depression osmometer. Urine-specific gravity will be assessed using a digital refractometer. Thirst and mouth dryness will be assessed using 10-cm visual analogue scales.
Blood samples will be collected in the morning following an overnight fast of at least 10 hours. Blood analyses will include glucose, insulin, glycated hemoglobin, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, sodium, creatinine, urea, uric acid, cortisol, high-sensitivity C-reactive protein, and arginine vasopressin. Insulin resistance will be estimated using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Estimated glomerular filtration rate will also be calculated.
Body water distribution and bioelectrical properties will be assessed using whole-body and segmental bioelectrical impedance analysis. Measurements will include estimates of total body water, intracellular water, extracellular water, and the extracellular-to-intracellular water ratio. Raw bioelectrical impedance parameters, including resistance, reactance, impedance, and phase angle, will also be evaluated. Bioelectrical impedance vector analysis will be used to further characterize hydration status and soft tissue characteristics.
Neuromuscular function will be evaluated using handgrip strength and isokinetic knee testing. Handgrip strength will be measured using a portable hand dynamometer. Lower-limb neuromuscular function will be assessed using an isokinetic dynamometer. Outcomes from the isokinetic assessment will include maximum voluntary isometric contraction, rate of torque development, impulse, peak torque, peak power, total work, hamstrings-to-quadriceps strength ratios, and fatigue-related measures.
Functional capacity and fall-related physical performance will be assessed using the ViviFrail assessment protocol, including the Short Physical Performance Battery and the Timed Up and Go test. The Short Physical Performance Battery includes assessments of static balance, 4-meter gait speed, and repeated chair stands. The Timed Up and Go test measures the time required to stand from a chair, walk 3 meters, turn, return, and sit down.
Psychological outcomes will include mood state and health-related quality of life. Mood will be assessed using the Profile of Mood States questionnaire, which evaluates tension-anxiety, depression-dejection, anger-hostility, fatigue-inertia, vigor-activity, and confusion-bewilderment. Health-related quality of life will be assessed using the 36-Item Short Form Health Survey, which evaluates physical and mental health domains.
Habitual physical activity and dietary and fluid intake will be monitored during the study. Participants will complete food and fluid records during the intervention period, allowing the research team to quantify water intake from beverages and foods and to evaluate adherence to the intervention.
The primary statistical analysis will use linear mixed-effects models to evaluate the effects of the intervention. Models will include group, time, and the group-by-time interaction as fixed effects, with participant included as a random effect to account for repeated measurements within individuals. The group-by-time interaction will represent the primary effect of interest. Models may be adjusted for clinically relevant covariates, including age, sex, and baseline values of the dependent variable. Additional exploratory analyses may include other biologically relevant covariates.
The study is designed to determine whether a short-term increase in habitual water intake can modify AVP secretion and other physiological and functional measures in older adults who habitually consume relatively little water. By simultaneously evaluating endocrine, hydration, metabolic, renal, body water, neuromuscular, functional, psychological, and quality-of-life outcomes, the study will provide a comprehensive assessment of the potential physiological effects of increasing water intake in this population.
The intervention period is limited to 7 days to facilitate adherence and to evaluate early physiological responses to increased water intake. The study is not designed to determine the long-term effects of increased water intake on chronic disease, mortality, or long-term functional independence.
- Being tested
- Water
- Keywords
- Arginine vasopressin, Body water distribution, Neuromuscular function, Cardiometabolic health, Healthy aging
- Medical subject headings
- Dehydration, Water-Electrolyte Imbalance, Malnutrition, Diabetes Insipidus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
WaterOther
Participants will be assigned at random to either the experimental group (EG) or the control group (CG). Over the 7-day intervention period, the EG will be asked to increase total daily water intake (WI) to at least 45 mL·kg-¹·day-¹, while the CG will continue their usual water consumption, corresponding to ≤35 mL·kg-¹·day-¹. Total WI will account for water obtained from both beverages and food.
Participants allocated to the EG will be instructed to keep their usual dietary habits unchanged during the intervention so that the amount of water derived from food remains comparable to habitual intake. Accordingly, the intervention will involve an increase in fluid consumption only. The additional amount of water required to reach the target of ≥45 mL·kg-¹·day-¹ will be individually determined based on body mass and the estimated contribution of food to total WI. Vimeiro Original natural mineral water will be used as the additional source of fluid. This water has a total mineralization of
| Study group | Role | What they receive |
|---|---|---|
| Increased Water Intake | Experimental | Participants will maintain their habitual total water intake and usual dietary and physical activity patterns throughout the 7-day study period. Participants will not receive the hydration tools or behavioral support provided to the experimental group. Receives: Other: Water |
| No intervention | No intervention | Participants will maintain their habitual total water intake and usual dietary and physical activity patterns throughout the 7-day study period. No additional water, hydration tools, or behavioral support will be provided. Participants will complete daily food and fluid records to document their habitual intake during the intervention period. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Serum Arginine Vasopressin Concentration
Serum arginine vasopressin (AVP), will be assessed as a biomarker of the physiological regulation of water balance. Venous blood samples will be collected in the morning after an overnight fast. Serum AVP concentration will be determined using a radioimmunoassay (RIA) according to the standardized procedures of the clinical laboratory. The outcome will be expressed as the change in serum AVP concentration from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Secondary outcomes (33)
Change in Serum Cortisol Concentration
Serum basal cortisol concentration will be assessed as an endocrine biomarker. Venous blood samples will be collected in the morning following an overnight fast, with the time of blood collection recorded to account for the circadian variation in cortisol concentrations. Serum cortisol concentration will be determined using a chemiluminescence assay according to the standardized procedures of the clinical laboratory. The outcome will be expressed as the change in serum cortisol concentration from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Fasting Serum Glucose Concentration
Fasting serum glucose concentration will be assessed as a biochemical marker of glucose metabolism. Venous blood samples will be collected in the morning following an overnight fast of 8-12 hours. Serum glucose concentration will be determined using the hexokinase-glucose-6-phosphate dehydrogenase enzymatic method according to the standardized procedures of the clinical laboratory. The outcome will be expressed as the change in fasting serum glucose concentration from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Fasting Serum Insulin Concentration
Fasting serum insulin concentration will be assessed as a biochemical marker of insulin metabolism. Venous blood samples will be collected in the morning following an overnight fast of 8-12 hours. Serum insulin concentration will be determined using a chemiluminescence immunoassay according to the standardized procedures of the clinical laboratory. The outcome will be expressed as the change in fasting serum insulin concentration from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)
Insulin resistance will be estimated using the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), calculated from fasting serum glucose and fasting serum insulin concentrations. HOMA-IR will be calculated as: fasting insulin (μU/mL) × fasting glucose (mmol/L) / 22.5. The outcome will be expressed as the change in HOMA-IR from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in serum osmolality
Serum, osmolality (mOsm/kg) will be measured using a freezing-point depression osmometer (Mod OSMO1, Advanced Instruments, Canada). All osmolality measurements will be performed in duplicate.
Measured: Baseline and after 7 days of intervention
Change in saliva osmolality
Saliva osmolality (mOsm/kg) will be measured using a freezing-point depression osmometer (Mod OSMO1, Advanced Instruments, Canada). All osmolality measurements will be performed in duplicate. Unstimulated saliva samples will be collected with participants seated comfortably after resting quietly for 2 min, allowing saliva to accumulate passively in the mouth. Participants will then provide approximately 3-4 mL of saliva into Salivette collection tubes or until no additional saliva can be comfortably produced.
Measured: Baseline and after 7 days of intervention
Change in urine osmolality
Urine osmolality (mOsm/kg) will be measured using a freezing-point depression osmometer (Mod OSMO1, Advanced Instruments, Canada). Urine samples will be collected in sterile urine collection cups at the specified assessment time point. Participants will be instructed to provide a midstream urine sample after discarding the initial urine stream. All osmolality measurements will be performed in duplicate.
Measured: Baseline and after 7 days of intervention
Change in Urine Specific Gravity
Urine specific gravity (USG) will be assessed as a urinary marker of hydration status. A urine sample will be collected at the specified assessment time point, and USG will be determined using a digital refractometer (KERN ORM 1CO, KERN \& Sohn GmbH, Germany). The outcome will be expressed as the change in urine specific gravity from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Urine Color
Urine color will be assessed as a subjective urinary marker of hydration status. Urine color will be evaluated from a urine sample collected at the specified assessment time point using a standardized urine color scale. The outcome will be expressed as the change in urine color from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Total Water Intake
Total water intake (WI), including water obtained from beverages and foods, will be assessed using three-day food diaries. A certified dietitian will provide standardized instructions regarding portion sizes and food and beverage recording. Food Processor Plus® software will be used to estimate daily total water intake. The outcome will be expressed as the change in average daily total water intake from the screening/baseline assessment to the intervention period.
Measured: Baseline and during the intervention
Change in Body Mass Index
Body mass index (BMI) will be calculated as body mass in kilograms divided by height in meters squared (kg/m²). Body mass and height will be assessed under standardized conditions. The outcome will be expressed as the change in BMI from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Handgrip strength
Handgrip strength will be assessed using a portable hand dynamometer (Jamar Plus+). Participants will perform three maximal voluntary isometric contractions with each hand alternately. A 60-second rest period will be provided between attempts. The highest recorded value will be used for analysis. The outcome will be expressed as the change in handgrip strength from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Short Physical Performance Battery Score
Functional performance will be assessed using the Short Physical Performance Battery (SPPB), comprising static balance, 4-meter gait speed, and repeated chair stand tests. The SPPB score will be calculated according to the standardized scoring procedure. The outcome will be expressed as the change in SPPB score from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Timed Up and Go Test Performance
The Timed Up and Go (TUG) test will assess functional mobility and fall risk. Participants will stand from a chair, walk 3 meters, turn around a reference point, return to the chair, and sit down. The time required to complete the test will be recorded. The outcome will be expressed as the change in TUG completion time from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Total Body Water
Total body water (TBW) will be estimated using whole-body and segmental bioelectrical impedance analysis (BIA) using a phase-sensitive single-frequency analyzer (AKERN BIA 101/BIVA PRO; Akern Srl, Florence, Italy). Participants will rest in the supine position for 10 minutes before assessment. The outcome will be expressed as the change in estimated total body water from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Intracellular Water
Intracellular water (ICW) will be estimated using whole-body and segmental bioelectrical impedance analysis. The outcome will be expressed as the change in estimated intracellular water from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Extracellular Water
Extracellular water (ECW) will be estimated using whole-body and segmental bioelectrical impedance analysis. The outcome will be expressed as the change in estimated extracellular water from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Extracellular-to-Intracellular Water Ratio
The extracellular-to-intracellular water ratio (ECW/ICW) will be calculated from bioelectrical impedance-derived estimates of extracellular and intracellular water. The outcome will be expressed as the change in the ECW/ICW ratio from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Bioelectrical Impedance Phase Angle
Whole-body and segmental phase angle (PhA) will be obtained from resistance and reactance measurements using a phase-sensitive single-frequency bioelectrical impedance analyzer. The outcome will be expressed as the change in phase angle from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Resistance-to-Height Ratio
The resistance-to-height ratio (R/H) will be calculated from raw bioelectrical impedance resistance measurements normalized for participant height. The outcome will be expressed as the change in R/H from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Reactance-to-Height Ratio
The reactance-to-height ratio (Xc/H) will be calculated from raw bioelectrical impedance reactance measurements normalized for participant height. The outcome will be expressed as the change in Xc/H from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Impedance-to-Height Ratio
The Impedance-to-height ratio (Z/H) will be calculated from raw bioelectrical impedance reactance measurements normalized for participant height. The outcome will be expressed as the change in Z/H from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Perceived Thirst
Perceived thirst will be assessed using a 10-cm visual analogue scale (VAS). Participants will indicate their subjective level of thirst by placing a mark along the scale according to their perceived sensation. The outcome will be expressed as the change in thirst VAS score from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Profile of Mood States Score
Psychological state will be assessed using the Profile of Mood States (POMS), a 65-item self-administered questionnaire assessing six mood dimensions: tension-anxiety, depression-dejection, anger-hostility, fatigue-inertia, vigor-activity, and confusion-bewilderment. The outcome will be expressed as the change in POMS scores from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Change in Health-Related Quality of Life
Health-related quality of life will be assessed using the 36-Item Short Form Health Survey (SF-36). The questionnaire assesses eight domains of physical and mental health and provides physical and mental component summary scores. The outcome will be expressed as the change in SF-36 scores from baseline to the post-intervention assessment.
Measured: Baseline and after 7 days of intervention
Absolute and Relative Ankle Plantar-Flexion Peak Force
Absolute peak force (N) and relative peak force (N·kg-¹) during a seated maximal voluntary isometric plantar-flexion contraction of the dominant limb. The highest force value recorded across four trials will be used for analysis.
Measured: Baseline and after 7 days of intervention
Rate of Force Development During Isometric Ankle Plantar-Flexion
Rate of force development (RFD; N·s-¹) during maximal voluntary isometric plantar-flexion of the dominant limb, calculated over consecutive 50-ms intervals from contraction onset: 0-50, 50-100, 100-150, and 150-200 ms.
Measured: Baseline and after 7 days of intervention
Explosive Isometric Ankle Plantar-Flexion Force
Explosive force, expressed as the percentage of peak force (%F) attained at 50, 100, 150, and 200 ms following contraction onset during maximal voluntary isometric plantar-flexion of the dominant limb.
Measured: Baseline and after 7 days of intervention
Rate of Force Development During Dynamic Ankle Plantar-Flexion
Rate of force development (N·s-¹) during a standing bilateral rapid calf-raise task, calculated as peak force (N) divided by time to peak force (s).
Measured: Baseline and after 7 days of intervention
Functional Lower-Limb Performance
Number of completed repetitions during the 30-second sit-to-stand test (30-s STS), performed from a 43-cm armless chair.
Measured: Baseline and after 7 days of intervention
Mean Power During the 30-Second Sit-to-Stand Test
Mean lower-limb muscle power during the 30-s STS, estimated using a previously validated equation.
Measured: Baseline and after 7 days of intervention
Peak Force During the 30-Second Sit-to-Stand Test
Peak vertical ground reaction force (N) recorded during the concentric phase of each sit-to-stand repetition. The participant-level summary measure will be defined a priori.
Measured: Baseline and after 7 days of intervention
Fatigue Index During the 30-Second Sit-to-Stand Test
Fatigue index calculated to quantify the decline in performance across successive sit-to-stand repetitions during the 30-s STS. The calculation method will be specified a priori.
Measured: Baseline and after 7 days of intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Oct 2026
- Study start1 Nov 2026 (estimated)
- Primary completion31 Mar 2027 (estimated)
- Study completion31 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dehydrated, Water-Electrolyte Imbalance, MalnutritionStudies of the same condition, open and under way.
- 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
- Parallel groups
- Model description
- Participants will be randomly assigned in a 1:1 ratio to either an experimental group or a control group. The experimental group will increase total daily water intake to at least 45 mL/kg/day for 7 days, while the control group will maintain habitual water intake. Outcomes will be assessed at baseline and after the 7-day intervention. Randomization will be performed using a computer-generated sequence with permuted blocks and stratification by sex. The study is single-blinded, with the team member responsible for randomization not involved in outcome assessment or intervention delivery.
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 38 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Polytechnic University of Santarém
- Sponsor type
- University, hospital or other
- Collaborators
- SPRINT Sport Physical Activity and Health Research & Innovation Center
- Responsible party
- Principal investigator, Rúben Francisco, Polytechnic University of Santarém
- Investigators
- Rúben Francisco Francisco, PhD, Principal investigator, Sport Physical Activity and Health Research & Innovation Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07892742
- Sponsor's protocol ID
- DrinkAge
- Acronym
- DrinkAge
- Status last verified
- Oct 2026
- First submitted
- 18 Oct 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be made publicly available because of participant privacy and data protection considerations. The study data will be handled confidentially and access to identifiable information will be restricted to authorized members of the research team. De-identified data may be made available upon reasonable request, subject to approval by the research team, applicable ethical requirements, and institutional and data protection regulations.
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- DrinkAge Study: Effects of Increased Water Intake on Hormonal Response, Hydration Status, and Physical Function in Low-drinking Older Adults - a Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07892742
- Acronym / sponsor ID
- DrinkAge / DrinkAge
- Keywords
- Arginine vasopressin, Body water distribution, Neuromuscular function, Cardiometabolic health, Healthy aging
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 38 participants (estimated)
- Lead sponsor
- Polytechnic University of SantarémUniversity, hospital or other
- Collaborators
- SPRINT Sport Physical Activity and Health Research & Innovation Center
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 31 Mar 2027 (estimated)
- Study completion
- 31 Jul 2027 (estimated)
- First posted
- 23 Oct 2026 (actual)
- 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.
DrinkAge is a randomized controlled trial investigating whether increasing daily water intake can improve hydration and health-related outcomes in adults aged 60 years or older who habitually drink relatively little water.
The study will include 38 participants who habitually consume 35 mL/kg/day or less of water. Participants will be randomly assigned to either increase their daily water intake to at least 45 mL/kg/day or maintain their usual water intake for 7 days.
Before and after the 7-day intervention, participants will undergo assessments of hydration, blood and urine markers, hormone levels, body water distribution, body composition, muscle and physical function, mood, physical activity, and health-related quality of life.
The main purpose of the study is to determine whether increasing habitual water intake changes levels of arginine vasopressin, a hormone involved in the regulation of body water balance. The study will also investigate whether increasing water intake is associated with changes in hydration status, cardiovascular and kidney-related markers, stress-related hormones, body water distribution, physical performance, mood, and quality of life.
The results may help clarify whether increasing habitual water intake is a feasible strategy to improve hydration and support healthy ageing in older adults who habitually drink relatively little water.
Detailed description
The DrinkAge study is a 7-day randomized controlled trial designed to investigate the effects of increasing habitual water intake on hormonal regulation of water balance, hydration status, body water distribution, cardiometabolic and renal biomarkers, neuromuscular function, physical performance, mood, physical activity, and health-related quality of life in community-dwelling older adults who habitually consume relatively low amounts of water.
Older adults may be particularly susceptible to low habitual water intake because of age-related reductions in thirst perception and changes in renal water conservation, as well as medication use, mobility limitations, and other factors that may make adequate fluid consumption more difficult. Individuals who habitually consume relatively little water can maintain total body water and plasma osmolality through physiological mechanisms that conserve water. One of these mechanisms is increased secretion of arginine vasopressin (AVP), a hormone involved in the regulation of water balance and kidney water conservation. Although this response helps maintain water homeostasis, persistent activation of AVP has been associated with several metabolic, renal, cardiovascular, and stress-related outcomes.
Previous intervention studies in younger and middle-aged adults have reported that increasing habitual water intake can reduce copeptin, a validated surrogate marker of AVP secretion, and may improve some hydration and metabolic markers. However, evidence from randomized intervention studies in older adults remains limited. In addition, it is not well established whether increasing habitual water intake affects body water distribution, muscle function, functional capacity, mood, or quality of life in older adults who habitually drink relatively little water.
The primary aim of the DrinkAge study is to determine whether increasing habitual water intake for 7 days changes circulating plasma AVP concentration in low-drinking older adults. The study will also investigate whether the intervention changes objective and subjective markers of hydration, cardiometabolic and renal biomarkers, cortisol, body water compartments, bioelectrical impedance parameters, neuromuscular function, functional capacity, mood, physical activity, and health-related quality of life.
A total of 38 adults aged 65 years or older will be recruited from the community of Rio Maior, Santarém, Portugal. Participants must have a habitual total water intake of 35 mL/kg/day or less, including water obtained from beverages and foods. Participants must be community-dwelling, able to attend the study visits at the research laboratories, and able to walk independently without assistive devices. Participants must have a stable clinical condition and be able to provide informed consent and comply with the study procedures.
Potential participants will undergo a screening process to confirm eligibility. The screening process will include collection of demographic and clinical information, assessment of body mass and height, dietary and fluid-intake assessment, and evaluation of hydration biomarkers. Habitual total water intake will be assessed using a three-day food and fluid diary, including one weekend day. Participants with a habitual total water intake of 35 mL/kg/day or less will be classified as low drinkers and will proceed with the remaining eligibility assessment.
Participants who meet all eligibility criteria will be randomly assigned in a 1:1 ratio to either an experimental group or a control group. Randomization will be performed using a computer-generated allocation scheme by a member of the research team who is not involved in data collection or intervention delivery. Permuted blocks and stratification by sex will be used.
Participants assigned to the experimental group will increase their total daily water intake to at least 45 mL/kg/day for 7 days. The prescribed intake will be individualized according to body mass and the estimated contribution of food to total water intake. The intervention will consist of increasing fluid intake while participants maintain their habitual dietary patterns. The additional fluid provided during the intervention will be Vimeiro Original natural mineral water. Participants will receive pre-measured water bottles corresponding to their individualized daily prescription. The bottles will include graduated time markers to encourage the gradual distribution of water intake throughout the day.
Participants in the experimental group will also receive a hydration scorecard to record beverage type, volume, and time of consumption. Daily reminders will be provided during the intervention period to support adherence.
Participants assigned to the control group will be instructed to maintain their habitual water and fluid intake and usual dietary habits throughout the 7-day study period. Control participants will not receive the hydration tools or behavioral support provided to the experimental group.
Participants in both groups will be instructed to maintain their habitual dietary patterns, physical activity levels, caffeine consumption, and alcohol intake throughout the intervention. Any changes in medication, illness, unusual physical activity, or environmental conditions that could affect hydration status will be recorded.
Adherence to the intervention will be assessed using daily food and fluid records completed throughout the 7-day intervention. These records will be reviewed by a registered dietitian to estimate total daily water intake and determine whether participants achieved the prescribed water-intake target. Participants may also be asked to provide daily confirmations or photographs of beverage containers when necessary to improve the accuracy of intake reporting.
Assessments will be performed at baseline and immediately after the 7-day intervention under standardized laboratory conditions. Participants will undergo anthropometric, biochemical, hydration, body composition, neuromuscular, functional, psychological, and quality-of-life assessments.
The primary outcome is plasma arginine vasopressin concentration, measured at baseline and post-intervention.
Hydration status will be assessed using multiple physiological, biochemical, and perceptual measures. These will include serum, urine, and saliva osmolality; urine-specific gravity; urine color; and subjective measures of thirst and mouth dryness. Urine samples will be collected in the morning, and osmolality measurements will be performed using a freezing-point depression osmometer. Urine-specific gravity will be assessed using a digital refractometer. Thirst and mouth dryness will be assessed using 10-cm visual analogue scales.
Blood samples will be collected in the morning following an overnight fast of at least 10 hours. Blood analyses will include glucose, insulin, glycated hemoglobin, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, sodium, creatinine, urea, uric acid, cortisol, high-sensitivity C-reactive protein, and arginine vasopressin. Insulin resistance will be estimated using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Estimated glomerular filtration rate will also be calculated.
Body water distribution and bioelectrical properties will be assessed using whole-body and segmental bioelectrical impedance analysis. Measurements will include estimates of total body water, intracellular water, extracellular water, and the extracellular-to-intracellular water ratio. Raw bioelectrical impedance parameters, including resistance, reactance, impedance, and phase angle, will also be evaluated. Bioelectrical impedance vector analysis will be used to further characterize hydration status and soft tissue characteristics.
Neuromuscular function will be evaluated using handgrip strength and isokinetic knee testing. Handgrip strength will be measured using a portable hand dynamometer. Lower-limb neuromuscular function will be assessed using an isokinetic dynamometer. Outcomes from the isokinetic assessment will include maximum voluntary isometric contraction, rate of torque development, impulse, peak torque, peak power, total work, hamstrings-to-quadriceps strength ratios, and fatigue-related measures.
Functional capacity and fall-related physical performance will be assessed using the ViviFrail assessment protocol, including the Short Physical Performance Battery and the Timed Up and Go test. The Short Physical Performance Battery includes assessments of static balance, 4-meter gait speed, and repeated chair stands. The Timed Up and Go test measures the time required to stand from a chair, walk 3 meters, turn, return, and sit down.
Psychological outcomes will include mood state and health-related quality of life. Mood will be assessed using the Profile of Mood States questionnaire, which evaluates tension-anxiety, depression-dejection, anger-hostility, fatigue-inertia, vigor-activity, and confusion-bewilderment. Health-related quality of life will be assessed using the 36-Item Short Form Health Survey, which evaluates physical and mental health domains.
Habitual physical activity and dietary and fluid intake will be monitored during the study. Participants will complete food and fluid records during the intervention period, allowing the research team to quantify water intake from beverages and foods and to evaluate adherence to the intervention.
The primary statistical analysis will use linear mixed-effects models to evaluate the effects of the intervention. Models will include group, time, and the group-by-time interaction as fixed effects, with participant included as a random effect to account for repeated measurements within individuals. The group-by-time interaction will represent the primary effect of interest. Models may be adjusted for clinically relevant covariates, including age, sex, and baseline values of the dependent variable. Additional exploratory analyses may include other biologically relevant covariates.
The study is designed to determine whether a short-term increase in habitual water intake can modify AVP secretion and other physiological and functional measures in older adults who habitually consume relatively little water. By simultaneously evaluating endocrine, hydration, metabolic, renal, body water, neuromuscular, functional, psychological, and quality-of-life outcomes, the study will provide a comprehensive assessment of the potential physiological effects of increasing water intake in this population.
The intervention period is limited to 7 days to facilitate adherence and to evaluate early physiological responses to increased water intake. The study is not designed to determine the long-term effects of increased water intake on chronic disease, mortality, or long-term functional independence.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (investigator)
- Number of arms
- 2
- Model description
- Participants will be randomly assigned in a 1:1 ratio to either an experimental group or a control group. The experimental group will increase total daily water intake to at least 45 mL/kg/day for 7 days, while the control group will maintain habitual water intake. Outcomes will be assessed at baseline and after the 7-day intervention. Randomization will be performed using a computer-generated sequence with permuted blocks and stratification by sex. The study is single-blinded, with the team member responsible for randomization not involved in outcome assessment or intervention delivery.
| Arm | Type | Receives |
|---|---|---|
| Increased Water Intake | Experimental | Other: WaterParticipants will maintain their habitual total water intake and usual dietary and physical activity patterns throughout the 7-day study period. Participants will not receive the hydration tools or behavioral support provided to the experimental group. |
| No intervention | No intervention | –Participants will maintain their habitual total water intake and usual dietary and physical activity patterns throughout the 7-day study period. No additional water, hydration tools, or behavioral support will be provided. Participants will complete daily food and fluid records to document their habitual intake during the intervention period. |
Who may qualify
- Ages
- 60 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Age ≥60 years.
- Habitual total water intake (WI) ≤35 mL·kg-¹·day-¹, including water from drinking water, beverages, and food moisture, as determined by dietary assessment.
- Community-dwelling.
- Able to ambulate independently without the use of assistive devices.
- Able to attend all study visits at the SPRINT laboratories.
Key exclusion criteria (16 listed)
- Clinically unstable cardiovascular disease.
- Clinically unstable renal disease.
- Clinically unstable metabolic or endocrine disease.
- Clinically unstable type 2 diabetes.
- Any medical condition requiring fluid restriction.
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 |
|---|---|---|
| WaterParticipants will be assigned at random to either the experimental group (EG) or the control group (CG). Over the 7-day intervention period, the EG will be asked to increase total daily water intake (WI) to at least 45 mL·kg-¹·day-¹, while the CG will continue their usual water consumption, corresponding to ≤35 mL·kg-¹·day-¹. Total WI will account for water obtained from both beverages and food. Participants allocated to the EG will be instructed to keep their usual dietary habits unchanged during the intervention so that the amount of water derived from food remains comparable to habitual intake. Accordingly, the intervention will involve an increase in fluid consumption only. The additional amount of water required to reach the target of ≥45 mL·kg-¹·day-¹ will be individually determined based on body mass and the estimated contribution of food to total WI. Vimeiro Original natural mineral water will be used as the additional source of fluid. This water has a total mineralization of | Other | Increased Water Intake |
Primary outcome
Change in Serum Arginine Vasopressin Concentration
Time frame: Baseline and after 7 days of intervention
Serum arginine vasopressin (AVP), will be assessed as a biomarker of the physiological regulation of water balance. Venous blood samples will be collected in the morning after an overnight fast. Serum AVP concentration will be determined using a radioimmunoassay (RIA) according to the standardized procedures of the clinical laboratory. The outcome will be expressed as the change in serum AVP concentration from baseline to the post-intervention assessment.
33 secondary outcomes
Change in Serum Cortisol Concentration
Time frame: Baseline and after 7 days of intervention
Change in Fasting Serum Glucose Concentration
Time frame: Baseline and after 7 days of intervention
Change in Fasting Serum Insulin Concentration
Time frame: Baseline and after 7 days of intervention
Change in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)
Time frame: Baseline and after 7 days of intervention
Change in serum osmolality
Time frame: Baseline and after 7 days of intervention
Change in saliva osmolality
Time frame: Baseline and after 7 days of intervention
Change in urine osmolality
Time frame: Baseline and after 7 days of intervention
Change in Urine Specific Gravity
Time frame: Baseline and after 7 days of intervention
Change in Urine Color
Time frame: Baseline and after 7 days of intervention
Change in Total Water Intake
Time frame: Baseline and during the intervention
Change in Body Mass Index
Time frame: Baseline and after 7 days of intervention
Change in Handgrip strength
Time frame: Baseline and after 7 days of intervention
Change in Short Physical Performance Battery Score
Time frame: Baseline and after 7 days of intervention
Change in Timed Up and Go Test Performance
Time frame: Baseline and after 7 days of intervention
Change in Total Body Water
Time frame: Baseline and after 7 days of intervention
Change in Intracellular Water
Time frame: Baseline and after 7 days of intervention
Change in Extracellular Water
Time frame: Baseline and after 7 days of intervention
Change in Extracellular-to-Intracellular Water Ratio
Time frame: Baseline and after 7 days of intervention
Change in Bioelectrical Impedance Phase Angle
Time frame: Baseline and after 7 days of intervention
Change in Resistance-to-Height Ratio
Time frame: Baseline and after 7 days of intervention
Change in Reactance-to-Height Ratio
Time frame: Baseline and after 7 days of intervention
Change in Impedance-to-Height Ratio
Time frame: Baseline and after 7 days of intervention
Change in Perceived Thirst
Time frame: Baseline and after 7 days of intervention
Change in Profile of Mood States Score
Time frame: Baseline and after 7 days of intervention
Change in Health-Related Quality of Life
Time frame: Baseline and after 7 days of intervention
Absolute and Relative Ankle Plantar-Flexion Peak Force
Time frame: Baseline and after 7 days of intervention
Rate of Force Development During Isometric Ankle Plantar-Flexion
Time frame: Baseline and after 7 days of intervention
Explosive Isometric Ankle Plantar-Flexion Force
Time frame: Baseline and after 7 days of intervention
Rate of Force Development During Dynamic Ankle Plantar-Flexion
Time frame: Baseline and after 7 days of intervention
Functional Lower-Limb Performance
Time frame: Baseline and after 7 days of intervention
Mean Power During the 30-Second Sit-to-Stand Test
Time frame: Baseline and after 7 days of intervention
Peak Force During the 30-Second Sit-to-Stand Test
Time frame: Baseline and after 7 days of intervention
Fatigue Index During the 30-Second Sit-to-Stand Test
Time frame: Baseline and after 7 days of intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be made publicly available because of participant privacy and data protection considerations. The study data will be handled confidentially and access to identifiable information will be restricted to authorized members of the research team. De-identified data may be made available upon reasonable request, subject to approval by the research team, applicable ethical requirements, and institutional and data protection regulations.
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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.
Rúben Francisco Francisco, PhD principal investigator
Sport Physical Activity and Health Research & Innovation Center
Questions about this trial
What is this clinical trial studying?
A study testing Water in people with Dehydrated, Water-Electrolyte Imbalance, Malnutrition and Dehydration (Physiology), run by Polytechnic University of Santarém.
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 10 inclusion and 16 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: opening soon, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rúben Francisco Francisco, PhD (+351 243 309 520 ext. +351, rubenfrancisco@esdrm.ipsantarem.pt), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Serum Arginine Vasopressin Concentration (time frame: Baseline and after 7 days of intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Oct 2026.