Effects of Increased Water Intake on Hormonal Response, Hydration Status, and Physical Function in Low-drinking Older Adults

NCT07892742 | Not Yet Recruiting DMC

• 1 other identifier: DrinkAge
• Study Type: interventional
• Target: 38
• Locations: 0 countries
• Sites: N/A

Brief 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. 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.

Conditions

Dehydrated, Water-Electrolyte Imbalance, Malnutrition; Dehydration (Physiology)

Keywords

Arginine vasopressin; Body water distribution; Neuromuscular function; Cardiometabolic health; Healthy aging

Outcome Measures

Primary Outcomes (1)

• 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.

  Baseline and after 7 days of intervention

Secondary Outcomes (33)

• Change in Serum Cortisol Concentration

  Baseline and after 7 days of intervention

• Change in Fasting Serum Glucose Concentration

  Baseline and after 7 days of intervention

• Change in Fasting Serum Insulin Concentration

  Baseline and after 7 days of intervention

• Change in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)

  Baseline and after 7 days of intervention

• Change in serum osmolality

  Baseline and after 7 days of intervention

Study Arms (2)

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.

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.

Interventions

Water OTHER

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

Increased Water Intake

Eligibility Criteria

• Age: 60 Years - 85 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.
• 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.

You may not qualify if:

• 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.
• 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.

Sponsors & Collaborators

• Polytechnic University of Santarém: lead
• SPRINT Sport Physical Activity and Health Research & Innovation Center: collaborator

MeSH Terms

Conditions

Dehydration; Water-Electrolyte Imbalance; Malnutrition; Diabetes Insipidus

Interventions

Water

Condition Hierarchy (Ancestors)

Metabolic Diseases; Nutritional and Metabolic Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Nutrition Disorders; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Pituitary Diseases; Endocrine System Diseases

Intervention Hierarchy (Ancestors)

Hydroxides; Alkalies; Inorganic Chemicals; Anions; Ions; Electrolytes; Oxides; Oxygen Compounds

Study Officials

• Rúben Francisco Francisco, PhD

  Sport Physical Activity and Health Research & Innovation Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Rúben Francisco Francisco, PhD

CONTACT

+351 243 309 520; rubenfrancisco@esdrm.ipsantarem.pt

Miguel Gomes Gomes, PhD

CONTACT

+351 912 332 444; miguel.gomes@esdrm.ipsantarem.pt

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Masking Details: The study will be single-blinded. The team member responsible for randomization will not be involved in intervention delivery or outcome assessment. Outcome assessors will be blinded to participants' group allocation whenever feasible.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Researcher

Model Details: 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.

Study Record Dates

• First Submitted: October 18, 2026
• First Posted: October 23, 2026
• Study Start (Estimated): November 1, 2026
• Primary Completion (Estimated): March 31, 2027
• Study Completion (Estimated): July 31, 2027
• Last Updated: October 23, 2026

Record last verified: 2026-10

Data Sharing

• IPD Sharing: Will not share