Autonomic Adaptations to Hydration and Brain Functioning

Hydration Clinical Trial

Official title:

Autonomic Adaptation to Hydration and Brain Functioning

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03525470
• Other study ID #: DB-0123-Hydration
• Status: Completed
• Phase: N/A
• Start date: January 1, 2016
• Est. completion date: April 1, 2018

Study information

• Verified date: May 2018
• Source: Swansea University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The influence of relatively small decreases in hydration status have been little studied. On two occasions subjects will be allowed to lose about 0,5% of their body weight and one occasion 300ml of water will be consumed. Functional MRI will be used to monitor brain functioning when performing a mental arithmetic task. Heart rate variability will be monitored and related to differences in brain functioning when water has and has not been drunk

Description:

On two mornings twelve male participants will be exposed to a temperature of 30oC for four hours and either drink or not drink two 150ml glasses of water during that time. The subjects the participate in an fMRI protocol during which they complete a modified version of the Paced Auditory Serial Addition Test (PASAT): a challenging arithmetic task designed to elicit autonomic arousal.

Throughout the morning subjects will their heart rate variability (HRV) monitored. At periodic intervals subjects will rate their thirst and mood by visual analogue scales and at the end of the PASAT task they rate its difficulty. Changes in body temperature and fluid loss (perspiration and urine) and urine osmolality will be monitored.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 12
• Est. completion date: April 1, 2018
• Est. primary completion date: April 1, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 20 Years to 30 Years

Eligibility

Inclusion Criteria:

• Self declared as healthy and not taking any medication

Exclusion Criteria:

Related Conditions & MeSH terms

• Hydration

Intervention

Biological:
• Water
150 mil of water was drunk on two occasions

Other:
• No drink
Although body weight lost no drink consumed

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Swansea University

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	BOLD signal	Participants will be presented with an arithmetic task, modified for use in the scanner, similar to the Paced Auditory Serial Addition Task: a 'stressful' task that measures calculation ability and is known to elicit an autonomic response 35. Pairs of two digit numbers appeared on a screen in red and participants will be required to mentally add or subtract the numbers. After 2 seconds the screens will be removed and a second screen appeared containing a correct and an incorrect answer. Participants will be required to press either a left or right button to indicate which answer was correct ). The speed of presentation is designed to be just at the level that it is possible to perform the task although it required mental effort and was 'stressful'.This allows investigation of areas of the brain associated with working memory but also those associated with emotional arousal.	One hour in scanner (1300-1400 hours)
Primary	Heart-rate variability	Differences in inter-beat intervals derived from RS800 Polar heart rate monitor with a sampling rate of 1000Hz. Profile to be analysed using the Kubios software	Differences on two testing occasions (0900 and 1300 hours) will be related to BOLD
Secondary	Ratings of ,mood and perceived effort	Using visual analogue scales mood and perceived effort will be rated.	Rated baseline (0830 hours), 30 mins later, 280 minutes later
Secondary	Change in body weight	Scales, sensitive to 5 grams, will be used to monitor changes in body weight	Measured at baseline (0830 hours), after 290 minutes (before urinating) and 300 mintues (after urinating)
Secondary	Osmolality	Using an Osmomat 300 freezing point osmometer the osmolality of urine will be measured at the beginning and end of testing sessions	Baseline (0830 hours) and after 300 minutes