The Effect of Hydration on Postprandial Metabolic Responses

ConditionGlycaemia

Trial statusNot yet recruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age18-45

SponsorLoughborough University

About this trial

Certain populations, such as industrial workers and endurance athletes are particularly susceptible to dehydration due to exposure to heat for long periods of time causing evaporative water loss via sweating. The physical and cognitive decrements associated with dehydration have been widely researched, however the effect of dehydration on metabolism is lesser known. As climate change is causing temperatures to rise, and metabolic diseases such as type 2 diabetes are more common, the effect of dehydration on metabolism, specifically glycemic response to meals, needs to be established for future recommendations in clinical, environmental and athletic settings.

Therefore, the aim of this study is to investigate the effect of acute exercise-induced dehydration on subsequent metabolic responses to feeding (i.e. glycaemia and insulinaemia).

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Male or female

Generally fit and healthy

Participate in endurance or intermittent exercise at least 3 times a week or minimum of 150 minutes moderate intensity activity per week

Disqualifiers

< 18 or > 45

Any health condition that may affect study outcomes (e.g., endocrine/liver/renal/cardiovascular disease)

Any morbidity that affects ability to cycle

Smoker or vaper

Trial design

Design model

Crossover

Treatments tested in this trial

Water intake
Other intervention
Water ingested to fully replace sweat losses during exercise.
Water restriction
Other intervention
Water restriction to induce hypohydration of \~3% body mass through sweat losses during exercise.

Treatment groups

16 Participants

are divided into 2 treatment groups

Group A: EuhydratedExperimental treatment 1 intervention

Group B: HypohydratedExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

Plasma glucose

Measured using colorimetric assay from venous blood samples

Time frame

6 hours

Secondary outcomes

Plasma insulin

Measured using ELISA from venous blood samples

Time frame

6 hours

Plasma osmolality

Measured using freezing point depression from venous blood samples

Time frame

6 hours

Plasma volume change

Determined from haemoglobin and haematocrit measures in blood samples collected before and after drink ingestion

Time frame

6 hours

Urine volume

Determined from urine samples collected before and after exercise

Time frame

6 hours

Other outcomes

N-back task for working memory (cognitive function)

The task will comprise three progressively harder memory loads (1-Back, 2-Back, 3-Back). Each stimulus type will be used in all memory loads. Participants will have to respond using the space bar when they see a stimulus that is presented one, two, or three steps previously, dependent on the load condition. Each phase will comprise 50 trials with ten targets presented centrally on a plain white screen. Each stimulus will be presented for 1000 ms unless the participant responds and in which case the next trial will begin. Commission errors and correct responses will be used as indices of performance. Commission errors occur when participants respond to non-targets.

Time frame

3 hours

Go/no-go task for response inhibition (cognitive function)

Participants will be instructed to press the space bar when an image of a tree appears onscreen ("go" stimulus) and to inhibit responding when an image of a football is presented (the "no-go" stimulus). The task will comprise 200 trials, of which 10% will be no-go trials. Each trial will last 500 ms and will have a black image on a white background. The sequence of stimuli will be the same for each participant. In order to allow for pre-potent tendencies to develop, 50 go trials will precede the first no-go trial. Increased commission error responses (i.e. responding incorrectly on a no-go trial) will indicate reduced response inhibition. Commission errors and correct responses will be measured as indices of performance.

Time frame

3 hours

Oculomotor function antisaccade task

Each trial will start with a 1-second instruction screen prompting participants to focus on the target. A central fixation point will be displayed for one second, followed by a brief blank interval and then the appearance of a red distractor. The distractor will appear randomly to the left or right of the fixation point and will remain visible for 2 seconds. Participants will be instructed to maintain fixation at the centre and then make a saccade in the opposite direction as soon as the distractor appears. The task will include 24 trials, with four additional practice trials. The primary variables measured will be reaction time mean and standard deviation, which reflect inhibition latency and variability. Antisaccade errors, or the number of incorrect saccades, will also be calculated.

Time frame

3 hours

Oculomotor function prosaccade task

Each trial will begin with a 1-second instruction screen, followed by a central fixation point and a brief blank interval. A green target then will appear randomly to the left or right of the fixation point for 2 seconds. Participants will be instructed to fixate at the centre and then make a saccade towards the target. The task will include a total of 14 trials, with four additional practice trials. The variables measured will be reaction time mean and standard deviation, which indicate prosaccade latency and variability.

Time frame

3 hours

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Loughborough University

Lead sponsor

National Institute for Health Research Leicester Biomedical Research Centre

Collaborator

Source ClinicalTrials.gov

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