Trial Outcomes & Findings for The Effect of Hydration Status on Glycemic Control and Appetite Regulation (NCT NCT02841449)

Results Overview

Primary analysis is time trends (i.e. ANOVA effects), supported by indices of the glycemic response (e.g. iAUC, time to peak). Blood was taken pre-muscle biopsy (if participants opted in for a muscle biopsy), before consuming the glucose drink (after the biopsy, where applicable), then at 15 minutely samples for 120 minutes. After the meal test, blood was drawn at 10 minutely intervals for 60 minutes, starting 30 minutes after commencement of eating.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

16 participants

Primary outcome timeframe

Measured on day 5 on both trial arms, using the blood sample drawn before the glucose beverage is consumed and the blood samples drawn for the subsequent 120 minutes

Results posted on

2020-06-22

Participant Flow

n = 17 recruited; n = 1 withdrew prior to starting the study due to surgery (unrelated to study)

Participant milestones

Participant milestones
Measure	Hypohydrated First, Then Rehydrated After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg body mass to consume over the rest of the day (e.g. a 75 kg participantwould consume 225 mL water. After a 3-35 day washout, they will repeat the protocol but after the heat tent be given 40 mL/kg body mass + 150 % body mass losses from the heat tent in water. Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated First, Then Hypohydrated After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 3000 mL + 1125 mL \[750 g \* 1.5\], totalling 4125 mL). Following a 3-35 d washout, participants would then repeat the protocol but after the heat tent be given 3 mL/kg body mass of water to consume over the rest of the day. Rehydrated: Participants rehydrate after the heat tent procedure
Overall Study STARTED	7	9
Overall Study COMPLETED	7	9
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

crossover study so participants all did both trial arms

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Hypohydrated First, Then Rehydrated n=7 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg body mass to consume over the rest of the day (e.g. a 75 kg participantwould consume 225 mL water. After a 3-35 day washout, they will repeat the protocol but after the heat tent be given 40 mL/kg body mass + 150 % body mass losses from the heat tent in water. Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated First, Then Hypohydrated n=9 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 3000 mL + 1125 mL \[750 g \* 1.5\], totalling 4125 mL). Following a 3-35 d washout, participants would then repeat the protocol but after the heat tent be given 3 mL/kg body mass of water to consume over the rest of the day. Rehydrated: Participants rehydrate after the heat tent procedure	Total n=16 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=7 Participants • crossover study so participants all did both trial arms	0 Participants n=9 Participants • crossover study so participants all did both trial arms	0 Participants n=16 Participants • crossover study so participants all did both trial arms
Age, Categorical Between 18 and 65 years	7 Participants n=7 Participants • crossover study so participants all did both trial arms	9 Participants n=9 Participants • crossover study so participants all did both trial arms	16 Participants n=16 Participants • crossover study so participants all did both trial arms
Age, Categorical >=65 years	0 Participants n=7 Participants • crossover study so participants all did both trial arms	0 Participants n=9 Participants • crossover study so participants all did both trial arms	0 Participants n=16 Participants • crossover study so participants all did both trial arms
Age, Continuous	30 years STANDARD_DEVIATION 8 • n=7 Participants	31 years STANDARD_DEVIATION 10 • n=9 Participants	30 years STANDARD_DEVIATION 9 • n=16 Participants
Sex: Female, Male Female	3 Participants n=7 Participants	5 Participants n=9 Participants	8 Participants n=16 Participants
Sex: Female, Male Male	4 Participants n=7 Participants	4 Participants n=9 Participants	8 Participants n=16 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment United Kingdom	7 participants n=7 Participants	9 participants n=9 Participants	16 participants n=16 Participants

PRIMARY outcome

Timeframe: Measured on day 5 on both trial arms, using the blood sample drawn before the glucose beverage is consumed and the blood samples drawn for the subsequent 120 minutes

Primary analysis is time trends (i.e. ANOVA effects), supported by indices of the glycemic response (e.g. iAUC, time to peak). Blood was taken pre-muscle biopsy (if participants opted in for a muscle biopsy), before consuming the glucose drink (after the biopsy, where applicable), then at 15 minutely samples for 120 minutes. After the meal test, blood was drawn at 10 minutely intervals for 60 minutes, starting 30 minutes after commencement of eating.

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Glycemic Response	303 mmol120 minl-1 Standard Deviation 121	306 mmol120 minl-1 Standard Deviation 113

SECONDARY outcome

Timeframe: Measured on day 5 on both trial arms, using the blood sample drawn before the glucose beverage is consumed and the blood samples drawn for the subsequent 120 minutes

Primary analysis is time trends (i.e. ANOVA effects), supported by indices of the insulinemic response (e.g. iAUC, time to peak). Bloods drawn at pre-biopsy, pre-OGTT, 15, 30, 45, 60, 90, 120 min and 0, 30, 60 minutes after the ad libitum meal test.

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Insulinemic Response	20860 pmol120 minl-1 Standard Deviation 8311	21937 pmol120 minl-1 Standard Deviation 8340

SECONDARY outcome

Timeframe: Measured on day 5 on both trial arms, using the blood sample drawn before the glucose beverage is consumed and the blood samples drawn for the subsequent 120 minutes (please note: may measure copeptin as a marker of arginine vasopressin)

Primary analysis is time trends (i.e. ANOVA effects), supported by indices of the response trends (e.g. iAUC, time to peak). Bloods drawn pre-biopsy, pre-OGTT, and then 15 minutely for 120 minutes, and then 10 minutely after the ad libitum meal test.

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Arginine Vasopressin and Copeptin Response	2704 pmol120 minl-1 Standard Deviation 2398	961 pmol120 minl-1 Standard Deviation 1488

SECONDARY outcome

Timeframe: Measured on day 5 on both trial arms, using the blood sample drawn before the participant starts eating the buffet and the subsequent post-buffet blood samples

Primary analysis is time trends (i.e. ANOVA effects), supported by indices of the response trend (e.g. iAUC, time to peak). Due to funding limitations, we only took one 60 minute postprandial measure of ghrelin.

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Ghrelin Response	180 pg/mL Standard Deviation 65	188 pg/mL Standard Deviation 71

SECONDARY outcome

Timeframe: Measured on day 5 on both trial arms from the pasta test meal

Differences in energy intake between the hypohydrated and rehydrated groups (two-tailed t-test)

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Energy Intake	1953 kJ Standard Deviation 742	2027 kJ Standard Deviation 926

SECONDARY outcome

Timeframe: Using the metabolic rate data collected on day 5 on both trial arms

Comparing respiratory quotient and metabolic rate

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Metabolic Rate	96.32 kJkg-1day-1 Standard Deviation 11.94	95.11 kJkg-1day-1 Standard Deviation 13.09

SECONDARY outcome

Timeframe: Collected on day 5 of both trial arms during the buffet

Comparing appetite response. Scales were visual analogue scales of hunger, fullness, how much you feel you can eat, thirst, and desire for sweet, salty, savoury and fatty foods. Scales were 0-100 mm vertical lines which participants marked where 0 = not at all/no desire and 100 = extremely/very high desire)

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Subjective Appetite Ratings fasted salt desire	21 mm Standard Deviation 25	42 mm Standard Deviation 27
Subjective Appetite Ratings fasted hunger	65 mm Standard Deviation 26	66 mm Standard Deviation 17
Subjective Appetite Ratings fasted fullness	8 mm Standard Deviation 8	21 mm Standard Deviation 17
Subjective Appetite Ratings fasted "how much can you eat"	69 mm Standard Deviation 19	65 mm Standard Deviation 20
Subjective Appetite Ratings fasted thirst	93 mm Standard Deviation 10	60 mm Standard Deviation 19
Subjective Appetite Ratings fasted sweet desire	42 mm Standard Deviation 29	39 mm Standard Deviation 24
Subjective Appetite Ratings fasted savoury desire	54 mm Standard Deviation 29	67 mm Standard Deviation 22
Subjective Appetite Ratings fasted fatty desire	32 mm Standard Deviation 26	45 mm Standard Deviation 21

SECONDARY outcome

Timeframe: pQCT scans on day 4 of the trial before the dehydration protocol in the heat tent, and on day 5 before the OGTT

Comparing muscle size in the dehydrated and rehydrated state.Taken from the pQCT scans

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Muscle Volume	-2.9 percent change from basline Standard Deviation 2.7	0.0 percent change from basline Standard Deviation 2.1

SECONDARY outcome

Timeframe: Daily (i.e. 5 consecutive days for each trial arm)

Taken from bioelectrical impedance weighing scales

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Body Water Content	-0.4 kg change from baseline Interval -0.8 to 0.0	0.1 kg change from baseline Interval -0.3 to 0.6

OTHER_PRE_SPECIFIED outcome

Timeframe: Measured from the blood samples on day 4 and day 5 on both trial arms

Change from baseline

Outcome measures

Outcome measures
Measure	Hypohydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 3 mL/kg lean body mass to consume over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass would consume 191 mL water \[63.75 kg \* 3 mL\]) Hypohydrated: Participants remain hypohydrated after the heat tent procedure	Rehydrated n=16 Participants After being dehydrated in the heat tent, participants in this trial arm will be given 40 mL/kg lean body mass plus 150 % of their water losses (from the heat tent procedure) over the rest of the day (e.g. a 75 kg participant with a body composition of 85 % fat free mass and lost 1 % of their body mass in the heat tent (0.75 kg) would consume 2550 mL \[63.75 kg \* 40 mL\] + 1125 mL \[750 g \* 1.5\], totalling 3675 mL). Rehydrated: Participants rehydrate after the heat tent procedure
Serum Osmolality	9 mosmol/kg Standard Deviation 6	1 mosmol/kg Standard Deviation 4

OTHER_PRE_SPECIFIED outcome

Timeframe: Measured from the blood samples on day 4 and day 5 on both trial arms

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr Harriet Carroll

University of Bath

Phone: +447706548573

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place