Clinical trial NCT05591573: The Impact of Glycemic Index on Sleep and Memory Consolidation
Official title: The Impact of Glycemic Index on Sleep and Memory Consolidation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Sleep Architecture
Cognitive Function
Mood
Glucose Metabolism
Lead sponsor: Swansea University
Sponsor class: OTHER
First posted: 2022-10-24
Enrollment: 20
Sex: MALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: In a randomized, double-blind, and counterbalanced order (AB/BA), participants will receive either a high glycemic index or low glycemic index pre-bed drink. After a 1-week washout period, participants will consume the alternate drink.
Primary purpose: OTHER

Brief summary: The study will test whether the consumption of a low versus a high glycemic index pre-bed drink influences sleep architecture, memory consolidation, nocturnal glucose metabolism, and mood.

Detailed description: Few studies have examined the impact of meal composition on sleep. Most research has focused on carbohydrate intake, although reports are sporadic and confounded by the manipulation of other macronutrients. Nonetheless, the pattern of results appears to depend on the nature of the sleep variable under investigation e.g., latency, duration, or efficiency. The study will determine whether manipulating the glycemic index of a pre-bed drink influences sleep architecture, procedural and declarative memory consolidation, nocturnal glucose metabolism, and mood.

Participants will stay in the sleep laboratory for three nights, each night separated by one week (visit 1, 2, and 3). The first night is an acclimatisation night. The same procedure will be followed on all three nights, as described below.

On the morning of each visit, a continuous glucose monitor will be set up and worn until 8pm the following evening. Participants will be asked to return to the sleep laboratory at 7pm, having fasted for five hours, and asked to consume a standardised evening meal. Several mood questionnaires will be completed throughout the evening and a polysomnography will be set up. Two memory tasks will be administered at approximately 10pm. Immediately after this, participants will consume either water (night 1), or a low glycemic index or high glycemic index drink (night 2 or 3). Participants will retire to bed at approximately 11pm and woken up between 6.30am - 8am, depending on personal preference.

In the morning, the memory tasks will be administered again, as well as two mood questionnaires. Participants will be asked to wear a Pro-Diary watch throughout the day, which measures mood and hunger. At 8pm, both the continuous glucose monitor and Pro-diary watch will be collected from the participant.

Eligibility criteria: Inclusion Criteria:

* Male (given that the menstrual cycle may influence sleep polysomnography)
* Good health
* Not taking any medication known to effect sleep or metabolism
* Normal sleep duration (i.e. between 6.5 - 9 hours of sleep per night)
* A sleep efficiency score above 80% (Pittsburg Sleep Quality Index)
* Normal sleep schedule (i.e. fall asleep between 10pm and 12pm)
* No difficulty sleeping in new places

Exclusion Criteria:

* Diagnosis of any physical or mental disorder e.g. diabetes, cardiovascular disorders, gastrointestinal disorders, sleep problems, epilepsy, or mood disorders
* Unhealthy weight (BMI over 30)
* Drink more than 300mg of caffeine per day (3 - 4 standard sized 8-oz cups)
* Work nights or shifts
* Smoke/vape
* Regularly drink alcohol (\>3 glasses per day)
* Used recreational drugs within the last 6 months
* Take part in \>3 hours of vigorous exercise per week
* Any known food allergies or intolerances
* Nocturnal eating or regular consumption of alcohol before bed (assessed by the Meal Pattern Questionnaire)

Primary outcomes:
measure: Sleep onset latency (polysomnography)
timeFrame: Bedtime (approx. 11.00pm) to wake time (approx 7.30am)
measure: Total sleep time (polysomnography)
timeFrame: Bedtime (approx. 11.00pm) to wake time (approx 7.30am)
measure: Wake after sleep onset (polysomnography)
timeFrame: Bedtime (approx. 11.00pm) to wake time (approx 7.30am)
measure: Sleep efficiency (polysomnography)
timeFrame: Bedtime (approx. 11.00pm) to wake time (approx 7.30am)
measure: Sleep stages (polysomnography)
timeFrame: Bedtime (approx. 11.00pm) to wake time (approx 7.30am)
measure: Arousal index (polysomnography)
timeFrame: Bedtime (approx. 11.00pm) to wake time (approx 7.30am)
measure: Leeds Sleep Evaluation Questionnaire
timeFrame: Administered 10 - 20 minutes after waking up in the morning,
Secondary outcomes:
measure: Glucose response (continuous glucose monitor)
timeFrame: 25 hours during night 2 and night 3 (weeks 2 and 3)
measure: Finger tapping task (procedural memory)
timeFrame: Completed at 10pm, and between 6.30 - 8am the following morning, on night 2 and night 3 (week 2 and 3).
measure: Story recall task (declarative memory)
timeFrame: Completed at 10pm, and between 6.30 - 8am the following morning, on night 2 and night 3 (week 2 and 3).
measure: Epworth Sleepiness Scale
timeFrame: Administered at 8pm on the evening after night 2 and night 3 (week 2 and 3).
measure: Mood and hunger
timeFrame: Completed five times throughout the evening and twice in the morning (immediately after waking up and 20-30 minutes later) on night 2 and night 3 (week 2 and 3). .
measure: Mood
timeFrame: Prompted from 9.30am - 5.30pm after night 2 and night 3 (week 2 and 3).
measure: Actigraphy
timeFrame: Night 2 and night 3 (week 2 and 3).
Other outcomes:
Locations:
city: Swansea
country: United Kingdom
facility: Swansea University
state: West Glamorgan
Study officials:
affiliation: Swansea University
name: Hayley Young
role: STUDY_DIRECTOR
References: