Circadian Rhythm Sleep Disorder, Jet Lag Type
Conditions
Brief summary
The aims of this study are to compare 3 different treatments for circadian adjustment to a laboratory protocol which will mimic westward air travel across 8 time zones. One treatment will involve simply following the new schedule for 3 days. Another treatment will also involve exposure to bright light for 1 hour per day. A third treatment will involve exposure to bright light + exercise for 1 hour per day + consuming a melatonin tablet. Adjustment to the shifted schedule will be assessed by comparing measures of sleep, mood, mental performance, physical performance, and timing of melatonin across the 3 treatment conditions.
Detailed description
Design Overview. Following a 1 week home baseline, N=36 young adults will spend 6 days in the laboratory (Figure 3 and Table 1). Following am 8 h baseline polysomnographic recording (PSG) on Night 1, participants will undergo a 26 h baseline circadian assessment via an ultrashort sleep-wake protocol involving 2 h wake intervals and 1 h sleep intervals, repeated throughout the protocol. Following baseline circadian assessment, participants will be placed on a 16 h wake-8 h sleep schedule in which the wake-sleep and light-dark schedule is delayed 8 h for 3 days (analogous to traveling 8 time zones west). Participants will be randomized to one of 3 treatments (n=12 per treatment) administered each of the 3 days of the shifted schedule: (1) placebo control, (2) bright light, and (3) bright light + exercise + melatonin. PSG recording will occur on the last night of the shifted schedule, followed by an end-of-study 26 h ultrashort sleep wake schedule. On baseline Day 1 and Days 2-3 of the shifted schedule, sleepiness, mood, and mental performance will be assessed every 3 h during wake. During all four 8 h sleep periods, sleep will also be recorded with the Z-machine, which assesses sleep stages from 3 EEG electrodes. During the ultrashort sleep-wake schedules, mental performance, physiological performance, urinary aMT6s, mood, and sleepiness will be measured around-the-clock.
Interventions
BEHAVIORALBright Light
3 consecutive days of 1 hour bright light
BEHAVIORALBright Light + Exercise + Melatonin
3 consecutive days of bright light, exercise, and melatonin
BEHAVIORALControl
3 consecutive days of dim red light + light stretching + placbo
Sponsors
University of California, San Diego
University of Arizona
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Participants are informed that we are exploring different types of stimuli (including exercise, melatonin, and light) to help adjust to simulated jet lag.
Intervention model description
Random assignment to one of three conditions
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
1. age 18-45 years 2. At least moderate level of habitual physical activity (twice per week, 20 min of aerobic exercise at 60% of maximal effort or higher
Exclusion criteria
(1)Having more than one risk factor for coronary artery disease: (2) having any symptom or sign of cardiopulmonary disease; (3) recent shift-work experience (previous 2 months) or travel across multiple time zones (previous 4 weeks); (4) having an abnormal sleep-wake schedule (i.e., reported bedtime before 9:00 pm or after 2:00 am; wake time before 5:00 am or after 10:00 am); (5) being an extreme night owl or morning lark, as assessed by the Horne-Ostberg Mornngness-Eveningness Scale;70 (6) having a high risk sleep apnea or another sleep disorder; (7) depressed mood \[Center for Epidemiologic Studies-Depression Scale (CES-D) \> 16\];71 (7) use of medications likely to distort melatonin excretion or cardiovascular responses to exercise; (8) use of sleeping pills more than 1 night per week; (9) having high sensitivity to light; (10) abuse of alcohol or drugs (amount per week; related problems such as missing work); (11) any physical or mental health condition that would contraindicate participation in exercise or other rigors of the experiment.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change (shift) in the acrophase of urinary 6-sulphatoxymelatonin (aMT6s) excretion | 6.5 days | Change (shift) in the cosine fitted peak for the assessments (every 90 min) during lab days 2-3 compared with the assessments taken during days 6-7 |
| Change (shift) in the acrophase of the rhythm of the median reaction time | 6.5 days | Change (shift) in the cosine fitted peak for the assessments (psychomotor vigilance, every 3 h) taken during days 2-3 compared with the assessments taken during days 6-7 |
| Change in sleep duration | 5 days | Change in total sleep time assessed during night one in the lab and night 5 in the lab duration |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change (shift) in the acrophase of the Total Mood Disturbance composite scale of on the Profile of Mood States questionnaire | 5 days | Change (shift) in the cosine-fitted peak of the rhythm of total mood disturbance assessed during days 2-3 compared with total mood disturbance assessed during days 6-7 |
| Change in sleep recorded with z-machine | 5 days | Z machine recorded sleep with electrodes on the mastoid bones. Change in sleep assessed in eight 1-h sleep intervals on days 2-3 and days 6-7 |
| Change (shift) in the acrophase of the Stanford Sleepiness Scale | 5 days | Change (shift) in the cosine-fitted peak of the rhythm of the Stanford Sleepiness Scale assessed during days 2-3 compared with the Stanford Sleepiness Scale mood disturbance assessed during days 6-7 |
| Change (shift) in the acrophase of the Wingate Anaerobic Performance Test | 5 days | Change (shift) in the cosine-fitted peak of the rhythm of the Wingate Anaerobic Performance Test assessed on days 2-3 and day 6-7. |
Countries
United States
Contacts
Primary ContactShawn Youngstedt, PhD
Backup ContactSalma Patel, MD
Outcome results
None listed