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Completed

NCT Number: NCT04505800

Tryptophan Supplementation to Improve Night Shift Workers' Health

This randomized cross-over double-blinded trial aims to investigate the health effect of oral l-tryptophan supplementation on workers who rotate night shift work, and to examine the influences of different frequencies and timings of supplementation on the health effects.

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Key information

Conditions

Sleep Behavior Behavioral Symptoms Burnout Burnout, Psychological Cortisol Deficiency Melatonin Deficiency Mood Stress, Psychological

Age range

20 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

National Yang-Ming University

Taipei, 112, Taiwan

About this study

This study aims to investigate the health effect of oral l-tryptophan supplementation on workers who rotate night shift work, and to examine the influences of different frequencies and timings of supplementation on the health effects. Night shift work affects melatonin and cortisol variation, insomnia, mood issues, and metabolic syndrome. Short-term tryptophan supplementation was shown to improve melatonin, sleep quality, and cortisol response to acute stress. Little is known whether a longer term of longer-term tryptophan supplementation would alleviate the health impacts of night shift work. Nevertheless, melatonin and cortisol have their normal circadian patterns. Nothing is known about what temporal structure of tryptophan supplement would maximize its health effects on night shift workers melatonin and cortisol levels. We will conduct a double-blind cross-over randomized controlled trial to examine the benefits of oral tryptophan administration (3g/day, t.i.d.) on night shift workers' health outcomes: melatonin and cortisol levels, sleep quality, moods and work performance. We expect to reveal the health effect of tryptophan supplementation in night shift workers by using sophisticated study design.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age: adults >=20 y/o
  • Adults who had night shift schedule >1 month before enrollment, and will have similar night shift schedule in the following 2 months. (Eligible night shift schedule: >1 day of evening or night shift in a week)
  • People who will not have plans to travel to another time zone in the following 2-3 months
  • People who will plan to stay in the same job position for the following 3 months
  • People who have no experience in taking tryptophan or melatonin supplement in the past month
  • Body weight >= 50kg and <=80kg
  • Non-pregnant, non-breastfeeding, not taking contraceptives
  • Not under treatment of steroids, not taking sleeping pills

Exclusion criteria

  • diagnosis of renal or liver diseases
  • diagnosis of Cushing's Disease, Addison's disease
  • psychiatric diagnosis, such as depression and anxiety disorders
  • neurological diseases such as dementia, epilepsy, Parkinson's disease

Treatment and study plan

Tryptophan supplement

Dietary Supplement
  • Pure L-tryptophan in capsules (500mg/capsule)
  • 3g tryptophan per day (2 capsules, t.i.d.), at 8AM, 4PM, and 0AM (± 1 hour)

Maltose

Dietary Supplement

Maltose

Primary outcomes

  1. Melatonin level in the morning

    Time frame: 3 weeks

    Morning (8AM) saliva melatonin level change in the phase

  2. Melatonin level in the afternoon

    Time frame: 3 weeks

    Afternoon (4PM) saliva melatonin level change in the phase

  3. Melatonin level at midnight

    Time frame: 3 weeks

    Midnight (0AM) saliva melatonin level change in the phase

  4. Cortisol level in the morning

    Time frame: 3 weeks

    Morning (8AM) saliva cortisol level change in the phase

  5. Cortisol level in the afternoon

    Time frame: 3 weeks

    Afternoon (4PM) saliva cortisol level change in the phase

  6. Cortisol level at midnight

    Time frame: 3 weeks

    Midnight (0AM) saliva cortisol level change in the phase

Secondary outcomes

  1. Sleep quality

    Time frame: 3 weeks

    Pittsburg Sleep Quality Score (range: 0-21) at the end of the phase. The higher score indicates worse sleep quality

  2. Mood states, depression

    Time frame: 3 weeks

    Depression, Anxiety, Stress Scales. Depression score (range 0-42) changes in the phase. The higher score, the more depressed.

  3. Mood states, anxiety

    Time frame: 3 weeks

    Depression, Anxiety, Stress Scales. Anxiety score (range 0-42) changes in the phase. The higher score, the more anxious.

  4. Mood states, stress

    Time frame: 3 weeks

    Depression, Anxiety, Stress Scales. Stress score (range 0-42) changes in the phase. The higher score, the more stressful.

Sponsors and collaborators

Lead sponsor

National Yang Ming Chiao Tung University

Other

Registry information

Official study title

Chrononutrition of Using L-tryptophan Supplementation to Alleviate the Impacts of Night Shift Rotation on Circadian Hormones and Health Outcomes

Important dates

Study start
2019
Primary completion
2020
Study completion
2020
First posted
Aug 10, 2020
Registry last updated
Mar 22, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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