Tryptophan Supplementation to Improve Night Shift Workers' Health

March 19, 2021 updated by: Hsin-Jen Chen, National Yang Ming University

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

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Taiwan
      • Taipei, Taiwan, 112
        • National Yang-Ming University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Tryptophan supplement
  • Pure L-tryptophan in capsules (500mg/capsule)
  • 3g tryptophan per day (2 capsules, t.i.d.), at 8AM, 4PM, and 0AM (± 1 hour)
Dietary supplement: Tryptophan supplement
  • Pure L-tryptophan in capsules (500mg/capsule)
  • 3g tryptophan per day (2 capsules, t.i.d.), at 8AM, 4PM, and 0AM (± 1 hour)
Placebo Comparator: Maltose
  • Placebo is maltose powder capsule (500mg/capsule)
  • 3g maltose powder per day (2 capsules, t.i.d.), at 8AM, 4PM, and 0AM (± 1 hour)
Dietary supplement: Maltose
Maltose

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Melatonin level in the morning
Time Frame: 3 weeks
Morning (8AM) saliva melatonin level change in the phase
3 weeks
Melatonin level in the afternoon
Time Frame: 3 weeks
Afternoon (4PM) saliva melatonin level change in the phase
3 weeks
Melatonin level at midnight
Time Frame: 3 weeks
Midnight (0AM) saliva melatonin level change in the phase
3 weeks
Cortisol level in the morning
Time Frame: 3 weeks
Morning (8AM) saliva cortisol level change in the phase
3 weeks
Cortisol level in the afternoon
Time Frame: 3 weeks
Afternoon (4PM) saliva cortisol level change in the phase
3 weeks
Cortisol level at midnight
Time Frame: 3 weeks
Midnight (0AM) saliva cortisol level change in the phase
3 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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
3 weeks
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 weeks
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.
3 weeks
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.
3 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
National Yang Ming University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 23, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 6, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 10, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 22, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 19, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • YM106114F

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

IPD Plan Description

The participants did not provide agreement to the researchers.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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