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Completed

NCT Number: NCT02642640

Interaction of Melatonin and MTNR1B Genotype on Glucose Control - Study 1

This project aims to test the impact of melatonin and MTNR1B variation on regulation glucose regulation in a highly controlled in-laboratory setting and ex vivo in pancreatic islets.

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Key information

Conditions

Glucose Circadian Rhythm Genes Melatonin

Age range

21 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Brigham and Women's Hospital

Boston, Massachusetts, 02115, United States

About this study

The investigators' recent GWAS discovery of MTNR1B as a novel type 2 diabetes gene has sparked great interest into the role of melatonin in glycemic control, for which the mechanism is largely unknown. This research will determine the effect of melatonin and MTNR1B on glycemic control under highly-controlled, in-laboratory protocols while manipulating circulating melatonin concentrations (both up and down) and assessing glycemic control by frequently-sampled intravenous glucose tolerance tests, as well as in ex vivo human pancreatic islets. This research will provide mechanistic insights into the metabolic effects of melatonin and the MTNR1B risk variant and may help in evidence-based approaches and personalized recommendations to improve glycemic control in night shift workers and late-night eaters.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Body Mass Index: 20 and 35 kg/m2
  • Age: 21-55 years of age
  • Caucasian
  • Non-smoking
  • With regular sleep-wake cycle
  • Passed medical and psychological screening tests

Exclusion criteria

  • Acute, chronic or debilitating medical conditions
  • History of neurological or psychiatric disorder
  • History of sleep disorder or regular use of sleep-promoting medication
  • Current prescription, herbal, or over-the-counter medication use
  • Traveling across 2 or more time zones within past 3 months
  • Worked night or rotating shift work within past 1 year
  • Drug or alcohol dependency

Treatment and study plan

melatonin

Dietary Supplement

5 mg of melatonin per os.

Placebo

Drug

Primary outcomes

  1. Disposition Index

    Time frame: During frequently sampled intravenous glucose tolerance test after melatonin/placebo administration on Day 2/4 (melatonin/placebo order randomized) in the laboratory visit

    Disposition index is determined by frequently sampled intravenous glucose tolerance test. It is a composite measure of β-cell function adjusted for insulin sensitivity-was calculated as the product of insulin sensitivity and insulin secretion indices. High value means stronger β-cell function. Theoretical minimum is 0, no theoretical maximum.

Secondary outcomes

  1. First-phase Beta-cell Responsivity

    Time frame: During frequently sampled intravenous glucose tolerance test after melatonin/placebo administration on Day 2/4 (melatonin/placebo order randomized) in the laboratory visit

    First-phase beta-cell responsivity to glucose is determined by frequently sampled intravenous glucose tolerance test. It likely represents exocytosis of previously primed and docked insulin secretory granules (commonly called the readily releasable pool). It is given by the ratio between the incremental amount of C-peptide secreted during the first phase and the maximum increment of the plasma glucose concentration.High value means stronger β-cell responsivity. Theoretical minimum is 0, no theoretical maximum.

  2. Insulin Sensitivity

    Time frame: During frequently sampled intravenous glucose tolerance test after melatonin/placebo administration on Day 2/4 (melatonin/placebo order randomized) in the laboratory visit

    Insulin sensitivity is determined by frequently sampled intravenous glucose tolerance test. It is defined in quantitative terms as the effect of insulin to catalyse the disappearance of glucose from plasma.High value indicates better insulin sensitivity. Theoretical minimum is 0, no theoretical maximum.

  3. Glucose Tolerance

    Time frame: During frequently sampled intravenous glucose tolerance test after melatonin/placebo administration on Day 2/4 (melatonin/placebo order randomized) in the laboratory visit

    glucose 3-hour incremental AUC during frequently sampled intravenous glucose tolerance test. High value indicates higher glucose level during the test, which is bad. Theoretical minimum is 0, no theoretical maximum.

Sponsors and collaborators

Lead sponsor

Brigham and Women's Hospital

Other

Collaborators

  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Registry information

Important dates

Study start
2016
Primary completion
2022
Study completion
2022
First posted
Dec 30, 2015
Registry last updated
Feb 12, 2026

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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