Dietary Intake of Tryptophan and Metformin Response

This study will examine the influence of dietary intake of tryptophan on response to metformin. The investigators hypothesize that dietary tryptophan alteration will influence metformin response.

Study Overview

• Status: Completed
• Conditions: Fasting Glucose; Metformin Response; Tryptophan Concentration; Metformin Concentration; Diet Tolerability
• Intervention / Treatment: Drug: Metformin; Other: Low tryptophan diet; Other: High tryptophan diet

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 40 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. healthy adult male or non-pregnant female volunteers (age 20-40)
2. able and willing to give consent

Exclusion Criteria:

1. Age less than 20 or greater than 40
2. Women who are pregnant, nursing, or at risk of becoming pregnant
3. Body mass index (BMI) less than 20 or greater than 28
4. Changes of more than 5 pounds in weight (increase or decrease) during the month prior to enrollment in the study
5. Participation in more than 300 minutes of exercise per week during the month prior to enrollment in the study
6. Known diabetes or pre-diabetes (based on prior diagnoses, use of medications to lower glucose; or fasting blood glucose > 100mg/dL at screening)
7. Untreated hypertension (defined as systolic blood pressure > 140mmHg and diastolic blood pressure > 90mmHg)
8. Current or past mood disorder, including major depression, anxiety, or bipolar disorder
9. Conditions causing intestinal malabsorption, including celiac disease or a history of intestinal or gastric bypass surgery
10. History of liver disease and/or aspartate aminotransferase (AST) or alanine aminotransferase (ALT) more than 3 times upper limit of normal (ULN)
11. Estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 as calculated by the Modification of Diet in Renal Disease equation
12. Currently taking or intending to take during the study duration any medication known to affect glycemic parameters, such as glucocorticoids, growth hormone, or fluoroquinolones
13. Use of medications and herbal or vitamin supplements during the study
14. Contraindications to safe use of metformin, including planned radiologic or angiographic study requiring contrast within one week of the study completion
15. Objection to taking metformin
16. Participation in any other interventional study during the study duration
17. Use of nicotine-containing products, including inhaled, chewed, or patches during the study.
18. Use of drugs of abuse.
19. Restrictions that prevent adherence to standardized meals or unwillingness to adhere to a pre-specified meal plan, including abstinence from alcohol and limitation of caffeine intake to one drink daily.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: QUADRUPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Low tryptophan diet; 2 days of a low tryptophan diet	Drug: Metformin; 2 doses of 500 mg metformin given approximately 12 hrs apart; Other: Low tryptophan diet
EXPERIMENTAL: High tryptophan diet; 2 days of a high tryptophan diet	Drug: Metformin; 2 doses of 500 mg metformin given approximately 12 hrs apart; Other: High tryptophan diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
change in fasting glucose	2 days

Secondary Outcome Measures

Outcome Measure	Time Frame
change in tryptophan concentration	2 days

Other Outcome Measures

Outcome Measure	Time Frame
tolerability of dietary tryptophan alteration	2 days

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Investigators: Principal Investigator: Geoffrey Walford, MD, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start: August 1, 2014
• Primary Completion (ACTUAL): March 1, 2016
• Study Completion (ACTUAL): March 1, 2016

Study Registration Dates

• First Submitted: July 3, 2014
• First Submitted That Met QC Criteria: July 8, 2014
• First Posted (ESTIMATE): July 9, 2014

Study Record Updates

• Last Update Posted (ESTIMATE): March 16, 2016
• Last Update Submitted That Met QC Criteria: March 14, 2016
• Last Verified: March 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Hypoglycemic Agents; Physiological Effects of Drugs; Psychotropic Drugs; Antidepressive Agents; Antidepressive Agents, Second-Generation; Metformin; Tryptophan
• Other Study ID Numbers: 2014P001226