NCT04658134

Brief Summary

This study aims to evaluate the effects of oral glycine supplementation on plasma glycine concentration, intracellular glutathione (GSH) concentration, plasma acylglycine concentration, urine acylglycine concentration, and insulin resistance in subjects with morbid obesity. This is an open-labelled trial. 20 adults with morbid obesity will be recruited. Following screening and baseline metabolic evaluations, eligible subjects will be given oral glycine supplements for 14 ± 5 days. Upon completing glycine supplementation, subjects will return for their post-supplement metabolic assessment. The investigators hypothesize that oral glycine supplementation in morbidly obese patients normalizes plasma glycine concentration, increases intracellular GSH concentration, increases plasma and urinary acylglycine concentration, and improves insulin resistance.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
20

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Jan 2021

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

December 1, 2020

Completed
7 days until next milestone

First Posted

Study publicly available on registry

December 8, 2020

Completed
1 month until next milestone

Study Start

First participant enrolled

January 20, 2021

Completed
11 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 15, 2021

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 15, 2021

Completed
Last Updated

March 17, 2021

Status Verified

March 1, 2021

Enrollment Period

11 months

First QC Date

December 1, 2020

Last Update Submit

March 16, 2021

Conditions

Morbid ObesityGlycine; Metabolic Disorder

Keywords

Morbid obesityInsulin ResistanceGlycine metabolism

Outcome Measures

Primary Outcomes (4)

  • Amino acid concentration

    Post-treatment changes amino acid concentration in plasma and red blood cell

    14 days

  • Acylglycine concentration

    Post-treatment changes acylglycine concentration in plasma and urine

    14 days

  • Acylcarnitine concentration

    Post-treatment changes acylcarnitine concentration in plasma and urine

    14 days

  • Glutathione concentration

    Post-treatment changes in glutathione concentration in plasma and red blood cell

    14 days

Secondary Outcomes (1)

  • Insulin resistance index

    14 days

Study Arms (1)

Glycine supplementation

EXPERIMENTAL

Glycine supplementation

Dietary Supplement: Glycine

Interventions

GlycineDIETARY_SUPPLEMENT

Oral glycine tablets (100 mg/kg/day) in divided doses

Glycine supplementation

Eligibility Criteria

Age21 Years - 65 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Age: 21-65 years
  • BMI ≥ 32.5 kg/m2
  • Able to provide informed consent
  • Able to maintain present diet throughout the study duration

You may not qualify if:

  • Weight \> 150 kg
  • Type 2 Diabetes Mellitus
  • Allergy to soy
  • Ongoing treatment with weight-loss medications (e.g. orlistat, phentermine, liraglutide)
  • Systemic steroid usage (eg. prednisolone, hydrocortisone, cortisone, dexamethasone)
  • Renal impairment (estimated creatinine clearance estimated by Cockcroft-Gault Equation \< 60 ml/min)
  • Haemoglobin concentration \< 10 g/L
  • Serum alanine aminotransferase or aspartate aminotransferase above 2x upper limit of normal
  • Uncontrolled hypertension (BP \> 180/110 mmHg)
  • Pregnancy
  • Nursing mothers
  • Uncontrolled thyroid disease
  • Surgery requiring general anaesthesia within 4-weeks before enrolment
  • Psychiatric disorders requiring medication
  • Significant alcohol intake (\> 1 unit per day for women and \> 2 units per day for men)
  • +2 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Singapore General Hospital

Singapore, 169856, Singapore

RECRUITING

Related Publications (1)

  • Tan HC, Hsu JW, Tai ES, Chacko S, Wu V, Yen PM, Kovalik JP, Jahoor F. Metabolic impact of dietary glycine supplementation in individuals with severe obesity. Sci Rep. 2025 Oct 17;15(1):36433. doi: 10.1038/s41598-025-20511-x.

    PMID: 41107432DERIVED

MeSH Terms

Conditions

Obesity, MorbidMetabolic DiseasesInsulin Resistance

Interventions

Glycine

Condition Hierarchy (Ancestors)

ObesityOverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and SymptomsHyperinsulinismGlucose Metabolism Disorders

Intervention Hierarchy (Ancestors)

Amino AcidsAmino Acids, Peptides, and Proteins

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
OTHER
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 1, 2020

First Posted

December 8, 2020

Study Start

January 20, 2021

Primary Completion

December 15, 2021

Study Completion

December 15, 2021

Last Updated

March 17, 2021

Record last verified: 2021-03

Locations

SG(1)