Glutathione Metabolism in Adolescents With Type 1 Diabetes - Study A

Not Applicable

Completed

• Conditions: Diabetes Mellitus, Type 1
• Interventions: Other: Cysteine isotope infusion at normoglycemia vs hyperglycemia; Drug: Regular Insulin

• Registration Number: NCT00858897
• Lead Sponsor: Nemours Children's Clinic

Brief Summary

Glutathione is normally present at high (millimolar) levels in blood and plays an important role in the body's defense against oxidative stress, that is, against the damage caused to the body by reactive oxygen species produced by the metabolism of most nutrients, including glucose. Glutathione is a small peptide made from 3 amino acids, glutamate, cysteine, and glycine.

This study is looking at how blood sugar levels may affect the way glutathione is made and used by the body. Since glutathione is continuously synthesized and broken down, the amount of glutathione present in blood depends on the balance between its rate of synthesis and its rate of use.

In earlier studies, the investigators found that in poorly controlled diabetic teenagers, glutathione was low, not because its production was decreased, but because it was used at an excessive rate. In this study, the investigators want to determine how short-term changes in blood sugar levels affect glutathione levels. This will help improve our understanding of how diabetes affects metabolism.

Detailed Description

Adolescents with uncomplicated T1D will receive two, 5-hour infusions of deuterium-labeled cysteine on 2 separate days, a few weeks apart, while blood glucose will be maintained, using intravenous insulin infusion:

* in the hyper-glycemic range (200-250 mg/dL) on one study day, and

* near normoglycemia (80-140 mg/dL) on the other study day.

The order of the study days will be randomized.

We will determine whether the level of blood glucose at the time of study affects blood glutathione concentration, and, if so, whether this is associated with changes in the fractional rate of glutathione synthesis, as determined from the incorporation of labeled cysteine into blood glutathione over the course of the 5-hr infusion of labeled cysteine.

Study Timeline

• Study Start: 2007-06
• Primary Completion: 2008-02
• Study Completion: 2009-02
• Study First Submitted: 2009-03-06
• Study First Submitted QC: 2009-03-09
• Study First Posted: 2009-03-10
• Results First Submitted: 2023-04-21
• Status Verified: 2023-06
• Results First Submitted QC: 2023-06-17
• Last Update Submitted: 2023-06-17
• Results First Posted: 2023-07-10
• Last Update Posted: 2023-07-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 10

Inclusion Criteria

• Type 1 diabetes, using usual criteria such as: glycosuria, hyperglycemia prior to treatment
• BMI <25 kg/m2
• Age 14-18
• HbA1c>7.5%
• No evidence of diabetic complications
• Written informed consent from parents or legal guardian, and assent from patient

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Exclusion Criteria

• Presence of significant anemia (hemoglobin <11g/dL)
• Presence of intercurrent illness such as infection
• Presence of chronic disease such as other endocrine deficiency, chronic respiratory or cardiac disease
• Chronic use of medication other than insulin
• Use of vitamin or mineral supplements within 2 weeks of study

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Normoglycemia	Regular Insulin	80-140 mg/dL
Hyperglycemia	Cysteine isotope infusion at normoglycemia vs hyperglycemia	200-250 mg/dL
Normoglycemia	Cysteine isotope infusion at normoglycemia vs hyperglycemia	80-140 mg/dL
Hyperglycemia	Regular Insulin	200-250 mg/dL

Primary Outcome Measures

Name	Time	Method
Glutathione Concentration	Up to 30 minutes post- 5 hour infusion on Day 1 (First Intervention) and up to 30 minutes post- 5 hour infusion on Day 14 (Second Intervention)	umol/L

Trial Locations

Locations (1)

Nemours Children's Clinic; 🇺🇸 Jacksonville, Florida, United States