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Diabetes Mellitus, Type 1NCT02772783

Dietary Glycemic Index, Brain Function and Food Intake in Patients With Type 1 Diabetes Mellitus

A study testing high GI meal, low GI meal and euglycemic insulin clamp in people with Diabetes Mellitus, Type 1, run by Boston Children's Hospital at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Processed carbohydrates cause rapid changes in blood sugar and have been associated with overeating and obesity. We have shown that test meals high in processed carbohydrate affect brain areas involved in addiction, craving and overeating. Read more about this study

Who is it for?
Ages 18 to 45 years, men only
Conditions the study is for
Diabetes Mellitus, Type 1
What is being tested?
high GI meal, low GI meal and euglycemic insulin clamp
Could I receive a placebo?
No, everyone receives an active treatment
How many people
15 participants
Where
1 siteUnited States
Study dates
Jul 2016to May 2018
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • Men only
  • No healthy volunteers
  • Adult

Who may be able to join

  • Type 1 diabetes for a minimum of 3 years
  • BMI 20-35 kg/m2
  • Use of insulin pump
  • Willing and able to: Maintain weight and document for duration of the study

Who cannot join

  • Insulin resistance (current insulin requirement > 1.5 U/kg/d)
  • Insulin requirement < 0.5 unit/kg/day (cut-off for preserved beta-cell function)
  • HbA1C ≥ 8.0%
  • DKA within 2 months
  • Frequent hypoglycemia (BG <50 mg/dl), > 3 times per week
  • Fluctuations in body weight >10% over preceding year
Show all 13Show fewer
  • Smoking or illicit substance abuse
  • High levels of physical activity (≥60 minutes per day, ≥ 4 days per week)
  • Current weight loss diet
  • Medical problems, medications or dietary supplements that may affect metabolism, insulin action, body weight, appetite, energy expenditure, or gastrointestinal absorption (e.g. celiac disease)
  • Allergies to compounds or intolerance of the liquid meals
  • MRI exclusion criteria
  • Other conditions according to self-report that would prohibit participation based and researcher assessment

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Beth Israel Deaconess Medical Center

    Boston, Massachusetts, 02115

Other trials in United States

About this study

Processed carbohydrates cause rapid changes in blood sugar and have been associated with overeating and obesity. We have shown that test meals high in processed carbohydrate affect brain areas involved in addiction, craving and overeating. It is unknown whether the changes in blood sugar or the associated higher insulin levels mediate this brain activation and its likely adverse effects.

Answering this question is important for patients with type 1 diabetes who have elevated risks of obesity and disordered eating: If blood sugar is the causal mechanism, optimal insulin coverage should be protective. If insulin is the causal mechanism, however, a diet high in processed carbohydrate could predispose to overeating and weight gain, as this diet requires higher insulin doses.

To disentangle these factors, we will study brain activation and relevant blood markers in 15 men with diabetes. In 4 sessions, we will examine meals with differential carbohydrate properties while giving insulin infusions.

Read the detailed description

A total of 15 male participants (age 18-45) with T1DM will be recruited. Participants will be enrolled in the study for a total of 1-3 months, and participate in a pre-test visit and three test visits, each after a 10-12-hr overnight fast. Participants will be instructed to consume their regular, weight maintaining diet between visits.

At the pre-test visit, the study director or PI will meet participants, confirm eligibility and obtain informed consent. Participants will receive a low glycemic index (GI) meal with optimal iv insulin coverage using a negative feedback algorithm to maintain euglycemia (euglycemic clamp). Insulin requirement will be quantified. At some time during the visit, participants will present to the BIDMC research imaging facility for a practice MRI session, during which they will undergo a brief imaging sequence to get accustomed to the scanning process and eliminate anxiety as a confounder of imaging data.

At each of 3 test visits, one of the following experimental conditions will be applied in a randomized, blinded cross-over design: (a) high GI meal with euglycemic clamp, (b) low GI meal with euglycemic clamp, (c) high GI meal with primed-variable insulin infusion at the rate established during the pre-test visit. After steady state is established, baseline laboratory evaluation and MRI imaging will be obtained, followed by the test meal. Imaging will be repeated at 1 and 4 hours postprandial. Blood samples for pertinent metabolic and hormonal parameters will be obtained every 30 minutes. Each test-visit concludes with a standard weighed meal to quantify ad-libitum intake.

Being tested
high GI meal, low GI meal, euglycemic insulin clamp, primed-variable insulin infusion
Keywords
brain, fMRI, carbohydrate, insulin clamp, intake regulation, overweight, glycemic index
Medical subject headings
Diabetes Mellitus, Type 1, Overweight

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • high GI mealOther

    High and low GI liquid test meals are matched for macronutrient composition (60% carbohydrate, 15% protein, 25% fat), micronutrient profiles, physical properties, palatability and sweetness. Meals will provide 25% of individual daily energy requirements as estimated by the Harris Benedict equation. A high glycemic index of ~90 is achieved by using corn syrup as a carbohydrate source.

  • low GI mealOther

    High and low GI liquid test meals are matched for macronutrient composition (60% carbohydrate, 15% protein, 25% fat), micronutrient profiles, physical properties, palatability and sweetness. Meals will provide 25% of individual daily energy requirements as estimated by the Harris Benedict equation. A low glycemic index of ~40 is achieved by using uncooked corn starch as a carbohydrate source.

  • euglycemic insulin clampDrug

    Insulin will be given intravenously for 5 hours. During the entire clamp protocol, glucose levels will be measured every 5 minutes. A basal insulin infusion will be started at 80% of the patients insulin pump basal rate, and will be adjusted between 0.1 and 2.5 mU/kg•min, depending upon the patient's plasma glucose level in relation to the target range target of 90-100 mg/dl.

  • primed-variable insulin infusionDrug

    A primed-variable infusion of insulin will be administered at the rate established to achieve euglycemia after a low glycemic index meal. This is expected to result in moderate hyperglycemia as the high GI meal is associated with higher insulin requirements. For patient safety, glucose levels will be measured every 30 minutes. If glucose levels are > 400 mg/dl or < 60 mg/dl, insulin infusion will be adjusted to maintain glucose levels target of 60-400 mg/dl.

Study groups in NCT02772783
Study groupRoleWhat they receive
high GI meal, euglycemic insulin clampExperimentalA nutritional shake with high GI will be consumed. Regular insulin will be administered intravenously according to a negative feedback algorithm to maintain euglycemia.This condition results in euglycemia with high insulin levels.
Receives: Other: high GI meal; Drug: euglycemic insulin clamp
high GI meal, fixed insulin infusionExperimentalA nutritional shake with high GI will be consumed. Regular insulin will be administered intravenously at a rate previously established to maintain euglycemia after a low glycemic index meal. This condition results in moderate hyperglycemia with low insulin levels.
Receives: Other: high GI meal; Drug: primed-variable insulin infusion
low GI meal, euglycemic insulin clampActive comparatorA nutritional shake with low GI will be consumed. Regular insulin will be administered intravenously according to a negative feedback algorithm to maintain euglycemia. This condition results in euglycemia with low insulin levels.
Receives: Other: low GI meal; Drug: euglycemic insulin clamp

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Nucleus Accumbens Blood Flow

    Cerebral blood flow in the right and left nucleus accumbent was measured by arterial spin labeling (MRI). Blood flow was normalized for whole brain perfusion and corrected for baseline perfusion in the respective brain area and meal order, as per our a priori statistical analysis plan.

    Measured: 4 hrs postprandial

Secondary outcomes (5)
  1. Nucleus Accumbens Blood Flow

    Cerebral blood flow in the right and left nucleus accumbent was measured by arterial spin labeling (MRI). Blood flow was normalized for whole brain perfusion and corrected for baseline perfusion in the respective brain area and meal order, as per our a priori statistical analysis plan.

    Measured: 1 hr postprandial

  2. Blood Flow in Other Brain Areas Involved in Intake Regulation - Dorsal Caudate

    Cerebral blood flow was measured by arterial spin labeling (MRI). Grouped MRI data was visually inspected for postprandial differences between conditions. Blood flow from a cluster contracting the conditions in the right dorsal caudate, just lateral to the nucleus accumbent, was extracted, normalized for whole brain perfusion and corrected for baseline perfusion in the respective brain area and meal order, as per our a priori statistical analysis plan.

    Measured: 4 hrs postprandial

  3. Blood Flow in Other Brain Areas Involved in Intake Regulation - Ventrolateral Striatum

    Cerebral blood flow was measured by arterial spin labeling (MRI). Grouped MRI data was visually inspected for postprandial differences between conditions. Blood flow from a cluster contracting the conditions in the right ventrolateral striatum, just lateral to the nucleus accumbent, was extracted, normalized for whole brain perfusion and corrected for baseline perfusion in the respective brain area and meal order, as per our a priori statistical analysis plan.

    Measured: 1 hr postprandial

  4. Functional Connectivity of Nucleus Accumbens, Hypothalamus and Other Brain Areas Involved in Intake Regulation

    Cerebral blood oxygen concentration level was measured by resting state functional MRI (rs-fMRI). Seed based analysis was performed with the seed on the right Nucleus Accumbens. Functional connectivity between Nucleus Accumbens and Hypothalamus was assessed through extraction of temporal correlation measures.

    Measured: 4 hrs postprandial

  5. Functional Connectivity of Nucleus Accumbens, Hypothalamus and Other Brain Areas Involved in Intake Regulation

    Cerebral blood oxygen concentration level was measured by resting state functional MRI (rs-fMRI). Seed based analysis was performed with the seed on the right Nucleus Accumbens. Functional connectivity between Nucleus Accumbens and Hypothalamus was assessed through extraction of temporal correlation measures. Functional connectivity between Nucleus Accumbens and other brain areas was visually assessed.

    Measured: 1 hr postprandial

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 May 2016 (estimated)
  2. Study startJul 2016
  3. Primary completionMay 2018
  4. Study completionMay 2018

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
15 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02772783
Sponsor's protocol ID
IRB-P00022176
Other IDs
IRB- 2016P000079
Status last verified
May 2021
First submitted
11 May 2016
Last updated
18 Jun 2021
Data monitoring committee
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing high GI meal, low GI meal and euglycemic insulin clamp in people with Diabetes Mellitus, Type 1, run by Boston Children's Hospital at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 18 Jun 2021. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 18 Jun 2021). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Nucleus Accumbens Blood Flow (time frame: 4 hrs postprandial). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jun 2021.

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