Dietary Glycemic Index, Brain Function and Food Intake in Patients With Type 1 Diabetes Mellitus
| Status: | Completed |
|---|---|
| Conditions: | Diabetes, Diabetes |
| Therapuetic Areas: | Endocrinology |
| Healthy: | No |
| Age Range: | 18 - 45 |
| Updated: | 5/10/2018 |
| Start Date: | July 2016 |
| End Date: | May 2018 |
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.
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.
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.
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.
Inclusion Criteria:
- 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
Exclusion Criteria:
- 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
- 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
We found this trial at
1
site
330 Brookline Ave
Boston, Massachusetts 02215
Boston, Massachusetts 02215
617-667-7000
Phone: 857-218-3896
Beth Israel Deaconess Medical Center Beth Israel Deaconess Medical Center (BIDMC) is one of the...
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