Closed-loop Control of Postprandial Glucose Levels After Meals With Different Macronutrients Content in Adults With Type 1 Diabetes

An Open-label, Randomized, Four-way, Cross-over Study to Examine the Efficacy of Single-hormone Closed-loop System in Regulating Glucose Levels in Adults With Type 1 Diabetes Following Meals of Various Macronutrient Contents: a Pilot Study

Carbohydrates are the main determinant of post-meal glucose excursion. However, fat and protein have been shown to also impact the postprandial glucose control, adding to the complexity of meal insulin calculation. Few studies have looked at the effect of macronutrients other than carbohydrates on postprandial glucose excursions with the closed-loop strategy. The objective of this study is to test whether the single-hormone closed-loop strategy can achieve similar post-meal glucose control with meals with a fixed carbohydrate content, but high in protein and/or fat when compared to a meal with a fixed carbohydrate content only.

Inclusion Criteria:

1. Males and females ≥ 18 years old.
2. Clinical diagnosis of type 1 diabetes for at least one year.
3. The subject will have been on insulin pump therapy for at least 3 months and currently using fast-acting insulin analog (Lispro, Aspart or Guilisine).
4. Last (less than 3 months) HbA1c ≤ 10%.

Exclusion Criteria:

1. Clinically significant microvascular complications: nephropathy (estimated glomerular filtration rate below 40 ml/min), neuropathy (especially diagnosed gastroparesis) or severe proliferative retinopathy as judged by the investigator.
2. Recent (< 3 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery.
3. Ongoing pregnancy.
4. Severe hypoglycemic episode within 1 month of screening.
5. Agents affecting gastric emptying (Motilium®, Prandase®, all GLP-1 analogs) as well as oral anti-diabetic agents (Metformin, SGLT-2 inhibitors and DPP-4 inhibitors) if not at a stable dose for 3 months. Otherwise, these medications are acceptable and will be kept stable during the entire protocol.
6. Oral steroids unless patients present a low stable dose (e.g. 10 mg or less of prednisone per day or physiological doses, less than 35 mg/day, of hydrocortisone Cortef®). Inhaled steroids at stable dose in the last month are acceptable.
7. Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator (e.g. unstable psychiatric condition).
8. Failure to comply with team's recommendations (e.g. not willing to change pump parameters, follow algorithm's suggestions, etc).