Incretin Hormones in Type 1 Diabetes Mellitus;Effect of Metformin Treatment

Gut-derived Incretin Hormones in the Pathophysiology of Type 1 Diabetes Mellitus; Effect of Metformin Treatment

Investigators aim is to conduct an RCT to study the effect of adjunct metformin treatment to insulin monotherapy in patients with type 1 diabetes, targeting the intestinal incretin secretion. The patients will be randomly allocated to metformin or placebo treatment for 4 months

Compared to the large armamentarium of antidiabetic agents for Type 2 Diabetes Mellitus (T2DM), the insulinocentric therapeutic approach in Type 1 Diabetes Mellitus (T1DM) has distracted the scientific perspective from the rise of novel therapies. Insulin monotherapy has long overshadowed the overall hormonal dysregulation that demarcates T1DM . In specific, the significance of the gut-derived incretin hormones GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic peptide), which are implicated with glucose metabolism via the gut-pancreatic axis, has been merely addressed.

Investigators' goal in the current protocol is to delineate the glucoregulatory role of incretin hormones in T1DM and the therapeutic advantages of adjunct metformin treatment over insulin monotherapy. In the absence of such knowledge, the development of effective strategies to improve metabolic homeostasis and ameliorate complications in T1DM patients will remain problematic. The central hypothesis of the study is that metformin, as an incretin-secretagogue, will enhance postprandial incretin secretion in T1DM patients, which will be reflected in reduced glucagon secretion and improvement in glycemic volatility. Mechanistic insight will be provided through changes in specific amino acids and metabolites patterns, chronic inflammation and the microbiome composition.

Inclusion Criteria:

• Age ≥ 18 years
• T1DM (Diagnosis of diabetes before the age of 35 years and insulin use within 1 year of diagnosis)
• Treatment with multiple daily insulin injections (MDI) or continuous subcutaneous insulin infusion (CSII)

Exclusion Criteria:

• Any cardiovascular disease within the last 3 months
• NYHA stage 3 or 4 heart failure
• Uncontrolled angina
• Liver failure [AST>135 IU/L or ALT>129IU/L (3 x the upper normal limit)] • Kidney failure or GFR<60 ml/min/1.73m2
• Gastrointestinal disease or gastroparesis
• Prior diagnosis of cancer within 2 years
• Other medication that affect glucose metabolism within the last 3 months (metformin, SGLT2, GLP-1 analogues, amylin analogues, systemic glucocorticosteroids)
• Untreated or uncontrolled thyroid disease
• Pregnancy or breastfeeding
• Alcohol consumption > 2-drinks per day or other substance abuse