Liraglutide in Adolescents With Type 1 Diabetes

Type 1 diabetes (T1DM) affects approximately 1:500 children and represents the major form of diabetes in the pediatric population (1). Diagnosis of T1DM is based on symptoms consistent with hyperglycemia (polyuria, polydipsia, and weight loss) and elevated blood sugars. Diagnosis of T1DM is confirmed by measuring serum autoantibodies against insulin and other beta-cell proteins. Subcutaneous insulin is the mainstay of diabetes care; however, ability to achieve optimal glycemic control is impacted by multiple factors including diet, exercise, and psychosocial barriers. The Diabetes Control and Complications Trial and follow-up EDIC trial were landmark studies demonstrating that improving glycemic control significantly reduces the risk of both micro and macro-vascular disease (2). While technologic advances in blood sugar monitoring, insulin analogs and insulin delivery devices have been made, it is estimated that less than 40% of individuals meet recommended glycemic standards as set forth by the American Diabetes Association; these estimates may be lower in the pediatric population. Thus, adjuvant pharmacologic therapies that improve glycemic control are being tested in patients with T1DM. Incretin hormones are a class of intestinal peptides that are released in response to nutrient intake (3). The best described incretin hormones are glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). These hormones act at the level of direct stimulation of pancreatic β-cell function and through extra-pancreatic mechanisms. They primarily potentiate glucose-dependent insulin secretion from the β-cell; other β-cell effects include increasing insulin biosynthesis, stimulating β-cell replication, and preventing apoptosis. Secondary effects of incretin hormones include suppression of glucagon secretion, inhibition of gastric emptying, and potentiation of hepatic glucose uptake (3). Currently, there are two GLP-1 analogs approved by the Food and Drug Adminstration as adjuvant treatment of Type 2 diabetes mellitus in adults (\> 18 years) who fail to reach glycemic targets with metformin and/or oral hypoglycemic agents. The two drugs - exenatide (BID) and liraglutide (QD) are administered subcutaneously. They have been demonstrated to improve glycemic control in this population and, in some individuals, lead to sustained weight loss. This study aims to determine whether acute exposure to liraglutide decreases the mean weekly blood glucose levels in adolescents with T1DM. In addition, we will determine whether liraglutide decreases glucose excursions following a meal challenge. The overall hypothesis to be tested is that short-term exposure (7 days) to liraglutide improves glycemic control in adolescents/young adults with T1DM treated with continuous subcutaneous insulin infusion.