Effectiveness and Safety of GLP-1 Receptor Agonists in Patients with Type 1 Diabetes.

: GLP-1 receptor agonists (GLP-1RA) are used in the management of type II diabetes mellitus or obesity, although its role in patients with type I diabetes mellitus (T1DM) has been debated. This study aimed to investigate the efficacy and safety of GLP-1RA in patients with T1DM using real-world data. : This multicenter, retrospective study was conducted at three tertiary medical centers in Riyadh, Saudi Arabia. The study followed up patients (>16 years old) with T1DM treated with insulin followed by GLP-1RA add-on therapy. The efficacy outcomes included changes in HbA1c, body weight, and insulin requirements from baseline to each follow-up visit. The main safety outcomes assessed included hypoglycemic events and gastrointestinal (GI) adverse events. : The study included 144 patients with a mean age of 33.0 ± 10.1 years. Semaglutide was the most used GLP-1RA (63.9%) followed by liraglutide (34.0%). From baseline to 3-month follow-up, HbA1c (mean difference (MD) = -0.8%; = 0.0053), weight (MD = -2.4 kg; = 0.0253), and daily basal insulin dose (MD = -2.1 units; = 0.0349) were significantly reduced. Likewise, HbA1c (MD = -0.5%; = 0.0004), weight (MD = -3.6 kg; < 0.0001), and daily basal insulin (MD = -2.4 units; = 0.0282) were significantly reduced at the 4-6-month follow-up. The significant reductions in HbA1c, weight, and daily basal insulin levels were consistent for up to 18-month follow-up. Only one patient had a major hypoglycemic event, whereas 8.3% of the patients had GI adverse events. : Overall, significant improvements in glycemic control, weight loss, and insulin requirements were observed with the use of GLP-1RA in patients with T1DM, with a limited number of GI adverse events.