Glucagon-like peptide-1 receptor agonist therapy effects on glycemic control and weight in a primary care clinic population

Glucagon-like peptide-1 receptor agonist (GLP-1a) medications have been shown in randomized controlled trials (RCTs) to have consistent and impressive effectiveness in lowering hemoglobin A1c (HbA1c) and weight, but limited data exist on the efficacy of GLP-1a medications in clinical practice. We studied the association between GLP-1a therapy and changes in weight and HbA1c in a real-world patient population. In this retrospective cohort study of patients seen in a primary care clinic between 2012 and 2021, we examined the change in weight and HbA1c over 12 months in a cohort of patients with at least one prescription for a GLP-1a. Within this cohort, treatment was defined as having ≥2 GLP-1a prescriptions at a therapeutic dosage separated by ≥10 months. The cohort included 693 patients of whom 393 (57%) were treated with GLP-1a therapy. The treatment group had a mean change in body mass index (BMI) of -0.83 kg/m² (±2.88) compared to -0.70 kg/m² (±2.99) in the without GLP-1a group (p = 0.57). Treated patients had a mean change in HbA1c of -1.00% (±2.07) compared to -0.83% (±1.92) in the without GLP-1a group (p = 0.27). For treated and without GLP-1a patients, respectively, the proportion of patients with a decrease in BMI was 65 versus 64% (p = 0.86), and the proportion with a decrease in HbA1c was 73 versus 69% (p = 0.28). In clinical practice, GLP-1a therapy was associated with more modest reductions in weight and HbA1c than shown in prior RCTs. As GLP-1a use continues to expand throughout primary care, the real-world impact of this pharmacotherapy will require further evaluation.