Background and aim: Glucagon-like peptide-1 receptor agonists (GLP-1 RA) therapy provides glycemic benefits to individuals with type 2 diabetes (T2D). However, the effects of GLP-1 RA therapy in combination with FreeStyle Libre systems (FSL) are unknown. This study aimed to compare changes in HbA1c between people acquiring GLP-1 with FSL (GLP-1+FSL) vs. GLP-1 without FSL (GLP-1).
Methods: This real-world study utilized Optum's de-identified Market Clarity Data, a linked electronic health records (EHR)-claims database and included adults with T2D and HbA1c ≥8% who acquired their first GLP-1 RA medication between 2018-2022. GLP-1+FSL subjects acquired their first FSL within ±30 days of their first GLP-1 acquisition. Cohorts were matched 1:5 on baseline insulin therapy, age, sex, baseline HbA1c and GLP-1 type. Paired changes in HbA1c were compared between unmatched and matched groups at six months.
Results: The study included 24,724 adults in the unmatched cohort (GLP-1+FSL, n=478; GLP-1, n=24,246). The matched cohort included 478 GLP-1+FSL users and 2,390 GLP-1 users: mean age 53.5±11.8 and 53.5 ±11.3 years, HbA1c 10.25±1.68% and 10.22±1.69%, respectively. HbA1c reduction was greater in the GLP-1+FSL group compared to the GLP-1 group in the unmatched cohort (-2.43% vs. -1.73%, difference 0.70%, p<0.001, respectively) and in the matched cohort (-2.43% vs. -2.06%, difference 0.37%, p<0.001). GLP-1+FSL vs. GLP-1 treatment was associated with greater HbA1c reduction in the intensive insulin (-2.32% vs. -1.50%), non-intensive insulin (-2.50% vs. 1.74%), and noninsulin group (-2.46% vs. -1.78%), as well as in patients using semaglutide (2.73% vs. 1.92%) and dulaglutide (2.45% vs. 1.71%) GLP-1 RA, all p<0.001.
Conclusions: Adults with sub-optimally controlled T2D, initiating GLP-1 RA with FreeStyle Libre, had greater improvement in HbA1c compared to those treated with GLP-1 RA only. These results suggest an additional glycemic benefit of FSL when used with a GLP-1 RA in T2D treatment.