Trends in first-line glucose-lowering medication use among US adults with type 2 diabetes from 2019 to 2023.

Background: The introduction of newer classes of glucose-lowering therapies has dramatically altered the diabetes therapeutic landscape. However, little is known about trends in the use of first-line glucose-lowering therapies over time.

Objective: To describe trends in the use of first-line glucose-lowering therapies from 2019 to 2023 among patients with type 2 diabetes (T2D) and changes over time in the demographic and clinical characteristics of patients initiating these therapies.

Methods: This retrospective study identified patients aged 18 years and older from the Komodo Healthcare Map database who filled any glucose-lowering medication between January 2019 and May 2023. The prevalence of first-line glucose-lowering therapy use among patients with T2D was calculated in each month. Pearson χ² and Kruskal-Wallis rank sum tests were used to compare patients' demographic and clinical characteristics such as cardiovascular disease, heart failure, or chronic kidney disease by type of first-line glucose-lowering medication.

Results: The study cohort of 964,914 patients was predominantly made up of female patients (68%) and had a mean age of 54 (SD = 13). The majority of patients initiated metformin before 2022 (74%-83%), followed by insulin (6%-11%), sulfonylureas (3%-7%), glucagon-like peptide 1 receptor agonists (GLP-1RAs) (2%-5%), sodium-glucose cotransporter 2 inhibitor (SGLT2is) (1%-4%), and dipeptidyl peptidase-4 inhibitors (1%-3%). From January 2022 to May 2023, first-line use of GLP-1RAs and SGLT2is increased from 6% and 4% to 18% and 7%, respectively. In contrast, first-line use of metformin, sulfonylureas, and dipeptidyl peptidase-4 inhibitors declined from 76%, 4%, and 2% to 64%, 2%, and 1% over the same period, respectively. Relative to 2019-2021, first-line GLP-1RA users in 2022-2023 were likely to be younger, female, and covered by Medicaid and to have fewer comorbidities as determined by the Charlson Comorbidity Index. In contrast, first-line SGLT2i users were more likely to be older and to have more comorbidities over the same period.

Conclusions: This study shows a significant shift in the use of first-line glucose-lowering therapies from metformin to GLP-1RAs and SGLT2is. The proportion of first-line GLP-1RA and SGLT2i users with cardiovascular disease, heart failure, or chronic kidney disease has increased significantly over time, aligning with guidelines from the American Diabetes Association. Further studies are merited to evaluate the cost-benefit implications of this shift in first-line glucose-lowering use.