Real-World Harm Reduction of Metformin Plus DPP4 Inhibitors versus Metformin Plus Sulfonylureas in Older Adults: A Target Trial Emulation Using German Claims Data.

Objective: This study complements evidence from randomized controlled trials on the harms (e.g., hypoglycemia) of sulfonylureas compared with dipeptidyl peptidase-4 inhibitors (DPP4i) in the treatment of type 2 diabetes in older adults using real-world data. Existing evidence suggests an increased risk of hypoglycemia, falls, fractures, and cardiovascular events.

Methods: Using target trial emulation, we analyzed a retrospective cohort drawn from German routine claims data. We included patients older than 65 years who initiated DPP4i (sitagliptin, vildagliptin, or saxagliptin) or sulfonylureas (glibenclamid or glimepirid) as add on to metformin between 2011 and 2018. Confounding was adjusted for through overlap weighting, and the average treatment effects were estimated in the overlap population using generalized linear models.

Results: Among 171,318 eligible patients, 111,865 (65%) received DPP4i and 59,453 (35%) sulfonylureas. Patients treated with DPP4i had a higher prevalence of all observed comorbidities. Applying overlap weights to adjust for confounding, patients treated with DPP4i had a higher rate of combined all-cause hospitalizations and outpatient visits compared with those treated with sulfonylureas (rate ratio = 1.03, 95% CI 1.02-1.03) in the total population. In contrast, we found a protective effect of DPP4i on the risk for severe hypoglycemia in the subgroups of new users (ratio rate (RR) = 0.51, 95% CI 0.33, 0.76) and patients with severe renal insufficiency (RR = 0.31, 95% CI 0.16, 0.61).

Conclusions: Deprescribing sulfonylureas and using DPP4i instead may slightly reduce harm in some subgroups of older adults, which supports recommendations of existing lists of potentially inappropriate medications.