Effects of dipeptidyl peptidase-4 inhibitors and sulphonylureas on cognitive and physical function in nursing home residents

Aims: Dipeptidyl peptidase-4 inhibitors (DPP4Is) may mitigate hypoglycaemia-mediated declines in cognitive and physical functioning compared with sulphonylureas (SUs), yet comparative studies are unavailable among older adults, particularly nursing home (NH) residents. We evaluated the effects of DPP4Is versus SUs on cognitive and physical functioning among NH residents. Materials and Methods: This new-user cohort study included long-stay NH residents aged ≥65 years from the 2007-2010 national US Minimum Data Set (MDS) clinical assessments and linked Medicare claims. We measured cognitive decline from the validated 6-point MDS Cognitive Performance Scale, functional decline from the validated 28-point MDS Activities of Daily Living scale, and hospitalizations or emergency department visits for altered mental status from Medicare claims. We compared 180-day outcomes in residents who initiated a DPP4I versus SU after 1:1 propensity score matching using Cox regression models. Results: The matched cohort (N = 1784) had a mean ± SD age of 80 ± 8 years and 73% were women. Approximately 46% had no or mild cognitive impairment and 35% had no or mild functional impairment before treatment initiation. Compared with SU users, DPP4I users had lower 180-day rates of cognitive decline [hazard ratio (HR) = 0.61, 95% confidence interval (CI) 0.31-1.19], altered mental status events (HR = 0.71, 95% CI 0.39-1.27), and functional decline (HR = 0.89, 95% CI 0.51-1.56), but estimates were imprecise. Conclusions: Rates of cognitive and functional decline may be reduced among older NH residents using DPP4Is compared with SUs, but larger studies with greater statistical power should resolve the remaining uncertainty by providing more precise effect estimates.