Treatment Patterns and Outcomes, Before and After Humulin R U-500 Initiation, Among High-Dose Type 2 Diabetes Mellitus Patients in the United States.

OBJECTIVE: Severely insulin-resistant type 2 diabetes (T2D) patients face unique treatment challenges. Humulin R U-500 (U-500R) as insulin monotherapy with both basal/bolus properties addresses these challenges, although it remains understudied. This retrospective study compared real-world patient characteristics, treatment patterns, and outcomes before and after U-500R initiation. METHODS: Adults with T2D on dispensed doses of >180 units/d U-500R monotherapy (index date=first fill) with ≥9-month continuous enrollment both pre- and post-index date and ≥180 units/d insulin pre-index were identified using Veterans Health Administration data (January 1, 2014-January 30, 2017). Overall group was further stratified into elderly and 201 to 300 units dispensed total daily dose (dTDD) subgroups. Syringe and KwikPen users were separately analyzed as subcohorts. Treatment patterns (dTDD), insulin dosage (units/kg), proportion of days covered (PDC) with insulins, and outcomes (HbA1c and hypoglycemic events) were descriptively evaluated, with regression models used to confirm associations between exposure and outcomes. RESULTS: Among 951 U-500R initiators (overall group), mean dTDD (248.5 vs 392.1), percentage of patients with insulin dosage >2 units/kg (38.6% vs 88.1%), and mean PDC (73% vs 77%) significantly increased from the pre- to post-index periods (all P<.001). Changes in HbA1c (9.3% vs 8.5%; P<.0001) and hypoglycemia events per patient per year (2.1 vs 3.1, P<.0001) were statistically significant and confirmed by regression models (P<.0001). Subgroups (elderly, 492; 201 to 300 units, 148) and device subcohorts (syringe, 714; KwikPen, 244) showed similar trends. CONCLUSION: U-500R initiation was associated with significantly improved treatment compliance patterns and glycemic control, with modest increase in hypoglycemia events.