Real-World Analysis of Long-Acting and NPH-Containing Insulins on Glycemic Control

Introduction Affordability of insulin products has become a concern in the past several years as the average price of various insulin products has increased. While awaiting legislation at the federal level that would address issues leading to high insulin costs, providers may have shifted prescribing practices to prescribe the lowest-priced insulin products to achieve patients' treatment goals. Objective To compare the prevalence of hypoglycemic events between patients receiving lower-cost neutral protamine Hagedorn (NPH)-containing human insulins and higher-cost long-acting insulin analogs in Medicare Part D enrollees within a management services organization, as well as assessing glycemic control and changes in body mass index. Methods This was a multicenter, retrospective study conducted at three primary care clinics. The co-primary outcomes were percent difference of documented mild and severe hypoglycemic events between individuals receiving NPH-containing human insulin and long-acting insulin. Results A total of 72 patients met inclusion criteria and were receiving NPH-containing human insulins or the long-acting insulin analogs, 15 and 57 patients, respectively. Severe hypoglycemic events occurred in 3.5% vs 0% of the long-acting insulin analog and NPH-containing human insulin group, respectively (P = 0.999). Mild hypoglycemic episodes were experienced by 31.6% versus 33.3% of long-acting insulin analog and NPH, respectively (P = 0.539). For secondary outcomes, no difference was observed in glycemic control outcomes across insulin groups. Conclusion Among Medicare Part D patients with type 2 diabetes mellitus, the use of NPH-containing human insulins was not associated with an increased risk of mild or severe hypoglycemia-related episodes or reduced glycemic control compared with long-acting insulin. Study findings suggest that lower-cost, NPH-containing human insulins may be an alternative to higher-cost, long-acting insulin analogs.