Switching from Neutral Protamine Hagedorn (NPH) Insulin to Insulin Glargine 300 U/mL in Older and Younger Patients with Type 2 Diabetes: A Post Hoc Analysis of a Multicenter, Prospective, Observational Study

Introduction Older age and longer disease duration are key risk factors for hypoglycemia in patients with type 2 diabetes (T2D) who receive insulin. Previous studies have shown that insulin glargine 300 U/mL (Gla-300) improves glycemic control and reduces the risk of hypoglycemia, but whether this effect is observed in older patients switching from neutral protamine Hagedorn (NPH) insulin is unclear. Methods In this multicenter, observational study involving patients with T2D aged >= 18 years with glycated hemoglobin (HbA(1c)) >= 8%, we compared the safety and effectiveness of switching from NPH insulin to Gla-300 in subgroups of patients differing by age (< 65 vs. >= 65 years) and duration of diabetes (<= 13 vs. > 13 years). Results A total of 469 participants were included in the study. From baseline to 6 months after switching to Gla-300, mean HbA(1c) decreased from 9.23% to 8.13% (p < 0.001) among patients aged <= 65 years (224 patients), and from 9.15% to 8.20% (p < 0.001) among those aged > 65 years (245 patients). The proportion of patients with >= 1 episodes of hypoglycemia decreased from 19.1% to 13.6% (p = 0.11) among those aged <= 65 years, and from 26.9% to 13.0% (p < 0.001) among those aged > 65 years; the reduction was significantly greater in those aged > 65 years (p = 0.001). The reduction in HbA(1c) was greater in those with a disease duration <= 13 years (p = 0.007), but the reduction in hypoglycemia was greater in those with a disease duration > 13 years (p < 0.0003). Conclusion The switch from NPH insulin to Gla-300 improved glycemic control in older patients with T2D and in those with a longer disease duration. Older patients with T2D and those with a longer disease duration benefited even more from the switch to Gla-300 than younger patients and those with a shorter disease duration, with significantly greater reductions in the risk of hypoglycemia.