Comparison of Safety and Efficacy of Insulin Glargine and Neutral Protamine Hagedorn Insulin in Older Adults with Type 2 Diabetes Mellitus: Results from a Pooled Analysis

OBJECTIVES: To compare the safety and efficacy of adding insulin glargine or neutral protamine Hagedorn (NPH) insulin to existing oral antidiabetic drug (OAD) regimens in adults with type 2 diabetes mellitus. DESIGN: Pooled analysis of data from five randomized controlled trials with similar designs. SETTING: Three hundred forty-two centers in more than 30 countries worldwide. PARTICIPANTS: Randomly selected individuals aged <= 80 with a body mass index <= 40 kg/m(2) and a glycosylated hemoglobin (HbA1c) level of 7.5% to 12.0%. MEASUREMENTS: Fixed-and random-effects models were used to compare outcomes after 24 or 28 weeks of treatment (insulin glargine, n = 1,441; NPH insulin, n = 1,254) according to age (>65, n = 604 vs < 65, n = 2,091) and age based on treatment (e.g., >= 65 receiving insulin glargine vs NPH insulin). Outcomes included change in HbA1c, fasting blood glucose (FBG), insulin dose, and hypoglycemia incidence and event rates. RESULTS: At end point, participants aged 65 and older receiving insulin glargine had greater reductions in HbA1c and FBG than those receiving similar doses of NPH insulin. In contrast, for participants younger than 65, there were no statistically significant differences in reductions in HbA1c or FBG between insulin glargine and NPH insulin. Daytime hypoglycemia rates were similar in all groups, although the rates of nocturnal symptomatic and severe hypoglycemia were lower with insulin glargine than NPH insulin. CONCLUSION: Addition of insulin glargine to oral antidiabetic drugs in older adults with poor glycemic control may have modestly better glycemic benefits than adding NPH insulin, with low risk of hypoglycemia. J Am Geriatr Soc 60:51-59, 2012.