Controlling hypoglycemia is of great concern in this population, because of potential accidents or falls. In addition, elderly patients are at increased risk for adverse events associated with drug therapy; therefore, treatment must be chosen carefully, pointed out Barry Goldstein, MD, PhD, Vice President of Diabetes and Endocrinology Clinical Development, Merck & Co, who presented the results at the 2012 ADA annual meeting.
Similar Glucose Reductions with Sitagliptin and a Sulfonylurea
A post hoc pooled analysis of 3 double-blind clinical trials in which older patients (aged ≥65 years) were treated with 100 mg of oral sitagliptin, a once-daily DPP-4 inhibitor, showed that these patients achieved blood glucose reductions similar to the reductions seen in patients managed with a sulfonylurea (glipizide or glimepiride). The investigators compared the changes from baseline in the level of hemoglobin (Hb) A1c, fasting plasma glucose, body weight, and the proportion of patients who experienced ≥1 episodes of symptomatic hypoglycemia.
In 2 of the studies, patients with diabetes whose disease had been managed with diet alone or with metformin were randomized to receive sitagliptin or glipizide (each as monotherapy or in combination with metformin) for 104 weeks. In the third study, patients were randomized to receive sitagliptin or glimepiride for 30 weeks.
The pooled analysis focused on results at or close to 30 weeks in each of the 3 trials and included 373 patients who completed the trials through this time point.
Among this older patient population, 178 patients who were taking sitagliptin had a 0.73% mean reduction in HbA1c from baseline, which was similar to the 195 patients who took a sulfonylurea (0.78% mean HbA1c reduction). In the patients receiving a sulfonylurea, 28.2% experienced ≥1 episodes of symptomatic hypoglycemia compared with 6.2% of patients receiving sitagliptin, a significant difference.
Comparing Saxagliptin Use in Older and Younger Patients
The second post hoc analysis of saxagliptin was led by Bernard Charbonnel, MD, Professor of Endocrinology and Metabolic Diseases, Centre Hospitalier Universitaire de Nantes, France. In this analysis, the researchers conducted a subanalysis of outcomes from a 24-week, placebo-controlled trial of treatment with saxagliptin in 104 older patients (aged ≥65 years) and in 351 younger patients (aged <65 years).
All the patients had type 2 diabetes and an inadequate response to insulin alone or to insulin in combination with metformin. This trial showed that adding saxagliptin at a 5-mg daily dose improved glycemic control, regardless of metformin use, and the drug was generally well tolerated.
This subanalysis showed that improvement in glycemic control from baseline to week 24 with saxagliptin add-on therapy was similar in the elderly and nonelderly groups (interaction of treatment by age, P = .942 for HbA1c; P = .184 for fasting plasma glucose; and P = .291 for 120-minute postprandial glucose), demonstrating that saxagliptin added to insulin, with or without metformin, was just as effective in older patients as it was in younger populations.
At week 24, the overall incidence rates of adverse events with saxagliptin and placebo were 54.9% and 57.6%, respectively, in the older patients. No older patients discontinued the study because of adverse events, whereas 1.7% and 2.5% of the younger patients discontinued the study in the saxagliptin and placebo groups, respectively.