Efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients

(J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00221.x, 2012) Aims/Introduction: To determine the efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients after 3 months’ therapy. Materials and Methods: A retrospective, observational study of 741 type 2 diabetes patients was carried out; 110 received sitagliptin monotherapy, and 631 received combination therapy with sitagliptin when other oral medications were insufficient. The primary outcome measure was glycated hemoglobin (HbA(1c)) measured at 0, 4 and 12 weeks of sitagliptin therapy. Results: In the monotherapy and combination therapy groups, HbA(1c) decreased significantly after 12 weeks. Target HbA(1c) (<7%) was achieved in 39.1% overall. On logistic regression analysis, baseline HbA(1c) was the strongest contributing factor for achieving target HbA(1c); baseline body mass index and duration of diabetes were also significant factors. A total of 82 patients (11%) were unresponsive to sitagliptin. These patients’ baseline body mass index was significantly higher and their baseline HbA(1c) was significantly lower than those of patients who responded to sitagliptin. The most commonly co‐administered drugs were sulfonylureas (508 patients). In these patients, the dose of sulfonylurea decreased with time. In 66 patients whose sulfonylurea dosage was reduced when sitagliptin was started, HbA(1c) and bodyweight decreased significantly after 12 weeks. A total of 24 patients receiving sulfonylureas had mild hypoglycemia, but none discontinued sitagliptin. Conclusions: Sitagliptin was effective and safe as both monotherapy and combination therapy in Japanese type 2 diabetes patients. When sulfonylureas were ineffective, sitagliptin improved glycemic control. In patients whose sulfonylurea dose was reduced at the start of sitagliptin, blood glucose improved and bodyweight decreased after 12 weeks.