Determining predictors of response to exenatide in type 2 diabetes.

OBJECTIVES: To determine predictors of glycemic response to exenatide and to assess change in glycosylated hemoglobin (A1C) and whether a correlation exists between weight loss and glycemic response. DESIGN: Retrospective observational cohort study. SETTING: United States in 2009. PATIENTS: 100 adult patients with type 2 diabetes prescribed exenatide. INTERVENTION: Retrospective chart review of patients to collect demographic data, weight, serum creatinine, diabetes education, and concurrent diabetes medications. MAIN OUTCOME MEASURES: Patients were categorized as responders or nonresponders based on change in A1C. Responders had an A1C decrease of 0.5% or more and nonresponders had an A1C decrease of less than 0.5% from baseline to post-exenatide initiation. Demographic data for each cohort were analyzed. RESULTS: 100 patients met inclusion criteria (61 responders and 39 nonresponders). Responders had a mean A1C decrease of 1.57%, whereas nonresponders had a mean A1C increase of 0.23% (P < 0.001). Post hoc linear regression analysis revealed that baseline A1C was a predictor of response to exenatide (P < 0.001). Binary logistic regression analysis demonstrated that no other variables were predictors of response to exenatide (P > 0.05 for all). No correlation was found between weight loss and exenatide and glycemic response (P = 0.99). CONCLUSION: Our data indicate that patients with a higher baseline A1C are more likely to have a glycemic response to exenatide than patients with a lower baseline A1C.