Objective: Latent autoimmune diabetes in adults (LADA) etiologically belongs to type 1 diabetes (T1D), shares clinical features of both T1D and type 2 diabetes (T2D) and is characterized by islet β cell dysfunction and insulin resistance.Our recent study has shown that sitagliptin may potentially protect islet function in LADA patients, however no study has reported the impact of sitagliptin on β cell function and insulin sensitivity of LADA patients in clamp test.Methods: Nine subjects with recent-onset LADA who received insulin therapy with 100 mg/d sitagliptin (n=5) or without sitagliptin (n=4) were recruited for clamp tests.Hyperglycemic and hyperinsulin euglycemic clamp tests were performed at baseline, 12th months and 24th months during treatment period.Fasting and 2-hour postprandial blood glucose, HbA1c and lipid profiles, clinical data (such as height, weight, blood pressure, waistline) was obtained at each follow-up visit time.