Dipeptidyl Peptidase 4 Inhibitor Sitagliptin Maintains β-Cell Function in Patients With Recent-Onset Latent Autoimmune Diabetes in Adults: One Year Prospective Study

Context: Dipeptidyl peptidase 4 (DPP-4) inhibitors have been widely used in type 2 diabetes. An important unanswered question concerns the effect of DPP-4 inhibition on β-cell function in patients with autoimmune diabetes. Objective: The objective of the study was to investigate the effects of the DPP-4 inhibitor on β-cell function in patients with recent-onset latent autoimmune diabetes in adults (LADA). Design and Setting: This study was an open-label, randomized-controlled study conducted in the Department of Endocrinology at the Second Xiangya Hospital. Patients and Intervention: Thirty recently diagnosed LADA patients were randomized 1:1 to receive insulin therapy with 100 mg/d sitagliptin (group A, n = 15) or without sitagliptin (group B, n = 15) for 12 months. Main Outcome Measures: Fasting and 2-hour postprandial blood samples were obtained at baseline and after 3, 6, 9, and 12 months of treatment to determine blood glucose, glycosylated hemoglobin, and C-peptide levels. Results: There were no differences in the clinical baseline data between the two groups. During the 12 months of follow-up, there were no significant differences in glucose and glycosylated hemoglobin levels between the two groups. At 12 months, fasting C-peptide (FCP), 2-hour postprandial C-peptide (CP), and ΔCP (ΔCP = 2 h CP−FCP) levels were not different in group A (P > .05) compared with baseline, whereas in group B the levels of FCP, 2-hour CP and ΔCP were significantly decreased compared with baseline (P < .05). Levels of 2-hour CP were higher in group A than group B at 12 months (P < .05). Conclusions: LADA patients treated with sitagliptin and insulin maintained β-cell function by comparison with insulin alone.