Adults with long-duration type 2 diabetes have blunted glycemic and β-cell function improvements after bariatric surgery

OBJECTIVE: This study investigated the effect of type 2 diabetes duration on glucose regulation 24 months post-bariatric surgery. METHODS: Twenty-seven adults with short (<5 years) and long-duration (≥10 years) type 2 diabetes received a mixed-meal tolerance test at baseline and 24 months (m) post-surgery. Body weight, insulin sensitivity, 1(st) and 2(nd) phase meal-stimulated insulin secretion, disposition index (i.e. DI or pancreatic β-cell function), and incretin responses were examined. RESULTS: Adults with short-duration type 2 diabetes had better HbA(1c), greater insulin secretory capacity, and greater DI compared with adults with long-duration type 2 diabetes, despite similar weight loss and incretin responses. Diabetes duration correlated with smaller improvements in HbA(1c) and DI, but not weight loss. CONCLUSIONS: Enhanced β-cell function characterizes the effect of bariatric surgery in adults with diabetes for <5 years, independent of weight loss or incretins. Additional therapy post-surgery may be required to improve glycemia for people with long-standing type 2 diabetes.