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

Abstract

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 postsurgery. Body weight, insulin sensitivity, first- and second-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 postsurgery may be required to improve glycemia for people with long-standing type 2 diabetes.

Figure 1

Effect of bariatric surgery on Hb_A1c and DI in subjects with short vs. long-duration type 2 diabetes. Change in Hb_A1c (A), 1st phase DI (B), and 2nd phase DI (C) from baseline to 24 months post-surgery. Compared with baseline, *p=0.04 and ^p=0.01. DI = disposition index (meal-stimulated insulin secretion rate [iAUC C-peptide/iAUC Glucose] multiplied by insulin sensitivity).

Figure 2

Correlations between diabetes duration and 1^st phase DI (A), 2^nd phase DI (B), and Hb_A1c (C). DI = disposition index (meal-stimulated insulin secretion rate [iAUC C-peptide/iAUC Glucose] multiplied by insulin sensitivity). Hb_A1c reflects absolute difference between Post-Pre.