Glycemia, Insulin Sensitivity, and Secretion Improve 3 Months Post-sleeve Gastrectomy in Youth With Type 2 Diabetes.

Abstract

Context: Metabolic bariatric surgery reduces weight in youth with severe obesity; however, its impacts on youth-onset type 2 diabetes (T2D) are unclear.

Objective: We evaluated short-term outcomes in youth with T2D 3 months after vertical sleeve gastrectomy (VSG).

Design: Longitudinal, observational study in the Impact of Metabolic surgery on Pancreatic, Renal, and cardiOVascular hEalth in youth with T2D study (IMPROVE-T2D).

Setting: Academic medical university and children's hospital.

Participants: Fourteen youth with T2D [mean age ± SD 16.8 ± 1.4 years; 50% female, pre-VSG hemoglobin A1c (HbA1c) 6.6 ± 0.2%; diabetes duration 17.6 ± 13.8 months; age at diabetes diagnosis 15.9 ± 1.4 years; body mass index (BMI) 46.7 ± 2 kg/m²].

Interventions: Participants underwent a mixed-meal tolerance test (MMTT), body composition, and indirect calorimetry before and 3 months after VSG.

Main outcomes: Glycemic control (HbA1c, diabetes medications), insulin sensitivity (Matsuda Index, Homeostasis Model of Insulin Sensitivity, oral minimal model), and secretion (C-peptide model).

Results: After VSG, weight and BMI decreased (25.2 ± 5.6 kg [19%], -8.7 ± 2 kg/m² [18%], respectively, P < .001). Body fat decreased (4.5%, P = .012), with reductions of 14.1 ± 5.4 kg of fat mass (P = .005) and 4.5 kg of fat-free mass (P = .034). HbA1c decreased from 6.6 ± 0.2% to 5.7 ± 0.2% (P = .003), with 86% of participants no longer requiring diabetes medications. Glucose was lower throughout the MMTT, with insulin, C-peptide, free fatty acids, glucagon-like peptide-1, and peptide-YY significantly changing postsurgery (P < .05 for all). Insulin sensitivity and insulin secretion rate during the MMTT significantly improved.

Conclusion: Three months post-VSG, youth showed significant improvements in weight, body composition, insulin sensitivity and secretion, and glycemic control, with most no longer requiring diabetes medications.