The Effect of Corticosteroid Withdrawal on Glucose Metabolism and Anti-GAD Antibodies in Simultaneous Pancreas–Kidney Transplant Patients

Context: Corticosteroid withdrawal may reduce insulin resistance; however, it could also influence pancreatic autoantibody profile in simultaneous pancreas–kidney (SPK) transplant patients. Objective: To evaluate the effect of corticosteroid withdrawal on glucose metabolism and anti-glutamic acid decarboxylase (GAD) antibody titers in SPK patients with type 1 diabetes after 12 months of follow-up. Design: In this retrospective study, fasting glucose and glycated hemoglobin (A1c) were compared before and after 3, 6, and 12 months of corticosteroid withdrawal in 80 SPK patients. In addition, weight, anti-GAD, and C-peptide levels were compared before and after withdrawal. Finally, fasting and postglucose, insulin, and C-peptide levels were compared before and after withdrawal in 25 patients undergoing oral glucose tolerance test (OGTT). Results: Fasting glucose levels did not change during corticosteroid discontinuation. After 12 months, A1c slightly increased from 4.6% (0.4%) to 4.8% (0.6%) (P < .01) and C-peptide decreased from 2.8 (1.1) ng/mL to 2.4 (1.3) ng/mL (P <. 01). In patients submitted to OGTT, glucose, insulin, and C-peptide levels did not change. There was no alteration in the proportion of anti-GAD positive tests (41% vs 45%). Anti-GAD titers remained stable or decreased in 70% of positive patients. Conclusion: Corticosteroid withdrawal has no significant effect on glucose metabolism and on anti-GAD profile among SPK patients.