The Effect of Curative Treatment on Hyperglycemia in Patients With Cushing Syndrome

Abstract

Abstract Context Hyperglycemia is a common complication of Cushing syndrome (CS). Objective We aimed to determine the impact of curative procedure on hyperglycemia and its management in patients with CS. Methods This retrospective longitudinal cohort study took place 2000 to 2019 in a referral center among adults with endogenous CS and hyperglycemia. Main outcome measures included glycated hemoglobin A1c (HbA1c), intensity of hyperglycemia therapy, and improvement of hyperglycemia. Results In 174 patients with CS (pituitary in 106, ectopic in 25, adrenal in 43), baseline median HbA1c was 6.9% (range, 4.9-13.1), with 41 (24%) patients not on any therapy for hyperglycemia, 93 (52%) on oral medications, and 64 (37%) on insulin (median daily units of 58; range, 10-360). Following CS remission, at the end of follow-up (median 10.5 months), 37 (21%) patients demonstrated resolution of hyperglycemia, 82 (47%) demonstrated improvement, and 55 (32%) had no change or worsening in hyperglycemia. At the end of follow-up, HbA1c decreased by 0.84% (P < .001) and daily insulin dose decreased by a mean of 30 units (P < .001). Biochemical hypercortisolism severity score (severe vs moderate/mild: odds ratio [OR] of 2.4 [95% CI, 1.1-4.9]), and CS subtype (nonadrenal vs adrenal: OR of 2.9 [95% CI, 1.3-6.4]), but not type of hyperglycemia (diabetes vs prediabetes: OR of 2.1 [0.9-4.9]) were associated with hyperglycemia improvement at the end of follow-up. Conclusion Two-thirds of patients with CS and hyperglycemia demonstrate resolution or improvement of hyperglycemia after a curative procedure. Close monitoring during CS recovery is needed to ensure appropriate therapy modification.