Yusuf ÖZTÜRK, Mustafa KULAKSIZOĞLU
Endocrinology Research and Practice - 2026;30(3):1-5
Objective: Insulinoma is the most frequent cause of endogenous hyperinsulinemic hypoglycemia. Recurrent hypoglycemia may impair the hypothalamic-pituitary-adrenal axis. This study evaluated the cortisol response during hypoglycemia in patients with insulinoma and examined clinical and biochemical correlates of counter-regulation. Methods: This retrospective cross-sectional study included 14 insulinoma patients in whom cortisol was measured during hypoglycemia in a 72-hour fasting test. Controls comprised 28 individuals who underwent an insulin tolerance test: 14 with normal adrenocortical function (NAF) and 14 with secondary adrenal insufficiency (SAI). Cortisol levels were compared across groups, and correlations with clinical/biochemical variables were analyzed in the insulinoma group. Results: Cortisol levels were significantly lower in insulinoma patients than in NAF patients (P < .001) but comparable to those in SAI patients (P = .709). HbA1c correlated positively with cortisol response (r = 0.73, P = .003), while symptom duration showed a negative but nonsignificant association. Conclusion: An attenuated cortisol response was observed during hypoglycemia in patients with insulinoma. The positive correlation between hemoglobin A1c and cortisol levels suggests that chronic exposure to recurrent hypoglycemia may weaken the counter-regulatory response; however, this finding should be validated in larger prospective studies.
