Is Adrenocorticotropic Hormone Deficiency Really Rare in Patients with Idiopathic Growth Hormone Deficiency and Normal Thyroid Function Tests

Abstract

Background/Aim: It was the aim of this study to evaluate subtle adrenocorticotropic hormone deficiencies in a group of patients with idiopathic growth hormone deficiency and without thyroid-stimulating hormone deficiency. Methods: Growth hormone and cortisol responses to an insulin tolerance test of 25 patients (15 males and 10 females) were evaluated at diagnosis (11.8 ± 2.5 years) and at the time of retesting (14.6 ± 1.6 years). A cortisol response <416, 416–555 and >555 nmol/l was defined as inadequate, blunted and normal, respectively. Results: Baseline cortisol responses to the insulin tolerance test were subnormal in 10 of the 25 patients (6 had blunted responses and 4 had inadequate responses). The mean ± SD of normal, blunted and inadequate cortisol response at diagnosis was 722.2 ± 127.8, 480.4 ± 37.4 and 317.7 ± 81.7 nmol/l, respectively. Five of these patients showed improved cortisol response at retesting. Three of the 15 patients who had a normal baseline cortisol response developed blunted cortisol response at re-evaluation. The mean ± SD of normal and blunted plus inadequate cortisol response at retesting was 668.1 ± 116.1 and 467.3 ± 64 nmol/l, respectively. All patients with a subnormal cortisol level were asymptomatic. Conclusion: Asymptomatic adrenocorticotropic hormone deficiency patients should be followed up closely, and treatment should be considered in a stress situation after re-evaluation of the hypothalamic-pituitary-adrenal axis.

Correlation between adrenal function, growth hormone secretion, and insulin sensitivity in children with idiopathic growth hormone deficiency

“…Our data are in agreement with another study which showed subnormal cortisol response to ITT in 10 out of 25 children (40%) with idiopathic GHD [25]. Similarly, Lange et al reported in a group of adults previously treated for idiopathic childhood-onset GHD a percentage of 44% of asymptomatic AI.…”