What is a primary cause of secondary adrenal insufficiency?

The primary cause of secondary adrenal insufficiency is long-term corticosteroid use. When corticosteroids are administered over an extended period, they can suppress the hypothalamic-pituitary-adrenal (HPA) axis. This suppression occurs because the body receives an external source of glucocorticoids, leading to decreased secretion of adrenocorticotropic hormone (ACTH) from the pituitary gland. With lower levels of ACTH, the adrenal glands are stimulated less, which can result in inadequate cortisol production when the corticosteroid medication is reduced or withdrawn. This condition exemplifies how the endocrine feedback loops can be disrupted by external hormonal interventions.

Other options do not directly relate to causing secondary adrenal insufficiency. Excessive thyroid hormone production primarily affects metabolism and does not influence the adrenal glands in the same way. Overactivity of the pancreas typically pertains to insulin production and glucose metabolism rather than adrenal function, and inadequate insulin secretion relates specifically to diabetes management, not adrenal insufficiency. Thus, the correct understanding of the causes of secondary adrenal insufficiency focuses on the impact of long-term corticosteroid therapy on adrenal gland stimulation.