What is the prevalence of secondary adrenal insufficiency?

From the Guidelines

Secondary adrenal insufficiency affects approximately 1 in 10,000 children and is relatively uncommon in adults, with the most common cause being exogenous glucocorticoid therapy. The prevalence of secondary adrenal insufficiency is not as well-defined in adults as it is in children, but it is estimated to be higher than primary adrenal insufficiency 1.

Causes and Risk Factors

• Exogenous glucocorticoid therapy is a common cause of secondary adrenal insufficiency, as it suppresses the hypothalamic-pituitary-adrenal axis when used at supraphysiological doses for more than 2-3 weeks 1.
• Other causes include pituitary tumors, pituitary surgery or radiation, traumatic brain injury, and certain inflammatory or infiltrative diseases affecting the pituitary gland.
• The condition develops gradually as the pituitary gland fails to produce adequate ACTH (adrenocorticotropic hormone), which in turn leads to insufficient cortisol production by the adrenal glands.

Key Characteristics

• Unlike primary adrenal insufficiency, aldosterone production typically remains intact since it's regulated primarily by the renin-angiotensin system rather than ACTH 1.
• Treatment involves glucocorticoid replacement therapy, which is crucial for managing the condition and preventing life-threatening complications during periods of stress.

Management and Treatment

• Glucocorticoid replacement therapy is typically administered with hydrocortisone 15-25 mg daily divided into 2-3 doses, or prednisone 3-5 mg daily 1.
• Patients with secondary adrenal insufficiency usually do not require mineralocorticoid replacement, as aldosterone production remains intact.

From the Research

Prevalence of Secondary Adrenal Insufficiency

• Secondary adrenal insufficiency is considered a common condition, although it is often underestimated and underdiagnosed 2.
• It is the most common subtype of adrenal insufficiency, caused by certain medications and pituitary destruction 3.
• The estimated prevalence of central adrenal insufficiency, which includes secondary adrenal insufficiency, is 150-280 per million 4.

Causes and Risk Factors

• The most frequent endogenous cause of secondary adrenal insufficiency is a tumor of the hypothalamic-pituitary region, usually associated with panhypopituitarism secondary to tumor growth or to its treatment with surgery or irradiation 2.
• Other causes include nontumoral disorders, such as infiltrative lesions, infective processes, vascular alterations, traumatic brain injury, empty sella, or genetic disorders 2.
• Long-term administration of exogenous glucocorticoids can also determine secondary and/or tertiary hypoadrenalism 2.

Diagnosis and Management

• Diagnosis of secondary adrenal insufficiency can be complex, as no single test has sufficient sensitivity to identify all patients with the condition 2.
• Clinical judgment and follow-up are crucial for the assessment of corticotropin deficiency 2.
• Corticosteroid replacement therapy is the gold standard for management of secondary adrenal insufficiency 5.
• Recovery of adrenal function is possible in some patients, with approximately one in six patients with secondary adrenal insufficiency recovering adrenal function over time 6.