Is an adrenocorticotropic hormone (ACTH) level of 10 and a cortisol level of 9.4 indicative of adrenal insufficiency in a 52-year-old postmenopausal woman?

From the Guidelines

For a 52-year-old postmenopausal woman, an ACTH level of 10 and a cortisol level of 9.4 are not indicative of adrenal insufficiency, as these values fall within normal reference ranges. Normal ACTH levels typically range from 7-69 pg/mL, while morning cortisol levels generally fall between 5-25 μg/dL, though reference ranges may vary slightly between laboratories 1. These hormones follow a diurnal pattern, with highest levels in the early morning and lowest levels in the evening, so the timing of the blood draw is important for proper interpretation.

Key Considerations

• The relationship between ACTH and cortisol is crucial in distinguishing between primary and secondary adrenal insufficiency, with low ACTH and low cortisol suggesting secondary adrenal insufficiency 1.
• Patients on corticosteroids for other conditions may have low morning cortisol and ACTH levels due to iatrogenic secondary adrenal insufficiency, making diagnosis challenging 1.
• Emergent therapy for suspected adrenal insufficiency involves dexamethasone, which allows for subsequent stimulation testing if needed, or hydrocortisone 100 mg if the diagnosis is confirmed 1.
• Education on stress dosing and the use of a medical alert bracelet are essential for patients with adrenal insufficiency 1.

Clinical Implications

• If symptoms such as unusual fatigue, weight loss, dizziness, or skin changes are present despite normal lab values, discussion with a healthcare provider is warranted to consider additional testing or monitoring 1.
• Hormone levels should be interpreted in the context of overall health status and symptoms, rather than as isolated numbers.
• The most recent guidelines from 2021 emphasize the importance of endocrine consultation, education on steroid stress dosing, and emergency interventions for patients with adrenal insufficiency 1.

From the Research

Adrenal Insufficiency Diagnosis

To determine if an adrenocorticotropic hormone (ACTH) level of 10 and a cortisol level of 9.4 is indicative of adrenal insufficiency in a 52-year-old postmenopausal woman, we need to consider the normal ranges and diagnostic criteria for adrenal insufficiency.

• The study 2 suggests that a mean basal morning serum cortisol of > or = 300 nmol/L excludes the possibility of adrenal insufficiency, and a level of < 110 nmol/L suggests adrenal insufficiency.
• However, the study 3 found that a morning serum cortisol (MSC) level of 234.2 mmol/L had a sensitivity of 83.3% and a specificity of 89.1% for predicting adrenal insufficiency.
• The study 4 compared total, salivary, and calculated free cortisol levels in patients with severe sepsis and found that salivary cortisol levels were higher in patients with high total cortisol levels.

Diagnostic Criteria

The diagnostic criteria for adrenal insufficiency vary, but the following points are relevant:

• A cortisol level of 9.4 is below the normal range, which may indicate adrenal insufficiency.
• An ACTH level of 10 is within the normal range, but the response to ACTH stimulation is more important for diagnosing adrenal insufficiency.
• The study 5 found that the 30-min cortisol response to ACTH is constant and unrelated to basal cortisol level or time of day.

Clinical Considerations

In clinical practice, the diagnosis of adrenal insufficiency is based on a combination of clinical symptoms, laboratory tests, and response to ACTH stimulation 6.

• The study 6 suggests that relative adrenal insufficiency is the most common cause of low cortisol levels and failed ACTH challenge in ill patients.
• Corticosteroid therapy may be beneficial in patients with septic shock, regardless of the diagnostic criteria for adrenal insufficiency.