From the Guidelines
The ACTH level of 44 pg/mL and cortisol level of 23 μg/dL in a 30-year-old male are both within normal reference ranges, so these values appear normal. Typically, ACTH normal ranges are approximately 7-69 pg/mL, while morning cortisol levels normally fall between 5-25 μg/dL, as seen in the context of primary adrenal insufficiency diagnosis 1. These hormones work together in the hypothalamic-pituitary-adrenal axis, with ACTH from the pituitary stimulating cortisol production by the adrenal glands. It's essential to consider the timing of the blood draw, as these hormones follow a diurnal pattern, with highest levels in the early morning and lowest levels at night, which is crucial for proper interpretation.
According to the consensus statement on the diagnosis, treatment, and follow-up of patients with primary adrenal insufficiency 1, the diagnostic test for primary PAI should be paired measurement of serum cortisol and plasma ACTH. In this case, the provided values do not indicate primary adrenal insufficiency, as the cortisol level is above the threshold of <250 nmol L-1, and the ACTH level, although elevated, does not necessarily suggest primary adrenal insufficiency without other clinical manifestations.
The key factors to consider in interpreting these results include:
- The clinical context, such as the presence of symptoms like unexplained collapse, hypotension, vomiting, or diarrhea, which could suggest adrenal insufficiency 1.
- The potential impact of stress, illness, medications, and other factors on these hormone levels.
- The importance of further evaluation if concerning symptoms persist, potentially including additional tests like a synacthen (tetracosactide) stimulated peak serum cortisol measurement, as recommended for diagnosing primary adrenal insufficiency 1.
Given the information provided and the normal reference ranges, no immediate action for primary adrenal insufficiency is warranted based solely on the ACTH and cortisol levels. However, a comprehensive clinical assessment considering the patient's overall health, symptoms, and medical history is necessary to determine the need for further evaluation or treatment.
From the Research
Normal ACTH and Cortisol Levels
- The normal range for ACTH and cortisol levels can vary depending on the laboratory and the individual's condition.
- According to the studies, there is no direct information on the normal range for a 30-year-old male with an ACTH level of 44 and a cortisol level of 23 2, 3, 4, 5, 6.
ACTH and Cortisol Relationship
- The relationship between ACTH and cortisol levels is complex, and cortisol levels can be influenced by various factors such as time of day, glucocorticoid treatment, and individual variability 2, 3, 4, 5, 6.
- A study found that the 30-min cortisol response to ACTH is constant, unrelated to basal cortisol level or time of day, and is the best criterion for measuring adrenal response in the short ACTH test 5.
Glucocorticoid Replacement Therapy
- The optimal replacement regimen of hydrocortisone in adults with severe ACTH deficiency remains unknown, and management strategies vary from treatment with 15-30 mg or higher in daily divided doses 3.
- A study suggested that a lower dose of hydrocortisone (10 mg/5 mg) produces a more physiological cortisol profile, without compromising quality of life, compared to higher doses still used in clinical practice 3.
Adrenocortical Function
- Adrenocortical function can be altered in critically ill patients, and the hypothalamus-pituitary-adrenal axis alterations may recover after ICU discharge 4.
- A study found that plasma ACTH and cortisol levels rose to supra-normal levels 1 week after ICU discharge, indicating recovery of a central adrenocortical suppression while in ICU 4.