Overview: Cortisol Morning TestIntroduction: The Cortisol Morning Test measures morning cortisol to diagnose adrenal disorders, causing fatigue, weight gain, or muscle weakness. Following 2023 AACE guidelines, it uses an immunoassay for high sensitivity, aiding in endocrine screening. This test is critical for guiding diagnosis, treatment, and improving outcomes in endocrinology for patients with suspected adrenal dysfunction.
Other Names: Morning Cortisol Assay, Adrenal Function Test.
FDA Status: Laboratory-developed test (LDT), meeting endocrinology standards for diagnostic accuracy.
Historical Milestone: Cortisol testing began in the 1960s with adrenal research. Morning cortisol assays emerged in the 1980s, and by the 2000s, high-sensitivity immunoassays improved accuracy.
Purpose: Diagnoses adrenal disorders like Addison's disease or Cushing's syndrome, guides treatment, and monitors morning cortisol levels in patients with fatigue or muscle weakness.
Test Parameters: 1. Cortisol
Pretest Condition: Fasting for 10-12 hours required to stabilize cortisol levels. Collect serum, plasma, or saliva in the morning (6-8 AM). Report symptoms like fatigue or muscle weakness, and list medications like steroids.
Specimen: 2-5 mL serum (SST), 2-4 mL plasma (EDTA), or 1-2 mL saliva (sterile container). Centrifuge serum/plasma within 1 hour. Transport in a biohazard bag within 8 hours.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document fatigue, muscle weakness, or history of adrenal disorders. Include current medications, especially steroids or hormone therapies.
Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for adrenal therapy.
Procedural Considerations: Uses an immunoassay to measure morning cortisol levels. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Non-fasting samples, stress, or improper collection timing may alter results. Hemolysis can degrade samples.
Clinical Significance: Low morning cortisol levels indicate Addison's disease, prompting supplementation. Elevated levels suggest Cushing's syndrome.
Specialist Consultation: Consult an endocrinologist for result interpretation. A neurologist referral is advised for neurological symptoms.
Additional Supporting Tests: ACTH test, evening cortisol test, or adrenal imaging to confirm adrenal disorders.
Test Limitations: Results may be affected by stress or medications. Clinical correlation is required.
References: AACE Adrenal Guidelines, 2023; Journal of Clinical Endocrinology, Nieman LK, 2022.
