Overview: Growth Hormone TestIntroduction: The Growth Hormone Test measures growth hormone (GH) levels to diagnose pituitary or growth disorders, causing short stature or fatigue. Following 2023 Endocrine Society 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 growth hormone deficiencies or excesses, such as acromegaly.
Other Names: GH Assay, Somatotropin Test.
FDA Status: Laboratory-developed test (LDT), meeting endocrinology standards for diagnostic accuracy.
Historical Milestone: GH testing began in the 1970s with pituitary research. Immunoassays improved in the 1990s, enhancing accuracy for growth disorders.
Purpose: Diagnoses pituitary or growth disorders, guides treatment, and monitors GH levels in patients with short stature, fatigue, or developmental issues.
Test Parameters: 1. Growth Hormone
Pretest Condition: Fasting for 10-12 hours required to stabilize hormone levels. Collect serum or plasma in the morning. Report symptoms like short stature or fatigue, and list medications.
Specimen: 2-5 mL serum (SST) or 2-4 mL plasma (EDTA). Centrifuge 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 short stature, fatigue, or history of pituitary disorders. Include current medications, especially growth hormone therapies or steroids.
Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for hormone therapy.
Procedural Considerations: Uses an immunoassay to measure GH levels. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Non-fasting, hemolysis, or medications (e.g., corticosteroids) can affect results. Stress or exercise may alter GH levels.
Clinical Significance: Abnormal GH levels suggest pituitary disorders (e.g., deficiency, acromegaly), prompting further testing or treatment. Normal levels may require dynamic testing.
Specialist Consultation: Consult an endocrinologist for result interpretation and management planning.
Additional Supporting Tests: IGF-1, GHRH test, or pituitary MRI to confirm pituitary or growth disorders.
Test Limitations: GH levels fluctuate naturally, requiring dynamic testing for accuracy. Results need clinical correlation.
References: Endocrine Society Pituitary Guidelines, 2023; Journal of Clinical Endocrinology & Metabolism, Melmed S, 2022.
