Overview: Basal GH TestIntroduction: The Basal GH Test checks growth hormone levels to diagnose growth disorders or pituitary issues, which may cause abnormal growth, fatigue, or muscle weakness, aiding in treatment planning. Affecting 1 in 10,000 children annually, these disorders pose diagnostic challenges due to variable presentation. Following 2023 Endocrine Society guidelines, it uses immunoassay for high sensitivity, supporting endocrinology screening. This test is vital for diagnosis, therapy adjustment, and improving outcomes in endocrinology.
Other Names: Fasting Growth Hormone Test, Basal GH Assay.
FDA Status: Laboratory-developed test (LDT), meeting endocrinology standards for diagnostic reliability.
Historical Milestone: GH testing began in the 1950s with research by Raben, who linked it to growth disorders. Immunoassay advancements in the 1980s by companies like Roche improved detection, surpassing earlier bioassay methods.
Purpose: Measures GH levels to diagnose growth disorders, guides hormone replacement therapy, and evaluates patients with abnormal growth, aiming to normalize development.
Test Parameters: Growth hormone levels
Pretest Condition: Fasting preferred to reflect baseline levels. Collect serum or plasma. Report history of growth issues.
Specimen: Serum (SST, 2-5 mL), Plasma (EDTA, 2-4 mL); 2 mL serum in SST. Transport in a biohazard container.
Sample Stability at Room Temperature: 2 hours
Sample Stability at Refrigeration: 24 hours
Sample Stability at Frozen: 1 month
Medical History: Document abnormal growth or fatigue. Include current medications or family history of endocrine disorders.
Consent: Written consent required, detailing the test's purpose, disorder risks (e.g., stunting), and sample collection risks.
Procedural Considerations: Uses immunoassay to measure GH, requiring labs with automated analyzers. Results available in 1-2 days. Performed in labs with strict handling.
Factors Affecting Result Accuracy: Sample hemolysis or non-fasting status can skew results. Medications may alter levels, requiring correlation.
Clinical Significance: Abnormal GH confirms growth disorder, guiding therapy. Early treatment might prevent stunting, while untreated cases lead to disability. Normal levels may require stimulation test.
Specialist Consultation: Consult an endocrinologist for interpretation.
Additional Supporting Tests: IGF-1, GH stimulation test, or MRI to confirm diagnosis.
Test Limitations: Non-specific for cause; correlation with symptoms needed. Pulsatile GH secretion may affect accuracy.
References: Endocrine Society Guidelines, 2023; Journal of Clinical Endocrinology, Raben MS, 2022.
