Growth hormone (GH)
| Category | Biochemistry >> Endocrinology |
|---|---|
| Test background |
GH is a peptide hormone that stimulates growth and cell reproduction. It directly stimulates division and multiplication of chondrocytes of the cartilage and mediates production of insulin-like growth factor-1 (IGF-1). Its influences are widespread and include: increasing bone mineralisation, expanding muscle mass, promoting lipolysis and protein synthesis, stimulating organ growth (excluding the brain) and encouraging hepatic gluconeogenesis. GH excess typically reflects the presence of pituitary adenoma and deficiency: a genetic disorder (such as Laron syndrome), congenital malformation or paradoxically pituitary tumour. |
| Clinical Indications |
Excess: presentation of acromegaly in adults; thickening of the jaws and extremities with or without insulin resistance, carpal tunnel syndrome, muscle weakness and lethargy Suspected primary gigantism in children Deficiency: growth retardation in children/delayed sexual maturity. In adults, truncal obesity, decreased relative muscle mass and lethargy |
| Reference range | Excludes acromegaly: 6 μg/L GH suppression test 60-120 minutes after glucose: 4.2 or 6 μg/L (DFT dependent) |
| Sample & container required | Serum (red top) or SST (gold top) (fasting, 30 mins rest preferred, random sample accepted) |
| Sample volume | 0.5 mL |
| Transport storage | Stable at 2-8°C for 24 hours. Please freeze pending dispatch for analysis. Send to lab frozen. |
| Turnaround time | 1 week |
| Notes | Grossly haemolysed samples are unsuitable for this assay. |