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 Required Serum (red top) or SST (gold top) (fasting, 30 mins rest preferred, random sample accepted)