Growth hormone

Growth hormone (GH or HGH), also known as somatotropin or somatropin, is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Secretion of growth hormone (GH) in the pituitary is regulated by the neurosecretory nuclei of the hypothalamus.

In addition to increasing height in children and adolescents, growth hormone has many other effects on the body:

• Increases calcium retention, and strengthens and increases the mineralization of bone
• Increases muscle mass through sarcomere hypertrophy
• Promotes lipolysis
• Increases protein synthesis
• Stimulates the growth of all internal organs excluding the brain
• Plays a role in homeostasis
• Reduces liver uptake of glucose
• Promotes gluconeogenesis in the liver^[37]
• Contributes to the maintenance and function of pancreatic islets
• Stimulates the immune system
• Increases deiodination of T4 to T3^.

Quality of life

Several studies, primarily involving patients with GH deficiency, have suggested a crucial role of GH in both mental and emotional well-being and maintaining a high energy level. Adults with GH deficiency often have higher rates of depression than those without.^[40] While GH replacement therapy has been proposed to treat depression as a result of GH deficiency, the long-term effects of such therapy are unknown.^[40]

Cognitive function

GH has also been studied in the context of cognitive function, including learning and memory.^[41] GH in humans appears to induce cognitive function and may be useful in the treatment of patients with cognitive impairment that is a result of GH deficiency.^[41]