• The disease
• Diagnosis
• Treatment options

Definition

Growth hormone (GH,) plays a key role in regulating growth in children and adolescents, but is also essential for adults for its role in regulating overall body functioning and protecting against aging.

Growth hormone is secreted by the pituitary – a gland in the brain – under the control of the hypothalamus, which is the area of the brain that connects the central nervous system and the endocrine system. Growth hormone interacts with IGF-1 in the liver.

Growth hormone deficiency is caused by a a problem in the pituitary gland and/or the hypothalamus. GH deficiency occurs when there is insufficient hormone secreted by the pituitary gland. When this happens, the amount of IGF-1 produced by the liver is also too low.

Symptoms and impact on health

The health consequences of growth hormone deficiency vary for children and adults:

• In children, a deficiency in the hormone has serious consequences for growth, resulting in:
  • small stature,
  • delayed development,
  • weak bone structure,
  • childish face,
  • excess body fat, especially around the abdomen,
  • decreased muscle mass, leading to weakness and difficulty performing physical exercise.

 

• In adults, growth hormone deficiency has both metabolic and physiological consequences:
  • excess body fat, especially around the abdomen,
  • muscle weakness,
  • decreased vitality and energy, with increased fatigue after physical activity,
  • bone tissue composition is affected with increased risk of fractures as a result,
  • elevated cholesterol and cardiovascular risk,
  • impaired psychological well-being and lower quality of life (reduced self-control, lower libido and weaker ability to concentrate).

Etiology or causes of growth hormone deficiency

The causes of growth hormone deficiency in children remains unknown for the most part (idiopathic in 75% of cases), but the deficiency is sometimes organic:

• congenital abnormal formation of the pituitary gland,
• lesion in the pituitary gland and/or hypothalamus caused by an infiltration (infiltrative disease), radiation therapy directed at the brain, severe head trauma, tumor, or infection, amongst others.
• hereditary condition.

In adults, it is important is to distinguish between a congenital deficiency (familial or sporadic) and an acquired deficiency (in adulthood) of unknown origin, or with damage to the hypothalamus- pituitary region (by a tumor, infiltration, necrosis, trauma, surgery, or radiotherapy).

Incidence

There is no accurate estimate of the number of children with growth hormone deficiency. In Europe and the United States, it varies between about one in 4,000 to 10,000 children. This variation is due to clinical polymorphism, the limits to growth hormone stimulation tests and problems interpreting the diagnostic threshold value.

In adults, the incidence of deficiencies discovered at birth is one in 5,000 to 10,000. For acquired deficiencies, the incidence is 10 per million per year.