Exploring the factors that affect growth
Each child’s potential for height is based on genes inherited from both parents. Parents tend to have children that are about their own height. However, if some growth disorder is suspected, a physical examination and review of the family history may yield important clues about a childs growth potential.
Nutrition also influences growth. Children need a good balanced diet that is full of nutrients in order to grow properly and reach their full potential.
Children with medical conditions that prevent the body from using nutrients are often smaller than expected. Some examples of these conditions are cystic fibrosis, diabetes, and various digestive disorders. Children, particularly girls, who deliberately limit their food intake can inhibit their growth rate.
Factors that promote healthy growth include regular exercise, adequate rest, and a nurturing environment.
How hormones affect growth
Several hormones are needed for normal growth. An important one is growth hormone made by the pituitary gland. Apart of the brain called the hypothalamus signals the pituitary gland to release growth hormone during sleep, after exercise, and when the, level of blood glucose, a simple sugar needed for energy, is low. Even after reaching full height, the pituitary gland continues to make growth hormone. While adults dont need the hormone to grow, they may benefit from its effect on metabolism.
Other hormones that affect growth are produced by the thyroid, adrenals, pancreas, ovaries, and testes. If growth problems are suspected, the thyroid is usually evaluated first, as it has a strong influence on growth rate.
Under the influence of hormones in childhood, bones form as cartilage, then gradually lengthen and
calcify into bone. Until full growth is achieved, areas of cartilage remain at the ends of bones. These are called growth plates. X-rays of the hand show the status of growth plates and enable doctors to estimate bone age and how much growth can be expected. Eventually, when the growth plates harden into bone, further growth is not possible.
When things go wrong
If hormone levels are high, children may experience early development. In a condition called precocious puberty, children show signs of puberty earlier than usual. They also grow at a faster rate than other children of the same age. The bones mature too fast, and the growth plates may close too soon, which may affect adult height.
A lack of hormones may result in children who are small for their age. They may not mature at the time normally expected. On x-ray, their growth plates reflect a delayed bone age.
Correcting hormone imbalance
Fortunately, hormone imbalances can often be corrected. Hormone levels that are low can be brought up to normal with synthetic hormones that work just like the ones the body makes naturally. Hormone levels that are too high may be treated with drugs or other hormones that have an opposite effect.
It is very important to follow instructions and take hormone replacement other medications exactly as your doctor tells you.
Special Considerations
Children may suffer from feeling “different” from others their age, which can lead to emotional upsets. It is usually best to get help from medical professionals who specialize in disorders of the endocrine system. They can provide medical care, information, practical advice, and help with emotional and social concerns.
Early influences on maturation rate and growth
Genes
Congenital factors
- Chromosomal variations -Turner and Down syndromes
- Birth defects (congenital heart disease, kidney malformation)
Environment
- Intrauterine growth retardation – smoking, alcohol/drug use
- Idiopathic
Nutritional factors influencing growth
Inadequate diet
- Anorexia, bulimia
Diseases that prevent the body from using nutrients
- GI (celiac, Crohns, motility problems), CF, diabetes not adequately controlled
Hormonal influence on growth
Hypothalamus in the brain controls the pituitary with two peptides
- GHRH signals the release of growth hormone (GH)
- GHRIH (somatostatin) inhibits GH release
GH travels through the blood stream
- GH stimulates growth plates of long bones
- GH signals release of insulin-like growth factor I (IGF-1) by the liver and other tissues
Other hormones affecting growth
- Thyroxine secreted by the thyroid promotes growth
- Cortisol secreted by the adrenal glands in excess can inhibit growth
- Insulin produced by the pancreas is needed for normal growth
- Estrogens and androgens affect growth and maturation
Psychosocial factors
- Home environment
- Stress
Therapy
- Appropriate diet with adequate nutrients
- Nurturing environment
- Hormone replacement therapy
- Hormone suppression therapy
Special considerations
- School performance
- Body image
- Social interaction
