GROWTH DISORDER

Underlying Conditions of Growth Abnormalities: It is often said that maintaining a normal growth pattern is a good indicator of a child's overall good health. Failure to grow at least 2 1/2 inches each year can be natures early warning sign that something underlying (unseen) is abnormal and needs medical evaluation. Growth is influenced by many factors such as heredity, genetic or congenital, illness and medications, nutrition, hormones, and psychosocial environment. Measurements of growth-height and weight - are a very inexpensive service that should be offered by all health care providers rendering care to children. Additionally it is also important that these be done correctly and included as a part of sick visits as well as "well child" check-ups.

Normal height growth rates vary according to age. Children during the first year of life should grow 7-10 inches. During the second year growth slows to an average of 5 inches /year. During the third year growth averages 3 inches/year. From age 4 years until puberty, growth should be at least 2 inches/year. Pubertal changes prompt a growth spurt of 2 ½ -4 ½ inches/year for girls usually starting by 10 years. However, boys experience both puberty and this growth spurt later - usually starting by 12 years and averaging 3 - 5 inches/year. After pubertal changes are completed and bone ends fuse, no further growth is possible.

Growth Hormone Excess : Signs and Symptoms

Adults with acromegaly will usually have large hands and feet, thick lips, coarse facial features, a protruding forehead and jaw, and widely spaced teeth. Often patients perspire excessively. Many of the signs and symptoms evolve slowly, so the diagnosis is often made years after the symptoms begin.

There are numerous symptoms that may be associated with acromegaly:

In children with gigantism, the main symptom is increased linear growth (height) causing extremely tall stature. This can also be associated with obesity, increased head size (macrocephaly) and a prominent forehead (also called frontal bossing).

Diagnostic Tests

GH stimulates the production of another chemical called insulin-like growth factor-1 (IGF-1) by the liver and by many body tissues. Because of the link between excess GH and excess IGF-1, measuring the level of IGF-1 in the blood is an effective screening test for GH excess. Another diagnostic test is measuring GH during an oral glucose tolerance test. Still another test is a magnetic resonance imaging (MRI) scan of the pituitary and hypothalamus. An MRI can determine whether a tumor is the cause of the excess hormone secretion.

Sometimes tests confirm that a patient has GH excess, but the MRI shows no obvious pituitary tumor. In this case, studies are undertaken to find another type of tumor in a body organ which produces a neurohormone, growth hormone-releasing hormone, normally produced by the hypothalamus. This ectopic hormone production has the capacity to stimulate the excessive release of growth hormone by the pituitary gland.

Growth Hormone Deficiency : Signs and Symptoms

Children. Most children with GHD grow less than two inches per year, whereas children with normal GH usually grow at least two inches annually. Some children with congenital GHD may grow normally until age two or three, but then their growth rate slows. Others may have a slow growth starting soon after birth.

Some children with GHD have extra fat in the abdomen and face. Their blood sugar levels also may be low. They may experience emotional distress because of their appearance, which differs from that of other children their own age. As adolescents, they may be slow to show signs of sexual maturity.

A primary care physician or pediatrician who suspects a child has GHD on the basis of a persistently below average growth rate with no other identifiable cause, should refer the patient to a pediatric endocrinologist for evaluation.

Adults. Adults with GHD fall into two general categories. Some individuals may have had GHD as a child and continue to have the deficiency. Other individuals may have acquired the deficiency after reaching maturity. The consequences of GHD in adults result from a lack of both GH and IGF-1.

The disorder has several possible symptoms in adults:

Diagnostic Tests

Although there is no gold standard for the diagnosis of GHD, GH stimulation tests are commonly used in patients who have symptoms, low IGF-1, and normal levels of other pituitary hormones. Because the pituitary gland secretes GH in bursts throughout the 24 hours, random measurements of levels in the blood are useless.

In applying a growth hormone stimulation test, if a patient’s GH levels in blood are outside the lower limits of a normal response, it is likely the patient has GHD. GH stimulation tests are not perfect, however, and some endocrinologists question their utility. Some children with putative GHD have stimulated GH concentrations in blood that are above the arbitrary cutoff values for the tests.

Although no stimulation test is perfect, the insulin tolerance test tends to be an excellent predictor of GHD. The test involves giving the patient insulin after an overnight fast to lower their blood sugar. Failure to respond to insulin-induced hypoglycemia is a strong indication of GHD. (This test is not appropriate for patients who have seizures or coronary artery disease.)

A good alternative to the insulin tolerance test is a stimulation test that uses GH-releasing hormone together with arginine — an amino acid necessary for the release of GH. This test is inappropriate for patients with liver or kidney disease.

Hormones and Growth Disorders

One of the glands in your body is called the pituitary gland (say: peh-too-eh-ter-ee). It's found at the bottom of your brain and is shaped like a peanut. It may be small in size, but it's pretty big in importance. One of the chemical messengers the pituitary gland sends out to your body is called growth hormone, which (no surprise) is essential for growth.

When the pituitary gland doesn't make enough growth hormone — and sometimes other pituitary hormones as well — the condition is called hypopituitarism (say: hi-po-peh-too-eh-ter-is-em). This can slow down a kid's growth. There are special tests to find out if children don't produce enough growth hormone. If they don't, daily shots of growth hormone can often help these kids grow to be normal-sized adults.

Another gland that produces hormones important for growth is your thyroid (say: thi-royd). You may be able to feel it if you press gently with your fingers across the front of your neck, just under your Adam's apple. It is shaped like a butterfly and moves up and down when you swallow.

Your thyroid makes a hormone called thyroxine (say: thi-rocks-in). If it makes too little, the condition is called hypothyroidism (say hi-po-thi-royd-is-em). Having too little thyroxine makes a kid grow more slowly. Doctors can do a simple blood test for hypothyroidism. If it's needed, a kid can take the missing hormone as a pill.