What Is Growth Hormone Deficiency?
The pituitary gland is a small gland, about the size of a pea. It is located at the base of the skull and secretes hormones. Some of these hormones control thyroid activity and body temperature. A growth hormone deficiency (GHD) occurs when a person’s pituitary gland does not produce enough growth hormone. It is a condition common in children.
It typically first concerns parents when they notice that their child is not meeting developmental milestones for height and weight. Growth hormone deficiency affects roughly one in 3,000 short children (Danna K. et al., 2010). The condition is also a symptom of several genetic diseases, including Turner syndrome and Prader-Willi syndrome.
Growth hormone deficiency is very treatable. Excellent outcomes are typical for children who are diagnosed early. If left untreated, the condition can result in shorter-than-average height and delayed puberty. Although it is far less common, adults can also develop GHD.
What Causes Growth Hormone Deficiency?
If GHD is not present at birth, it may be caused by a tumor in the brain. These tumors are normally located at the site of the pituitary gland or the nearby hypothalamus region (Parks JS et al., 2011).
Children with cleft lips and/or cleft palates are also more likely to have GHD because they probably have poorly developed pituitary glands. In children and adults, serious head injuries, infections, and radiation treatments can also cause GHD (referred to as acquired growth hormone deficiency).
Symptoms of Growth Hormone Deficiency
Children with GHD are shorter than their same-sex peers and have younger, rounder faces. They may also appear chubby around the abdomen or have “baby” fat, even though their body proportions are normal. If GHD develops later in a child’s life, such as from a brain injury or tumor, its main symptom is delayed puberty. In some instances, sexual development is halted.
Many teens with GHD experience low self-esteem due to their developmental delays. Short stature and/or a slow rate of maturing—as in young women who have not developed breasts or young men whose voices have not changed—may be especially troubling.
How Is Growth Hormone Deficiency Diagnosed?
Physicians will look for signs of GHD if your child is not meeting his or her height and weight milestones. If there is the potential for GHD, a physician will often request information from the parents regarding the growth rates of other children in the family. Parents may be questioned about their own growth rates as they approached puberty. If GHD is suspected, a number of tests can confirm the diagnosis.
Blood tests can be used to measure the level of growth hormone in the body. However, a blood test with a lower-than-normal result is not enough evidence to make a diagnosis. That is because the levels of growth hormone in the body change radically throughout the day and night.
Kidney and thyroid function tests may also be done to determine how the body is producing and using hormones. X-rays of the hand can reveal whether or not the child’s growth plates have fused, indicating his or her level of bone growth. If a tumor or other damage to the pituitary gland is suspected, MRI imaging scans are used to get a detailed look inside the brain. Through testing, doctors can learn if the pituitary condition was present at birth or brought on by an injury or tumor.
How Is Growth Hormone Deficiency Treated?
Since the mid-1980s, synthetic growth hormones have been used with great success to treat both children and adults. (Prior to that time, natural growth hormone was removed from cadavers for treatment.)
Growth hormone is given by injection, typically into the body’s fatty tissues, such as the back of the arms, thighs, or buttocks. It is best delivered on a daily basis. Side effects are generally minor, but may include redness at the injection site, headaches, hip pain, and scoliosis (curving of the spine). In rare cases, long-term growth hormone injections may contribute to the development of diabetes, especially in people with a family history of that disease (Danna K. et al., 2010).
Children with congenital GHD are often treated with growth hormone until they reach puberty, though some remain in treatment for their entire lives. Often, children who have too little growth hormone in their youth produce enough naturally as they enter adulthood. Others must continue to receive treatment. By monitoring hormone levels in your blood, doctors can determine if you need ongoing injections.
Growth Hormone Deficiency in Adults
Adults can benefit from growth hormone injections if they have GHD due to damage to the pituitary gland from a brain tumor, surgery, infection, or radiation exposure. Symptoms of acquired growth hormone deficiency (AGHD) include low energy level, decreased sex drive, and weight gain, especially in the mid-section.
Another symptom of AGHD is reduced bone strength. This may lead to more frequent fractures, especially in older adults. Feeling tired and lacking stamina are common in people with low growth hormone levels. Increased sensitivity to hot or cold temperatures is also common. A variety of psychological symptoms, such as depression, lack of concentration, poor memory, and even bouts of anxiety or emotional distress are other symptoms of the condition.
Adults with AGHD typically have high levels of fats in the blood as well as high cholesterol. These abnormalities are not due to poor diet, but rather to changes in the body’s metabolism due to low levels of growth hormone. Therefore, adults with AGHD are at a greater risk for diabetes and heart disease (>Grinspoon, S. 2007).