What is Growth Hormone Deficiency?
Growth hormone deficiency (GHD) occurs when the pituitary gland fails to produce enough growth hormone. It primarily affects children, with adults being less commonly affected. The pituitary gland is a small gland about the size of a pea, located at the base of the brain, and responsible for releasing multiple hormones that regulate functions like thyroid activity and body temperature.
GHD affects approximately 1 in 4,000 to 1 in 10,000 children and 2 to 3 in 10,000 adults. Additionally, GHD can be a symptom of several genetic conditions, such as Prader-Willi syndrome.
As a parent, you might be concerned if your child isn’t meeting height and weight milestones, but if your child has GHD, it is important to know that the condition is treatable. Children diagnosed early typically respond very well to treatment. If left untreated, however, GHD can result in shorter stature and delayed puberty.
Growth hormone remains important even after puberty. In adulthood, growth hormone plays a key role in maintaining body structure and metabolism. Although GHD is less common in adults than in children, it can still occur.
Causes of Growth Hormone Deficiency
Congenital Growth Hormone Deficiency
Congenital GHD refers to cases where the condition is present from birth, often due to genetic mutations or incomplete development of the pituitary gland.
Acquired Growth Hormone Deficiency
Acquired GHD (AGHD) is typically caused by brain tumors, head injuries, infections, or radiation treatments. Tumors are often located on the pituitary gland or in the nearby hypothalamus region of the brain.
The majority of GHD cases are idiopathic, meaning no clear cause is found.
Symptoms of Growth Hormone Deficiency
Symptoms in Children
Children with GHD are usually shorter than their peers and have rounder, younger-looking faces. They may also have “baby fat” around their abdomen, even if their body proportions appear otherwise normal.
If GHD develops later in childhood due to a brain tumor or injury, the primary symptom may be delayed puberty. In some cases, sexual development may stop altogether.
Symptoms in Adolescents and Adults
Many teenagers with GHD experience low self-esteem due to developmental delays, such as shorter stature or a slower rate of physical maturation. For instance, young women may not develop breasts, and young men may not experience voice changes at the same rate as their peers.
Adults with AGHD may experience fatigue, low stamina, and sensitivity to temperature extremes. Additionally, they are more likely to have psychological issues, including:
- Depression
- Difficulty concentrating
- Memory problems
- Anxiety and emotional distress
Adults with AGHD typically have higher levels of fat in their blood, as well as increased cholesterol levels. These changes are not due to diet, but rather to alterations in metabolism caused by low growth hormone levels. Adults with AGHD are at higher risk for diabetes and heart disease.
How is Growth Hormone Deficiency Diagnosed?
If your child is not meeting height and weight growth standards, your doctor may look for signs of GHD. They will ask about your child’s growth history and any family history of growth patterns. If GHD is suspected, the doctor may order tests to confirm the diagnosis.
Since growth hormone levels fluctuate throughout the day and night, a single blood test showing lower-than-normal results is not enough to make a diagnosis. Instead, the doctor may use the following tests:
- IGF-1 and IGFBP-3 Tests: These are stable markers of growth hormone function that are measured in the blood.
- Growth Hormone Stimulation Test: If screening tests suggest GHD, this test may be used to confirm the diagnosis.
- X-ray of Bone Growth: X-rays of your child’s hand can show the level of bone development. If a child’s bone age is significantly younger than their chronological age, GHD could be the cause.
- MRI Scan: If a tumor or damage to the pituitary gland is suspected, an MRI can provide a detailed view of the brain.
How is Growth Hormone Deficiency Treated?
Since the mid-1980s, synthetic growth hormones have been used with great success to treat GHD in both children and adults. Prior to synthetic growth hormone, natural growth hormone derived from cadavers was used for treatment.
Growth hormone is typically administered by injection, usually into fatty tissues such as the back of the arms, thighs, or buttocks. The most effective treatment is daily injections.
Side Effects
Most side effects are mild, including:
- Redness at the injection site
- Headaches
- Hip pain
- Worsening of preexisting scoliosis (curvature of the spine)
In rare cases, long-term use of growth hormone injections may contribute to the development of diabetes, particularly in individuals with a family history of the condition.
Long-Term Treatment and Outlook
Children with congenital GHD are often treated with growth hormone until they reach puberty. Some people who had low growth hormone in childhood may begin producing enough as they enter adulthood, but others may require ongoing treatment throughout their lives. Your doctor will monitor blood hormone levels to determine whether ongoing injections are needed.
Long-Term Outlook
Many individuals respond very well to treatment. The earlier treatment begins, the better the results. If you suspect that you or your child has GHD, it’s important to consult a doctor as soon as possible.
For more information about growth hormone deficiency, visit Children’s Hospital and Endocrine Practice Journal .
