What Is Growth Hormone Deficiency?

Overview

Growth Hormone Deficiency (GHD), commonly known as dwarfism or pituitary dwarfism, is a medical condition in which the body produces or secretes low levels of growth hormone (GH) and can affect both children and adults. It has a prevalence of approximately 2-3 cases per 10,000 individuals in the population making it a relatively rare condition.¹

The pituitary gland, located deep within the brain, produces a hormone called growth hormone. This hormone is essential for normal growth, development, and metabolism during childhood and adolescence. The body receives instructions to produce growth hormones from different sources, including the hypothalamus. When there is an issue with the hypothalamus, pituitary gland, or in the communication between them, the normal release of growth hormone is disrupted, resulting in a deficiency of this hormone. Additionally, growth hormone plays a role in releasing other hormones, acting as chemical messengers. For example, it signals the liver to produce insulin-like growth factor (IGF-1), which is crucial for promoting growth during childhood.

Although GHD is a rare condition, awareness of GHD is essential for healthcare professionals, parents, and the general public to promote early diagnosis, appropriate treatment, support, and ongoing research for better outcomes and quality of life for individuals with GHD.

In this article, we will delve into the types, causes, symptoms, management and treatment options for growth hormone deficiency.

Different kinds of growth hormone deficiency

There are three primary categories of GHD, which are as follows:

• Congenital Growth Hormone Deficiency: Congenital GHD is present from birth and is usually caused by genetic abnormalities or malformations in the pituitary gland, which is present in the baby’s brain.
• Acquired Growth Hormone Deficiency: Acquired GHD refers to cases where the deficiency develops later in life due to damage to the pituitary gland. Both children and adults can experience acquired GHD.
• Idiopathic Growth Hormone Deficiency: The term "idiopathic" signifies that the cause of GHD is unknown. In some instances, GHD occurs without a known identifiable cause. 

Causes of growth hormone deficiency

Damage to the pituitary gland or hypothalamus can occur either due to abnormal development before birth (congenital) or as a result of events during or after birth (acquired) thereby causing GHD.

Congenital growth hormone deficiency can occur when there are mutations in genes involved in the development of the pituitary gland. However, the cause of most cases of congenital GHD is still unknown.

Acquired causes of growth hormone deficiency include

• Brain tumours located in the hypothalamus or pituitary gland
• Head trauma
• Radiation therapy is used during cancer treatment, especially if it affects the hypothalamus and pituitary
• Diseases that infiltrate the hypothalamus or disrupt its connection with the pituitary gland, such as histiocytosis
• Autoimmune conditions like lymphocytic hypophysitis.

Signs and symptoms of growth hormone deficiency

The signs and symptoms of growth hormone deficiency (GHD) can vary depending on the age at which the condition begins.²

Symptoms of GHD in Infants and Children:

GHD in infants and children primarily manifests as poor growth. The main indicator is slow height growth each year after the child's third birthday, with a growth rate of less than approximately 1.4 inches per year.

Further symptoms of GHD in children and infants include:

• Facial appearance is younger than expected for their age
• Impaired hair and nail growth
• Delayed development of teeth
• Delayed onset of puberty
• Low levels of blood sugar (hypoglycemia) in infants and toddlers
• Micropenis (very small penis) in newborns assigned male at birth

Symptoms of Adult-Onset GHD:

Symptoms of GHD that develop in adulthood can be more challenging to identify. Symptoms may include:

• Reduced overall sense of well-being
• Feelings of anxiety and/or depression
• Decreased energy levels
• Increased body fat, particularly around the abdomen
• Decreased muscle tone
• Decreased bone density leading to osteoporosis
• Insulin resistance, which is a contributing factor for Type 2 diabetes
• Elevated levels of LDL-cholesterol and triglycerides, increase the risk of heart disease

Management and treatment for growth hormone deficiency

People with GHD are typically treated with synthetic human growth hormones through daily injections. This prescription medicine is administered at home as a bedtime injection under the skin. There is also a new option of a sustained-release growth hormone, given weekly as an injection.

Regular check-ups with a doctor are necessary for individuals receiving GH therapy. In children, the doctor monitors growth response to growth hormone, changes in blood levels of IGF1 and bone age through X-rays.

GH therapy is effective in improving growth and achieving a normal adult height. Early diagnosis and treatment yield the best results. Some children can experience up to four inches (10 centimetres) of growth in the first year of treatment. Therapy continues until the child reaches its full adult height. In adulthood, re-evaluation is done to determine if GH therapy should be continued, but most childhood-onset cases of isolated GHD do not require therapy in adult life.

Diagnosis

To diagnose GHD, the healthcare provider will conduct a thorough assessment to rule out other conditions and evaluate the child's overall health. This includes:

• Checking for normal variations of growth, such as familial short stature.
• Assessing for other disorders like thyroid hormone deficiency or kidney disease.
• Considering genetic conditions that may contribute to growth issues.

The healthcare provider will inquire about the child's symptoms, medical history, and family health history. Additionally, a physical examination will be conducted, and the health and growth of the child may be monitored over several months.

Diagnostic tests may also be performed, which can include:

• Blood tests: These measure growth hormone and other related hormone levels. Sometimes, the blood tests are conducted after administering a substance that typically stimulates growth hormone production.
• X-ray: This imaging test uses a small amount of radiation to create images of internal tissues. X-rays of the left hand and wrist are commonly taken to estimate the child's bone age. In cases of delayed puberty or hormone problems, the bone age may be less than the chronological age.
• CT scan: This imaging technique involves a series of X-rays and a computer to produce detailed images of the body. It provides a comprehensive view of bones, muscles, fat, and organs, offering more detail than regular X-rays.
• MRI: Magnetic resonance imaging employs powerful magnets and a computer to generate high-resolution images of bodily tissues, aiding in the diagnostic process.

These tests help healthcare providers gather important information to confirm or rule out growth hormone deficiency and determine the most appropriate course of action for the child's health.

FAQs

How can I prevent growth hormone deficiency?

GHD is primarily caused by factors such as genetic mutations, congenital abnormalities, or acquired conditions that affect the pituitary gland or hypothalamus. Since these factors are largely beyond our control, it is challenging to prevent GHD from occurring in most cases.

However, there are a few general measures that can promote overall health and support optimal growth and development:

• Prenatal care: Ensuring adequate prenatal care during pregnancy is essential for the healthy development of the baby
• Early detection and treatment: Timely diagnosis and management of any medical conditions affecting the pituitary gland or hypothalamus, such as brain tumours or head injuries, can help minimize the risk of GHD.
• Healthy lifestyle: Encouraging a healthy lifestyle can support normal growth and development in children.
• Avoiding toxins and trauma: Taking precautions to minimize exposure to toxins and avoiding head injuries can help reduce the risk of acquired GHD.
• Genetic counselling: In cases where GHD is linked to genetic conditions or familial factors, genetic counselling may be beneficial.

How common is growth hormone deficiency?

Growth hormone deficiency (GHD) has an estimated prevalence of approximately 2-3 cases per 10,000 individuals in the population. It is relatively a rare medical condition.¹

Who is at risk of growth hormone deficiency?

Overall, while GHD can affect individuals across different age groups, children and individuals with underlying medical conditions or a history of brain-related issues are more commonly affected.

When should I see a doctor?

If you suspect that you or your child may have GHD, it is important to consult a healthcare professional for a thorough evaluation. Here are some indications of when to see a doctor regarding GHD:

• Delayed growth: If your child's growth is significantly below the average rate for their age or if they are consistently falling behind their peers in terms of height, it may be a cause for concern and warrant a visit to the doctor.
• Short stature: If you or your child is noticeably shorter than other family members or peers of the same age and sex, it is advisable to seek medical advice.
• Slow development: If your child's physical development seems delayed compared to their peers, like delayed puberty or slow progression through puberty stages, it may be a sign of GHD and should be evaluated by a healthcare professional.
• Unexplained symptoms: If you or your child experience symptoms often associated with GHD, such as fatigue, decreased muscle strength, decreased bone density, or changes in lipid profiles, it is recommended to consult a doctor for further assessment.

Summary

Growth hormone deficiency is a medical condition that can significantly impact the growth, development, and overall well-being of affected individuals. Early diagnosis and appropriate treatment, such as growth hormone replacement therapy, can help mitigate the symptoms and improve the quality of life for both children and adults with GHD. If you suspect GHD in yourself or your child, it's important to consult with a medical professional specialized in endocrinology or pediatric endocrinology for proper evaluation and guidance.