ROLE OF THE PITUITARY GLAND IN GROWTH
In some cases, a lack of normal growth in children may be caused by a deficiency in a certain hormone, learns Kasmiah Mustapha
THE growth hormone is critical in the growth and health of all tissues of the body. Synthesised and stored in the pituitary gland, it controls many of the body’s functions. In children it fuels growth and strengthens bones and muscles, while in adults it helps them stay healthy. However, children and adults can suffer from growth hormone deficiency (GHD).
It happens when the child is born without the pituitary gland or the gland does not produce enough growth hormone.
GHD in adults is caused by harm to the brain or the pituitary gland. This may be congenital or due to surgery or radiation treatment of the pituitary gland.
“For children, if you wait until they are 11 to 12 years, it will be too late. To get optimum height increase, we need at least three years of treatment.” Associate Professor Dr Muhammad Yazid Jalaludin
GROWTH CHART
Universiti Malaya Medical Centre consultant paediatric endocrinologist Associate Professor Dr Muhammad Yazid Jalaludin says due to GHD, children are unable to achieve normal growth rates and may suffer other health issues such as lower muscle mass and bone mineral density, elevated blood pressure, lowdensity lipoprotein levels (LDL) as well as an increased risk of cardiovascular disease.
“Growth hormone starts to play a prominent role in a child’s physical development 2 to 5 years of age. Children with growth hormone deficiency do not grow properly. In addition to the short stature, the child is overweight, especially with abdominal fat and does not have enough muscle bulk. Their bones are thinner and can easily break.”
Dr Muhammad Yazid says parents and doctors should plot a growth chart to track a child’s height. A child should grow about 5cm to 7cm per year and if he is growing less than 4cm a year, it is time to refer him to a paediatric endocrinologist, who specialises in treating growth and hormone problems.
Unfortunately, the condition is rarely spotted as parents and family members tend to think short children will start to grow once they hit puberty, he says.
“Treatment of growth hormone deficiency should start as soon as possible once the patient is diagnosed to achieve the best possible outcome. The growth hormone therapy is to fix not only the growth issue but also to avoid other major diseases at an early age, such as high cholesterol and brittle bone disease.
“For children, if you wait until they are 11 to 12 years, it will be too late. To get optimum height increase, we need at least three years of treatment. But for a girl, the treatment is no longer effective if she is already menstruating.”
He says in Malaysia, recombinant human growth hormone for patients with growth hormone deficiency has been commercially available since 1985. However, usage of growth hormone therapy has not increased as fast as it could, due to lack of awareness — not just among the public but also among some healthcare practitioners.
RARE OCCURRENCE
Dr Muhammad Yazid says as GHD affects only a small segment of the population, about 0.0003 per cent, many healthcare practitioners may never have encountered such cases. This can cause misdiagnosis, which leads to delay in treatment and negatively affects the outcome.
“For example, small for gestational age (SGA) patients are often misdiagnosed or are diagnosed late, leading to a less-than-optimum treatment outcome. They are the largest group that can benefit from growth hormone therapy, compared to other patients with growth hormone disorders.
“Increasing awareness and subsequently making every effort to diagnose and treat children at an early stage is crucial, as the therapy should-begin as soon as possible to optimise the benefits”.
However, Dr Muhammad Yazid warns that growth hormone therapy should not be used before consulting a doctor. Patient requirements should be evaluated on a case-by-case basis before commencing treatment. This includes the selection of the most appropriate dosage for the individual patient.
Meanwhile, adults with GHD have increased body fat, reduced muscle bulk, reduced strength and physical fitness, mood swings and anxiety. They also face an increased risk of cardiovascular conditions related to elevated blood pressure and high LDL cholesterol level. The growth hormone therapy aims to treat these conditions.
kasmiah@nst.com.my