Growth hormone deficiency (GHD) is a rare pediatric condition that leads to slower than normal growth in children. It impacts only 1 in 4,000 to 1 in 10,000 children1, but it can trigger additional muscle and bone problems, as well as emotional and mental stress. Early diagnosis of growth hormone deficiency can change the course of a child’s health and future. Pediatric stimulation testing offers a clear path toward identifying growth hormone deficiency and providing timely treatment.
The pediatric endocrinologists at Maimonides Children’s Hospital are regional leaders in providing this testing. They can see children with suspected GHD within a few weeks of referral, potentially increasing access to this evaluation.
“The awareness of short stature and height problems is very high,” says Irina Kazachkova, MD, Director of Pediatric Endocrinology at Maimonides. “Pediatric stimulation testing is necessary to address this concern and get these children the treatment they need to avoid long-term problems.”
Diagnosing Growth Hormone Deficiency
GHD is a hormonal condition that occurs when a child’s pituitary gland doesn’t produce enough of the growth hormone somatotropin. In the most severe cases, growth velocity may slow down in infancy or right after birth, but it is most commonly discovered in patients around 2 to 3 years of age. In addition to growth reduction, this condition also contributes to several other health problems, including delayed tooth development, late-onset puberty, less hair growth, and low bone density.
Timely GHD diagnosis and treatment is critical, Dr. Kazachkova says. With appropriate treatment, children can reach a normal height, develop better lean muscle mass and bone density, and lower some of their risks for cardiovascular disease later in life.
Accurately diagnosing GHD can be a multistep process. Pediatricians and primary care providers use standard sex-appropriate height, weight, and BMI charts to determine if a child has short stature and/or slower than normal growth velocity. They match child’s height to genetic height, also called mid-parental height, and to pubertal status in older children. Blood and bone age tests also provide valuable information. But none of these details can point to a definitive diagnosis, Dr. Kazachkova says.
“Assessment of pituitary GΗ production is difficult because GH secretion is pulsatile, with the most consistent surges in sleep,” explains Dr. Kazachkova. “Between normal pulses of GΗ secretion, serum GH levels are low, often below the limits of sensitivity of most conventional assays. Thus, measurement of a random serum GΗ level is not helpful in diagnosing GНD — instead, insulin-like grοԝth factor 1 (ІGF-1) and insulin-like growth factor binding protein-3 (ІGFBΡ-3) are measured because they reliably represent GH sufficiency or deficiency.”
With this in mind, the diagnosis of GHD is made with a combination of clinical assessment and height and GV measurements, IGF-1 and ІGFBΡ-3 levels, and GН stimulation tests.
Pediatric GH stimulation testing makes it possible to discern GH levels as they fluctuate; it’s a more targeted blood test that evaluates a patient’s growth hormone level at a designated time after direct exposure to stimuli. Based on the results, providers can see specific growth hormone level changes and can diagnose growth hormone deficiency if a patient’s growth hormone level does not rise to within the normal range (10 ng/mL to 50 ng/mL) after stimulation.
Pediatric Stimulation Testing
Pediatric stimulation testing is a lengthy process, Dr. Kazachkova says. This fasting, ambulatory test can last between two and five hours, and it requires multiple blood draws to monitor growth hormone levels.
There are five different medications providers can use to stimulate growth hormone production. Maimonides endocrinologists use two: arginine and clonidine. Arginine is an intravenous medication, and clonidine is a blood pressure medication, delivered as a pill, that also triggers an increase in growth hormone. With both medications, providers conduct blood tests every 30 minutes to pinpoint when and at what measurement the patient’s level peaks.
Streamlined Access to Treatment
While pediatric stimulation testing is vital for proper diagnosis, it has another, equally important role, Dr. Kazachkova says. It opens the door for children to get easier access to the daily synthetic hormone injection therapy that endocrinologists most commonly prescribe for this condition.
“GH stimulation testing determines final diagnosis of GH deficiency, and thus a patient’s eligibility for growth hormone treatment,” she says. “GH isn’t a medication we can freely use without appropriate testing and eligibility criteria, but as soon as a child is diagnosed with growth hormone insufficiency or deficiency, the availability of growth hormone treatment is virtually 100%.”
The Maimonides Difference
As pioneers in pediatric endocrine care, the Maimonides Children’s Hospital team is dedicated to bringing specialized testing and compassionate care to children and families across our region. Although pediatric stimulation testing is an outpatient procedure, it’s a lengthy process. Sitting through hours of testing can be difficult for young children and their parents, Dr. Kazachkova says. To make patients as comfortable as possible, the multidisciplinary team of endocrinologists, nurse practitioners, and nurses perform all testing at Maimonides’ Infusion Center.
“Our Infusion Center is fully set up to make this testing process as relaxed as possible,” she says. “They have extensive experience with infusions to make medication delivery easier.”
Beyond clinical expertise, Maimonides provides a calming environment designed to ease the testing experience for young children and their families, with a multidisciplinary team is on hand to monitor and attend to children throughout the entire test. Additionally, each infusion bay is equipped with comfortable chairs, televisions, and entertainment materials to reduce stress and anxiety for each patient.
For children showing signs of growth delay, Dr. Kazachkova says, pediatricians and primary care providers should consider an early referral for specialist evaluation. In many cases, Maimonides endocrinologists offer expedited next-day appointments and the expertise necessary to ensure accurate diagnosis and timely intervention. This rapid access allows primary care providers to move children quickly toward the care they need, giving families peace of mind and confidence in their child’s growth journey.
“If a provider is concerned about a child with short stature, I advise them to send that patient to us for evaluation,” she says. “We can determine if they need pediatric stimulation testing and can help them enroll in treatment upon diagnosis.”
For more on pediatric stimulation testing and our comprehensive approach to growth disorders, visit https://maimo.org/treatments-care/childrens-hospital/pediatric-endocrinology-and-diabetes-care/ or call (718) 283-7500 to make a referral.
1: https://pmc.ncbi.nlm.nih.gov/articles/PMC3279941/
