From the Guidelines
A comprehensive medical evaluation is necessary to assess the 16-year-old male with no height gain over 4 years, focusing on potential endocrine disorders, nutritional deficiencies, chronic diseases, and genetic conditions. This evaluation should start with a detailed medical history, including birth history, childhood growth patterns, timing of puberty, family heights, chronic illnesses, medications, and nutritional status 1. A thorough physical examination should be performed, focusing on height, weight, BMI, arm span, sitting height, and Tanner staging to assess pubertal development.
Key considerations in the evaluation process include:
- Ordering laboratory tests such as complete blood count, comprehensive metabolic panel, thyroid function tests, IGF-1, bone age X-ray, and karyotype if indicated 1
- Assessing growth potential by calculating genetic target height based on parental height and evaluating the extent to which the epiphysis of the left wrist is open on radiography 1
- Considering endocrine disorders like growth hormone deficiency, hypothyroidism, or constitutional delay of growth and puberty, as well as nutritional deficiencies, chronic diseases (inflammatory bowel disease, celiac disease, kidney disease), and genetic conditions 1
Referral to a pediatric endocrinologist is essential for specialized evaluation and potential treatment options, which might include growth hormone therapy if appropriate and if growth plates haven't fused. Early intervention is crucial as treatment options become limited once growth plates close, typically around age 16-18 in males 1. The lack of height gain during what should be a period of significant growth warrants urgent medical attention. Regular measurement of height and calculation of height velocity over a minimum period of 6 months, compared with standardized growth charts, is also recommended 1.
From the FDA Drug Label
Therapy with Nutropin AQ should be supervised by a physician who is experienced in the diagnosis and management of pediatric patients with short stature associated with growth hormone deficiency (GHD), chronic kidney disease, Turner syndrome, idiopathic short stature, or adult patients with either childhood-onset or adult-onset GHD. Response to growth hormone (GH) therapy in pediatric patients tends to decrease with time However, in pediatric patients failure to increase growth rate, particularly during the first year of therapy, suggests the need for close assessment of compliance and evaluation of other causes of growth failure, such as hypothyroidism, under-nutrition, advanced bone age and antibodies to recombinant human GH (rhGH)
To access lack of height gain in a 16-year-old male with no increase in height over a 4-year period, the following steps should be taken:
- Evaluate compliance with any current growth hormone therapy
- Assess for other causes of growth failure, including:
- Hypothyroidism
- Under-nutrition
- Advanced bone age
- Antibodies to recombinant human GH (rhGH) It is essential to consult a physician experienced in the diagnosis and management of pediatric patients with short stature to determine the best course of action 2.
From the Research
Potential Causes of Lack of Height Gain
- Growth hormone deficiency (GHD) is a possible cause of lack of height gain in a 16-year-old male, as it can manifest differently at various developmental stages 3.
- Thyroid hormone changes can also affect growth hormone therapy, and regular monitoring of thyroid function is recommended in patients treated with recombinant human growth hormone (rhGH) 4.
Evaluation and Treatment
- A clinical and biochemical diagnosis of GHD can be challenging, and the diagnosis based on GH secretion stimulation tests may have limited usefulness for predicting therapy indications 3.
- Growth hormone treatment can lead to substantial height gain in children with idiopathic short stature (ISS), similar to those with isolated idiopathic GH deficiency (IGHD) 5.
- Thyroid function during growth hormone therapy can be affected, with changes in thyroxine (T4) to triiodothyronine (T3) conversion, and T3 levels may be decreased compared to an untreated healthy control group 6.
Mechanisms and Effects
- The effects of growth hormone on thyroid function are mediated by type 2 iodothyronine deiodinase in humans, which can lead to increased serum free triiodothyronine (fT3) levels and decreased serum free thyroxine (fT4) levels 7.
- Growth hormone therapy can alter thyroid function, and acromegaly often involves thyroid disease, highlighting the importance of monitoring thyroid function in patients treated with rhGH 7.