Side effects of Growth Hormone Treatment
Although few patients experience adverse events from growth hormone therapy, the following complications have been recognized:
Carbohydrate metabolism: Growth hormone has an anti-insulin effect, and carbohydrate metabolism has been monitored in many clinical studies of growth hormone therapy. A review of large databases containing more than 35,000 patients on growth hormone and more than 75,000 patients with years of exposure indicates no greater incidence of type 1 diabetes than would be expected in the general population of age-matched children. One study of an increased incidence of type 2 diabetes in children undergoing growth hormone therapy with risk factors for diabetes suggests that growth hormone may cause earlier expression of this condition.
Benign intracranial hypertension (pseudotumor cerebri): A clear association between intracranial hypertension and growth hormone therapy is observed. The incidence appears to be about 0.001 (21 cases reported out of 19,000 patients receiving growth hormone, or 50,000 patient-years). Usually, severe headache symptoms (occasionally with vomiting) develop during the first 4 months of therapy. The risk of this complication increased in children receiving growth hormone for chronic renal insufficiency. In most cases, cessation of growth hormone therapy resolved the intracranial hypertension; the growth hormone then could be restarted at a lower dose and slowly titrated back to the usual dose.
Fluid homeostasis: Growth hormone affects fluid homeostasis, which may lead to edema and even carpal tunnel syndrome. These problems are more common in adults receiving growth hormone. When these occurrences become sufficiently serious to require action, stopping the growth hormone provides resolution. Restarting the growth hormone at a lower dose and slowly titrating it back to the usual dose is usually possible.
Skeletal and joint problems: Children receiving growth hormone therapy are more susceptible to slipped capital femoral epiphysis (SCFE). Yet children with growth hormone deficiency (GHD), hypothyroidism, or renal disease seem to have increased risk for SCFE, even without growth hormone therapy. When a child receiving growth hormone therapy complains of hip or knee pain, a careful physical examination is vital, and, if warranted, hip radiography. Scoliosis progression is another skeletal-related complication of growth hormone therapy. Scoliosis relates to the rapid growth that occurs with therapy and is not a direct effect of the growth hormone. Patients with scoliosis who are treated with growth hormone should have their scoliosis monitored during therapy.
Prepubertal gynecomastia: Although adolescent gynecomastia is common, prepubertal gynecomastia occurs less frequently. Such cases have been reported in association with growth hormone therapy, although whether the gynecomastia is related to the growth hormone is unclear. Prepubertal gynecomastia is a benign condition that resolves without sequelae.
Leukemia: Several worldwide databases have been examined in response to sporadic reports of leukemia in patients undergoing growth hormone therapy. When patients with other risk factors (eg, previous history of leukemia, radiation, chemotherapy) are excluded, no increased risk of leukemia has been demonstrated. No evidence suggests an association between growth hormone therapy and leukemia in otherwise healthy children.