True or false? Clinicians should use 2 growth hormone stimulation tests to diagnose patients suspected of idiopathic AGHD. Answer plus 5 more.
The Endocrine Society Clinical Practice Guidelines for evaluation and treatment of adult growth hormone deficiency (AGHD), published in 2011, are the latest authority on how to evaluate and treat patients with the disease.
How will your answers match up with the Endocrine Society Task Force’s recommendations for AGHD treatment? Test your knowledge in this 6-question quiz.
1. Patients with childhood-onset growth hormone deficiency (GHD) should be retested for AGHD if they reach adult height and display which of the following:
A. Embryopathic lesions responsible for hormone deficits
B. Known genetic mutations
C. Irreversible structural lesions/damage
D. A and C
E. A, B, and C
Answer: E. A, B, and C. Multiple studies have reported that GHD in children that is a result of embryopathic lesions, genetic mutations, and damage to the hypothalamic-pituitary axis does not revert to normal growth hormone status when transitioning to adulthood.
2. Clinicians should use 2 growth hormone stimulation tests to diagnose patients suspected of idiopathic AGHD.
Answer: A. True. Idiopathic AGHD is a rare diagnosis and growth hormone stimulation tests have a high false positive rate, so clinicians should use 2 tests to confirm diagnosis. Low insulin growth factor-1 (IGF-I) is also an indicator of a correct diagnosis of idiopathic AGHD.
3. A patient with a low IGF-I level and without which of the following conditions should receive growth hormone stimulation testing to diagnose AGHD:
A. Liver disease
B. Poorly controlled diabetes
C. Oral estrogen therapy
D. All of the above
Answer: D. All of the above. Low IGF-I levels can be indicative of AGHD provided a patient does not have a blunted response to growth hormone as a result of increased oral estrogen such as seen in cases of a liver disease, poorly controlled diabetes, and during administration of oral estrogen therapy.
4. Provocative testing for AGHD is optional if a patient has one or more deficiencies present in pituitary axes.
Answer: B. False. The Endocrine Society guidelines state that deficiencies in 3 or more pituitary axes “strongly suggests” the presence of GHD, and provocative testing may be unnecessary. One study revealed that deficiencies in 3 pituitary axes together with an IGF-1 level of <84 ng/mL was equally predictive of disease as proactive growth hormone testing.
5. Patients with GHD who have an abnormal dual-energy X-ray absorptiometry (DXA) scan should receive a repeat measurement at which of the following time points:
A. 3 months
B. 6 months
C. 1 year
D. 2 years
Answer: D. 2 years. DXA measurements should be repeated every 2 years in patients with abnormal results, and the guidelines note that testing should be done “expeditiously” for patients transitioning from childhood to adulthood in whom growth hormone therapy has been stopped.
6. Dosing of growth hormone should be based on body weight, with fixed doses of sequential growth hormone administered beginning at 4 µg/kg, 8 µg/kg and 12 µg/kg per day.
Answer: B. False. Although dosing of growth hormone for adults was initially adopted from pediatric practice, researchers soon learned that fixed doses were supraphysiological and associated with side effects of AGHD such as joint stiffness, arthralgias, paresthesias, peripheral edema, and myalgias.
Endocrine Society, Molitch ME, Clemmons DR, et al. Evaluation and treatment of adult growth hormone deficiency: An endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2011;96:1587-1609.