Adult GH Deficiency: Quick 6-question Quiz

As clinicians and researchers continue to advance their understanding of adult growth hormone deficiency (AGHD), knowing who is at risk for developing AGHD and how they will respond to therapy grows ever more important.

So, who is at risk for AGHD? What are the recommended diagnostic tools? How does growth hormone replacement therapy (GHRT) affect patients? Take our 6-question quiz on a few facts and some emerging evidence.

1. Patients should be tested for AGHD if there is evidence of hypothalamic-pituitary disease or related trauma, and in instances where there is an intention to treat with growth hormone.

A. True
B.  False

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Answer: A. True

Not all patients with reduced growth hormone or insulin growth factor-1 (IGF-1) are candidates for AGHD testing, such as elderly individuals or those patients with excess visceral adipose tissue, and so should not be subjected to diagnostic procedures.

2. Recent studies have found that AGHD  has resulted from involvement in popular sports including which of the following:

A. Boxing
B. Kickboxing
C. Football
D. Ice hockey
E. A and C
F. All of the above

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Answer: F.All of the above

Research has shed light on an increasing prevalence of disorders unrelated to pituitary adenomas or their treatment, including traumatic brain injury and head trauma related to sports such as ice hockey, boxing, kickboxing, football, soccer, and rugby.

3. Arginine, clonidine and L-dopa, used to diagnose GHD in children, are valid for diagnosing AGHD.

A. True
B. False 

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Answer: B. False

The current Endocrine Society clinical practice guidelines do not recommend these biochemical tools for diagnosis of AGHD. The clinical guidelines recommend the insulin tolerance test (ITT) as a preferred diagnostic tool and where it is not available or contraindicated, the glucagon stimulation test can be used. 

4. What is the validated cut-off value for peak GH response in the insulin tolerance test (ITT) for a biochemical diagnosis of severe AGHD (assuming no influence from factors such as age, GH secretion type, and body mass index)?

A. <3 µg/L
B. 4 µg/L - 5 µg/L
C. 5 µg/L - 6 µg/L
D. >6 µg/L

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Answer: A. <3 µg/L

Clinical guidelines state a valid cut-off value for peak GHD response to the ITT for a diagnosis of AGHD is <3 µg/L.

5. As is the case with GH treatment in children, replacement GH doses in adults are calculated on the basis of body weight.

A. True
B. False

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Answer: B.False

GH replacement dose calculated for adults based on body weight has led to a high frequency of adverse side effects, related primarily to fluid retention (eg, paresthesias, joint stiffness, myalgia). Instead, initiation in adults is with low doses followed by gradual uptitration to reach normal IGF-1 levels.

6. Which of the following is/are known health benefits of GHRT in AGHD?

A. Increased exercise capacity
B. Lower diastolic blood pressure
C. Improved total cholesterol
D. Increased bone mass
E. A and B
F. B and C
G. All the above

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Answer: D.All of the above

GHRT is known to improve exercise capacity and cardiovascular risk markers such as diastolic blood pressure and total cholesterol; GHRT has also been shown to increase bone mass and lean body mass.

References:

• Boguszewski CL. Update on GH therapy in adults. F1000Res. 2017; doi:10.12688/f1000research.12057.1.
   
• Molitch ME, Clemmons DR, Malozowski S, et al. Evaluation and treatment of adult growth hormone deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96:1587–609. 10.1210/jc.2011-0179