Approach To Testing Growth Hormone (GH) Secretion In Obese Subjects

Identification of adults with GH deficiency (GHD) is challenging because clinical features of adult GHD are not distinctive and because clinical suspicion must be confirmed by biochemical tests. Adults are selected for testing for adult GHD if they have a high pretest probability of GHD, ie, if they have hypothalamic-pituitary disease, if they have received cranial irradiation or central nervous system tumor treatment, or if they survived traumatic brain injury or subarachnoid hemorrhage. Testing should only be carried out if a decision has already been made that if deficiency is found it will be treated. There are many pharmacological GH stimulation tests for the diagnosis of GHD; however, none fulfill the requirements for an ideal test having high discriminatory power; being reproducible, safe, convenient, and economical; and not being dependent on confounding factors such as age, gender, nutritional status, and in particular obesity. In obesity, GH secretion is reduced, GH clearance is enhanced, and stimulated GH secretion is reduced, causing a false-positive result. This functional hyposomatotropism in obesity is fully reversed by weight loss. In conclusion, GH stimulation tests should be avoided in obese subjects with very low pretest probability.

Learning Objectives

Upon completion of this educational activity, participants shouldbe able to:

  • Identify patients who require GH stimulation testing for the diagnosis of adult GH deficiency.
  • Select an appropriate GH stimulation test.
  • Interpret the results of the GH stimulation test in an obese hypopituitary patient according to the available BMI-related cutoff limits defined for that test.

Additional Information

Target Audience: 
Physician-in-practice
Fellow
Resident
Clinical researcher
Scientific researcher
Educator/Teacher
Pharmacist
Nurse/Nurse practitioner
Physician assistant
Allied health professional
Other
Competency Area: 
Professionalism
Patient Care and Procedural Skills
Medical Knowledge
Topic Area: 
General Endocrinology
Growth Disorders
Level of Outcomes: 
Level 1 (Participation)
Level 2 (Satisfaction)
Level 3A (Learning: Declarative Knowledge (Knows))
Level 3B (Learning: Procedural Knowledge (Knows How))
Level 4 (Learning: Competence (Shows How))
Activity summary
Available credit: 
  • 1.00 AMA PRA Category 1 Credits
  • 1.00 CME Certificate of Participation
Course opens: 
05/01/2013
Course expires: 
05/31/2015
Rating: 
0

Disclosure Policy

Authors, editors, and Endocrine Society staff involved in planning this JCEM Journal-based CME activity are required to disclose to The Endocrine Society and to learners any relevantfinancial relationship(s) of the individual or spouse/partner that have occurred within the last12 months with any commercial interest(s) whose products orservices are discussed in the CME content. The Endocrine Societyhas reviewed all disclosures and resolved all identifiedconflicts of interest.

The following author reported no relevant financial relationships: Vera Popovic MD, PhD, FRCP

The following JCEM Editors reported relevant financial relationships:

The Editor-in-Chief, Leonard Wartofsky, M.D., is a Consultant for Asurogen, Genzyme, and IBSA, and is on the Speaker's Bureau for Genzyme. Kenneth Burman, M.D., is a Consultant for Medscape and UpToDate; a Reviewer for the Endocrine Fellows Foundation; and has received Institutional Grants for Research from Amgen, Eisei, and Pfizer. Samuel Dagogo-Jack, M.D., is a Consultant for Merck and Novo Nordisk; a Grantee for the American Diabetes Association, AstraZeneca, Boehringer Ingelheim, National Institutes of Health, and Novo Nordisk; and a Grant Reviewer for the American Diabetes Association and National Institutes of Health. Silvio Inzucchi, M.D., is a Consultant/Advisor for Boehringer Ingelheim, Genentech, Janssen, Merck, and Takeda; has DSMB Activity with Amgen, Esai, and Gilead; and receives CME support from Abbott, Amylin, Boeringher-Ingelheim, Merck, and Takeda. Kieren Mather, M.D., received an Investigator-initiated Grant from Novo Nordisk. Lynnette Nieman, M.D., is an Author/Editor for UpToDate, and receives Research Support from HRA-Pharmaceutical.

The following JCEM Editors reported no relevant financial relationships: Paolo Beck-Peccoz, M.D.; David Ehrmann, M.D.; David Handelsman, Ph.D.; Michael Kleerekoper, M.D.; Merrily Poth, M.D.; Constantine Stratakis, M.D.

Endocrine Society staff associated with the development of contentfor this activity reported no relevant financial relationships.

Acknowledgement of Commercial Support

JCEM Journal-based CME activities are not supported by grants, other funds, or in-kindcontributions from commercial supporters.

Available Credit

  • 1.00 AMA PRA Category 1 Credits
  • 1.00 CME Certificate of Participation

Accreditation Period

Course opens: 
05/01/2013
Course expires: 
05/31/2015