Low Dose Growth Hormone (GH) on Insulin Sensitivity and Cortisol Production Rates

Summary

Study hypothesis: Growth hormone (GH), through its generation of free 'bioavailable' insulin-like growth factor (IGF)-I, can improve insulin sensitivity in adults with GH deficiency. Study aims: The purpose of this study is to determine the mechanism of how low dose GH treatment affects the body's sensitivity to insulin actions and whether this low GH dose can affect the body's handling of steroid hormone levels (cortisol clearance) in adults with GH deficiency. Study design: Men and women with confirmed GH deficiency, but not recently been on GH treatment will be invited to participate in this study. The subjects will be assessed at the initial visit to ascertain their suitability before further participating in the study. If suitable, an equal number of men and women will be randomized to receive either low dose GH or placebo injection for 3 months. Before, during and after treatment, the subjects will be assessed at regularly with blood tests, scans and fat biopsies. At the first and final visit, testing will include scans to measure the amount of whole body fat and fat in the stomach area, muscle, and liver; blood tests to measure levels of cortisol, and fat tissue (taken from a biopsy) analysis to measure the density of IGF-I in the muscle; whereas blood tests to examine insulin sensitivity will also be collected. This study will use Genotropin and Genotropin pen devices, and the the data will be analyzed using a computer statistical program where the identity of the subjects will be coded to maintain confidentiality.

Timeline

Start

2006-01

Primary completion

2012-01

Completion

2012-01

Publications

• Background Yuen KC, Frystyk J, White DK, Twickler TB, Koppeschaar HP, Harris PE, Fryklund L, Murgatroyd PR, Dunger DB. Improvement in insulin sensitivity without concomitant changes in body composition and cardiovascular risk markers following fixed administration of a very low growth hormone (GH) dose in adults with severe GH deficiency. Clin Endocrinol (Oxf). 2005 Oct;63(4):428-36. doi: 10.1111/j.1365-2265.2005.02359.x.
• Background Yuen K, Frystyk J, Umpleby M, Fryklund L, Dunger D. Changes in free rather than total insulin-like growth factor-I enhance insulin sensitivity and suppress endogenous peak growth hormone (GH) release following short-term low-dose GH administration in young healthy adults. J Clin Endocrinol Metab. 2004 Aug;89(8):3956-64. doi: 10.1210/jc.2004-0300.
• Background Yuen K, Wareham N, Frystyk J, Hennings S, Mitchell J, Fryklund L, Dunger D. Short-term low-dose growth hormone administration in subjects with impaired glucose tolerance and the metabolic syndrome: effects on beta-cell function and post-load glucose tolerance. Eur J Endocrinol. 2004 Jul;151(1):39-45. doi: 10.1530/eje.0.1510039.
• Yuen KC, Roberts CT Jr, Frystyk J, Rooney WD, Pollaro JR, Klopfenstein BJ, Purnell JQ. Short-term, low-dose GH therapy improves insulin sensitivity without modifying cortisol metabolism and ectopic fat accumulation in adults with GH deficiency. J Clin Endocrinol Metab. 2014 Oct;99(10):E1862-9. doi: 10.1210/jc.2014-1532. Epub 2014 Jul 11.

Drugs

Indications