Laboratory Studies

A single measurement of plasma GH levels is difficult to interpret because of the pulsatile secretion of GH. Levels of IGF-1 vary little during the day; therefore, assays of IGF-1 have been used as a better indicator of the status of the GH–IGF-1 axis. Plasma IGF-1 levels decrease with aging, and an inverse correlation exists between age and IGF-1 levels. A cutoff IGF-1 level cannot be used for diagnostic purposes because the GH–IGF-1 axis is influenced by other factors besides aging (see Pathophysiology). Furthermore, evidence of an association between IGF-1 levels and measures of muscle strength, body composition, and physical functioning in older adults is lacking.

According to 2007 consensus guidelines for the diagnosis and treatment of adults with GH deficiency,^[19]the following patients should be considered for testing for growth hormone deficiency (GHD):

Patients with signs and symptoms of hypothalamic-pituitary disease
Those who have received cranial irradiation or tumor treatment
Those with traumatic brain injury or subarachnoid hemorrhage

In these patients, a low IGF-1 concentration increases the likelihood of GHD. Further testing may include a stimulation test, such as the insulin tolerance test (ITT), GHRH + arginine testing, GHRH + GHRP testing, or a glucagon stimulation test. The ITT is contraindicated in patients with ischemic heart disease or seizure disorders, and many authorities prefer not to use the ITT in patients older than 60 years.^[20]Patients who are deficient in at least three pituitary hormones and have an IGF-I level below the reference range have a greater than 97% chance of being GH deficient. For more details on how to diagnose GHD, see Hypopituitarism (Panhypopituitarism).

Medication

Sattler FR. Growth hormone in the aging male. Best Pract Res Clin Endocrinol Metab. 2013 Aug. 27(4):541-55. [Medline]. [Full Text].
Waters DL, Baumgartner RN, Garry PJ, Vellas B. Advantages of dietary, exercise-related, and therapeutic interventions to prevent and treat sarcopenia in adult patients: an update. Clin Interv Aging. 2010. 5:259-70. [Medline].
Harman SM, Blackman MR. The effects of growth hormone and sex steroid on lean body mass, fat mass, muscle strength, cardiovascular endurance and adverse events in healthy elderly women and men. Horm Res. 2003. 60(Suppl 1):121-4. [Medline].
Harman SM, Blackman MR. Use of growth hormone for prevention or treatment of effects of aging. J Gerontol A Biol Sci Med Sci. 2004. 59:652-8. [Medline].
Kiel DP, Puhl J, Rosen CJ, Berg K, Murphy JB, MacLean DB. Lack of an association between insulin-like growth factor-I and body composition, muscle strength, physical performance or self-reported mobility among older persons with functional limitations. J Am Geriatr Soc. 1998 Jul. 46(7):822-8. [Medline].
Sherlock M, Toogood AA. Aging and the growth hormone/insulin like growth factor-I axis. Pituitary. 2007. 10(2):189-203. [Medline].
Liu H, Bravata DM, Olkin I, et al. Systematic review: the safety and efficacy of growth hormone in the healthy elderly. Ann Intern Med. 2007 Jan 16. 146(2):104-15. [Medline].
[Guideline] 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. 2006 May. 91(5):1621-34. [Medline]. [Full Text].
Lin L, Saha PK, Ma X, et al. Ablation of ghrelin receptor reduces adiposity and improves insulin sensitivity during aging by regulating fat metabolism in white and brown adipose tissues. Aging Cell. 2011 Dec. 10(6):996-1010. [Medline].
Holzenberger M. Igf-I signaling and effects on longevity. Nestle Nutr Workshop Ser Pediatr Program. 2011. 68:237-49. [Medline].
Stochholm K, Berglund A, Juul S, Gravholt CH, Christiansen JS. Socioeconomic factors do not but GH treatment does affect mortality in adult-onset growth hormone deficiency. J Clin Endocrinol Metab. 2014 Nov. 99(11):4141-8. [Medline]. [Full Text].
Mihaila S, Mincu RI, Rimbas RC, et al. Growth hormone deficiency in adults impacts left ventricular mechanics: a two-dimensional speckle-tracking study. Can J Cardiol. 2015 Jun. 31(6):752-9. [Medline].
Melmed S. Idiopathic adult growth hormone deficiency. J Clin Endocrinol Metab. 2013 Jun. 98(6):2187-97. [Medline]. [Full Text].
[Guideline] Fleseriu M, Hashim IA, Karavitaki N, et al. Hormonal replacement in hypopituitarism in adults: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2016 Nov. 101(11):3888-921. [Medline]. [Full Text].
[Guideline] Cook DM, Yuen KC, Biller BM, Kemp SF, Vance ML, for the American Association of Clinical Endocrinologists. American Association of Clinical Endocrinologists medical guidelines for clinical practice for growth hormone use in growth hormone-deficient adults and transition patients - 2009 update. Endocr Pract. 2009 Sep-Oct. 15 Suppl 2:1-29. [Medline].
American Geriatrics Society 2015 Beers Criteria Update Expert Panel. American Geriatrics Society 2015 updated Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2015 Nov. 63(11):2227-46. [Medline].
Veldhuis JD, Iranmanesh A, Weltman A. Elements in the pathophysiology of diminished growth hormone (GH) secretion in aging humans. Endocrine. 1997 Aug. 7(1):41-8. [Medline].
Topaloglu O, Gokay F, Koparal SS, et al. Visceral fat measurement by ultrasound as a non-invasive method - can it be useful in evaluating subclinical atherosclerosis in male patients with hypopituitarism and growth hormone deficiency?. Endokrynol Pol. 2014. 65(3):195-202. [Medline].
[Guideline] Ho KK. Consensus guidelines for the diagnosis and treatment of adults with GH deficiency II: a statement of the GH Research Society in association with the European Society for Pediatric Endocrinology, Lawson Wilkins Society, European Society of Endocrinology, Japan Endocrine Society, and Endocrine Society of Australia. Eur J Endocrinol. 2007 Dec. 157(6):695-700. [Medline].
Rudman D, Feller AG, Nagraj HS, et al. Effects of human growth hormone in men over 60 years old. N Engl J Med. 1990 Jul 5. 323(1):1-6. [Medline].
Kokshoorn NE, Biermasz NR, Roelfsema F, Smit JW, Pereira AM, Romijn JA. GH replacement therapy in elderly GH-deficient patients: a systematic review. Eur J Endocrinol. 2011 May. 164(5):657-65. [Medline].
Samaras N, Papadopoulou MA, Samaras D, Ongaro F. Off-label use of hormones as an antiaging strategy: a review. Clin Interv Aging. 2014. 9:1175-86. [Medline].
Urban RJ. Growth hormone and testosterone: anabolic effects on muscle. Horm Res Paediatr. 2011. 76 Suppl 1:81-3. [Medline].
Brill KT, Weltman AL, Gentili A, et al. Single and combined effects of growth hormone and testosterone administration on measures of body composition, physical performance, mood, sexual function, bone turnover, and muscle gene expression in healthy older men. J Clin Endocrinol Metab. 2002 Dec. 87(12):5649-57. [Medline].
Elgzyri T, Castenfors J, Hagg E, Backman C, Thoren M, Bramnert M. The effects of GH replacement therapy on cardiac morphology and function, exercise capacity and serum lipids in elderly patients with GH deficiency. Clin Endocrinol (Oxf). 2004 Jul. 61(1):113-22. [Medline].
Haydar ZR, Blackman MR, Tobin JD, Wright JG, Fleg JL. The relationship between aerobic exercise capacity and circulating IGF-1 levels in healthy men and women. J Am Geriatr Soc. 2000 Feb. 48(2):139-45. [Medline].
Baker LD, Barsness SM, Borson S, et al. Effects of growth hormone–releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial. Arch Neurol. 2012 Nov. 69(11):1420-9. [Medline].
Bach MA, Rockwood K, Zetterberg C, et al. The effects of MK-0677, an oral growth hormone secretagogue, in patients with hip fracture. J Am Geriatr Soc. 2004 Apr. 52(4):516-23. [Medline].
Papadakis MA, Grady D, Black D, et al. Growth hormone replacement in healthy older men improves body composition but not functional ability. Ann Intern Med. 1996 Apr 15. 124(8):708-16. [Medline].
Kaiser FE, Silver AJ, Morley JE. The effect of recombinant human growth hormone on malnourished older individuals. J Am Geriatr Soc. 1991 Mar. 39(3):235-40. [Medline].
Morley JE. Scientific overview of hormone treatment used for rejuvenation. Fertil Steril. 2013 Jun. 99(7):1807-13. [Medline].
Borst SE. Interventions for sarcopenia and muscle weakness in older people. Age Ageing. 2004 Nov. 33(6):548-55. [Medline].
Blackman MR, Sorkin JD, Munzer T, et al. Growth hormone and sex steroid administration in healthy aged women and men: a randomized controlled trial. JAMA. 2002 Nov 13. 288(18):2282-92. [Medline].
Nutropin (R) [somatropin (rDNA origin) for injection] prescribing information. Genentech Inc. Available at http://www.gene.com/medical-professionals/medicines/nutropin-aq. Accessed: November 13, 2015.
Vitiello MV, Moe KE, Merriam GR, Mazzoni G, Buchner DH, Schwartz RS. Growth hormone releasing hormone improves the cognition of healthy older adults. Neurobiol Aging. 2006 Feb. 27(2):318-23. [Medline].
Sellami M, Bragazzi NL, Slimani M, et al. The effect of exercise on glucoregulatory hormones: a countermeasure to human aging: insights from a comprehensive review of the literature. Int J Environ Res Public Health. 2019 May 15. 16(10):[Medline]. [Full Text].
Gonzalez S, Windram JD, Sathyapalan T, Javed Z, Clark AL, Atkin SL. Effects of human recombinant growth hormone on exercise capacity, cardiac structure, and cardiac function in patients with adult-onset growth hormone deficiency. J Int Med Res. 2017 Dec. 45(6):1708-19. [Medline]. [Full Text].
Kuzma M, Kuzmova Z, Zelinkova Z, et al. Impact of the growth hormone replacement on bone status in growth hormone deficient adults. Growth Horm IGF Res. 2014 Feb. 24(1):22-8. [Medline].