Lavin Chapter 12

Chapter 12 • Growth Hormone in Adults   141

3. GH dosing should take age, sex, and estrogen status into consideration. 4. During GH treatment, patients should be monitored at regular intervals, such as every 1 to 2 months during dose titration and every 6 months thereafter with a clinical assessment and an evaluation for adverse effects, IGF-1 levels, and other parameters of GH response. XXIV. CONCLUSION A. The treatment of GHD in adults has been reported to improve quality of life and energy levels, reduce pain, improve depression, enhance self-esteem, improve cho- lesterol and LDL levels, enhance cognitive psychometric performance, improve exercise capacity, and improve muscle strength. GH therapy offers benefits in body composition, skeletal integrity, and quality of life measures. However, reductions in cardiovascular events and mortality have yet to be absolutely demonstrated. B. Many endocrinologists remain skeptical of using GH as treatment for GH-deficient adults and, therefore, a large fraction of patients who have this deficiency are not treated. It appears that more long-term treatment data will be required to provide reassurance as to whether GH treatment is a safe and necessary form of hormone replacement therapy for adult patients with GHD. XXV. FUTURE CONSIDERATIONS In animal models, IGF-1 promotes survival and myelinization of neuronal cells as well as stimulating brain angiogenesis in response to hypoxic stimuli caused by ischemia or trauma. It is possible that higher serum IGF-1 levels could promote an increased delivery of IGF-1 from the periphery to brain-damaged cells. IGF-1 can cross the blood–brain barrier. Low IGF-1 levels during the acute phase of stroke are associated with a poor outcome or even death. Higher IGF-1 levels, on the other hand, were observed in patients with better outcomes, suggesting a possible neuroprotective role of IGF-1 and its potential use to improve motor and cognitive recovery during rehabilitation after stroke. The role of GH in normal aging is poorly understood. This is a new area of research, and additional recommendations about risks and benefits will evolve in the near future. Decreases in GH secretion with age may contribute to cognitive changes associated with aging. Future studies are needed to prove that cognitive performance, short-term memory, and basic processing speed are improved with GH treatment. SELECTED REFERENCES Aimeretti G, Ghigo E. Should every patient with traumatic brain injury be referred to an endocrinologist? Nat Clin Pract Endocrinol Metab 2007;3(4):318–319. Barake M, Klibanski A, Tritos NA, et al. The effect of HGH on bone mineral density in adults with growth hormone deficiency. J Clin Endocrinol Metab 2014;99(3):852–860. Bennett RM. Adult growth hormone deficiency in patients with fibromyalgia. Curr Rheumatol Rep 2002;4(4):306–312. Böger RH. Nitric oxide and the mediation of the hemodynamic effects of growth hormone in humans. J Endocrinol Invest 1999;22(5 suppl):75–81. Bondanelli M, Ambrosio MR, Onofri A, et al. Predictive value of circulating insulin-like growth factor I levels in ischemic stroke outcome. J Clin Endocrinol Metab 2006;91:3928–3934. Bourron O, Le Bouc Y, Berard L, et al. Impact of age-adjusted insulin-like growth factor 1 on major cardiovascular events after acute myocardial infarction. Results from the FAST-MI registry. J Clin Endocrinol Metab 2015;100(5):1879–1886. Burger AG, Monson JP, Colao AM, et al. Cardiovascular risk in patients with growth hormone deficiency: effects of growth hormone substitution. Endocr Pract 2006;12(6):682–689. Chikani V, Cuneo RC, Hickman I, et al. Impairment of anaerobic capacity in adults with GHD. J Clin Endocrinol Metab 2015;100(5):1811–1818. Climent VE, Picó A, Sogorb F, et al. Growth hormone therapy and the heart. Am J Cardiol 2006;97:1097–1102. Colao A, Di Somma C, Cuocolo A, et al. Does a gender-related effect of growth hormone (GH) replacement exist on cardiovascular risk factors, cardiac morphology, and performance and atherosclerosis? Results of a two-year open, prospective study in young adult men and women with severe GH deficiency. J Clin Endocrinol Metab 2005;90(9):5146–5155.