Growth Hormone Replacement in Adults and Elderly
The systemic benefits of exogenous Growth Hormone therapy in the healthy elderly remain unclear and controversial. Studies have not been able to demonstrate a clear anabolic effect of replacement of Growth Hormone in elderly subjects, possibly because Growth Hormone replacement cannot completely correct the alterations in binding recommended proteins.
Some studies have reported improvements in bone mineral density and muscle strength mass. Sarcopenia is related to increased tendency to fall, decrease in bone mineral density, decreased wound healing, and a decreased ability to maintain body temperature.
Mechano growth factor (MGF) is a muscle-specific splice variant of IGF-1 that activates muscle stem cell proliferation, which is necessary for muscle regeneration. Treatment with exogenous GH plus resistance training has been shown to upregulate MGF in elderly muscle. Effects on muscle strength and quality of life have not been clearly documented. In addition, there is the concern that high normal serum IGF-1 may be associated with increased risk for breast and prostate cancers.
Additional adverse effects include carpal tunnel syndrome, fluid retention, and decreased glucose tolerance. Endogenous overproduction of Growth Hormone results in a decreased life span in mice and humans, and Growth Hormone -deficient or -resistant mice exhibit a high level of resistance to oxidative stress and have increased longevity. Individuals with the A þ IGF-1 receptor gene poly- morphism tend to have lower free IGF-1 levels, and these individuals are overrepresented in long-lived subjects. Therefore, it is still debatable whether longterm Growth Hormone therapy will promote anti-aging HGH or pro-aging effects.
Growth Hormone may have a therapeutic role for short-term treatment of the frail elderly during acute illness, injury, or surgery. Several studies have shown acceleration of weight gain, an increase in muscle strength and endurance, and improved surgical recovery in malnourished or immobilized elderly patients.