From the Guidelines
Growth hormone replacement therapy is not recommended for healthy aging adults with decreased growth hormone levels, as the risks associated with synthetic hormone therapy outweigh the potential benefits. Growth hormone levels naturally decline with aging, typically beginning around age 30 and decreasing by approximately 14% per decade thereafter 1. This decline, sometimes called somatopause, contributes to many age-related changes including decreased muscle mass, increased fat tissue (particularly abdominal fat), reduced bone density, thinning skin, and diminished energy levels. While growth hormone replacement therapy is available through injections such as somatropin (Genotropin, Humatrope, Norditropin), it is primarily reserved for those with documented growth hormone deficiency from pituitary disease, not the natural decline with aging 1.
The typical dose for adults with deficiency ranges from 0.1 to 0.3 mg daily, administered subcutaneously. However, side effects can include joint pain, fluid retention, carpal tunnel syndrome, insulin resistance, and potentially increased cancer risk 1. Instead of hormone replacement, most physicians recommend focusing on lifestyle modifications to naturally support hormone balance, including:
- Regular resistance exercise
- Adequate sleep (7-9 hours)
- Stress management
- Proper nutrition with sufficient protein intake These approaches can help mitigate the effects of declining growth hormone without the risks associated with synthetic hormone therapy. Additionally, studies have shown that testosterone replacement therapy may have benefits for bone health in adult male subjects, but the potential benefits and risks of treatment need to be considered appropriately for each patient with cancer history 1.
It is essential to note that the evidence for growth hormone replacement therapy in healthy aging adults is limited, and most studies have focused on individuals with documented growth hormone deficiency 1. Therefore, lifestyle modifications and careful consideration of the risks and benefits of hormone replacement therapy are crucial in managing decreased growth hormone levels with aging.
From the Research
Decreased Growth Hormone with Aging
- Growth hormone (GH) secretion declines progressively with aging, leading to various age-related changes, including a decrease in lean body mass, an increase in body fat, and adverse changes in lipoproteins 2.
- The decline in GH secretion with aging is also known as somatopause, and it has been proposed that reversing this decline may be beneficial in older adults without evidence of pituitary pathology 3.
- However, most information on GH treatment in older adults comes from non-placebo-controlled studies, and there is still limited experience with its long-term benefits, side effects, and risks 2, 3.
Effects of Decreased Growth Hormone
- Decreased GH levels have been associated with increased visceral adiposity, decreased lean body mass, bone mineral density, and exercise capacity, as well as dyslipidemia, insulin resistance, and impaired quality of life 4.
- Adult growth hormone deficiency (AGHD) is a well-known phenomenon that affects both males and females, and it is marked by various neuropsychiatric, cognitive performance, cardiac, metabolic, muscular, and bone symptoms and clinical features 5.
Diagnosis and Treatment of Adult Growth Hormone Deficiency
- The diagnosis of AGHD requires a systematic approach, including evaluation of patients at risk for pituitary dysfunction, measurement of serum insulin-like growth factor I (IGF-I) levels, and stimulation testing 4.
- GH replacement therapy is effective in reversing many of the changes associated with AGHD, but there is still limited experience with its long-term benefits, side effects, and risks, and it is only indicated for individuals with childhood-onset GHD transitioning to adulthood or new-onset GHD due to hypothalamic or pituitary pathologic processes 2, 3.
- A combination of GH and IGF-1 treatment may be a solution for some patients with AGHD who are resistant to direct GH treatment 5.