What is Growth Hormone?
Growth hormone (GH), also known as somatotropin, is a
peptide hormone produced by the anterior pituitary gland, which is located at
the base of the brain. It plays a critical role in various physiological
processes throughout life, although its most well-known function is promoting
growth during childhood and adolescence. Here are some of the key roles and
functions of growth hormone:
1. Growth
Promotion: During childhood and adolescence, growth hormone stimulates the
growth of bones, cartilage, and other tissues by promoting the proliferation
and differentiation of cells. This is why growth hormone is particularly
important for the proper development of height and skeletal structure during
the growth years.
2. Metabolism:
Growth hormone has significant metabolic effects on various tissues. It helps
regulate the breakdown of fats (lipolysis) for energy use and can spare glucose
for vital functions by promoting the use of fatty acids as an energy source.
3. Insulin-Like
Growth Factor-1 (IGF-1) Production: Growth hormone stimulates the liver and
other tissues to produce insulin-like growth factor-1 (IGF-1), a hormone that
plays a pivotal role in mediating many of the growth-promoting effects of
growth hormone. IGF-1 also has anabolic effects on various tissues, including
muscle and bone.
4. Muscle
Growth: Growth hormone is involved in the development and maintenance of
lean muscle mass. It stimulates the uptake of amino acids into cells and the
synthesis of proteins, supporting muscle growth and repair.
5. Bone
Health: Growth hormone and IGF-1 are essential for bone growth and
maintenance. They promote the formation of bone tissue (osteogenesis) and help
regulate bone density by influencing the activity of osteoblasts (bone-forming
cells) and osteoclasts (bone-resorbing cells).
6. Cell
Regeneration and Repair: Growth hormone has a role in cellular regeneration
and tissue repair, which can affect wound healing and overall tissue health.
7. Immune
Function: Some studies suggest that growth hormone may play a role in
modulating immune system function and influencing immune responses to
infections and other challenges.
8. Cognitive
Function: While the exact mechanisms are not fully understood, there is
some evidence to suggest that growth hormone might have an impact on cognitive
function and emotional well-being.
Growth Hormone Changes as We Age
As males age, there are several changes that can occur in
the production and regulation of growth hormone (GH). Growth hormone is
primarily produced and released by the pituitary gland, and it plays a crucial
role in growth, metabolism, and various physiological processes. Here are some
key points about how growth hormone changes in aging males:
·
Decreased Production: One of the most
notable changes is a decrease in the production of growth hormone. This decline
begins in early adulthood and continues throughout life. By the time males
reach their 60s, growth hormone production can be significantly reduced
compared to younger years.
·
Pulsatile Release: Growth hormone is
typically released from the pituitary gland in a pulsatile manner, with higher
levels secreted during certain periods, such as during deep sleep. Aging is
associated with alterations in the frequency and amplitude of these pulses,
leading to reduced overall secretion.
·
IGF-1: IGF-1 levels also decline with age
due to reduced growth hormone secretion and decreased responsiveness of tissues
to growth hormone.
·
Body Composition Changes: Declining
growth hormone levels in aging males can contribute to changes in body
composition, including an increase in body fat and a decrease in lean muscle
mass. This can lead to reduced muscle strength and physical performance.
·
Bone Health: With reduced growth hormone
production, bone density may decrease, potentially leading to an increased risk
of fractures and osteoporosis.
·
Metabolism: Growth hormone has metabolic
effects, including regulating glucose and lipid metabolism. Reduced growth
hormone levels in aging males can contribute to insulin resistance and an
altered lipid profile.
·
Cognitive Function: Changes in growth
hormone levels and IGF-1 in aging males might be linked to cognitive decline,
although the exact mechanisms are not fully understood.
·
Aging-Related Diseases: Low growth
hormone levels have been associated with certain age-related diseases,
including cardiovascular disease, metabolic syndrome, and reduced quality of
life.
It's important to note that the changes in growth hormone
levels and their effects can vary from individual to individual. While some
males may experience more pronounced declines in growth hormone production,
others might maintain relatively higher levels. Additionally, medical
interventions like hormone replacement therapy (HRT) are sometimes used to
address growth hormone deficiencies in aging individuals. However, the use of
HRT comes with its own set of risks and benefits and should be carefully
considered under the guidance of a qualified medical professional.
Do some adults need HGH treatment?
Adults who have a growth hormone deficiency — not the
expected decline in growth hormone due to aging — might be prescribed
synthetic HGH by their health care provider.
Growth
hormone deficiency is usually caused by a benign tumor on the pituitary
gland (pituitary adenoma) or by treatment of an adenoma with surgery or
radiotherapy.
For adults who have a growth hormone deficiency,
injections of HGH can:
·
Increase exercise capacity
·
Increase bone density
·
Increase muscle mass
·
Decrease body fat
HGH treatment is also approved to treat adults with
AIDS- or HIV-related growth hormone deficiency that causes irregular
distribution of body fat.
HGH treatment is approved in the United States only
for treatment of growth hormone deficiency — and related problems associated
with HIV infection. HGH is only effective if administered as an
injection.
There's no pill form of human growth hormone available.
Some dietary supplements that claim to boost levels of HGH come in
pill form, but research doesn't show a benefit.
HGH is considered a controlled substance by the Food
and Drug Administration. Using HGH for a condition that isn't
approved, such as building muscle or as an anti-aging treatment in older
adults, is illegal.
