This is an article on Free Testosterone. What is it and why do we need or have it in our bodies? What does it do and how does it affect us?
Where is Testosterone produced?
Testosterone is the male sex hormone. It is produced in several tissues including testes, adrenal cortex, liver, ovaries, and brain from cholesterol-derived dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione.
All of these referred to above are called pre-hormones, which, when needed, act as inactive reservoirs for subsequent testosterone production.
Most of the testosterone in the male body , exists in an inactive state, because approximately 98% is in the blood and bound to proteins called sex hormone binding globulin (SHBG) 80% and albumin (18%). Less than 2% of testosterone is “free” and not bound to a protein. This small amount, 2% of “Free” testosterone, is active hormone.
Free testosterone and albumin-bound testosterone are also referred to as bioavailable testosterone. This is the testosterone that is easily used by your body.
Pituitary Gland – Luteinizing Hormone
The pituitary gland in your brain controls the amount of testosterone your body makes. It makes or stores many different hormones, including the Luteinizing hormone.
Hormones heavily control the human body’s reproductive system, and luteinizing hormone is one of those hormones. With different roles in the bodies of men and women, this important hormone is crucial to ensuring a healthy reproductive system.
This hormone stimulates testosterone production in men and egg release (ovulation) in women
What does it do?
Testosterone produces its actions in three ways.
It directly acts to,
- stimulate protein production in muscle,
- improve insulin sensitivity, and
- reduce fat through lipolysis.
It can also be converted to dihydrotestosterone (DHT).
What is Dihydrotestosterone?
Dihydrotestosterone is a hormone with powerful androgenic properties. Dihydrotestosterone is an androgen, which means it is a hormone that triggers the development of male characteristics.
Dihydrotestosterone blood levels in men are one-tenth those of testosterone.
However, DHT is five times more active and is responsible for libido, spermatogenesis, muscle development, and bone density.
Dihydrotestosterone can also be converted (known as aromatization after the chief enzyme involved in the conversion – aromatase) to estradiol. Estradiol, also spelled oestradiol, is an oestrogen steroid and the major female sex hormone. It is responsible for the development of female sexual characteristics.
On the other hand, women have only one-tenth of the testosterone blood levels of men, but testosterone is the most abundant and active hormone in the female body.
In women the level of testosterone are approximately ten-fold higher than those of estradiol, making testosterone the most abundant active hormone in the female body.
In this complex system in women, androgens influence bone and muscle mass, fat distribution, sexual behavior, libido, thermal control, cognition, visual-spatial skills, and learning.
Age, unfortunately, alters the hormonal picture for both men and women.
As men age, androgen levels steadily decline.
Since low testosterone is associated with
- atherosclerotic lipid changes,
- increased visceral obesity,
- insulin resistance, and
- risk of type 2 diabetes mellitus,
- coronary artery disease becomes a natural consequence of this age-related androgen change.
For women, there can be a more abrupt hormonal change, which for some begins even in their late 40s.
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- Ovarian estradiol begins to drop during that period and is often very low in most women by age 52.
- Women’s androgen levels, in contrast, decline over 50% between age 20 and 40, but then remain stable from age 40 to 60 as a result of continued ovarian production.
- During those few years leading up to and into menopause, many women experience anxiety, depressed mood, decreased libido, and sleep disorders. Is this from the loss of estradiol alone, or is the ratio of estradiol to testosterone critical for women’s overall health?
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