Aging and decline in Testosterone levels
By Body Satva Essentials Team www.bodysatva.com
Testosterone is the male sex hormone. It is produced in the testes
and is essential for sexual activity and reproduction. It is the hormone
responsible for the secondary sexual characteristics like facial hair, body
hair, male pattern baldness and virile features. The greater musculature in men
is attributed to Testosterone and Bodybuilders are great fans of Testosterone.
The ovaries also produce a small quantity of Testosterone.
The body produces Testosterone in a carefully regulated manner.
The pituitary gland and the hypothalamus send messages to the testes to produce
testosterone. The hypothalamus controls Testosterone production through a
hormone called Gonadotropin releasing
hormone (GnRH). This hormone stimulates the pituitary gland to release Follicle stimulating hormone (FSH) and Luteinizing Hormone (LH) which in turn stimulates the testes to produce
Testosterone. When the levels of Testosterone are high, the brain sends a
signal to the pituitary gland to make less LH. If the Testosterone levels are
low, the brain sends signals to make more LH, leading to an increase in
Testosterone production by the testes. If
external Testosterone is provided, the natural production is suppressed by
this mechanism. Prolonged external supplementation of Testosterone can lead to
atrophy of the testes and a total shut down of natural production.
The levels of total testosterone are generally between 300 to 1200
nanograms per deciliter (ng /dl). Testosterone is mostly bound to other
proteins and only 2% circulates as free
testosterone. In Bodybuilding circles, it is believed that free
testosterone is the major contributor to muscle anabolism. About 40% of total testosterone is bound to ‘Sex Hormone
Binding Globulin (SHBG) and 58% is bound to albumin. Elderly men have a
greater quantity of SHBG.
Serum testosterone has a circadian rhythm in normal young men,
with peak levels in the morning, coinciding with sunrise, and low levels in the
evening, coinciding with sunset. This appears to be nature’s way of preparing
us for the activities during the day. Foraging for food, hunting or escaping
from predators was possible due to this special feature. The modern lifestyles
are probably out of tune with nature’s design. The ancient pattern of multiple
bouts of intense activity and frequent eating is just not followed today. This
alone may cause many imbalances. Recently studies have shown that intense short
bursts of exercise stimulate testosterone release. Conversely, sedentary
lifestyles may contribute to low testosterone levels. In elderly men, the early
morning peak of Testosterone is blunted compared to younger males.
There is a steady decline in the levels of Testosterone, with
increasing age. The decline begins in the late thirties and continues to
decline at 0.8 % per year according to some studies and 1.6% per year
(Massachusetts Male Ageing Study, MMAS; Feldman et al., 2002). Aging is
associated with lower levels of LH and therefore Testosterone. Simultaneously,
there is an increase in SHBG, leading to lower levels of free Testosterone
available to tissues like muscles.
When aging is faster than, the chronological aging, in one or more
organs of the body, the risk of disease and death rises alarmingly. The damaged
‘weak link’ may affect the survival of the whole organism.
Low testosterone levels were linked with an increase in mortality
in a cohort of male veterans, according to the results of a study reported in
Archives of Internal Medicine [1]. Low
testosterone was defined as a total testosterone level of less than 250 ng/dL
or a free testosterone level of less than 0.75 ng/dL.
Physical
symptoms of low Testosterone in males, include low sex drive, erectile
dysfunction, lower sperm count, low energy, depression and flabby breasts
(Gynecomastia). This is sometimes called ‘Andropause’, but it is not a well-defined
term.
At a later stage, brittle bones, loss of memory and senility may set in. There are many other causes of low testosterone which may require urgent medical attention. For many years Testosterone Replacement Therapy (TRT) was being used for improving the quality of life of elderly men. However, there were doubts about the Cardiovascular safety and also about the possibility about prostatic hypertrophy or even prostate cancer. In recent years many meta analyses have laid all those fears to rest. In a long-term observational study, it was found that TRT with Testosterone Undecanoate (TU) reduced CV mortality by 66% to 92%. It was concluded that long-term TU was well tolerated with excellent adherence suggesting a high level of patient satisfaction. [2]
At a later stage, brittle bones, loss of memory and senility may set in. There are many other causes of low testosterone which may require urgent medical attention. For many years Testosterone Replacement Therapy (TRT) was being used for improving the quality of life of elderly men. However, there were doubts about the Cardiovascular safety and also about the possibility about prostatic hypertrophy or even prostate cancer. In recent years many meta analyses have laid all those fears to rest. In a long-term observational study, it was found that TRT with Testosterone Undecanoate (TU) reduced CV mortality by 66% to 92%. It was concluded that long-term TU was well tolerated with excellent adherence suggesting a high level of patient satisfaction. [2]
Normal Testosterone Levels by Age in Healthy Men
Adapted from Vermeulen
et al, Androgens and the Aging Male (pp. 3-14). New York: Parthenon
Publishing
Age
|
Total Testosterone ng/dl
|
Free testosterone ng/dl
|
SHBG nmol/L
|
25-34
|
617
|
12.3
|
35.5
|
35-44
|
668
|
10.3
|
40.1
|
45-54
|
606
|
9.1
|
44.6
|
55-64
|
562
|
8.3
|
45.5
|
65-74
|
524
|
6.9
|
48.7
|
75-84
|
471
|
6.0
|
51.0
|
85-100
|
376
|
5.4
|
65.9
|
Note: There is significant variation (plus or
minus 25-30%) in levels between individuals.
ng/dl = nanograms per deciliter and
nmol/L = nanomoles/Liter
A healthy lifestyle which includes participation in sports and
moderate to rigorous exercise may be one of the best ways to prolong youth.
Natural and artificial methods of boosting Testosterone will be the subject of
another article on Body Satva.
Prolong Youth by
leading an ‘enlightened and balanced
life’
References:
1. Shores MM et al, Arch Intern Med. 2006 Aug 14-28;166(15):1660-5
2. Traish AM et al, Journal of Cardiovascular Pharmacology and Therapeutics 2017, Vol. 22(5) 414-433
1. Shores MM et al, Arch Intern Med. 2006 Aug 14-28;166(15):1660-5
2. Traish AM et al, Journal of Cardiovascular Pharmacology and Therapeutics 2017, Vol. 22(5) 414-433
Disclaimer
Body
Satva Essentials’ Team has taken maximum care to ensure authenticity of the
information provided, by sourcing from reputed medical journals and books. Body
Satva Essentials’ Team urges members to seek professional advice before
commencing any regimen of diet, exercise and medication.
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