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| Testosterone
Improves Cardiovascular Health and Your Sex Life |
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Did you know that testosterone
deficiency predisposes men to heart disease,
depression and a host of other ailments associated with normal
aging?
The problem is that most doctors are ignorant of the fact that cells
throughout the body require testosterone to properly function.
Insufficient testosterone causes males to lose strength, virility,
cognitive function and their youthful health. The long-term
consequence of testosterone deficiency is possible death from a wide
range of diseases.
Testosterone remains a misunderstood hormone to all but the most
dedicated health enthusiasts. The general public is afraid of
testosterone because some young athletes have abused it. Others
think it causes prostate cancer. Scientific studies, on the other
hand, clearly show that lack of testosterone is an underlying
culprit behind many age-related disorders.
Today's physicians practice medicine as if low testosterone has no
impact on an aging man's health. For example, if a male patient is
depressed, anti-depressant drugs are prescribed that often fail to
correct the underlying problem. Anti-depressant drugs have many
unpleasant side effects including impotence, which can make a man
feel even more depressed. Published studies document that
testosterone replacement is an effective anti-depressant in many
men.
Men who complain of impotence are routinely prescribed Viagra®, a
drug with both unpleasant and potentially lethal side effects.
Testosterone can be far more effective than Viagra because it
stimulates sexual receptor sites in the genitalia and the brain1
(where it enhances desire).
When testosterone levels are low, the body tries to compensate by
making more cholesterol, a precursor to adrenal testosterone
production. Many men prescribed statin drugs can obtain the same
cholesterol-lowering effect by restoring their testosterone level to
a more youthful range.2
The most profound effect that testosterone has in the body may be
its ability to prevent atherosclerosis and heart attack. A series of
new studies reveal that testosterone is a critical missing link that
cardiologists are failing to account for in treating those with
coronary artery disease and congestive heart failure.3 This article
discusses the beneficial functions of testosterone and describes
methods for safely restoring levels to healthy ranges.
In youth, testosterone levels are at their peak. Vitality,
assertiveness, and libido all thrive in their hormone-induced glory.
As we age, however, the endogenous level of this essential androgen
begins to drop drastically. By the time a man is 30 years old, he
will have already started down the path of testosterone deficiency,
losing as much as 2% every year for the rest of his life.4 This
means that by the time he reaches 60 years of age, he will be
functioning with about 60% less testosterone than he had in his
twenties.
It is now estimated that as many as 40 million men in the U.S.
suffer from inadequate levels of testosterone-and most of them don't
even know it.5 They only know that they are depressed, or that their
sex drive is not what it used to be. But a lowered sex drive is not
the biggest problem associated with testosterone deficiency.
Recent research has revealed that testosterone, long thought to be a
causative factor in heart disease, actually prevents many forms of
this killer.6 In fact, at youthful levels testosterone can keep
diseases such as atherosclerosis at bay almost indefinitely.7 With
this revelation comes a whole new problem: How do you re-establish
youthful levels of testosterone?
Testosterone: What is it?
Historically speaking, testosterone has been the subject of much
speculation and scrutiny. Long before scientists knew what
testosterone was or where it came from, ancient cultures were
carving statues depicting testicles as the symbols of fertility and
virility. As of 1400 AD, the Chinese were regularly processing urine
from young men and mixing it with ground bull testicles to produce
an extract used for treating impotence, prostate enlargement and
infertility.8
Today, we have a much greater understanding of the production and
purpose of testosterone. We now know, for example, that testosterone
is the major androgen hormone produced in males; that it is created
predominantly by the Leydig cells in the testes in response to the
release of luteinizing hormone (LH) by the pituitary gland. We also
know that it is carried by the bloodstream and binds to specific
target cells where it exerts tissue-dependent effects, such as
masculinization, anabolism (tissue building) and sexual arousal.
Testosterone is a major growth hormone that stimulates the
production of red blood cells within the bone marrow.9 Testosterone
also inhibits cells called osteoclasts that enhance bone breakdown.
When testosterone deficiency occurs, as with aging and in other
conditions, a lack of inhibition of these very same cells stimulates
bone loss that leads ultimately to osteoporosis.10
But despite our seemingly vast knowledge on the subject, much of the
value of testosterone has yet to be elucidated. Researchers are just
now discovering that not only does testosterone affect us sexually,
but that it is also responsible for numerous biological actions
including protein synthesis, oxygen uptake, cholesterol regulation
and immune surveillance.11
Of these new discoveries, one of the most controversial-and
potentially life saving-is testosterone's beneficial effect on the
cardiovascular system.
The myth of testosterone
Diseases of the heart and blood vessels have become a nationwide
epidemic, killing more than half a million men in the U.S. every
year.12 While it's commonly known that the chances of developing
heart disease grows proportionally with age, the fact that the
increased risk may be tied to the progressive reduction of available
testosterone has not yet been universally accepted by conventional
medicine.
Owing to early studies that showed men to be twice as likely to die
from coronary heart disease than women, it has long been believed
that physiologically high levels of testosterone has a deleterious
effect on the cardiovascular system. This theory has further been
supported by cases of sudden cardiac death and other cardiovascular
disorders that have been induced by the abuse of anabolic steroid
drugs such as methyltestosterone.13
Another complication was that for many years, endocrinologists
failed to believe that testosterone levels dropped in relation to
age. Older patients with heart disease were tested and their
testosterone levels found to be within the youthful range.
Unfortunately, scientists were looking for the wrong type of
testosterone measuring the total amount of testosterone rather than
focusing on the free testosterone.
We now know that much of an aging man's testosterone is "tied up" or
bound to a protein called sex hormone-binding globulin (SHBG). Once
bound to SHBG, testosterone is no longer available for use by the
rest of the body, becoming in effect biologically inert. As a
result, the typical male has only a small amount of bio-available or
"free" testosterone accessible-roughly about four percent of the
total testosterone. Furthermore, research has shown that this free
testosterone becomes increasingly bound with age, leaving available
levels of testosterone low while total levels appear normal.14
But despite having to overcome the hurdles of medical dogma that
erroneously devalued testosterone for decades, researchers have
finally established an indisputable link between its youthful levels
and a healthy cardiovascular system.
To lay the groundwork for our examination of these cardiovascular
benefits, we'll begin with a brief discussion of the cardiac disease
most often induced by low levels of testosterone: atherosclerosis.
The foundation of heart disease
Atherosclerosis is the most common form of cardiovascular disease.
It is the accumulation of fatty plaque deposits in the arteries,
resulting in stenosis-a narrowing of the arterial diameter, which
restricts blood flow to vital organs.15
Depending on the location of the stenosis, atherosclerosis can
manifest itself in several different ways. Should the blockage occur
in one or more of the arteries that supply the heart, coronary
artery disease (CAD) results. The most common clinical manifestation
of CAD is angina pectoris (chest pain). This occurs when the oxygen
needs of the heart muscle are inadequate.
In essence, the heart muscle is crying out for more oxygen. Angina,
therefore, is symptomatic of narrowed coronary arteries and their
inability to allow proper blood flow to suit the heart's need during
physical exertion or emotional stress. If blockage of coronary flow
is complete, it will result in a heart attack (myocardial infarction
or MI).16
If the blockage appears in the arteries supplying the brain, the
result is called a cerebrovascular accident or stroke.17 Restricted
blood flow to the legs-known as claudication-interferes with the
ability to walk, resulting in pain and disability due to a lack of
oxygen caused by the impaired blood flow. When such stenosis becomes
severe, infection and gangrene may follow, often leading to
amputation of the afflicted limb.18
To treat these disorders, common medical practice relies on various
techniques such as angioplasty and coronary artery bypass grafts.19
Angina is most often treated with medication such as nitroglycerin
which rapidly dilates the coronary arteries allowing more blood to
flow to the malnourished heart.20 The effects of nitroglycerin do
not last long.
Although these procedures are often effective at temporarily keeping
the disease manageable, preventing atherosclerosis in the first
place is by far the best solution. To do this, you need
testosterone.
The testosterone effect
While it was only recently that the relationship between
cardiovascular fitness and testosterone was firmly established,
evidence for the beneficial effect of testosterone has been
scientifically suggested for almost 100 years. During World War I,
for example, a Danish surgeon named Thorkild Rovsing removed the
intact testicles of a recently killed soldier and transplanted them
into the body of an old man suffering from gangrene. Inexplicably to
physicians of the day, the gangrene healed.21
Decades later, leading testosterone researcher Maurice Lesser, M.D.,
of the Boston University School of Medicine published the results of
100 consecutive angina pectoris patients who were treated with
testosterone for at least four months. Prior to their treatment,
Lesser reported that each patient had a clearly defined diagnosis of
angina based on their medical history. The results showed that 91%
of the patients reported either marked or moderate improvement in
the number of angina attacks as compared with the pre-treatment
rate.22
Following the Lesser studies, research into the cardiovascular
benefit of testosterone erupted. Numerous researchers reported that
cardiac function in elderly men with heart disease improved
dramatically when treated with testosterone. Other studies found
that testosterone effectively reduced blood pressure and improved
vascular circulation.23 As late as 1993, however, the reason for
these effects remained unclear.
Finally, however, in 1994 Dr. Gerald B. Phillips at Columbia
University College of Physicians and Surgeons discovered the answer
while conducting a cross-sectional study of 55 men who were
undergoing coronary angiography. At the time of the angiography,
none of these men had ever had a heart attack or stroke.
When serum testosterone levels from these men were analyzed, they
revealed that as testosterone levels decreased, the degree of
arterial occlusion increased. Phillips observed that low
testosterone levels were associated with several risk factors for
heart attack such as high insulin levels, abnormal glucose
metabolism, low levels of HDL cholesterol and high blood pressure.
Moreover, he further proposed that the converse was also true:
testosterone protects against heart disease in men.24
The research continues
Since Dr. Phillips published his findings, an enormous body of
research has gone on to confirm the cardiovascular benefits of
testosterone.
In one of the most comprehensive studies, researchers in the
Netherlands evaluated the effect of low levels of testosterone in
elderly men. Known as the Rotterdam Study, this population-based
investigation examined the relationship between total and
bio-available testosterone with aortic atherosclerosis among 1,032
nonsmoking men and women aged 55 years and over.
For six years, baseline data on the subjects was collected and
evaluated and upon final examination, researchers concluded that men
with the lowest levels of total and bio-available testosterone had
the highest risk for severe aortic atherosclerosis. Conversely, men
with the highest levels of both total and bio-available testosterone
were protected against atherosclerosis.25 These results confirmed
Dr. Phillips' finding that low serum testosterone is correlated with
increased heart disease.
With a clear link between atherosclerosis and low levels of
testosterone established, researchers have expanded their scope to
examine the other cardiovascular benefits of this hormone. For
example, recent studies have revealed that testosterone improves
insulin sensitivity in healthy men, suggesting a role in preventing
Type II diabetes.26
Other studies have found that in men with angina, supplemental
testosterone therapy not only clinically improves symptoms but also
reduces objective measurements of ischemia (impaired blood flow).27
Still more research has determined that testosterone induces
vasodilatation and may be helpful in cases of chronic congestive
heart failure,28 is responsible for maintaining heart muscle protein
synthesis,29 and reduces the levels of harmful LDL cholesterol.30
The other benefits of testosterone
While the relationship between youthful levels of testosterone and a
healthy cardiovascular system cannot be denied, it is far from the
end of the story. Research has slowly started to uncover many of the
hidden benefits of testosterone, such as its effect on bone growth
and stability, depression, obesity and libido.
Osteoporosis
Osteoporosis is a metabolic bone disease characterized by the
serious loss of bone mass and microdisintegration resulting in an
increased risk of fracture. Although more commonly associated with
post-menopausal women, osteoporosis affects more than five million
men in the United States each year.
Without a doubt, low testosterone is one of the major causes of
osteoporosis in aging men. Researchers in Germany have recently
published a report estimating that 50% of all bone fractures in
males over 60 years old is a result of osteoporosis induced by low
testosterone levels.31 Complementing that report, researchers in
France studying the relationship between testosterone and male
osteoporosis have found that by age 80, as much as 20% of the bone
mass density of males was lost in part due to the lower levels of
testosterone.32
The mechanism behind testosterone's effect on bone mass and
stability was the recent topic of study for a group of Canadian
researchers. According to their report, low levels of testosterone
indirectly diminished bone mass by extending the longevity,
generation and activity of bone-destroying osteoclast cells. The
explanation for this is simply that testosterone is an inhibitor of
osteoclast function. Lowering the testosterone level removes this
inhibitory effect and allows osteoclasts to resorb (breakdown) bone.
This study suggests that by maintaining youthful levels of
testosterone, osteoclast (bone degrading) activity and the
subsequent loss of bone mass can be reduced. This effect of
testosterone on osteoclast activity is also of vital importance in
men receiving androgen deprivation therapy for prostate cancer. Such
patients have biochemical evidence of immediate bone loss.
The severity of this problem has led to the use of drugs that
inactivate the osteoclast; these are called bisphosphonates. Common
examples of oral bisphosphonates are Fosamax and Actonel, and of
intravenous bisphosphonates are Aredia and Zometa.33 When
bisphosphonates are given, osteoclast activity is inhibited and bone
formation is favored. It is important that such patients receive
bone supplements such as Bone Assure to allow for healthy bone
formation.
Depression
A consistent finding in the scientific literature is that depression
is frequently associated with low levels of testosterone.34 However,
because practicing physicians often have only a basic understanding
of testosterone deficiency, many patients suffering from its effects
are misdiagnosed. Furthermore, because of the misplaced stigma
associated with testosterone, psychiatrists rarely consider
testosterone replacement therapy as a viable course of treatment.
Unfortunately for the patient, a common side effect of prescription
antidepressants is a suppressed libido. Those suffering from
depression must then choose between this drug-induced reaction and a
normal sex life. If more psychiatrists tested their patients' blood
for free testosterone and prescribed natural testosterone therapies
when appropriate, the need for antidepressant drugs could
potentially be avoided.
At Harvard University, researchers recently conducted a study to
compare levels of testosterone among HIV-positive men who had
HIV-related weight loss. The researchers also gave some subjects
injections of testosterone to find out if supplements of this
hormone had an impact on feelings of depression. The researchers
found that men who had low levels of testosterone were more likely
to be depressed than men who had normal levels of this hormone.
Moreover, when the depressed men received regular injections of
testosterone their mood significantly improved.35
Researchers at Columbia University also found evidence supporting a
relationship between advanced age, low testosterone and depression.
In their study, depressed men over 75 years-old were found to have
on average 35 percent lower free testosterone levels than younger
men. In addition, 25 percent of those tested were determined to be
severely testosterone deficient. Treatment with supplemental
testosterone resulted in a reduction of depressive symptoms, further
demonstrating the antidepressant effects of testosterone.36
Testosterone and obesity
Obesity is a vicious cycle. Fat cells are known to be a source of
aromatase, the enzyme responsible for convert-ing testosterone into
estrogen.37 Low testosterone results in the formation of abdominal
fat, which in turn causes more aromatase enzyme formation and thus
even lower levels of testosterone. The result is one of the most
common findings of researchers studying the relationship between
testosterone and obesity: obese men have low levels of testosterone
and extraordinarily high levels of estrogen.38
This fact was again confirmed in a study recently published in Aging
Male which stated that increased estradiol levels due to free
testosterone aromatization is highly significant and positively
related to body fat mass and more specifically to subcutaneous
abdominal fat. Even more intriguing, the study found that obese men
not only had a significantly lower testosterone level and higher
levels of estradiol, but that their estrogen levels were greater
than the average post-menopausal woman.39
Since research has shown that boosting the testosterone decreases
the abdominal fat mass, reverses glucose intolerance and reduces
lipoprotein abnormalities in the serum, it is especially important
for overweight men to consider some form of testosterone therapy.
Libido
Sexual stimulation and erection begin in the brain where neuronal
testosterone-receptor sites are prompted to ignite a cascade of
biochemical events that involve testosterone-receptor sites in the
nerves, blood vessels, and muscles. Free testosterone promotes
sexual desire and then facilitates performance, sensation and the
ultimate degree of fulfillment. Without adequate levels of free
testosterone, the quality of the male sex life is adversely
affected. Studies have found that men with low testosterone
routinely suffer from a decreased sex drive, genital atrophy, and
impotence.40
Upon re-establishing youthful levels, subjects commonly report
increased feelings of vitality, a higher sex drive, better sexual
performance and even penile enlargement and increased genital
sensitivity. Low testosterone levels achieved in men on androgen
deprivation therapy are associated with decrease in size of the
testicles and penis. These findings are reversible and men on the
off-cycle of androgen deprivation therapy who have testosterone
recovery note a return towards normal in the size of their
genitalia.41
Recently, researchers in Taiwan examined the relationship between
low testosterone levels and the male libido. In that study, the
serum total testosterone levels of 53 symptomatic men older than 50
years were measured and compared to a control group of 40 young,
asymptomatic men. The results showed that men with a diminished
libido had a significant decrease in testosterone levels (mean 268
ng/dl) as compared with the control group (553 ng/dl).
Furthermore, 89 percent of the subjects suffering from low
testosterone reported a lack of energy; 79 percent reported erectile
dysfunction; 70 percent reported a loss of pubic hair; and 66
percent reported a decrease in sexual endurance. From this data, the
researchers concluded that low levels of testosterone are directly
related to both advanced age and diminished sex drive.42
Why do testosterone levels fall?
Aging in males involves a torrent of hormonal, biochemical and
physiological changes that accompany the down-regulation of the
brain's ability to initiate testosterone production.
In some men, the testes lose their ability to produce testosterone,
regardless of how much luteinizing hormone (LH) is being produced.
In such cases, the pituitary gland is signaling the testes (via LH
secretion) to produce testosterone. But since the testes have lost
their functional ability, no testosterone is forthcoming. The
pituitary gland, however, continues to secrete LH because there is
not enough testosterone in the blood to provide a feedback mechanism
to shut down LH production.43
In other cases, it's the pituitary gland that malfunctions and fails
to produce sufficient amounts of LH, thus preventing healthy testes
from secreting testosterone.44 In either case, blood tests can
determine the levels of free testosterone and estradiol to help
determine the appropriate therapeutic approach.
Other causes of low testosterone result not from faulty feedback
mechanisms, but rather because of the aromatization (conversion) of
testosterone to estrogen (see Figure 1). Studies have found that in
many aging males, the already diminished levels of free testosterone
are further compromised by being converted to estradiol-a high
potency form of estrogen-via the action of the aromatase. One recent
report even found that the estrogen levels of the average
54-year-old man are higher than the average 59-year-old woman.45
While estrogen is a necessary hormone for men, at high levels it has
been associated with an increased risk of heart attack or stroke.46
Furthermore, high serum levels of estrogen trick the brain into
thinking that enough testosterone is being produced, thereby
reducing the natural production and availability of testosterone
even more.
This happens because at high levels, estrogen saturates testosterone
receptors in the hypothalamus, which subsequently stops sending
hormone signals to the pituitary gland. Another consequence of
estrogen production is stimulation of sex hormone-binding globulin
(SHBG) by estrogen. An increase in SHBG further binds testosterone
and lowers the free testosterone level.
Optimal Reference ranges for testosterone and estradiol
Because the methods to test levels of testosterone and estradiol
vary with the laboratory, it is always important to understand the
reference ranges from your selected company. Below are the normal
and optimal ranges of testosterone and estradiol
for LabCorp.
Reference ranges used by LabCorp
Hormone
Conventional/normal
Optimal
Free Testosterone
9.3-26.5 pg/ml
20-33 pg/ml
Estradiol
3-70 pg/ml
10-30 pg/ml
Total Testosterone
241-827 ng/dL
750-1100 ng/dL
A word about prostate cancer
Men with existing prostate cancer should follow the opposite
approach as it relates to testosterone. Prostate cancer patients are
normally prescribed testosterone ablation therapy (using a drug that
blocks the pituitary's release of LH and another drug that blocks
the testosterone-receptor sites on the cells).47 Early-state
prostate cancer cells can often be controlled by totally suppressing
testosterone in the body. Late-stage prostate cancer patients are
sometimes put on drugs that produce estrogenic effects to suppress
prostate cancer cells that no longer depend on testosterone for
growth.
Regrettably, prostate cancer patients on ablation therapy often
temporarily suffer many of the unpleasant effects of low
testosterone--called Androgen Deprivation Syndrome.48 Before
initializing a therapy that boosts the free testosterone level, a
blood PSA (prostate specific antigen) test and digital rectal exam
are recommended for men over 40 or for those 35 years of age or
older with a family history of prostate cancer. While restoring free
testosterone to healthy physiological levels has not been shown to
cause prostate cancer, it can induce existing cancer cells to
proliferate faster.
What you should have learned from this article
Aging men suffer from a variety of ailments that directly relate to
low levels of testosterone. Mainstream doctors don't even consider a
man's testosterone status when treating disease. Yet as you have
just learned, insufficient testosterone can cause or contribute to
the most common disorders and discomforts that aging men face.
While men clamor for drugs like Viagra®, their doctors overlook the
fact that testosterone deficiency is a major reason for loss of
sexual desire and ability to perform. Men who properly boost their
levels of free testosterone while suppressing excess estrogen can
enjoy a much more fulfilling sex life.
The lethal dangers of a testosterone deficiency are now documented
in numerous published studies. Low testosterone results in increased
coronary atherosclerosis and osteoporosis. These two diseases are
not unrelated in as much as calcium depleted from the bone is often
deposited into the arterial wall. Pathological breakdown of bone can
increase cancer risk by releasing growth factors such as
transforming growth factor beta 1 (TGF-B1 ) into the blood where
they stimulate cancer cells to proliferate.
Obesity and Type II diabetes are at epidemic levels in the United
States. Men who suffer from abdominal obesity (pot belly) are the
most likely to suffer cardiovascular and other diseases. Low
testosterone results in increased deposition of fat in the abdomen
and decreased insulin sensitivity, resulting in higher than desired
levels of insulin in the blood. Men seeking to lose weight and
prevent Type II diabetes and its complications should restore free
testosterone levels to youthful ranges.
Aging men often complain they don't "feel as young" as they used to.
Some are clinically depressed. When testosterone levels are restored
in depressed men with low testosterone, depression scores improve
and men report enhanced feeling of emotional well being.
The physicians at Griffin Medical Group specialize in treating
testosterone deficiency. Griffin Medical Group is located at 1650
Adams Avenue, Costa Mesa, California. For further information or an
appointment please call (714) 549-6500 and ask for Alan Glover.
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