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THE CHALLENGES OF USING ANDROGENS TO MAINTAIN HEALTH IN THE ELDERLY
Tan, R.S.
Baylor College of Medicine and University of Texas, Houston, USA
This talk will be focused on some of the challenges we face in using
androgens to maintain health. Undeniably, the quality
of life of elderly men can be improved with androgen
replacement. However, the use of androgens to maintain
health, though very promising, is less studied. The
challenges will be discussed in turn. To begin, one
of the greatest challenges for the clinician is whether
the "symptoms" of aging can be caused by low testosterone.
In many cases, this is so as evidenced by reversal
of symptoms with hormonal replacement. In other cases,
it is less apparent, especially in the presence of
multiple comorbidities. The astute diagnostician should
able to decipher between low testosterone symptom
complex and conditions such as anemia, depression,
hypothyroidism, chronic disease states, side effects
of medications and even psychological disorders. The
second challenge is the reliability of screening instruments
including the ADAM and the AMS. While sensitive, they
lack specificity. The third challenge is the issue
of whether fertility declines with aging and its relationship
with androgens. The fourth challenge is the definition
of low testosterone. Depending on whether one uses
total, free or bioavialable testosterone, the prevalence
differs. In addition, while standardization with laboratory
values is desirable to make a diagnosis, could there
be existence of relative hypogonadism? The fifth challenge
is the choice of blood test. While arguably, the dialysis
equilibrium for free testosterone is probably the
gold standard, it is not widely available to clinicians.
Age and obesity confound testosterone levels through
its effects on SHBG. The sixth challenge is that saliva
testing for hormones has been contemporary in some
areas in the United States but its validity has not
been well documented yet. The seventh challenge is
that of late, there are propositions for the use of
prohormones such as DHEA and even progesterone to
slow the aging process. The main issue has been that
while it is true that there are studies of association
to prove the hypotheses, causal relationships are
lacking, particularly in human models. The eighth
challenge is that of the role of estrogens in men.
Undeniably, estrogens are important in men, such as
for bone health and possibly the brain; but much is
unknown at this point. A summary of some of studies
showing an association with low testosterone and comorbidities
such as depression, hip fractures and coronary artery
occlusion will be presented. Intervention studies
showing the positive effects on these comorbid states
will also be presented. There will be a discussion
on the effects of androgens on the prostate as well
as the recent recommendation from the Institute of
Medicine.
Ref: Tan RS. Aging Men's Health, 1st edition, Thieme Medical
Publishers, NY, NY, 2005.
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