Introduction To Male
Testosterone
Benefits of Testosterone Replacement Therapy
A number of benefits of
testosterone replacement therapy have been recorded, including better
stability with moods, energy levels, and libido. Testosterone
replacement has also been shown to enhance libido and the frequency of
sexual acts and sleep-related erections.5 Transdermal
testosterone replacement therapy, in particular, has been linked to
positive effects on fatigue, mood, and sexual function, as well as
significant increases in sexual activity.6 More specifically,
testosterone replacement therapy has been shown to improve positive mood
parameters, such as feeling of friendliness, reducing negative mood
parameters, such as anger and irritability.7
Testosterone replacement
therapy is also associated with potentially positive changes in body
composition. In hypogonadal men, testosterone replacement therapy has
demonstrated a number of effects, including an increase in lean body
mass and decrease in body fat,8 and increases in muscle size.9
Testosterone replacement
with transdermal testosterone delivery systems in HIV-infected men with
low testosterone levels has been associated with statistically
significant gains in lean body mass (p=0.02), increased red cell counts,
and improvements in emotional distress.10 Transdermal
testosterone has also been administered to HIV-positive women, yielding
positive trends in weight gain and quality of life.11
Improvements in bone
density have also been shown with testosterone replacement therapy.
Increases in spinal bone density have been realized in hypogonadal men,12 with most treated men maintaining bone density above the fracture
threshold.13
Contraindications to
Testosterone Replacement Therapy
Testosterone replacement
is contraindicated in men with carcinoma of the breast or known or
suspected carcinoma of the prostate, as it may cause rapid growth of
these tumors. Hormone therapy is also inappropriate in men with severe
benign prostatic hypertrophy (BPH)-related bladder outlet obstruction.
Use of testosterone to improve athletic performance or correct short
stature is potentially dangerous and inappropriate.
Lipid Abnormalities
Physiologic testosterone
replacement is known to reduce total cholesterol, low density
lipoprotein (LDL), and high density lipoprotein (HDL) levels. Some
authorities recommend that lipid values be followed closely in men
receiving testosterone replacement therapy.
Prostate Changes
Although PSA is not
specific for prostate cancer, it is a good surrogate for judging the
effects of androgens on the prostate. In one study of
testosterone-treated men, PSA rose to normal levels but no higher than
in the controls, leading the authors to conclude that
testosterone-induced prostate growth should not preclude hypogonadal men
from testosterone replacement therapy. Indeed, another study indicates
that even men who achieved supraphysiologic levels of serum testosterone
had no significant changes in PSA levels.14
The effects of transdermal
testosterone replacement on prostate size and PSA levels in hypogonadal
men have also been evaluated.15 Prostate size during therapy
with transdermal testosterone was comparable to that reported in normal
men, and PSA levels were within the normal range.
Prostate Cancer
There appears to be little
association between testosterone replacement therapy and the development
of prostate cancer. The etiology of prostate cancer is apparently
multifactorial, and dietary, geographic, genetic, and other influences
are all thought to play a role in the development of the disease. Recent
studies indicate that testosterone levels have no apparent systematic
relationship to the incidence of prostate cancer.16,17
References |
