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- Review -
Hypogonadism and erectile dysfunction: an overview
Nilgun Gurbuz, Elnur Mammadov, Mustafa Faruk Usta
Section of Andrology, Department of Urology, Akdeniz University School of Medicine, Antalya 07070, Turkey
Abstract
In humans androgen decline is presented as a clinical picture which includes decreased sexual interest, diminished
erectile capasity, delayed or absent orgasms and reduced sexual pleasure. Additionally, changes in mood, diminished
well being, fatigue, depression and irritability are also associated with androgen insufficiency. The critical role of
androgens on the development, growth, and maintanence of the penis has been widely accepted. Although, the exact
effect of androgens on erectile physiology still remains undetermined, recent experimental studies have broaden our
understanding about the relationship between androgens and erectile function. Preclinical studies showed that
androgen deprivation leads to penile tissue atrophy and alterations in the nerve structures of the penis. Furthermore,
androgen deprivation caused to accumulation of fat containing cells and decreased protein expression of endothelial
and neuronal nitric oxide synthases (eNOS and nNOS), and phosphodiesterase type-5 (PDE-5), which play crucial
role in normal erectile physiology. On the light of the recent literature, we aimed to present the direct effect of
androgens on the structures, development and maintanence of penile tissue and erectile physiology as well. Furhermore,
according to the clinical studies we conclude the aetiology, pathophysiology, prevalance, diagnosis and treatment
options of hypogonadism in aging men. (Asian J Androl 2008 Jan; 10: 36_43)
Keywords: testosterone; erectile physiology; symptomatic late onset hypogonadism
Correspondence to: Dr Mustafa Faruk Usta, Section of Andrology, Department of Urology, Akdeniz University School of Medicine,
Dumlupinar Bulvari, Kampus 07070, Antalya, Turkey.
Tel: +90-242-249-6000 ext. 6819 Fax: +90-242-237-6343
E-mail: musta@akdeniz.edu.tr; mususuta53@hotmail.com
DOI: 10.1111/j.1745-7262.2008.00375.x
1 Introduction
The gradual decline of reproductive and erectile functions in the aging male has become the focus of experimental
and clinical researchs in several countries [1, 2]. The aim of this communication is to discuss the etiology,
pathophysiology, prevalance, diagnosis and current treatment options for hypogonadism in aging men. Recently, the
importance of androgens in the regulation of erectile physiology has been investigated in experimental animal models.
The results of these studies has expanded our understanding of the cellular, molecular, and physiological mechanisms
regulated by androgens, which play critical roles in the modulation of erectile physiology. This paper details much of
the recent data.
2 Hypogonadism: definition and
etiology
Men with low sexual desire have been treated with testosterone for over 70 years, however, the issue of low
sexual desire has recently re-emerged as an important topic in the field of male sexual dysfunction [2, 3]. This
condition has been labelled the male climacteric or andropause, which is biologically incorrect. The recent literature
has adopted new terms such as androgen decline in aging male (ADAM) and symptomatic late onset hypogonadism
(SLOH). ADAM or SLOH is depicted as emotional and physical changes related to the aging process which parallel
the hormonal changes associated with aging [2]. A significant decrease in testosterone levels is the most widely
accepted change observed in the aging process, but changes in various other hormones are also observed and may be
involved in age-related sexual dysfunction. While
currently vascular-endothelial dysfunction is considered to
be the most important cause of aging related erectile
dysfunction (ARED), other pathological factors like hormonal
alterations need to be considered in ARED [2_4].
Furthermore there are interactions between the penis and
the central nervous system which are also influenced by
androgens [2].
In numerous studies the incidence of erectile
dysfunction (ED) increases with age, concurrent with a
progressive decline in androgen levels [5, 6]. The results of
the Baltimore Longitudinal Study on Aging documented
total serum testosterone levels decreasing approximately
1% per year in men from their 30s on [7]. In addition to
the gradual decline of testosterone, there are similar age
related decreases in production of several other hormones
including dehydroepiandrosterone, thyroxine, melatonin
and growth hormone [8].
A decrease in sexual interest and impaired quality of
erectile function is commonly encountered in men with
hypogonadism. Additionally, the testosterone decline is
associated with parallel declines in bone mass, muscle
mass/strength and physical function/fraility [9]. Furthermore,
the potential metabolic consequences of hypogonadism,
such as abdominal obesity, diabetes and markers of
diabetes (insulin resistance, impaired glucose tolerance, and
metabolic syndrome) have also been reported.
Investigating the association between hypogonadism and
metabolic syndrome, Makhsida et al. [10] reviewed the
English literature from 1998 to 2004 focused on
testosterone therapy. They concluded that metabolic syndrome
is strongly associated with hypogonadism and
testosterone therapy improves body mass, insulin secretion and
sensitivity, lipid profile and blood pressure [10].
Researchers from Austria evaluated the impact of age, body
mass index (BMI) and serum testosterone levels on
erectile function in 675 workers. The results of detailed
statistical analyses suggested that while BMI contributes
strongly to ED, low total testosterone (TT) and
bioavailable testosterone (BT) were related to International
Index of Erectile Dysfunction (IIEF)-5 scores and
specifically severe ED [11]. In another study Kaplan
et al. [12] evaluated the association between total serum
testosterone levels, obesity and the metabolic syndrome in
aging males and showed that total serum testosterone
levels in obese and severely obese aging men with the
metabolic syndrome registered approximately 150 ng/dL
and 300 ng/dL, respectivily, much lower than in a
cohort of aging men without metabolic syndrome. Based
on statistical analyses of this study, the presence of
diabetes, BMI greater than 30 kg/m2, and triglycerides
greater than 150 mg/dL all have a clinical relevant
association with low testosterone levels. The authors
suggested a possible association between ED and
pre-diabetes/diabetes involving a low hormonal influence [12].
Similarly, in a more recent paper Guay et
al. [13] reported that metabolic syndrome and insulin reistance are
strongly associated with hypogonadism. They recommended that men with ED should not only be evaluated
for cardiovascular risk factors but should also be screened
for hypogonadism [13]. Zohdy et al. [14] investigated
the penile hemodynamic parameters in hypogonadal men
with metabolic syndrome and showed that obesity was
associated with lower testosterne levels and disturbances
in penile hemodynamic parameters.
3 Hypogonadism: pathophysiology-preclinical and
clinical evidences
The hypothalamic-pituitary gonadal system is a closed
loop feedback mechanism, controling normal
reproductive function. Gonadal hormones including testosterone,
estrogens and other androgen precursors have inhibitory
effects on the luteinizing hormone (LH) and
follicle-stimulating hormone (FSH) secretions. While testosterone is
the major inhibitor of LH, the aromatized and
nonaromatized forms of testosterone, namely estradiol and
dihydrotestosterone (DHT), also inhibit LH [2]. Normally,
1%_2% of testosterone is free, about 30% is bound to
sex-hormone-binding-globulin (SHBG) with high affinity,
and the remainder is bound with low affinity to albumin.
The amount of testosterone not bound to SHBG is
referred to as BT. Alterations in SHBG caused by estrogens,
thyroid hormone and healty aging leads to increased or
reduced testosterone levels [2].
Montorsi and Oettel [15] reported that between the
ages of 40 to 70 years, TT decreases annually by
approximately 1.6%, free testosterone decreases by 2%,
and BT decreases by 2%_3%, whereas SHBG increases annually by 1.6%. Of note, aging related decreases of
serum testosterone cause concomitant increases of LH
and FSH levels [15].
3.1 The role of androgens in erectile physiology: lessons
learned from basic science
Erectile function is a complex neurovascular
phenomenon modulated by several biochemical and
physiological factors [16]. Normal erections need healthy penile
vascular tissues and intact neural innervation of the
penis [17]. Although some researchers believe that
androgens have a passive and negligible impact on erectile
function, there is a growing body of data implicating
androgens as of importance in normal erectile physiology.
Many authors have published that testosterone is
necessary for normal sexual desire, ejaculation and
spontaneous erections [2_5, 15, 16].
This section summarizes results from animal studies
documenting the role of androgens in cellular, molecular
and physiologic mechanisms associated with erectile
physiology. Attention is focused on the relationship
between testosterone and a number of recognized
structures/molecules associated with erectile physiology [17].
3.1.1 Testosterone-nerve structure and function
Researchers have investigated the potential role of
androgens in the structure and normal function of the
pelvic ganglion neurons, specifically how testosterone
has a critical role for the maturation and maintenance of
terminal axon density and neuropeptide content in the
vas deferens [17, 18]. Further the effects of
testosterone on erectile function via the spinal cord [17, 19].
Moreover, researchers have revealed the impact of
castration on loss of erectile function, penile dorsal nerve
ultrastructure and decreases in structural integrity and
function of the cavernosal nerve [17, 20]. These
significant structural changes in the cavernosal nerve were
reversed when castrated animals were treated with
testosterone [17]. Centrally in rodents, the medial preoptic
area which can induce erections is testosterone
dependent [17, 21].
3.1.2 Testosterone-nNOS expression and activity
The importance of the NOS/cyclic guanosine monophosphate pathway (c-GMP) is well documented.
Nitric oxide (NO) causes relaxation of the vascular smooth
muscle, which ultimately leads to penile erection [17].
The role of androgens on the expression of NOS isoforms
in the penile tissue has been demonstrated [17, 22, 23].
In castrated animals, replacement with testosterone and
5α-DHT restored erectile function as well as NOS
expression in the corpora cavernosa [17, 24].
3.1.3 Testosterone-phosphodiesterase type-5 (PDE-5)
activity
The role of PDE-5 in normal erectile physiology is
well recognized. PDE-5 catalyzes c-GMP which causes
vascular smooth muscle contraction and penile
detumescence. Regulation of PDE-5 is essential to normal erectile
physiology. Expression and activity of PDE-5 is
significantly decreased in castrated animals and restored with
androgen replacement [17, 25_27].
3.1.4 Testosterone-cellular growth and
differentiation
The impact of castration on trabecular smooth muscle
and extracellular matrix proteins is well established. While
there was a significant reduction in smooth muscle
content, connective tissue deposition was markedly
increased in castrated animals and the structure of the
tunica albuginea was altered [17, 28]. With time (4 weeks)
the tunica became thinner with fewer elastic fibers and
disorganizations of collagen [17, 29]. Additionally,
fat-containing cells have been encountered in the subtunical
area of the penis in castrated animals. This finding was
interesting and lead researchers to speculate that
hypogonadism contribute to venous leakage in castrated animals
[17, 30]. These results cumulatively suggest that
androgens play an important role in the overall structure of the
corpora cavernosa.
The regulatory effect of androgens on growth and
differentiation of vascular smooth muscle cells has been
shown where androgens induce pluripotent stem cells
along a muscle lineage and inhibit the differentiation of
the same cells into an adipocyte lineage [17, 31, 32].
Inhibition of 5α-reductase activity causes stromal
remodeling and smooth muscle dedifferentiation in the
prostate [17, 33]. Some researchers claim that 5α-DHT
deficiency induces smooth muscle dedifferentiation in the
penis. However this hypothesis needs further study.
3.1.5 Testosterone-diabetes related ED
In a recent study diabetes induced in both rabbits
and rats caused decreased testosterone levels.
Administration of testosterone improved erectile function and
increased PDE-5, eNOS and nNOS expression. The researchers also showed that testosterone replacement
restored sildenafil responsiveness in these animals [34].
3.2 The role of androgens in erectile physiology:
clinical inferrences
Clinical evaluation is important to further understand
the role of androgens in erectile physiology. Some
believe that the role of androgens on erectile physiology is
predominantly through effects in the central neural
system via effects on libido and sexual drive rather than the
function of the corpus cavernosum [15, 35]. Studies
have shown that serum levels of testosterone and free
testosterone were significantly lower in patients with ED
when compared to normal individuals [15, 36]. Others
have shown that there is a concomitant increase in
cavernous and peripheral testosterone levels during penile
erection, inferring a peripheral effect of testosterone
[15,37]. Carani et al. [38] found increased penile rigidity in
hypogonadal men who underwent testosterone therapy,
implying a possible direct end-organ effect. In support
of this finding, Aversa et al. [6] described that in men
with ED, low free testosterone levels correlated with
diminished relaxation of cavernosal, endothelial and smooth
muscle cells in response to vasoactive agents, which was
independent of men's age. Chronic antiandrogen therapy
significantly reduces PDE-5 mRNA protein levels and
impairs erectile function [15, 26]. Hence it has been
suggested that concomitant testosterone therapy may
improve the efficacy of PDE-5 inhibitors in hypogonadal
men [39]. Some clinicians now suggest a combination of
PDE-5 inhibitor and testosterone supplementation as the
treatment of choice in older men with SLOH who previously were unresponsive to PDE-5 inhibitor therapy [15].
The action of testosterone most probably acts through
its conversion to 5α-DHT [22]. This hypothesis is
supported by the observation that a selective type-2
5α-reductase inhibitor (namely finasteride) did not suppress
sleep-related erections. Since type-1 5α-reductase
enzyme is predominantly localized to the central nervous
system and not inhibited by finasteride, 5α-DHT should
be the major androgen responsible of libido [40]. Some
investigations have stated that finasteride does not cause
ED in men being treated for benign prostatic hyperplasia
(BPH) [41]. In contrast, Rosen et al. [42] reported that
both finasteride and dutasteride had similar deleterious
side effects on erectile function, ejaculation and sexual
desire. These findings further support the concept that
5α-DHT plays a crucial role in normal erectile physiology.
It is well recognized that surgical or medical castration
impairs libido and sexual function. Peters and Walsh
[43] investigated the effect of nafarelin, a potent
LH-releasing hormone (LH-RH) agonist, in patients with BPH.
While ED occurred in the majority of patients, almost
50% of these men recovered their erectile function with
cessation of LH-RH agonist [43]. Similarly, the effect
of the competitive nonsteroidal antiandrogen bicalutamide
in men treated for BPH showed that about 50% experienced ED. Surprisingly, sexual desire was not
affected compared to the control group [44]. These
observations support the hypothesis that androgen
deprivation contributes to ED and androgens help to maintain
normal erectile physiology.
Another interesting consideration is the role of
androgens in sleep related erections (SREs). There is a
recognized age-related decrease in the frequency and
duration of nocturnal erections [45]. Researchers have
speculated about a possible relationship between
testosterone and nocturnal erections. Cunningham
et al. [46] reported that in men with ED there is an association
between decreased serum testosterone levels and
abnormal SREs. Erections associated with visual stimulation
are not affected by hypogonadism, suggesting that these
types of erections are androgen independent versus
centrally regulated SREs which are testosterone dependent
[47]. Researchers now recognize that androgen
insufficiency in aging men is related to insomnia and some sleep
disturbances [15]. Schiavi et al. [48] showed that there
is a clear relationship between low levels of testosterone
and sleep efficiency, decreased latency to onset of rapid
eye movement (REM) activity, and number of REM episodes. Of interest, supraphysiologic administration
of testosterone reduced the total time slept, increased
the duration of hypoxemia and disrupted breathing
during sleep in men older than 60 years of age [49]. In
summary, SREs are an indicator of the quality of sleep
and are associated with age-related hypogonadism [15].
4 Hypogonadism: prevalence
The prevalence of SLOH can be estimated from
population based studies. Numerous cross-sectional and
longitudinal studies have shown that there is an age-related
decline in androgen production in adult men [7, 8].
Studies suggest a prevalence of SLOH varying from 2% to
70% [2, 16], with most trials reporting a prevalence rate
of 15_20%, while it is general higher in referral biased
studies [51]. Recently Araujo et al. [9] investigated the
prevalence of SLOH in men between the ages of 30 to
79 through the Boston Area Community Health (BACH)
survey. SLOH was defined as low total (< 300 ng/dL)
and free (< 5 ng/dL) testosterone and decreased libido,
ED, osteoporosis or fracture, or two or more following
symptoms: sleep disturbance, depressed mood, lethargy,
or diminished physical performance. Results of that
study showed that low testosterone and free testosterone
levels were present in 24% and 11% men respectively.
The prevalence of SLOH symptoms were: decreased libido (12%), ED (16%), osteoporosis/fracture (1%) and
two or more of the non-specific symptoms (20%). The
prevalence of SLOH was 5.6%, independent of race, and
increased markedly with age [9].
5 Diagnosis of hypogonadism
The diagnosis of hypogonadism in men should based
on both the suggestive clinical picture and the
biochemical findings of low androgens. Initially a sexual,
psychosocial and medical history should be obtained.
Following this a focused physical examination should be
performed on all aging men. Patients with SLOH may
present with characteristic symptoms including decreased sexual desire, impaired erections, poor sleep
related erections, reduced sexual pleasure, muscle atrophy,
and delayed or absent orgasm. Additionally, changes in
mood, diminished feelings of well being, loss of
motivation, fatigue, depression, anger, decrease in body hair,
osteoporosis due to decreased bone mineral density,
an increase in visceral fat are frequently observed in patients
with SLOH [2, 17]. Small and less firm testes are usually
consistent with hypogonadotrophic hypogonadism. Of
note, these findings need not all be present for the
diagnosis of SLOH. Furthermore, using screening
questionnaires as an adjunctive tool for the diagnosis of
hypogonadism can be helpful. The ADAM scale is commonly
used, its specificity is very low in the aging male. The
Aging Male Scale (AMS) and ANDROTEST are also both
reliable in detecting the presence or absence of androgen
deficiency symptoms [51_53]. However, these validated
questionnaires should not be considered alternative
instruments, but a useful supplement to a detailed
history and proper physical examination [2, 17].
As mentioned, the diagnosis of SLOH in men is based
on the clinical picture and biochemical documentation of
androgen deficiency. Low testosterone level alone is not
an indication for administration of hormonal therapy.
Several laboratory ranges for androgens are not always
reliable and sometimes at best are a rough approximation
of the androgen status [2, 17]. Furthermore there is no
absolute threshold value of testosterone which exactly
defines the state of androgen deficiency. Because only
unbound testosterone can act within cells, it is possible
that TT measurements may be misleading. In normal
men, 2% of testosterone is free and 30_60% is bound to
SHBG with high affinity. In contrast the remaining
amount of testosterone is bound to albumin and other
serum proteins with a much lower affinity. Changes in
SHBG can increase or reduce the effective testosterone
milieu, which suggest that SHBG at least in part
regulates androgen function. Therefore in patients who are
suspected for androgen deficiency, SHBG levels need to
be evaluated. On the other hand, some authorities suggest
that, determination of free testosterone levels
delivers a more reliable assessment about the androgen status of
adult men [2]. There are a number of biases inherent in
the methods used to determine free testosterone values.
Direct free testosterone measures using a testosterone
analogue assay do not provide reliable free testosterone
results. Although, equilibrium dialysis and
ultracentrifugation are reliable, they are not widely available and are
technically difficult. BT using ammonium sulphate
precipitation is generally used, reliable and less expensive [2].
The following provides a summary of biochemical
assessments for SLOH:
1) Measure serum TT between 8.00 and 11.00 a.m.
2) If testosterone levels are below the normal limit
(350 ng/dL) confirm the results with a second
determination together with measurement of LH, FSH and
prolactin. In the younger (< 40 years) men, low
testosterone levels concomitant with elevated gonadotrophins
indicates the presence of primary hypogonadism. In this
circumstance prolactin levels are needed to rule out
hyperprolactinemia.
3) In patients with a total testosterone level less than
200 ng/dL with accompanying signs and symptoms of hypogonadism, further calculation of free and/or BT is
not necessary. On the other hand free testosterone or
BT are required in men with SLOH who have a borderline
(200_400 ng/dL) testosterone value. In the first step, TT
(ng/dL), SHBG (nmol/L) and albumin (g/dL)
concentrations are measured. Calculation of the free testosterone
or BT levels can be performed with the help of the
International Society for the Study of the Aging Male
(ISSAM)Web page (www.issam.ch). Calculated values of free
testosterone less than 5 ng/dL is considered abnormal,
whereas values less than 110 ng/dL for BT suggests
androgen deficiency [2, 17].
6 Treatment of hypogonadism
The general goals of hormone replacement therapy
are to substitute the deficient hormone in a dose
arrangement that mimics the normal diurnal variation [2]. For
hypogonadism, androgen delivery systems include oral
testosterone, intramuscular depot injections, scrotal
transdermal patch systems, nongenital skin transdermal
patch systems, hydroalcholic testosterone gels, adhesive
buccal tablets, and more recently developed long acting
intramuscular depot injections [17, 54_60].
According to the suggestion of the Sexual Medicine
Society of North America (Annual meeting 2003):
`Testosterone supplementation should only be considered for
men who have signs and symptoms of hypogonadism accompanied by abnormal serum testosterone levels'
[2,17]. Furthermore, a normal prostate specific androgen
(PSA) and digital rectal examination (DRE) are required
at baseline [2].
Several clinical trials have demonstrated the benefits
of testosterone monotherapy on erectile function. In a
meta-analysis, 57% response rate for all testosterone
therapies has been reported, ranging from 64% for
primary to 44% for secondary hypogonadism [61].
Testosterone treatment in hypogonadal men with ED
improved sexual attitudes and performance in 61% of
patients [62]. In another study testosterone replacement
improved erectile function and penile vascular parameters
in 36% and 42% of patients, respectively [63].
Testosterone monotherapy with transdermal gel
formulation has been shown to improve sexual performance,
desire and motivation in men with hypogonadism.
Maximal effects were observed at approximately the 30th day
of a 6-month treatment [64]. A comprehensive
meta-analysis was performed using the data obtained from 17
randomized placebo-controlled trials to compare the
effects of testosterone replacement on the different
domains of sexual function. The results showed that
testosterone improved the number of nocturnal erections
and successful sexual intercourses, sexual thoughts,
scores of erectile function, and overall sexual
satisfaction in men with hypogonadism. Importantly, they
reported that, the beneficial effect of testosterone appeared
to attenuate over time and that long-term safety data were
still not available [65]. Elevated hematocrit, abnormal
liver function studies, lower urinary tract symptoms
(LUTS) and sleep apnea are contraindications for
testosterone replacement therapy. Enlargement of the
prostate size was a rarely encountered adverse event related
to testosterone replacement, which can be negated by
the concomitant use of finasteride [65]. In a recent
report Yassin et al. [66] investigate the effect of
long-acting testosterone undeconate on men with hypogonadism.
Briefly, sexual function was assessed by IIEF at baseline
and after 24 weeks of testosterone treatment. All
patients had serum testosterone levels restored to normal
within 6 to 8 weeks with concomittant improvement in
libido, erectile function in more than 50%, and no changes
in serum PSA or prostate volumes [66].
Combination treatment with oral PDE-5 inhibitors and
testosterone in hypogonadal men may ensure improvement in erectile function. In a study by Kalinchenko
et al. [67], 120 men with type-2 diabetes related ED were
evaluated to investigate the cause of failure to respond to
treatment with sildenafil. At baseline that patients had a
low sexual desire and low testosterone levels when
compared to age matched controls (patients with diabetes
who respond to sildenafil). After a two-week oral
testosterone undeconate course, testosterone levels were
restored to physiological levels and libido was normalized.
Subsequently, 70% of previous sildenafil nonresponders
regained adequate erectile ability [67]. Similarly, in a
placebo-controlled study Shabsigh et al. [68] have
investigated the effect of testosterone gel in combination
with sildenafil in men with ED and hypogonadism, who
were previously unresponsive to sildenafil alone. These
patients were evaluated at baseline, and 4, 8 and 12 weeks
during the treatment period. Serum TT and free
testosterone values significantly increased in the
testosterone gel group compared to the placebo group.
Furthermore, erectile function improved significantly in the group
receiving testosterone and sildenafil combination whereas
there was no significant change in erectile function in
the group treated with placebo and sildenafil. Additionally,
the group treated with testosterone gel and sildenafil
showed significant improvements from baseline in
orgasmic function, overall satisfaction, and in total scores
of sexual function questionnaires [68]. In another study,
the synergistic effect for testosterone therapy and
efficacy of PDE-5 inhibitor therapy in hypogonadal men with
ED showed that when testosterone treatment alone failed,
combination therapy with a PDE-5 inhibitor and
testosterone gel improved sexual function [69]. Vascular studies
revealed that testosterone administration improved
erectile response to both sildenafil and tadalafil by increasing
arterial inflow to the penis [40, 70].
6.1 Monitoring strategies in patient with SLOH
undergoing testosterone replacement therapy
Hypogonadal patients with ED undergoing
testosterone treatment, need to be evaluated at regular periods to
assess the efficacy of the treatment and the sexual,
medical, and psychosocial status of the patient.
Additionally, treatment related adverse events and drug
interaction effects need to be carefully monitored.
Recently, recommendations related to the monitorization of hypogonadal men who are receiving
testosterone replacement therapy were reported by Morales
et al. [2]. According to their recommendations:
1) Liver function studies are suggested at baseline.
Although most of the current testosterone preparations
are free of hepatic toxicity, periodic assessment during
testosterone therapy may be considered.
2) A fasting lipid profile at baseline and
re-assessment at 3 or 6 months during the testosterone treatment
period is recommended.
3) Recent studies suggest that the levels of PSA do
not change with 1-year testosterone therapy, and
testosterone therapy does not increase the risk of prostate
cancer [71, 72]. However, it is the standard practice in
men over 40 years of age to have DRE and PSA measurement at baseline, and after 3 to 6 months of therapy,
and yearly thereafter. Transrectal ultrasound guided
biopsy of the prostate is indicated if the DRE or PSA
values become abnormal.
4) Testosterone replacement therapy is
contraindicated in men suspected of having prostate or breast
cancer. Hypogonadal men previously treated for
prostate cancer and currently cancer-free may be considered
for testosterone replacement therapy.
5) Androgen replacement therapy is contraindicated
in men with severe bladder outlet obstruction, whereas
mild and moderate obstructions represents a relative
contraindication.
6) Normally, androgen replacement therapy improves
mood and well-being. However, if adverse behavioral
patterns such as aggressiveness and hypersexuality
develop, therapy needs to discontinued.
7) Periodic hematologic evaluations are suggested to
rule out polycythemia development during testosterone
treatment.
8) Exacerbation of sleep apnea has been reported to
may occur during testosterone treatment. Therefore
detailed assessment is necessary before and during
androgen replacement therapy
Acknowledgement
This paper was supported by The Research Foundation of the Akdeniz University School of Medicine. The
authors have nothing to disclose.
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