Is routine endocrine testing of impotent men necessary?

Hormones, Age, and Erectile Dysfunction: Should Routine Testing Be Part of the Initial Evaluation?

Background/Objectives: The aim of this study was to investigate the relationship between age, the severity of erectile dysfunction (ED), and the various hormones that may influence erectile function. Methods: A multicenter cross-sectional study was conducted between January 2015 and December 2023. The study assessed age, sexual function using the IIEF-15 questionnaire, and the levels of total testosterone (TT), free testosterone (FT), FSH, LH, estradiol, prolactin (PRL), and SHBG. Results: A total of 411 patients were included in the study. The mean age of the patients was 63.19 years. The vast majority (91.73%) exhibited some degree of ED. The severity of ED increases with age, ranging from 56.26 years for patients without ED to 73.12 years for those with severe ED. A statistically significant negative correlation was observed between IIEF and age, while a positive correlation was observed between IIEF and serum levels of TT and FT (p < 0.05). Age was significantly correlated with all evaluated hormones (p < 0.01), except estradiol and prolactin. Total testosterone levels progressively decreased with the increase in the severity of erectile dysfunction, from a median of 7.05 ng/mL in patients with normal erectile function to 3.56 ng/mL in those with severe symptoms, remaining above the normal minimum threshold across all groups, whereas free testosterone (FT) levels also declined progressively. All erectile dysfunction groups had median FT levels below the normal minimum threshold. FSH, LH, and SHBG showed an increase with each progressive severity of erectile dysfunction. The multivariate linear regression revealed that IIEF scores are significantly associated with age, TT, and FT levels, while FSH did not present a statistically significant association in this model. Conclusions: Age shows a significant statistical correlation with both the severity of erectile dysfunction and the levels of total testosterone, free testosterone, LH, FSH, and SHBG. Total and free testosterone levels are significantly associated with the severity of erectile dysfunction, with free testosterone median values remaining above the normal minimum threshold in all patients with erectile dysfunction. Therefore, free testosterone should be considered a routine test, alongside total testosterone. In contrast, LH, estradiol, SHBG, and prolactin do not demonstrate any statistical correlation with erectile dysfunction and should not be recommended as routine investigations.

Hyperprolactinemia and male sexual function: focus on erectile dysfunction and sexual desire

The present paper aims to analyze and discuss the available evidence supporting the relationship between male sexual function and elevated prolactin (PRL) levels (HPRL). Two different sources of data were analyzed. Clinical data were derived from a series of patients seeking medical care for sexual dysfunction at our Unit. Out of 418 studies, 25 papers were used with a meta-analytic approach to evaluate the overall prevalence of HPRL in patients with erectile dysfunction (ED) and to study the influence of HPRL and its treatment on male sexual function. Among 4215 patients (mean age 51.6 ± 13.1 years) consulting for sexual dysfunction at our Unit, 176 (4.2%) showed PRL levels above the normal range. Meta-analytic data showed that HPRL is a rare condition among patients with ED (2 [1;3]%). Either clinical and meta-analytic data confirm a stepwise negative influence of PRL on male sexual desire (S = 0.00004 [0.00003; 0.00006]; I = -0.58915 [-0.78438; -0.39392]; both p < 0.0001 from meta-regression analysis). Normalization of PRL levels is able to improve libido. The role of HPRL in ED remains inconclusive. Data from a meta-analytic approach showed that either HPRL or reduced T levels were independently associated with ED rates. The normalization of PRL levels only partially restored ED. HPRL did not significantly contribute to ED severity, in our clinical setting. In conclusion, treating HPRL can restore normal sexual desire, whereas its effect on erection is limited.

Sexual Dysfunction in Heroin Dependents: A Comparison between Methadone and Buprenorphine Maintenance Treatment

INTRODUCTION

Methadone has long been regarded as an effective treatment for opioid dependence. However, many patients discontinue maintenance therapy because of its side effects, with one of the most common being sexual dysfunction. Buprenorphine is a proven alternative to methadone. This study aimed to investigate sexual dysfunction in opioid-dependent men on buprenorphine maintenance treatment (BMT) and methadone maintenance treatment (MMT). The secondary aim was to investigate the correlation between sexual dysfunction and the quality of life in these patients.

METHODS

Two hundred thirty-eight men participated in this cross-sectional study. Four questionnaires were used, the Mini International Neuropsychiatric Interview, Opiate Treatment Index, Malay version of the International Index of Erectile Function 15 (Mal-IIEF-15), and World Health Organization Quality of Life-BREF Scale. Multivariate analysis of covariance was used to examine the relationship between MMT and BMT and the Mal-IIEF 15 scores while controlling for all the possible confounders.

RESULTS

The study population consisted of 171 patients (71.8%) on MMT and 67 (28.2%) on BMT. Patients in the MMT group who had a sexual partner scored significantly lower in the sexual desire domain (p < 0.012) and overall satisfaction (p = 0.043) domain compared with their counterparts in the BMT group. Similarly, patients in the MMT group without a sexual partner scored significantly lower in the orgasmic function domain (p = 0.008) compared with those in the BMT group without a partner. Intercourse satisfaction (p = 0.026) and overall satisfaction (p = 0.039) were significantly associated with the social relationships domain after adjusting for significantly correlated sociodemographic variables.

CONCLUSIONS

Sexual functioning is critical for improving the quality of life in patients in an opioid rehabilitation program. Our study showed that buprenorphine causes less sexual dysfunction than methadone. Thus, clinicians may consider the former when treating heroin dependents who have concerns about sexual function.

A relationship of sex hormone levels and erectile dysfunction: which tests should be done routinely?

PURPOSE

In this study, the relationship between sex hormone levels and erectile dysfunction (ED), as well as the necessity of routinely measuring sex hormone levels were evaluated.

MATERIALS AND METHODS

This study included one hundred patients admitted to a urology clinic for sexual dysfunction. To determine the hormone levels, following the history (included IIEF-5 score) and physical examination, triple blood samples were collected at intervals of 15 minutes between 08:00 and 10:00 am. Total and free testosterone, prolactin, follicle stimulating hormone and luteinizing hormone levels were studied.

RESULTS

Mean age was 43 (23-80) years. IIEF-5 score was less than 21 [9.8-4.3 (3-19)] in all study groups. There was a statistically significant correlation between tT and FSH, as well as between LH and FSH in Pearson (r =-0.513, p < 0.001, respectively) and also in Spearman tests (r=-0.224, p=0.042 and r=-0.459, p < 0.001, respectively). However, there was no correlation between age and serum hormone levels (p > 0.05). Of the 100 patients, 18 (18%) had low tT, 77 (77%) had normal and 5 (5%) had high tT levels. No statistically significant correlation was found between decreased libido and tT levels (p > 0.05). Twelve (66.6%) of the 18 patients with low tT had normal libido.

CONCLUSION

Analyzing the medical history in detail and performing a thorough physical examination can reduce the need for excessive studies and consultations, and enables patients to save time and costs.

The burden of testosterone deficiency syndrome in adult men: economic and quality-of-life impact

INTRODUCTION

Testosterone deficiency syndrome (TDS) causes a wide range of symptoms that can lead to significant morbidity. Preliminary evidence has also linked TDS with premature mortality and with a number of comorbid diseases including diabetes and metabolic syndrome. Such associations can lead to substantial economic and quality-of-life implications, the magnitude of which remains largely unknown.

AIM

To review the economic and quality-of-life consequences of a largely untreated condition and to consider the likely health economic benefits of testosterone treatment.

METHODS

A systematic review of four main areas: epidemiological evidence of the magnitude of TDS, estimates of cost of illness, impact on quality-of-life, and cost-effectiveness of testosterone treatment.

MAIN OUTCOME MEASURE

Review of peer-reviewed literature.

RESULTS

The lack of clear universally accepted diagnostic criteria and the uncertainty surrounding the link between TDS and some of its consequences complicate the estimation of the burden of illness of TDS. Consequences of TDS that potentially lead to increased economic burden include depression, sexual dysfunction, mild cognitive impairment, osteoporosis, cardiovascular disease, and mortality. However, although good evidence exists demonstrating an association between TDS and sexual dysfunction and cognitive impairment, evidence is less strong for depression, the incidence of fractures and mortality, and highly controversial for cardiovascular disease. The consequences that are likely to impact on patients' quality of life include sexual function, energy levels, body composition, mood, and cognitive function.

CONCLUSION

Understanding the burden is only the first step decision makers need to take to decide whether to allocate scarce resources to treat the condition. To make informed decisions on when and who to treat information is also needed on the cost-effectiveness of available treatments. Such data would highlight the benefits of treatment of TDS to physicians, patients, and to society as a whole.

Age Related Testosterone Depletion in Patients With Erectile Dysfunction

PURPOSE

We assessed the pattern of age related testosterone depletion in patients with erectile dysfunction.

MATERIALS AND METHODS

A total of 305 patients with erectile dysfunction who had a normal testosterone level at baseline visit and who completed the study were candidates for analysis. Erectile function was assessed using the International Index of Erectile Function. Patients underwent routine laboratory investigations plus total testosterone and prolactin assessment at the baseline visit and on a yearly basis for 4 years.

RESULTS

The mean age +/- SD was significantly higher in 210 patients with decreased testosterone (55.3 +/- 7.3 years) than in 95 patients with steady testosterone (remaining within the normal range) (50.8 +/- 10.2 years). There was a significant decrease in yearly mean testosterone level throughout the study in all the age groups (determined by decades) older than 30 years. Of the study population 68.9% had decreases in testosterone levels throughout the 4 years of visits. Hypogonadism (testosterone lower than normal range) developed in 7.6% of the study population. There was a significant decrease in mean testosterone at any visit in comparison to previous visits. There were significant associations between decreased levels of testosterone and increased severity of erectile dysfunction at baseline visit, longer duration and poor metabolic control of diabetes, ischemic heart disease, hyperprolactinemia and low desire.

CONCLUSIONS

This study clearly demonstrated a decrease in testosterone level throughout the 4-year followup in patients with erectile dysfunction. Patients with decreasing testosterone were older than patients with a steady testosterone level.

Testosterone levels in men with erectile dysfunction

OBJECTIVE

To investigate the frequency of hypogonadism in men with erectile dysfunction (ED) and to assess which factors are related with low testosterone levels.

PATIENTS AND METHODS

In all, 165 men with ED were assessed; the evaluation included: hormonal profiles, serum total and free testosterone (using Vermeulen's formula) levels, and self-reported questionnaires on erectile function and desire domains of the International Index of Erectile Function. The frequency of hypogonadism was established using total and free testosterone levels as diagnostic criteria. The factors that might influence testosterone levels were evaluated by univariate and multivariate statistical analysis, and a logistic regression was used to determine which factors can predict free testosterone levels below normal limits (biochemical hypogonadism).

RESULTS

Using the total testosterone levels, 4.8% of the men were hypogonadal, whereas when using the free testosterone levels, 17.6% were hypogonadal. In the univariate analyses, not smoking and hypertension were associated with lower total and free testosterone levels. Ageing, absence of nocturnal erections and a lower erectile function score were only associated with lower free testosterone serum levels. There was no association between total and free testosterone levels and desire. In the multivariate analysis, only total testosterone levels were related to hypertension, while free testosterone levels were related to age and nocturnal erections. For biochemical hypogonadism, simple logistic regression analysis selected age, erectile function score and aetiological diagnosis of ED as predictors. In the multivariate analysis only the erectile function score had significant independent prognostic value.

CONCLUSIONS

The frequency of hypogonadism is higher when free testosterone levels are used for diagnosis. The total and free testosterone levels were not related to the level of sexual desire in men with ED. The free testosterone levels could be related to the quality and frequency of nocturnal erections, and when ED is more severe, it is more probable that free testosterone levels are below the 'normal' limit.

Pattern of endocrinal changes in patients with sexual dysfunction

INTRODUCTION

Many patients with endocrinal changes (endocrinopathy) have some degrees of sexual dysfunction that necessitate assessment and treatment.

AIM

To assess the prevalence, and identify the pattern, of endocrinopathy in patients with sexual dysfunction in our community.

METHODS

A total of 1,248 male patients with sexual dysfunction were enrolled in this study. Patients were screened for erectile dysfunction (ED) and sexual desire by the erectile function and the sexual desire domains of the International Index of Erectile Function (IEEF). Patients underwent routine laboratory investigations as well as total testosterone and prolactin assessment. All patients were referred to an endocrinologist for clinical and biochemical assessment of their endocrine function. The evaluation consisted of comprehensive history taking, physical examination, and, as needed, laboratory investigations.

RESULTS

Mean ages+/-SD were 51.9+/-12.2 and 52.3+/-11.7 years for patients with and without endocrinopathy, respectively. Of the study population, 23.8% had endocrinopathy. The most frequent endocrinal changes were low testosterone level (15%), hyperprolactinemia (13.7%), and hypothyroidism (3.1%). There were significant associations between endocrinopathy and obesity, smoking, low desire, and premature ejaculation (P<0.05 for each). Also, significant associations were found between low desire and low testosterone level, hyperprolactinemia, and hypothyroidism (P<0.05 for each). Hyperprolactinemia was significantly associated with premature ejaculation (P<0.05) but not with low testosterone level (P>0.05). There was no significant association between endocrinopathy and age, cigarette smoking (number and duration), and ED (duration, severity, type of onset, and progression) (P>0.05 for each).

CONCLUSION

Endocrinopathy is not a rare condition among ambulatory patients with sexual dysfunction. This study provides a quantitative estimate of endocrinopathy in ambulatory patients with sexual dysfunction.

[Erectile dysfunction: the role of laboratory in the diagnostic and pronostic evaluation]

OBJECTIVE

To review and to update the different laboratory tests recommended for etiologic diagnostic of erectile dysfunction and to evaluate the effect these tests could have on the pronostic and therapeutic strategy of this pathology.

MATERIAL AND METHODS

We review the last articles related with etiopathogenics and pathophysiologics mechanisms of erectile dysfunction, including our studies on endothelial dysfunction and erectile dysfunction.

RESULTS

The depth and extension of the laboratory protocol in erectile dysfunction is not necessaryly the same in all situations. The age, coincidence of comorbilities, set a different limit between patients demanding complementaries investigations that go beyond the basic request.

CONCLUSIONS

The etiopathogenic laboratory work up in erectile dysfunction is currently changing incorporating news tests. The traditional search of commorbilities like diabetes, hepatic dysfunction, hypogonadism, hyperglucemia is getting broad with recents analitics evaluations related with potential markers of endothelial disease.

Androgen Deficiency in the Etiology and Treatment of Erectile Dysfunction

The evaluation and management of erectile dysfunction (ED) has evolved dramatically following the introduction of oral phosphodiesterase-5 inhibitors. Despite the limited role of directed diagnostic testing in the evaluation of the impotent patient, routine de-termination of a serum testosterone likely is indicated based on evidence that testosterone modulates erectile function, that hypogonadism is prevalent among elderly men and men with ED, and that symptomatology alone rarely detects hypogonadism. Forms of testosterone commonly used include oral, parenteral, transdermal, and implantable preparations, each with significant advantages and disadvantages. The risks and benefits of testosterone supplementation have been characterized incompletely and will require further validation before widespread use of testosterone as hormone replacement therapy in aging men.

Is routine hormonal measurement necessary in initial evaluation of men with erectile dysfunction?

To prospectively compare serum hormone levels and the incidence of hormonal pathologies between men with and without erectile dysfunction, and investigate risk factors that might predict hormonal pathologies in men complaining of erectile dysfunction. The study included 262 men with erectile dysfunction and 53 healthy men with no erectile dysfunction as a control group. All men enrolled in the study were evaluated with a detailed history, physical examination, international index of erectile function (IIEF-5), and serum hormone measurement. Hypotestosteronemia was considered as serum total testosterone value of < 3 ng/mL, and hyperprolactinemia was considered as serum prolactin level of > 18 ng/mL. Serum hormone levels and the incidence of hormonal abnormalities were compared between the two groups. In addition, risk factors for hormonal abnormalities were investigated. There were no significant differences in the mean serum FSH (p = 0.212), LH (p = 0.623), testosterone (p = 0.332) and prolactin values (p = 0.351) between the men with and without erectile dysfunction. Hypotestosteronemia was detected in 29 (11%) of the erectile dysfunction group and in 2 (3.7%) of the control group, revealing no significant difference (p = 0.104). Hyperprolactinemia was detected in 25 (9.5%) of the erectile dysfunction group and in 2 (3.7%) of the control group, revealing no significant difference (p = 0.171). To investigate risk factors that might predict hormonal pathologies, there were no significant differences in the patient age, duration of the sexual dysfunction, smoking history and duration, the presence of chronic disease and the type of erectile dysfunction. Our findings suggest that hormonal measurement should not be routinely performed in the initial evaluation of men presenting with erectile dysfunction, and may be necessary based only on the findings obtained with a careful history and physical examination.

Methadone Maintenance and Male Sexual Dysfunction

PURPOSE

This study reports the prevalence and types of sexual dysfunction in a sample of men on methadone maintenance for opioid dependence, and describes factors which may contribute to sexual dysfunction.

METHODS

92 opioid-dependent men were recruited from a methadone maintenance clinic and completed two questionnaires, a research interview and laboratory measures.

RESULTS

Fourteen percent reported some sexual dysfunction. Erectile dysfunction (r = 0.24, p = 0.020), libido dysfunction (r = 0.30, p = 0.003), and global dysfunction (r = 0.26, p = 0.013) increased with increasing age of the patient. Methadone dose showed a significant direct correlation with increased orgasm dysfunction, both before and after adjusting for duration of treatment (p = 0.012). None of the sexual dysfunction subscales or global dysfunction were associated with plasma testosterone or plasma prolactin levels.

CONCLUSIONS

The rate of global sexual dysfunction in methadonetreated men is similar to general population studies and should be evaluated using general population guidelines. Orgasm dysfunction is a special case and may respond to methadone dose reduction.

Prostatic Specific Antigen in Patients with Hypogonadism: Effect of Testosterone Replacement

INTRODUCTION

The effect of parenteral testosterone replacement therapy on prostatic specific antigen (PSA) level or the development or growth of prostate cancer is unclear.

AIM

To assess the effect of testosterone replacement on PSA level in patients with hypogonadism associated with erectile dysfunction (ED).

METHODS

A total of 187 male patients above the age of 45 with hypogonadism associated with ED were enrolled in this study. Patients were screened for ED by the erectile function domain of the International Index of Erectile Function (IIEF). Patients underwent routine laboratory investigations, plus total testosterone, and PSA assessment. Replacement treatment with parenteral testosterone every 2-4 weeks for 1 year was instituted. Total testosterone and PSA serum levels were assessed every 3 months during the treatment course.

RESULTS

Mean age +/- SD was 62.8 +/- 11.4. Of the patients 87.7% were sexually active. Of the patients 10.2% had mild, 40.6% had moderate and 49.2% had severe ED. Of the study population, 62.5% had ED complaints for less than 5 years and 84.5% had gradual onset of their complaint. The majority of the patients (91.4%) had either progressive or stationary course while the minority reported regressive course and improvement of the condition. There was a significant increase of the post-treatment testosterone level in comparison to pretreatment level (P < 0.05). No significant increase in the post-treatment PSA level in comparison to pretreatment (P > 0.05). No significant difference between pre- and post-treatment categories of PSA level (normal, borderline, high) in relation to the severity of ED (P > 0.05). There was no significant association between PSA level and the duration of testosterone replacement therapy in the study population (P > 0.05).

CONCLUSION

The current study demonstrated that the level of PSA was not significantly changed after 1 year of testosterone replacement therapy in patients with hypogonadism associated with ED.

Challenges in the assessment of erectile dysfunction and treatment with oral therapies: review with case examples

PURPOSE

To review the clinical dimensions, etiology, assessment, and treatment of erectile dysfunction (ED) and to increase awareness of oral therapies for this condition.

DATA SOURCES

Scientific literature, consensus guidelines, and manufacturers' product information and guidelines.

CONCLUSIONS

A prevalent condition, particularly in middle-aged and elderly men, ED is vastly underreported and undertreated. Oral therapies, including phosphodiesterase type 5 inhibitors, are effective and well tolerated in many patients and represent potential first-line treatments for ED.

IMPLICATIONS FOR PRACTICE

ED has been associated with both life-threatening illnesses and reduced quality of life. Improving recognition and treatment of this condition and counseling patients about ED represent important clinical opportunities. A broad and expanding array of ED treatments enable therapy to be individualized to the needs of patients and their partners.

Hyperprolactinemia and sexual function in men: a short review

Erectile dysfunction (ED), generally associated with reduced sexual desire and sometimes with orgasmic or ejaculatory dysfunction, is the major revealing symptom of hyperprolactinemia (HPRL) in men, a condition that should not be neglected since many cases result from pituitary tumors, likely to result in serious complications. It is generally believed that the mechanism of the prolactin (PRL)-induced sexual dysfunctions is a decrease in testosterone secretion. In fact, serum testosterone is normal in many hyperprolactinemic males and there are also testosterone-independent mechanisms, probably mainly set at the level of the brain's neurotransmitter systems. Systematic determinations of serum PRL found very low prevalences of marked HPRL (>35 ng/ml) in ED patients (0.76% in a compilation of over 3200 patients) as well as of pituitary adenomas (0.4%). In addition, the association of HPRL with ED may have been coincidental in some of these cases, since 10% of the HPRLs diagnosed by the usual immunological assays are composed of macroprolactins, which are biologically inactive or little active variants of PRL. Their identification requires a PRL chromatography that is restricted to some specialized laboratories. There is presently no consensus with regards to the screening for HPRL in ED: systematic determination of serum PRL may be justified since HPRL is a serious but reversible disease, while there is presently no reliable clinical, psychometric or hormonal criteria (including serum testosterone level) allowing to restrict its determination to certain categories of the ED patients without risk of neglecting some HPRLs. In case of consistent HPRL, searching for a hypothalamic or pituitary tumor is mandatory. Dopamine-agonist therapy is the first choice treatment for the PRL-induced sexual dysfunctions. Additional sexual counselling may be necessary for certain patients.

Endocrine Aspects of Sexual Dysfunction in Men

INTRODUCTION

Endocrine disorders of sex steroid hormones may adversely affect men's sexual function. Aim. To provide expert opinions/recommendations concerning state-of-the-art knowledge for the pathophysiology, diagnosis and treatment of endocrinologic sexual medicine disorders.

METHODS

An International Consultation in collaboration with the major urology and sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various male and female sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five continents developed in a scientific and debate process. Concerning the Endocrine committee, there were eight experts from seven countries.

MAIN OUTCOME MEASURE

Expert opinions/recommendations are based on grading of evidence-based medical literature, extensive internal committee discussion over 2 years, public presentation and deliberation.

RESULTS

Hypogonadism is a clinical and biochemical syndrome characterized by a deficiency in serum androgen levels which may decrease sexual interest, quality of erections and quality of life. Biochemical investigations include testosterone and either bioavailable or calculated free testosterone; prolactin should be considered when hypogonadism has been documented. If clinically indicated, androgen therapy should maintain testosterone within the physiological range avoiding supraphysiologic values. Digital rectal examination and determination of serum prostate specific antigen values are mandatory prior to therapy and regularly thereafter. Androgen therapy is usually long-term requiring regular follow-up, frequent monitoring of blood levels and beneficial and adverse therapeutic responses.

CONCLUSIONS

Safe and effective treatments for endocrinologic sexual medicine disorders examined by prospective, placebo-controlled, multi-institutional clinical trials are needed.

Laboratory evaluations of erectile dysfunction: an evidence based approach

PURPOSE

We evaluate the prevalence of laboratory abnormalities in men presenting for initial evaluation and therapy of erectile dysfunction.

MATERIALS AND METHODS

The computerized charts of men receiving treatment for erectile dysfunction from 1987 to 2002 were retrospectively reviewed. We pooled laboratory data for 3,547 men with erectile dysfunction to assess the prevalence of laboratory abnormalities. Values of the common laboratory screening tests for erectile dysfunction were recorded for testosterone, prolactin, luteinizing hormone, thyroid-stimulating hormone, hemoglobin A(Ic), prostate specific antigen, hemoglobin, cholesterol and creatinine.

RESULTS

Of those patients evaluated 18.7% had low testosterone, 4.6% had increased prolactin, 14.6% had abnormal luteinizing hormone, 4.0% had increased thyroid-stimulating hormone, 8.3% had increased prostate specific antigen, 26.5% had anemia and 11.9% tested had renal insufficiency. A high percentage of patients presenting with a primary complaint of erectile dysfunction had increased hemoglobin A(Ic) and total serum cholesterol levels (52.9% and 48.4%, respectively).

CONCLUSIONS

An evidence based approach to standardization of laboratory evaluations for men presenting with erectile dysfunction is recommended. Laboratory screening should be directed to identify those risk factors that may benefit from lifestyle modification and pharmacological intervention.

Endocrine causes of impotence (nondiabetes)

The endocrine system has a major role in erections in normal men and it can also be a cause of significant morbidity. The relationship between serum testosterone measurement and erectile function is complex. Androgen treatment should certainly be considered in patients without prostate cancer but with a clinical picture that suggests a relevant contribution of hypogonadism to the ED. Other, nondiabetic, endocrine abnormalities may need to be considered in the management or the patient with ED.

Sexual inactivity results in reversible reduction of LH bioavailability

We have recently documented significantly reduced serum testosterone (T) levels in patients with erectile dysfunction (ED). To understand the mechanism of this hypotestosteronemia, which was independent of the etiology of ED, and its reversibility only in patients in whom a variety of nonhormonal therapies restored sexual activity, we measured serum luteinizing hormone (LH) in the same cohort of ED patients (n=83; 70% organic, 30% nonorganic). Both immunoreactive LH (I-LH) and bioactive LH (B-LH) were measured at entry and 3 months after therapy. Based on outcome (ie number of successful attempts of intercourse per month), patients were categorized as full responders (namely, at least eight attempts; n=51), partial responders (at least one attempt; n=20) and non-responders (n=16). Compared to 30 healthy men with no ED, baseline B-LH (mean+/-s.d.) in the 83 patients was decreased (13.6+/-5.5 vs 31.7+/-6.9 IU/L, P<0.001), in the face of a slightly increased, but in the normal range, I-LH (5.3+/-1.8 vs 3.4+/-0.9 IU/L, P<0.001); consequently, the B/I LH ratio was decreased (3.6+/-3.9 vs 9.7+/-3.3, P<0.001). Similar to our previous observation for serum T, the three outcome groups did not differ significantly for any of these three parameters at baseline. However, outcome groups differed after therapy. Bioactivity of LH increased markedly in full responders (pre-therapy=13.7+/-5.3, post-therapy=22.6+/-5.4, P<0.001), modestly in partial responders (14.8+/-6.9 vs 17.2+/-7.0, P<0.05) but remained unchanged in non-responders (11.2+/-2.2 vs 12.2+/-5.1). The corresponding changes went in the opposite direction for I-LH (5.2+/-1.7 vs 2.6+/-5.4, P<0.001; 5.4+/-2.2 vs 4.0+/-1.7, P<0.05; 5.6+/-1.2 vs 5.0+/-1.2, respectively), and in the same direction as B-LH for the B/I ratio (3.7+/-4.1 vs 11.8+/-7.8, P<0.001; 4.2+/-4.3 vs 5.8+/-4.2, P<0.05; 2.1+/-0.7 vs 2.6+/-1.3, respectively). We hypothesize that the hypotestosteronemia of ED patients is due to impaired bioactivity of LH. This reduced bioactivity is reversible, provided that resumption of sexual activity is achieved regardless of the therapeutic modality. Because biopotency of pituitary hormones is controlled by the hypothalamus, LH hypoactivity should be due to the hypothalamic functional damage associated to the psychological disturbances which unavoidably follow sexual inactivity.

Severe erectile dysfunction is a marker for hyperprolactinemia

The need for routine prolactin (PRL) measurement in the initial evaluation of erectile dysfunction (ED) has been questioned because of the low rate of hyperprolactinemia (HP) in these men and the costs involved. In addition, it is widely thought that sexual desire problems are a good clinical marker for HP and/or low testosterone in men with ED. Within a 15-month period, 844 consecutive PRL and sexual hormone determinations were conducted in men at the Kingston General Hospital. Of these patients, 138 were comprehensively evaluated at the first visit for ED and completed the International Index of Erectile Function (IIEF). In the 138 patients, 2.2% had severe hyperprolactinemia (>35 ng/ml), within the range of 1-5% previously reported. No correlation between initial prolactin value and the sexual desire domain or the erectile function domain (EFD) of the IIEF was found for this population. However, all cases of severe HP were found to occur in men who scored less than 10 in the EFD of the IIEF. Low libido is widely accepted as a marker of HP. In this study, HP was found in patients not reporting major problems with a desire disorder. Clinically significant HP may be reliably found with routine biochemical evaluation and in this series was not detected in patients with EFD scores above 10. A routine PRL measurement is inexpensive and early detection of a serious and treatable disease may afford greater therapeutic success.

Lack of sexual activity from erectile dysfunction is associated with a reversible reduction in serum testosterone

The role of androgenic hormones in human sexuality, in the mechanism of erection and in the pathogenesis of impotence is under debate. While the use of testosterone is common in the clinical therapy of male erectile dysfunction, hypogonadism is a rare cause of impotence. We evaluated serum testosterone levels in men with erectile dysfunction resulting either from organic or non-organic causes before and after non-hormonal impotence therapy. Eighty-three consecutive cases of impotence (70% organic, 30% non-organic, vascular aetiology being the most frequent) were subjected to hormonal screening before and after various psychological, medical (prostaglandin E1, yohimbine) or mechanical therapies (vascular surgery, penile prostheses, vacuum devices). Thirty age-matched healthy men served as a control group. Compared to controls, patients with impotence resulting from both organic and non-organic causes showed reduced serum levels of both total testosterone (11.1 +/- 2.4 vs. 17.7 +/- 5.5 nmol/L) and free testosterone (56.2 +/- 22.9 vs. 79.4 +/- 27.0 pmol/L) (both p < 0.001). Irrespective of the different aetiologies and of the various impotence therapies, a dramatic increase in serum total and free testosterone levels (15.6 +/- 4.2 nmol/L and 73.8 +/- 22.5 pmol/L, respectively) was observed in patients who achieved normal sexual activity 3 months after commencing therapy (p < 0.001). On the contrary, serum testosterone levels did not change in patients in whom therapies were ineffective. Since the pre-therapy low testosterone levels were independent of the aetiology of impotence, we hypothesize that this hormonal pattern is related to the loss of sexual activity, as demonstrated by its normalization with the resumption of coital activity after different therapies. The corollary is that sexual activity may feed itself throughout the increase in testosterone levels.

Is the measurement of serum testosterone routinely indicated in men with erectile dysfunction?

OBJECTIVE

To investigate the usefulness of serum testosterone levels as a relevant or useful indicator of sexual potency in men attending an erectile dysfunction clinic.

PATIENTS AND METHODS

Ninety consecutive men attending the erectile dysfunction clinic completed a sexual-activity questionnaire, and underwent a focused physical examination and questioning about their medical history. The serum testosterone level was measured in all patients and the results analysed in relation to the patient's age. Patients with low serum testosterone levels commenced replacement therapy comprising three intramuscular injections of testosterone (Sustanontrade mark, Organon, The Netherlands) 250 mg every third week. Potency status and serum testosterone were reassessed after 3 months' treatment.

RESULTS

Of the 90 men, 28 (31%) were aged < 50 years whilst 62 (69%) were >/=50 years old. Nineteen (21%) patients overall had low testosterone levels; four of these were < 50 and 15 were >/=50 years old. Five of 90 patients had a decreased libido; two of these also had low testosterone levels and all were < 50 years old. Testosterone levels returned to normal in all patients who received replacement therapy but potency returned in only two (10%); both were in the older group.

CONCLUSION

Measuring testosterone was not helpful in assessing potency or libido and low serum levels were not related to age. Correcting low testosterone did not improve either impotence or libido.

Assessment and management of erectile dysfunction in men with diabetes

PURPOSE

Erectile dysfunction occurs earlier in men with diabetes than in the general population, affecting over 50% of male patients by age 60. This article summarizes the etiologies and presents methods of patient assessment and treatment options for erectile dysfunction.

METHODS

Assessments of neurologic and vascular complications related to diabetes should be included in a sexual function history. The assessment must be holistic and focus on organic as well as psychogenic causes. Diabetes educators must be prepared to discuss the various pharmacologic treatment options.

RESULTS

Sildenafil currently is the only oral medication available for erectile dysfunction. Injectable treatments have proven successful but with limited long-term use and poor patient acceptance. Implantable devices carry surgical risk and increased rates of infection.

CONCLUSIONS

All men with diabetes should be screened for erectile dysfunction. The availability of a new oral medication provides a patient-acceptable treatment option.

Androgen induction of DNA synthesis in the rat penis

OBJECTIVES

The androgen sensitivity of the mammalian penis has long been appreciated. However, the precise biochemical and structural sequelae of alterations in testosterone, and the mechanisms thereof, remain to be elucidated. Recently, the androgen dependence of rat penile erectile tissue was further clarified at our institution, where the induction of apoptosis was demonstrated in response to castration. In continuity, we report the results of a follow-up study of the regenerative capacity of the regressed, castrated rat penile erectile tissue when testosterone is replenished.

METHODS

Three groups of rats were used: normal control rats, castrated without testosterone replenishment, and castrated with subsequent testosterone replenishment. In the third group, castrated rats were given testosterone and killed at 24-hour intervals over 4 days. Specimens of the penis, small bowel, and prostate were obtained from all animal groups. Immunohistochemical identification of intraperitoneally administered 5-bromo-2'-deoxyuridine, a thymidine analogue, was performed to detect new DNA synthesis. The incorporation of this molecule into high molecular weight nuclear DNA served as a measure of DNA synthesis and, hence, cellular proliferation.

RESULTS

Testosterone-replenished castrated rat penile stromal cells, both cavernosal and spongiosal, showed more enhanced proliferative activity than those of both castrated unreplenished and uncastrated control rats. Trichrome staining permitted the differentiation of responsive cell subsets. Various cell types were found to respond to replenished testosterone, including myocytes, fibrocytes, endothelial cells, and Schwann cells. Pronounced DNA synthesis occurred as early as 48 hours after the replenishment of testosterone. For purposes of technique validation, sections of small bowel were examined, in which glandular crypt cells would be expected to show rapid turnover. The nuclei of these bowel sections stained in all animal groups throughout the experiment, thus validating the staining technique. The technique of castration and testosterone replenishment was validated by confirming the known response of rat ventral prostate to androgen withdrawal and replenishment.

CONCLUSIONS

Our findings provide evidence that testosterone induces cellular proliferation and new DNA synthesis in the penile erectile tissue of castrated rats. This response to testosterone is not limited to one cell type, but rather is multicellular.

New insights into erectile dysfunction: a practical approach

Erectile dysfunction (ED) is the most common sexual problem in men, after premature ejaculation, affecting up to 30 million in the United States. In a society in which sexuality is widely promoted, ED impacts on feelings of self-worth and self-confidence and may impair the quality of life of affected men and their partners. Damage to personal relationships can ensue; and the anger, depression, and anxiety engendered spill over into all aspects of life. Patients are often embarrassed or reluctant to discuss the matter with their primary care practitioners. Unfortunately, many physicians fail to take the opportunity to promote open discussion of sexual dysfunction. They too, may avoid the topic through personal embarrassment. Since the National Institutes of Health (NIH) Consensus Conference on Impotence in 1992, the inadequate level of public and professional understanding of ED has begun to be addressed. As a first step in breaking down the communication barriers between patients and practitioners, it is important that physicians have a thorough understanding of the wide variety of conditions associated with ED and how the different risk factors for ED may be readily identified. This review addresses the diagnosis of ED and identifies diagnostic tests that can be used by primary care physicians to determine the patients most at risk and the treatments most suited to meet the patients' and their partners' goal for therapy.

Endocrine screening in 1,022 men with erectile dysfunction: clinical significance and cost-effective strategy

PURPOSE

We reviewed the results of serum testosterone and prolactin determination in 1,022 patients referred because of erectile dysfunction and compared the data with history, results of physical examination, other etiological investigations and effects of endocrine therapy to refine the rules of cost-effective endocrine screening and to pinpoint actual responsibility for hormonal abnormalities.

MATERIALS AND METHODS

Testosterone and prolactin were determined by radioimmunoassay. Every patient was screened for testosterone and 451 were screened for prolactin on the basis of low sexual desire, gynecomastia or testosterone less than 4 ng./ml. Determination was repeated in case of abnormal first results. Prolactin results were compared with those of a previous personal cohort of 1,340 patients with erectile dysfunction and systematic prolactin determination. Main clinical criteria tested regarding efficiency in hormone determination were low sexual desire, small testes and gynecomastia. Endocrine therapy consisted of testosterone heptylate or human chorionic gonadotropin for hypogonadism and bromocriptine for hyperprolactinemia.

RESULTS

Testosterone was less than 3 ng./ml. in 107 patients but normal in 40% at repeat determination. The prevalence of repeatedly low testosterone increased with age (4% before age 50 years and 9% 50 years or older). Two pituitary tumors were discovered after testosterone determination. Most of the other low testosterone levels seemed to result from nonorganic hypothalamic dysfunction because of normal serum luteinizing hormone and prolactin and to have only a small role in erectile dysfunction (definite improvement in only 16 of 44 [36%] after androgen therapy, normal morning or nocturnal erections in 30% and definite vasculogenic contributions in 42%). Determining testosterone only in cases of low sexual desire or abnormal physical examination would have missed 40% of the cases with low testosterone, including 37% of those subsequently improved by androgen therapy. Prolactin exceeded 20 ng./ml. in 5 men and was normal in 2 at repeat determination. Only 1 prolactinoma was discovered. These data are lower than those we found during the last 2 decades (overall prolactin greater than 20 ng./ml. in 1.86% of 1,821 patients, prolactinomas in 7, 0.38%). Bromocriptine was definitely effective in cases with prolactin greater than 35 ng./ml. (8 of 12 compared to only 9 of 22 cases with prolactin between 20 and 35 ng./ml.). Testosterone was low in less than 50% of cases with prolactin greater than 35 ng./ml.

CONCLUSIONS

Low prevalences and effects of low testosterone and high prolactin in erectile dysfunction cannot justify their routine determination. However, cost-effective screening strategies recommended so far missed 40 to 50% of cases improved with endocrine therapy and the pituitary tumors. We now advocate that before age 50 years testosterone be determined only in cases of low sexual desire and abnormal physical examination but that it be measured in all men older than 50 years. Prolactin should be determined only in cases of low sexual desire, gynecomastia and/or testosterone less than 4 ng./ml.

Testosterone supplementation for hypogonadal impotence: assessment of biochemical measures and therapeutic outcomes

PURPOSE

Although hypogonadism is a rare cause of erectile failure, impotent men are frequently treated with supplemental androgens. The results of such treatment and the individual merits of available formulations remain controversial. A series of hypogonadal men participated in a trial of oral testosterone undecanoate to assess the effectiveness of the medication, and use of biochemical and clinical outcome measures.

MATERIALS AND METHODS

A consecutive sample of 23 hypogonadal impotent men received testosterone undecanoate orally for no less than 60 days. Serum levels of gonadotropins, testosterone, estrogens and sex hormone-binding globulin were measured before, during and after the trial. Sexual response and feeling of well-being were measured by daily diaries and visual analogue scales.

RESULTS

Testosterone undecanoate produced restoration of plasma testosterone levels in all patients but a measurable improvement in sexual attitudes and performance in only 61%. Visual analogue scores were effective discriminants of the therapeutic response but none of the conventional biochemical measures predicted or correlated with clinical outcome.

CONCLUSIONS

Testosterone undecanoate is an effective agent for treating hypogonadism. In hypogonadal impotent patients the most appropriate outcome measure for androgen supplementation is individual response to therapy, while conventional biochemical hormone determinations lack predictive value and fail to correlate with response.

The effects of testosterone on the cavernous tissue and erectile function

A review of the current literature is conducted to explore the developmental aspects, animal and human experiences and the effects of pharmacological manipulation to explain the role androgens play in sexual function with special emphasis on erectile function and the erectile tissue. This review reveals that androgens are necessary for the normal development of the penis and their deficiency results in significant structural abnormalities. Although androgen receptors in the penis decrease after puberty, they usually do not disappear completely. Animal data show that androgens support erectile function through a direct effect on the erectile tissue. Experimental castration results in impaired erectile response to central and peripheral stimulation and decrease in penile tissue concentration of nitric oxide synthase-containing nerves. Testosterone replacement reverses these abnormalities. In the rat penis, apoptosis is induced by castration and new DNA synthesis is induced by testosterone replenishment. Human data are less clear than animal data. Castration results in loss of libido and in erectile dysfunction. However, these effects are not universal. Testosterone enhances libido, frequency of sexual acts and sleep-related erections. Its effects on erotic erections are not clear.

Endocrine screening for sexual dysfunction using free testosterone determinations

PURPOSE

Controversy exists concerning the need for routine endocrine screening in impotent men. Debate also continues as to what hormonal studies are necessary, the role of the free fraction of testosterone and whether a history of decreased libido or testicular atrophy can predict these endocrinopathies.

MATERIALS AND METHODS

We reviewed 508 consecutive men who presented with sexual dysfunction within a 22-month period. Testosterone data were available for 268 patients (53%) and prolactin data were available for 170 (33%).

RESULTS

Hypogonadism, defined as 2 abnormal total testosterone levels, was found in 42 of our 268 patients (15.6%). A history of decreased libido by patient questionnaire and/or testicular atrophy on physical examination could not predict these cases. A normal free fraction of testosterone saved further unnecessary endocrine evaluation in 50% of patients with hypogonadism. Hypoprolactinemia was noted in 3 of 170 patients (1.8%).

CONCLUSIONS

Routine endocrine screening remains a necessary part of the evaluation for sexual dysfunction. A history of decreased libido and/or testicular atrophy on physical examination cannot predict hypogonadism. Measurement of free fraction of testosterone will further lessen unnecessary endocrine evaluations by 50% and should become standard practice in screening for hypogonadism. Prolactin levels are necessary only in patients with hypogonadism and/or a history of decreased libido.

Assessment and treatment of impotence

Impotence is a common problem. History is primarily relied on to diagnose psychogenic impotence. Sex therapy is an effective treatment. Antihypertensive and psychiatric medicines often cause impotence, but most medicines should be considered a cause if this is supported by the history. Hormonal causes should be suspected in a patient with decreased libido or decreased testicular size, and testosterone should be measured in these cases. Hormone replacement may restore sexual function in hypogonadal men. Doppler sonogram or arteriography should be used to diagnose vascular impotence for men who would be good surgical candidates. Only young men without other illness are considered. There is little need to test neurologic function because there is no specific treatment for neurogenic impotence. These patients and patients who do not respond to the aforementioned treatments should be offered the vacuum erection device, penile self-injection therapy, or penile prosthesis. Choice depends on comorbid illness as well as patient preference. A basic algorithm for the evaluation and treatment of impotence is given in Figure 2.

Routine prolactin measurement is not necessary in the initial evaluation of male impotence

The authors determined the prevalence of hyperprolactinemia in impotent men in a community setting and assessed the cost of case detection with routine estimation of serum prolactin. They recruited 299 consecutive patients with impotence and determined the hormonal levels (prolactin, luteinizing hormone, follicle-stimulating hormone, and testosterone). Pituitary gland imaging was done when the prolactin level was elevated. Simultaneous prolactin and testosterone levels were available for 212 patients. Three patients (1.4%) had elevated prolactin levels but none had pituitary tumor. Two of these had low testosterone levels. Overall, 51 patients (24.1%) had low testosterone levels. Cost of selective prolactin estimation in patients with low testosterone levels resulted in a net saving of $2,574 per case detected. The authors conclude that the prevalence of hyperprolactinemia in impotence is low. Routine measurement of prolactin levels in impotence is not indicated. Selective determination in patients with low testosterone reduces the cost of diagnostic evaluation.