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

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.

Hyperprolactinaemia due to hypothalamic-pituitary disease or drug-induced in patients with erectile dysfunction

One hundred and sixty-five patients with erectile dysfunction were assessed at the Athens Medical Sex Institute: 60 men (36.4%) considered their condition as organic, 52 (31.5%) rated it as mostly psychogenic, 45 (27.2%) thought it could be of mixed aetiology and 8 (4.8%) could not comment at all as to the aetiology. Initial psychologic evaluation rated the condition in the majority of cases as psychogenic (130 patients, 84.8%). No psychologist considered the erectile dysfunction as purely (100%) organic. After the urological and endocrine evaluation, vascular disorder was considered in 30 patients (18.2%), endocrine dysfunction in 16 patients (9.7%) and psychogenic in 109 patients (66.1%). Sixteen of the above patients had definite hyperprolactinaemia, two had large-sized prolactinomas as revealed by magnetic resonance imaging (MRI) and pituitary function tests. Four had nonfunctioning pituitary tumours, which was also based on MRI and pituitary tests. Four had small prolactin (PRL) adenomas. Drug-induced hyperprolactinaemia was suspected in six patients who used medications affecting PRL secretion and had no evidence of tumour on radiological evaluation. In conclusion, hyperprolactinaemia in men with erectile dysfunction needs to be evaluated before considering any other treatment.

Hyperprolactinemia and immunohistochemical expression of intracellular prolactin and prolactin receptor in primary central nervous system tumors and their relationship with cellular replication

The role of prolactin (PRL) in the CNS remains uncertain. We evaluated the presence of hyperprolactinemia, intracellular prolactin (ICP), and prolactin receptor (PRL-R) in primary CNS tumors, and their relationship with cellular replication with a prospective cross-sectional study of 82 consecutive patients with primary CNS tumors admitted for neurosurgical resection between October 2003 and September 2005. Patients submitted to a questionnaire, and venous blood samples were obtained for measurement of serum PRL and TSH. Immunohistochemical analyses were performed to evaluate the presence of ICP, PRL-R, and Ki-67. Serum PRL levels ranged from 2 to 70 ng/ml, and hyperprolactinemia was detected in 25 cases (30.5%). ICP was detected in 18 patients (21.9%), in whom PRL ranged from 2 to 32 ng/ml. A positive correlation was found between PRL levels and the presence of ICP (Student's t test, P = 0.022). The PRL-R was observed immunohistochemically in 32 cases (39%). The frequencies of hyperprolactinemia, ICP, and PRL-R were similar across the several histological types of CNS tumors. Ki-67 index was similar in all groups. Hyperprolactinemia and intracellular presence of PRL and PRL-R were common findings in this population, suggesting a role for PRL in CNS tumor genesis.

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.

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.

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.

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.

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.

Management of erectile dysfunction by the geriatrician

Erectile dysfunction (ED) is the most common health disorder to afflict elderly men. Although 67% of men aged 70 years have ED, and their interest in sexual intercourse remains high, less than 5% receive adequate treatment. In this report, we review recent developments in our understanding of the pathophysiology of ED, how geriatricians can perform an office-based evaluation, and rational (evidence-based) treatment of this important disorder.

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.

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.