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Erectile dysfunction

October 2007

Association between erectile dysfunction and coronary artery disease. Role of coronary clinical presentation and extent of coronary vessels involvement: the COBRA trial.

AIMS: To investigate the prevalence of erectile dysfunction (ED) in patients with CAD according to clinical presentation, acute coronary syndrome (ACS) vs. chronic coronary syndrome (CCS), and extent of vessel involvement (single vs. multi-vessel disease). METHODS AND RESULTS: 285 patients with CAD divided into three age-matched groups: group 1 (G1, n=95), ACS and one-vessel disease (1-VD); group 2 (G2, n=95), ACS and 2,3-VD; group 3 (G3, n=95), chronic CS. Control group (C, n=95) was composed of patients with suspected CAD who were found to have entirely normal coronary arteries by angiography. Gensini’s score used to assess extent of CAD. ED as any value <26 according to the International Index of Erectile Function (IIEF). ED prevalence was lower in G1 vs. G3 (22 vs. 65%, P<.0001) as a result of less atherosclerotic burden as expressed by Gensini’s score [2 (0-6) vs. 40 (19-68), P=0.0001]. Controls had ED rate values similar to G1 (24%). Group 2 ED rate, IIEF, and Gensini’s scores were significantly different from G1 [55%, P<0.0001; 24 (17-29), P=0.0001; 21 (12.5-32), P<0.0001] and similar to G3 suggesting that despite similar clinical presentation, ED in ACS differs according to the extent of CAD. No significant difference between groups was found in the number and type of conventional risk factors. Treatment with beta-blockers was more frequent in G3 vs. G1 and G2. In G3 patients who had ED, onset of sexual dysfunction occurred before CAD onset in 93%, with a mean time interval of 24 [12-36] months. In logistic regression analysis, age (OR=1.1; 95% confidence interval (CI), 1.05-1.16; P=<0.0001), multi-vessel vs. single-vessel (OR=2.53; 95% CI, 1.43-4.51; P=0.0002), and CCS vs. ACS (OR=2.32; 95% CI, 1.22-4.41; P=0.01) were independent predictors of ED. CONCLUSION: ED prevalence differs across subsets of patients with CAD and is related to coronary clinical presentation and extent of CAD. In patients with established CAD, ED comes before CAD in the majority by an average of 2 up to 3 years.

Eur Heart J. 2006 Nov;27(22):2632-9

Is the metabolic syndrome an independent risk factor for erectile dysfunction?

PURPOSE: We determined the role of the metabolic syndrome as an independent risk factor for erectile dysfunction. MATERIALS AND METHODS: Men participating in a health screening project completed the International Index of Erectile Function-5. The metabolic syndrome was defined according to the 2005 International Diabetes Federation consensus definition. Multiple linear regression, ANOVA and chi-square tests were used to investigate the impact of the metabolic syndrome on erectile dysfunction. RESULTS: A total of 2,371 men with a mean age of 46.1 years (SD 9.9, range 30 to 69) were analyzed. Of the men 33.4% (652) had no erectile dysfunction (International Index of Erectile Function-5 score 22 to 25), 59.7% (1,166) had mild erectile dysfunction (International Index of Erectile Function-5 score 17 to 21) and 6.9% (134) had moderate to severe erectile dysfunction (International Index of Erectile Function-5 score 5 to 16). The metabolic syndrome was present in 33.8% (794). In a multiple linear regression analysis an increased waist-to-hip ratio (p = 0.01) and metabolic syndrome (p = 0.01) turned out to be independently associated with a decreased International Index of Erectile Function-5 score. When stratified according to age, the metabolic syndrome was correlated to erectile dysfunction only in men 50 years old or older with an increase of severe erectile dysfunction by 48% (p = 0.01). CONCLUSIONS: The metabolic syndrome and an increased waist-to-hip ratio are independently associated with a decreased International Index of Erectile Function-5 score. The metabolic syndrome in men older than 50 years is significantly associated with a higher proportion of moderate to severe erectile dysfunction.

J Urol. 2007 Feb;177(2):651-4

Does testosterone have a role in erectile function?

PURPOSE: Despite the well-established role of testosterone in enhancing libido, its exact contribution to erections in men remains unclear. The main objectives of this review are to clarify the role of testosterone in erectile function and evaluate its therapeutic value in men with erectile dysfunction (ED). METHODS: Review of the relevant literature (English, French, and Spanish) from 1939 to June 2005 was conducted using data sources from MEDLINE, endocrinology text books, and hand searching of cross-references from original articles and reviews. Clinical trials, animal studies, case reports, reviews, and guidelines of major associations were included. RESULTS: Animal and preliminary human studies suggest that testosterone may facilitate erection by acting as vasodilator of the penile arterioles and cavernous sinusoids. Following castration, most, but not all, men had partial or complete loss of erection. Hypogonadism is not a common finding in ED, occurring in about 5% of cases, and in general, there is lack of association between serum testosterone levels, when present in normal or moderately low levels, and erectile function. Most trials using testosterone for treatment of ED in hypogonadal men suffer from methodological problems and report inconsistent results, but overall, suggest that testosterone may be superior to placebo. Erectile function is more likely to improve with testosterone therapy in patients with severe degrees of hypogonadism. Testosterone treatment may ameliorate the response to the phosphodiesterase 5 (PDE5) inhibitors in hypogonadal men and men with low-normal serum testosterone. Repeated measurement of morning serum total testosterone is a fairly accurate and easy method to evaluate androgenecity, but measurement of free or bioavailable testosterone is recommended in conditions that alter the levels of sex-hormone-binding globulin (SHBG), such as in the elderly and in obesity. CONCLUSIONS: Available data suggest that in most men circulating levels of testosterone, well below the normal range, are essential for normal erection and that higher levels of serum testosterone may not have major impact on erectile function. Screening for hypogonadism in all men with ED is necessary to identify cases of severe hypogonadism and some cases of mild to moderate hypogonadism, who may benefit from testosterone treatment.

Am J Med. 2006 May;119(5):373-82

Dehydroepiandrosterone in the treatment of erectile dysfunction: a prospective, double-blind, randomized, placebo-controlled study.

OBJECTIVES: In 1994, the Massachusetts Male Aging Study presented an inverse correlation of the serum levels of dehydroepiandrosterone (DHEA) and the incidence of erectile dysfunction (ED). We evaluated the efficacy of DHEA replacement in the treatment of ED in a prospective, double-blind, randomized, placebo-controlled study. METHODS: The inclusion criteria included ED, normal physical and neurologic examinations, serum levels of testosterone, dihydrotestosterone, prolactin, and prostate-specific antigen (PSA) within the normal range, and a serum DHEA sulfate level below 1.5 micromol/L. Also all patients had a full erection after a pharmacologic erection test with 100 microg prostaglandin E1; pharmacocavernosography showed no visualization in corporeal venous structures. Forty patients from our impotence clinic were recruited and randomly divided into two groups of 20 patients each. Group 1 was treated with an oral dose of 50 mg DHEA and group 2 with a placebo one time a day for 6 months. The International Index of Erectile Function (IIEF), a 15-item questionnaire, was used to rate the success of this therapy. RESULTS: Therapy response was defined as the ability to achieve or maintain an erection sufficient for satisfactory sexual performance according to the National Institutes of Health Consensus Development Panel on Impotence. DHEA treatment was associated with higher mean scores for all five domains of the IIEF. There was no impact of DHEA treatment on the mean serum levels of PSA, prolactin, testosterone, the mean prostate volume, and the mean postvoid residual urine volume. CONCLUSIONS: Our results suggest that oral DHEA treatment may be of benefit in the treatment of ED. Although our patient data base is too small to do relevant statistical analysis, we believe that our data show a biologically obvious trend that justifies further extended studies.

Urology. 1999 Mar;53(3):590-4; discussion 594-5

Ginkgo biloba for antidepressant-induced sexual dysfunction.

In an open trial ginkgo biloba, an extract derived from the leaf of the Chinese ginkgo tree and noted for its cerebral enhancing effects, was found to be 84% effective in treating antidepressant-induced sexual dysfunction predominately caused by selective serotonin reuptake inhibitors (SSRIs, N = 63). Women (n = 33) were more responsive to the sexually enhancing effects of ginkgo biloba than men (N = 30), with relative success rates of 91% versus 76%. Ginkgo biloba generally had a positive effect on all 4 phases of the sexual response cycle: desire, excitement (erection and lubrication), orgasm, and resolution (afterglow). This study originated from the observation that a geriatric patient on ginkgo biloba for memory enhancement noted improved erections. Patients exhibited sexual dysfunction secondary to a variety of antidepressant medications including selective serotonin reuptake inhibitor (SSRIs), serotonin and nonrepinephrine reuptake inhibitor (SNRIs) monoamine oxidase inhibitor (MAOIs), and tricyclics. Dosages of ginkgo biloba extract ranged from 60 mg qd to 120 mg bid (average = 209mg/d). The common side effects were gastrointestinal disturbances, headache, and general central nervous system activation. The article includes a discussion of presumed pharmacologic mechanisms, including effects on platelet activating factor, prostaglandins, peripheral vasodilatation, and central serotonin and norepinephrine receptor factor modulation.

J Sex Marital Ther. 1998 Apr-Jun;24(2):139-43

Clinical efficacy of Korean red ginseng for erectile dysfunction.

To investigate the efficacy in treating erectile dysfunction and to develop a natural drug without complications, the results of ginseng treatments are compared to placebo and other drug. A total of 90 patients with 30 patients in each group were closely followed. Changes in symptoms such as frequency of intercourse, premature ejaculation, and morning erections after treatment were not changed in all three groups (p > 0.05). However in the group receiving ginseng, changes in early detumescence and erectile parameters such as penile rigidity and girth, libido and patient satisfactions were significantly higher than that of other groups (p < 0.05). The overall therapeutic efficacies on erectile dysfunction were 60% for ginseng group and 30% for placebo and trazodone treated groups, statistically confirming the effect of ginseng (p < 0.05). No complete remission of erectile dysfunction was noted, but partial responses were reported. No cases of aggravation of symptoms were reported. AVS-penogram, which is a recording of penile hemodynamic changes during the natural erection after audiovisual erotic stimulation, is not changed after administration of ginseng. However if administered for a prolonged period of time, the cummulative effect on vascular flow might be seen. The administration of Korean red ginseng has shown to have superior effects compared to the placebo or trazodone. Definitely more researches are required to elucidate the mechanism of ginseng. The effects of saponin, extracted from ginseng, on smooth muscle of erectile tissues, can be evaluated using organ chamber or nitric oxide titration, thereby pinpointing the exact action mechanism of saponin. As more informations are available, possible breakthrough in treatment of erectile dysfunction could be arisen from active saponin extracted from red ginseng, bringing hopes to many sufferers of erectile dysfunction.

Int J Impot Res. 1995 Sep;7(3):181-6

A double-blind crossover study evaluating the efficacy of Korean red ginseng in patients with erectile dysfunction: a preliminary report.

PURPOSE: We investigated the efficacy of Korean red ginseng for erectile dysfunction using the International Index of Erectile Function, RigiScan (UroHealth Systems, Laguna Niguel, California), hormonal levels and penile duplex ultrasonography with audiovisual sexual stimulation. MATERIALS AND METHODS: A total of 45 patients with clinically diagnosed erectile dysfunction were enrolled in a double-blind, placebo controlled, crossover study (8 weeks on treatment, 2 weeks of washout and 8 weeks on treatment) in which the effects of Korean red ginseng and a vehicle placebo were compared using multiple variables. The ginseng dose was 900 mg, 3 times daily. RESULTS: Mean International Index of Erectile Function scores were significantly higher in patients treated with Korean red ginseng than in those who received placebo (baseline 28.0 +/- 16.7 and 38.1 +/- 16.6 versus 30.9 +/- 15.7, p <0.01). Scores on questions 3 (penetration) and 4 (maintenance) were significantly higher in the ginseng than in the placebo group (p <0.01). In response to the global efficacy question 60% of the patients answered that Korean red ginseng improved erection (p <0.01). Among other variables penile tip rigidity on RigiScan showed significant improvement for ginseng versus placebo. CONCLUSIONS: Our data show that Korean red ginseng can be as effective alternative for treating male erectile dysfunction.

J Urol. 2002 Nov;168(5):2070-3

Sexual function in men older than 50 years of age: results from the health professionals follow-up study.

BACKGROUND: Although many studies have provided data on erectile dysfunction in specific settings, few studies have been large enough to precisely examine age-specific prevalence and correlates. OBJECTIVE: To describe the association between age and several aspects of sexual functioning in men older than 50 years of age. DESIGN: Cross-sectional analysis of data from a prospective cohort study. SETTING: US health professionals. PARTICIPANTS: 31,742 men, age 53 to 90 years. MEASUREMENTS: Questionnaires mailed in 2000 asked about sexual function, physical activity, body weight, smoking, marital status, medical conditions, and medications. Previous biennial questionnaires since 1986 asked about date of birth, alcohol intake, and other health information. RESULTS: When men with prostate cancer were excluded, the age-standardized prevalence of erectile dysfunction in the previous 3 months was 33%. Many aspects of sexual function (including overall function, desire, orgasm, and overall ability) decreased sharply by decade after 50 years of age. Physical activity was associated with lower risk for erectile dysfunction (multivariable relative risk, 0.7 [95% CI, 0.6 to 0.7] for >32.6 metabolic equivalent hours of exercise per week vs. 0 to 2.7 metabolic equivalent hours of exercise per week), and obesity was associated with higher risk (relative risk, 1.3 [CI, 1.2 to 1.4] for body mass index >28.7 kg/m2 vs. <23.2 kg/m2). Smoking, alcohol consumption, and television viewing time were also associated with increased prevalence of erectile dysfunction. Men who had no chronic medical conditions and engaged in healthy behaviors had the lowest prevalence. CONCLUSIONS: Several modifiable health behaviors were associated with maintenance of good erectile function, even after comorbid conditions were considered. Lifestyle factors most strongly associated with erectile dysfunction were physical activity and leanness.

Ann Intern Med. 2003 Aug 5;139(3):161-8