Immediate Improvement in Penile Hemodynamics after Cessation of Smoking: Previous Results

Cigarette smoking and erectile dysfunction: an updated review with a focus on pathophysiology, e-cigarettes, and smoking cessation

Introduction

Cigarette smoking has major health implications and causes substantial damage to all organ systems. Approximately one-third of men are active smokers worldwide, and most men are unaware that cigarette smoking can contribute to erectile dysfunction (ED).

Objectives

This article aims to provide a comprehensive overview of research conducted on cigarette smoking and ED, with a particular focus on pathophysiology, electronic cigarettes (e-cigarettes), and smoking cessation.

Methods

A manual literature search was conducted on all research conducted on cigarette smoking and ED up to October 2022.

Results

Substantial evidence is now available showing that past and current cigarette smoking has dose-dependent associations with ED in studies controlling for age and important health comorbidities. Cigarette smoke contains nicotine, carbon monoxide, oxidant chemicals, and metals that can damage the endothelium and disrupt erectile processes. For current smokers, smoking abstinence can strengthen the endothelium and reverse diminished erectile function. The effect of e-cigarettes on endothelial damage and ED remains largely untested. E-cigarettes expose users to fine and ultrafine particles and toxins that can increase risk of cardiovascular injury, but these acute effects appear less potent than conventional cigarettes (long-term cardiovascular effects are still unknown). E-cigarettes are therefore likely to have less harmful effects on ED than conventional cigarettes.

Conclusions

Smoking cessation programs that focus on nicotine replacement therapy (transdermal patches, gum, or inhalers), behavioral counseling, social support, and education programs can be effective approaches to ED treatment in active smokers. Temporarily transferring from regular cigarettes to e-cigarettes—which transmit some of the same carcinogens as conventional cigarettes and are likely to have some long-term cardiovascular effects that disrupt erectile function—might also be useful for long-term smoking cessation and treatment of ED.

A systematic review and meta-analysis of sexual dysfunction in patients with hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition associated with significant psychosocial comorbidity. To date, the relationship between HS and sexual dysfunction has not been assessed through meta-analysis. A systematic review was performed by OVID Medline, EMBASE, Cochrane Central, PsycINFO via EBSCO, Web of Science, and LILACS. Original English language studies assessing HS and sexual function published prior to April 2020 were screened. Scores from the Female Sexual Function Index (FSFI), International Index of Erectile Function (IIEF), Arizona Sexual Experiences Scale (ASEX), Frankfurt Self-Concept Scale for Sexuality (FKKS SEX), and Dermatology Life Quality Index (DLQI) were analyzed. Sixteen studies met inclusion criteria, and nine were eligible for meta-analysis. Pooled mean FSFI score for female HS patients met criteria for sexual dysfunction (mean = 20.32, P < 0.001). Females with HS reported worse FSFI scores than controls (pooled mean difference = -5.704, P = 0.003, I² =0). Mean IIEF score among males with HS was 47.96 (P < 0.001). Males with HS also reported worse IIEF scores than controls (pooled mean difference = -18.77, P = 0.00, I²  = 0). Females with HS performed worse on sexual function inventories than males with HS (SMD = -0.72, P = 0.009, I²  = 0). Both male and female HS patients reported significantly more sexual impairment than same-sex controls. Female HS patients also experience more sexual impairment than males and on average meet criteria for sexual dysfunction (FSFI <26.55). Clinicians should be aware that their patients with HS, especially females, may be suffering from sexual dysfunction and treated them appropriately.

The Impact of Smoking on Sexual Function

OBJECTIVES

Smoking is a well-established risk factor for sexual dysfunction. However, the impact of smoking cessation on sexual function is unclear. We hypothesize that there is an improvement in sexual function following smoking cessation. To evaluate this hypothesis, we analyzed the association between cigarette smoking and smoking cessation with sexual function among participants of the Reduction by Dutasteride in Prostate Cancer Events (REDUCE) study.

MATERIALS AND METHODS

We analyzed baseline data of 6,754 men, ages 50-75 years-old divided into: lifelong nonsmokers, former smokers and current smokers. We examined total testosterone (TT, normal range ≥10 nmol/L) and sexual function variables: self-reported sexual activity, low libido and erectile dysfunction. Differences between current vs nonsmokers and former vs current smokers were analyzed using chi-square test, linear and logistic regressions.

RESULTS

A total of 3,069 (45.4%) men were nonsmokers, 2,673 (39.6%) former smokers, and 1,012 (15%) current smokers. Current smokers were significantly younger than former and nonsmokers (mean age 61.6, 63.2, 62.7 years), leaner (mean body-mass index 27.0, 27.7, 27.2 kg/m² ), and had less hypertension (32.4%, 41.6%, 36.8%, respectively, all P < 0.01). In uni- and multivariable analysis, current smokers had higher mean TT compared to nonsmokers (485.4, 451.2 nmol/L, P < 0.001), higher prevalence of low libido (25.6%, 21.0%, P=0.002) and erectile dysfunction (31.6%, 26.0%, respectively, P < 0.001) with comparable sexual activity (81.7%, 82.8%, respectively, P=0.420). In multivariable analysis, former smoker had statistically significant less prevalence of low libido (OR: 0.8, P=0.013) and erectile dysfunction (OR: 0.8, P=0.006) compared to current smokers.

CONCLUSION

Cigarette smoking was associated with worse sexual health compared to nonsmoker, while former smokers had better erectile function and libido than current smokers. Smoking cessation may improve male sexual health and counselling on smoking cessation may be considered at the time of sexual health evaluations.

Erectile Dysfunction Is a Hallmark of Cardiovascular Disease: Unavoidable Matter of Fact or Opportunity to Improve Men's Health?

Erectile dysfunction (ED) is an early manifestation of cardiovascular (CV) disease. For this reason, men with ED should be carefully assessed for CV risk factors in order to prevent future major adverse CV events (MACE). Traditional risk factors are not found in all subjects at high CV risk. In fact, a relevant proportion of MACE occurs in men who are apparently risk factor free. In men with ED, it is important to take into account not only traditional risk factors but also unconventional ones. Several parameters that derive from good clinical assessment of subjects with ED have proven to be valuable predictors of MACE. These include family history of cardiometabolic events, alcohol abuse, fatherhood, decreased partner’s sexual interest, severe impairment in erection during intercourse or during masturbation, impaired fasting glucose, increased triglycerides, obesity even without metabolic complications, decreased penile blood flows or impaired response to an intra-cavernosal injection test. Recognizing these risk factors may help in identifying, among subjects with ED, those who merit stricter lifestyle or pharmacological interventions to minimize their CV risk. Effective correction of risk factors in ED men considered as high risk, besides reducing CV risk, is also able to improve erectile function.

Update of the position paper on arterial hypertension and erectile dysfunction

: Sexual health is an integral part of overall health, and an active and healthy sexual life is an essential aspect of a good life quality. Cardiovascular disease and sexual health share common risk factors (arterial hypertension, diabetes mellitus, dyslipidemia, obesity, and smoking) and common mediating mechanisms (endothelial dysfunction, subclinical inflammation, and atherosclerosis). This generated a shift of thinking about the pathophysiology and subsequently the management of sexual dysfunction. The introduction of phosphodiesterase type 5 inhibitors revolutionized the management of sexual dysfunction in men. This article will focus on erectile dysfunction and its association with arterial hypertension. This update of the position paper was created by the Working Group on Sexual Dysfunction and Arterial Hypertension of the European Society of Hypertension. This working group has been very active during the last years in promoting the familiarization of hypertension specialists and related physicians with erectile dysfunction, through numerous lectures in national and international meetings, a position paper, newsletters, guidelines, and a book specifically addressing erectile dysfunction in hypertensive patients. It was noted that erectile dysfunction precedes the development of coronary artery disease. The artery size hypothesis has been proposed as a potential explanation for this observation. This hypothesis seeks to explain the differing manifestation of the same vascular condition, based on the size of the vessels. Clinical presentations of the atherosclerotic and/or endothelium disease in the penile arteries might precede the corresponding manifestations from larger arteries. Treated hypertensive patients are more likely to have sexual dysfunction compared with untreated ones, suggesting a detrimental role of antihypertensive treatment on erectile function. The occurrence of erectile dysfunction seems to be related to undesirable effects of antihypertensive drugs on the penile tissue. Available information points toward divergent effects of antihypertensive drugs on erectile function, with diuretics and beta-blockers possessing the worst profile and angiotensin receptor blockers and nebivolol the best profile.

People smoke for nicotine, but lose sexual and reproductive health for tar: a narrative review on the effect of cigarette smoking on male sexuality and reproduction

PURPOSE

To systematically review the impact of smoking habits on cardiovascular (CV) as well as on male sexual and reproductive function and to provide updated evidence on the role of electronic cigarettes (e-Cig) on the same topics.

METHODS

A comprehensive Medline, Embase, and Cochrane search was performed including the following words: smoking, CV system, CV risk, erectile dysfunction (ED), and male fertility. Publications from January 1, 1969 up to February 29, 2020 were included.

RESULTS

Smoking has a tremendous negative impact on CV mortality and morbidity. Current smoking behavior is also negatively associated with erectile dysfunction (ED) and impaired sperm parameters. E-Cig can release significantly lower concentrations of harmful substances when compared to regular combustible cigarettes. Whether or not the latter can result in positive CV, sexual, and fertility outcomes is still under study. Preliminary studies showed that exposure to e-Cig leads to lower vascular damage when compared to the traditional cigarette use. However, data on the long-term effects of e-Cig are lacking. Similarly, preliminary data, obtained in animal models, have suggested a milder effect of e-Cig on erectile function and sperm parameters.

CONCLUSION

Available evidence showed that e-Cig are much less dangerous when compared to the traditional tobacco use. However, it should be recognized that the risk related to e-Cig is still higher when compared to that observed in non-smoking patients. Hence, e-Cig should be considered as a potential tool, in the logic of harm reduction, to reduce the CV, sexual and fertility risk in patients refractory to the fundamental, healthy choice to definitively quit smoking.

Pharmacology and perspectives in erectile dysfunction in man

Penile erection is a perfect example of microcirculation modulated by psychological factors and hormonal status. It is the result of a complex neurovascular process that involves the integrative synchronized action of vascular endothelium; smooth muscle; and psychological, neuronal, and hormonal systems. Therefore, the fine coordination of these events is essential to maintain penile flaccidity or allow erection; an alteration of these events leads to erectile dysfunction (ED). ED is defined as the consistent or recurrent inability of a man to attain and/or maintain a penile erection sufficient for sexual activity. A great boost to this research field was given by commercialization of phosphodiesterase-5 (PDE5) inhibitors. Indeed, following the discovery of sildenafil, research on the mechanisms underlying penile erection has had an enormous boost, and many preclinical and clinical papers have been published in the last 10 years. This review is structured to provide an overview of the mediators and peripheral mechanism(s) involved in penile function in men, the drugs used in therapy, and the future prospective in the management of ED. Indeed, 30% of patients affected by ED are classified as "nonresponders," and there is still an unmet need for therapeutic alternatives. A flowchart suggesting the guidelines for ED evaluation and the ED pharmacological treatment is also provided.

Effect of a Smoking Cessation Program on Sexual Function Recovery Following Robotic Prostatectomy at Kaiser Permanente Southern California

INTRODUCTION

The association between cigarette smoking and erectile dysfunction has been well established. Studies demonstrate improvements in erectile rigidity and tumescence as a result of smoking cessation. Radical prostatectomy is also associated with worsening of erectile function secondary to damage to the neurovascular bundles. To our knowledge, no previous studies have examined the relationship between smoking cessation after prostate cancer diagnosis and its effect on sexual function following robotic prostatectomy. We sought to demonstrate the utility of a smoking cessation program among patients with prostate cancer who planned to undergo robotic prostatectomy at Kaiser Permanente Southern California.

METHODS

All patients who underwent robotic prostatectomy between March 2011 and April 2013 with known smoking status were included, and were followed-up through November 2014. All smokers were offered the smoking cessation program, which included wellness coaching, tobacco cessation classes, and pharmacotherapy. Patients completed the Expanded Prostate Cancer Index Composite-26 (EPIC-26) health-related quality-of-life (HR-QOL) survey at baseline and postoperatively at 1, 3, 6, 12, 18, and 24 months. There were 2 groups based on smoking status: Continued smoking vs quitting group. Patient's age, Charlson Comorbidity Score, body mass index, educational level, median household income, family history of prostate cancer, race/ethnicity, language, nerve-sparing status, and preoperative/postoperative clinicopathology and EPIC-26 HR-QOL scores were examined. A linear regression model was used to predict sexual function recovery.

RESULTS

A total of 139 patients identified as smokers underwent the smoking cessation program and completed the EPIC-26 surveys. Fifty-six patients quit smoking, whereas 83 remained smokers at last follow-up. All demographics and clinicopathology were matched between the 2 cohorts. Smoking cessation, along with bilateral nerve-sparing status, were the only 2 modifiable factors associated with improved sexual function after prostatectomy (6.57 points, p = 0.0226 and 8.97 points, p = 0.0485, respectively).

CONCLUSION

In the setting of robotic prostatectomy, perioperative smoking cessation is associated with a significant improvement in long-term sexual functional outcome when other factors are adjusted.

Can lifestyle modification affect men's erectile function?

Erectile dysfunction (ED) is a common condition affecting millions of men worldwide. The pathophysiology and epidemiologic links between ED and risk factors for cardiovascular disease (CVD) are well-established. Lifestyle modifications such as smoking cessation, weight reduction, dietary modification, physical activity, and psychological stress reduction have been increasingly recognized as foundational to the prevention and treatment of ED. The aim of this review is to outline behavioral choices which may increase ones risk of developing ED, to present relevant studies addressing lifestyle factors correlated with ED, and to highlight proposed mechanisms for intervention aimed at improving erectile function in men with ED. These recommendations can provide a framework for counseling patients with ED about lifestyle modification.

Effects of cigarette smoking on erectile dysfunction

Cigarette smoking is a leading cause of preventable morbidity and mortality in the United States. Although public policies have resulted in a decreased number of new smokers, smoking rates remain stubbornly high in certain demographics with 20% of all American middle-aged men smoking. In addition to the well-established harmful effects of smoking (i.e. coronary artery disease and lung cancer), the past three decades have led to a compendium of evidence being compiled into the development of a relationship between cigarette smoking and erectile dysfunction. The main physiologic mechanism that appears to be affected includes the nitric oxide signal transduction pathway. This review details the recent literature linking cigarette smoking to erectile dysfunction, epidemiological associations, dose dependency and the effects of smoking cessation on improving erectile quality.

Nicotine acutely inhibits erectile tumescence by altering heart rate variability

OBJECTIVE

To examine potential mechanisms underlying nicotine's effects on male sexual arousal by exploring the mediating role of heart rate variability (HRV).

METHODS

The sample comprised 22 healthy, nicotine-naïve men (mean age = 20.91 years; standard deviation = 2.43). Data were taken from a double-blind, randomized, placebo-controlled, crossover trial previously completed and published elsewhere. During each laboratory visit, time-domain parameters of HRV (standard deviation of normal-to-normal [NN] intervals, square root of the mean squared difference of successive NN intervals, and percent of NN intervals for which successive heartbeat intervals differed by at least 50 ms [pNN50]) along with the objective (via penile plethysmography) and subjective indices of sexual arousal were assessed.

RESULTS

Acute nicotine ingestion (compared with placebo) was associated with dysregulated sympathovagal balance, which in turn was related to relatively reduced erectile tumescence. HRV did not mediate relations between nicotine intake and self-reported indices of sexual arousal.

CONCLUSION

HRV mediated the association between nicotine ingestion and erectile capacity. Findings suggest that dysfunctional cardiac autonomic tone may be an underlying mechanism by which nicotine exerts its deleterious effects on erectile health.

Concurrent relations among cigarette smoking status, resting heart rate variability, and erectile response

INTRODUCTION

Heart rate variability (HRV) is a marker of sympathovagal balance; it has been implicated in erectile function and is also altered by tobacco use. Furthermore, smoking and erectile health are strongly related, given that smokers are at increased risk for erectile dysfunction. Few studies have explored the interrelationships between smoking, HRV, and erectile function concurrently.

AIM

The aim of this study was to examine potential mechanisms underlying tobacco's effects on penile hemodynamics by exploring the mediating role of HRV.

METHODS

The sample comprised 119 men (smokers = 64; nonsmokers = 55) (mean age 28.90 years; standard deviation (SD) 11.68; range 18-58) selected from the control conditions of three previously published experiments. Participants were free from a history of cardiovascular disease, myocardial infarct, and/or cardiac/cardiovascular medication use. During a laboratory visit, self-report, anthropometric, cardiovascular, and electrocardiographic data were assessed, as well as sexual arousal responses elicited from viewing an erotic film.

MAIN OUTCOME MEASURES

Objective sexual arousal indices (circumferential change via penile plethysmography), self-reported erectile function (per the erectile function domain score of the International Index of Erectile Function [IIEF-EF]), and time- (SD of beat-to-beat intervals) and frequency-domain parameters of HRV (ratio of low-frequency [LF] power to high-frequency [HF] power [LF/HF ratio]) were assessed.

RESULTS

Being a current long-term cigarette smoker was associated with dysregulated sympathovagal balance (higher LF/HF ratios, indicative of sympathetic nervous system dominance), which in turn showed inverse relations with magnitude of erectile tumescence. HRV did not mediate relations between tobacco use and either IIEF-EF scores or resting penile circumference.

CONCLUSIONS

Findings suggest that dysfunctional cardiac autonomic tone may be an underlying mechanism by which tobacco exerts its deleterious effects on erectile health. Further research is necessary to determine whether this relationship is mechanistic in nature, or whether it is better explained by other health factors.

Doppler study and evidences of perfusion changes in the ophthalmic artery of pregnant smokers

OBJECTIVES

To compare the ophthalmic artery (OA) perfusion of pregnant smokers and nonsmokers by Doppler indexes. Correlate these with the interval of last cigarette, cigarettes per day, years smoking and carbon monoxide expired (COex).

METHOD

Transversal study involving 70 pregnant smokers divided into 33 pregnant who smoked until 2 h: A group (AG) and B group (BG): 37, who smoked between 2 and 24 h before test. Control group (CG) was composed of 51 pregnant nonsmokers. Doppler indexes were assessed: PSV (Peak Systolic Velocity), EDV (End Diastolic Velocity), PI (Pulsatility Index), RI (Resistance Index) and PR (Peak Ratio). Groups were compared using ANOVA, Kruskal-Wallis test, Student's t test, Mann-Whitney and Pearson's correlation coefficient, whereas p < 0.05.

RESULTS

RI and PI were higher (p < 0.01) and PSV and EDV were lower (p < 0.05) in B group compared to other groups. A group presented higher PR (p < 0.01) compared to control. AG presented years of smoking, cigarettes per day, COex greater than BG and lower interval of last cigarette than BG.

CONCLUSIONS

The OA in pregnant smokers shows a biphasic pattern of perfusion correlated with the time of consumption of the last cigarette. There are signs of vasoconstriction and hypoperfusion to tobacco exposure between 2 and 24 and hyperperfusion in A Group compared to B Group.

Erectile dysfunction in heart failure patients: a critical reappraisal

Heart failure (HF) is a complex clinical syndrome with a constantly increasing incidence and prevalence in western countries. Total absence of sexual activity is registered in 30% of HF patients. Moreover, HF-induced reduction in exercise tolerance, side effects of HF medications and the coexistence of shared risk factors between HF and sexual dysfunction may further aggravate the sexual health of HF patients. The purpose of this review is to examine the pathophysiological mechanisms behind the association of erectile dysfunction (ED) and HF, the potential therapeutic approaches and the eventual indications for sexual activity in HF patients. Medline and Cochrane Library search was performed from January 1970 through October 2012 to retrieve relevant papers outlining the association between ED and HF. Many evidences have outlined a tight association between ED and HF pathophysiological standpoint. Shared risk factors, common pathogenic traits and epidemiologic association represent some of the links between these conditions. Erectile dysfunction has been recognized as an earlier predictor of cardiovascular events; moreover, HF itself may cause and/or worsen ED because of its particular feature and co-morbidities. Furthermore, some cardiovascular drugs may contribute to impaired erectile function. In stable patients with stable HF, sexual activity is generally not contraindicated but it should be encouraged, as a form of moderate-intensity physical exertion. An effective treatment of ED in HF patients should be founded on the correction of reversible risk factors, on the choice of cardiovascular drugs with the lowest effect upon patient's erectile function, and on the use of phosphodiesterase-5-inhibitors. Physicians should be aware of the close relation between HF and ED and of the related clinical and therapeutic implications, in order to improve patients quality of life and clinical outcome.

Association between cigarette smoking and erectile tumescence: the mediating role of heart rate variability

Cigarette smoking deleteriously affects erectile function, and conversely, quitting smoking improves erectile hemodynamics. Underlying mechanisms by which smoking (or reduction of smoking frequency) may affect erectile physiology are not well understood. This study examined the mediating role of heart rate variability (HRV; a marker of sympathovagal balance) among a sample of male chronic smokers from the United States. Sixty-two healthy men (Mage=38.27 years; s.d.=10.62) were assessed at baseline (while smoking regularly), at mid-treatment (while using a nicotine patch) and at follow-up, 4 weeks after patch discontinuation. Cigarette use, frequency-domain parameters of HRV (low frequency (LF), high frequency (HF), LF/HF ratio) and physiological sexual arousal responses (via penile plethysmography) were assessed at each visit. Results were consistent with mediation, in that greater reductions in cigarette use from baseline to follow-up were associated with longitudinal increases in LF, which in turn showed positive relationships with across-time changes in erectile tumescence. Neither HF nor LF/HF ratio mediated the relationship between smoking and erection. In conclusion, HRV mediated the inverse relationship between reductions in smoking and enhancements in erectile tumescence. Results underscore the possibility that cigarette use may deleteriously affect erectile function peripherally, in part, by disrupting cardiac autonomic function.

Association between smoking cessation and sexual health in men

OBJECTIVE

To provide the first empirical investigation of the association between smoking cessation and indices of physiological and subjective sexual health in men.

SUBJECTS AND METHODS

Male smokers, irrespective of erectile dysfunction status, who were motivated to stop smoking ('quitters'), were enrolled in an 8-week smoking cessation programme involving a nicotine transdermal patch treatment and adjunctive counselling. Participants were assessed at baseline (while smoking regularly), at mid-treatment (while using a high-dose nicotine transdermal patch), and at a 4-week post-cessation follow-up. Physiological (circumferential change via penile plethysmography) and subjective sexual arousal indices (continuous self-report), as well as self-reported sexual functioning were assessed at each visit.

RESULTS

Intent-to-treat analyses indicated that, at follow-up, successful quitters (n= 20), compared with those who relapsed (n= 45), showed enhanced erectile tumescence responses, and faster onset to reach maximum subjective sexual arousal. Although successful quitters displayed across-session enhancements in sexual function, they did not show a differential improvement compared with unsuccessful quitters.

CONCLUSIONS

Smoking cessation significantly enhances both physiological and self-reported indices of sexual health in long-term male smokers, irrespective of baseline erectile impairment. It is hoped that these results may serve as a novel means to motivate men to stop smoking.

Nitric oxide-mediated blood flow regulation as affected by smoking and nicotine

Cigarette smoking is a major risk factor for atherosclerosis, cerebral and coronary vascular diseases, hypertension, and diabetes mellitus. Chronic smoking impairs endothelial function by decreasing the formation of nitric oxide and increasing the degradation of nitric oxide via generation of oxygen free radicals. Nitric oxide liberated from efferent nitrergic nerves is also involved in vasodilatation, increased regional blood flow, and hypotension that are impaired through nitric oxide sequestering by smoking-induced factors. Influence of smoking on nitric oxide-induced blood flow regulation is not necessarily the same in all organs and tissues. However, human studies are limited mainly to the forearm blood flow measurement that assesses endothelial function under basal and stimulated conditions and also determination of penile tumescence and erection in response to endothelial and neuronal nitric oxide. Therefore, information about blood flow regulation in other organs, such as the brain and placenta, has been provided mainly from studies on experimental animals. Nicotine, a major constituent of cigarette smoke, acutely dilates cerebral arteries and arterioles through nitric oxide liberated from nitrergic neurons, but chronically interferes with endothelial function in various vasculatures, both being noted in studies on experimental animals. Cigarette smoke constituents other than nicotine also have some vascular actions. Not only active but also passive smoking is undoubtedly harmful for both the smokers themselves and their neighbors, who should bear in mind that they can face serious diseases in the future, which may result in lengthy hospitalization, and a shortened lifespan.

Anatomy, physiology, and pathophysiology of erectile dysfunction

INTRODUCTION

Significant scientific advances during the past 3 decades have deepened our understanding of the physiology and pathophysiology of penile erection. A critical evaluation of the current state of knowledge is essential to provide perspective for future research and development of new therapies.

AIM

To develop an evidence-based, state-of-the-art consensus report on the anatomy, physiology, and pathophysiology of erectile dysfunction (ED).

METHODS

Consensus process over a period of 16 months, representing the opinions of 12 experts from seven countries.

MAIN OUTCOME MEASURE

Expert opinion was based on the grading of scientific and evidence-based medical literature, internal committee discussion, public presentation, and debate.

RESULTS

ED occurs from multifaceted, complex mechanisms that can involve disruptions in neural, vascular, and hormonal signaling. Research on central neural regulation of penile erection is progressing rapidly with the identification of key neurotransmitters and the association of neural structures with both spinal and supraspinal pathways that regulate sexual function. In parallel to advances in cardiovascular physiology, the most extensive efforts in the physiology of penile erection have focused on elucidating mechanisms that regulate the functions of the endothelium and vascular smooth muscle of the corpus cavernosum. Major health concerns such as atherosclerosis, hyperlipidemia, hypertension, diabetes, and metabolic syndrome (MetS) have become well integrated into the investigation of ED.

CONCLUSIONS

Despite the efficacy of current therapies, they remain insufficient to address growing patient populations, such as those with diabetes and MetS. In addition, increasing awareness of the adverse side effects of commonly prescribed medications on sexual function provides a rationale for developing new treatment strategies that minimize the likelihood of causing sexual dysfunction. Many basic questions with regard to erectile function remain unanswered and further laboratory and clinical studies are necessary.

A population-based, longitudinal study of erectile dysfunction and future coronary artery disease

OBJECTIVE

To assess the association between erectile dysfunction (ED) and the long-term risk of coronary artery disease (CAD) and the role of age as a modifier of this association.

PARTICIPANTS AND METHODS

From January 1, 1996, to December 31, 2005, we biennially screened a random sample of 1402 community-dwelling men with regular sexual partners and without known CAD for the presence of ED. Incidence densities of CAD were calculated after age stratification and adjusted for potential confounders by time-dependent Cox proportional hazards models.

RESULTS

The prevalence of ED was 2% for men aged 40 to 49 years, 6% for men aged 50 to 59 years, 17% for men aged 60 to 69 years, and 39% for men aged 70 years or older. The CAD incidence densities per 1000 person-years for men without ED in each age group were 0.94 (40-49 years), 5.09 (50-59 years), 10.72 (60-69 years), and 23.30 (> or =70 years). For men with ED, the incidence densities of CAD for each age group were 48.52 (40-49 years), 27.15 (50-59 years), 23.97 (60-69 years), and 29.63 (> or =70 years).

CONCLUSION

ED and CAD may be differing manifestations of a common underlying vascular pathology. When ED occurs in a younger man, it is associated with a marked increase in the risk of future cardiac events, whereas in older men, ED appears to be of little prognostic importance. Young men with ED may be ideal candidates for cardiovascular risk factor screening and medical intervention.

Acute effects of nicotine on physiological and subjective sexual arousal in nonsmoking men: a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Chronic nicotine treatment has deleterious effects on vascular functioning and catecholamine modulation, which may compromise erectile functioning. Evidence that long-term cigarette smoking is an independent risk factor for introducing impotence is robust. However, limited studies have focused on the acute effects of smoking on physiological sexual response, and none have investigated the deleterious effects of isolated nicotine on human sexual arousal. Consequently, pathophysiological underpinnings of tobacco-induced-and particularly, nicotine-induced-erectile dysfunction are not well understood.

AIM

To provide the first empirical examination of the acute effects of isolated nicotine on sexual arousal in nonsmoking men.

METHODS

Twenty-eight sexually functional heterosexual men (mean age 21 years), each with less than 100 direct exposures to nicotine, participated in a double-blind, randomized, placebo-controlled, crossover trial. Participants received either Nicorette polacrilex gum (SmithKline Beecham Consumer Healthcare, Pittsburgh, PA, USA) (6 mg; approximately equivalent to smoking one high-yield cigarette) or placebo gum, matched for appearance, taste, and consistency, approximately 40 minutes prior to viewing an erotic film.

MAIN OUTCOME MEASURES

Physiological (circumferential change via penile plethysmography) and subjective (continuous self-report) sexual responses to erotic stimuli were examined, as well as changes in mood.

RESULTS

Nicotine significantly reduced erectile responses to the erotic films (P = 0.02), corresponding to a 23% reduction in physiological sexual arousal. This occurred in 16 of 20 men with valid physiological recordings. Nicotine had no significant effect on continuous subjective ratings of sexual arousal (P = 0.70) or on mood (all Ps > 0.05).

CONCLUSIONS

Isolated nicotine can significantly attenuate physiological sexual arousal in healthy nonsmoking men. These findings have implications for elucidating physiological mechanisms responsible for the effects of nicotine on sexual dysfunction, and for assisting public health policy in considering the deleterious effects of nicotine on sexual health.