Christopher B. Harte

The Inhibitory Effects of Nicotine on Physiological Sexual Arousal in Nonsmoking Women: Results from a Randomized, Double-Blind, Placebo-Controlled, Cross-Over Trial

INTRODUCTION Extensive research suggests that long-term cigarette smoking is an independent risk factor for the introduction of sexual dysfunction in men. However, results of limited data investigating this relationship in women are mixed. No studies have examined the acute effects of tobacco or nicotine on physiological sexual response in women. Controlled experimental studies examining acute effects of isolated nicotine intake on female physiological sexual responses are necessary in order to help elucidate tobaccos potential role in the development and/or maintenance of sexual impairment in women. AIM To examine whether isolated nicotine intake acutely affects sexual arousal responses in nonsmoking women. METHODS Twenty-five sexually functional women (mean age = 20 years) each with less than 100 direct exposures to nicotine completed two counterbalanced conditions in which they were randomized to received either nicotine gum (6 mg) or placebo gum, both administered double-blind and matched for appearance, taste, and consistency, approximately 40 minutes prior to viewing an erotic film. MAIN OUTCOME MEASURES Physiological (changes in vaginal pulse amplitude via vaginal photoplethysmography) and subjective (continuous self-report) sexual responses to erotic stimuli were examined, as well as changes in mood. RESULTS Nicotine significantly reduced genital responses to the erotic films (P = 0.05), corresponding to a 30% attenuation in physiological sexual arousal. This occurred in 11 of 18 women with valid physiological assessments. Nicotine had no significant effect on continuous self-report ratings of sexual arousal (P = 0.45), or on mood (all Ps > 0.05). CONCLUSIONS Acute nicotine intake significantly attenuates physiological sexual arousal in healthy nonsmoking women. Our findings provide support to the hypothesis that nicotine may be the primary pharmacological agent responsible for genital hemodynamic disruption, thereby facilitating a cascade of biochemical and vascular events which may impair normal sexual arousal responses.

Association between smoking cessation and sexual health in men

Study Type – Prevention (case series)

Evidence for a curvilinear relationship between sympathetic nervous system activation and women's physiological sexual arousal

There is increasing evidence that womens physiological sexual arousal is facilitated by moderate sympathetic nervous system (SNS) activation. Literature also suggests that the level of SNS activation may play a role in the degree to which SNS activity affects sexual arousal. We provide the first empirical examination of a possible curvilinear relationship between SNS activity and womens genital arousal using a direct measure of SNS activation in 52 sexually functional women. The relationship between heart rate variability (HRV), a specific and sensitive marker of SNS activation, and vaginal pulse amplitude (VPA), a measure of genital arousal, was analyzed. Moderate increases in SNS activity were associated with higher genital arousal, while very low or very high SNS activation was associated with lower genital arousal. These findings imply that there is an optimal level of SNS activation for womens physiological sexual arousal.

Recreational Use of Erectile Dysfunction Medications in Undergraduate Men in the United States: Characteristics and Associated Risk Factors

Mounting evidence indicates that erectile dysfunction medications (EDMs) have become increasingly used as a sexual enhancement aid among men without a medical indication. Recreational EDM use has been associated with increased sexual risk behaviors, an increased risk for STIs, including incident HIV infection, and high rates of concomitant illicit drug use. The aim of the present study was to investigate the characteristics and associated risk factors for recreational EDM use among young, healthy, undergraduate men. A cross-sectional sample of 1,944 men were recruited from 497 undergraduate institutions within the Unites States between January 2006 and May 2007. The survey assessed patterns of EDM use, as well as demographic, substance use, and sexual behavior characteristics. Four percent of participants had recreationally used an EDM at some point in their lives, with 1.4% reporting current use. The majority of recreational EDM users reported mixing EDMs with illicit drugs and particularly during risky sexual behaviors. Recreational EDM use was independently associated with increased age, gay, or bisexual sexual orientation, drug abuse, lifetime number of sex partners, and lifetime number of “one-night stands.” Recreational EDM users also reported a 2.5-fold rate of erectile difficulties compared to nonusers. Overall, recreational use of EDMs was associated with sexual risk behaviors and substance abuse; however, a relatively small proportion of undergraduates reported using EDMs. Results also suggest that a sizable portion of recreational EDM users are heterosexual men, and that use does not solely occur within the environments of venues that cater to men having sex with men.

Sexual motivation in women as a function of age.

INTRODUCTION Womens motivations to engage in sex are likely influenced by their past sexual experiences, the type of relationship in which they are involved in, and numerous lifestyle factors such as career and family demands. The influences of these factors undoubtedly change as women age. AIM This study aimed to examine potential differences in sexual motivation between three distinct age groups of premenopausal women. METHODS Women aged 18-22 years (N = 137), 23-30 years (N = 103), and 31-45 years (N = 87) completed an online survey that assessed the proportion with which they had engaged in sexual intercourse for each of 140 distinct reasons. MAIN OUTCOME MEASURES The YSEX? Questionnaire by Meston and Buss [1] was used to measure sexual motivation. The items of this questionnaire were composed of four primary sexual motivation factors (physical, goal attainment, emotional, insecurity), and 13 subfactors. RESULTS Women aged 31-45 years reported a higher proportion of engaging in sex compared with one or both of the younger age groups of women for nine of the 13 YSEX? subfactors: stress reduction, physical desirability, experience seeking, resources, social status, revenge, expression, self-esteem boost, and mate guarding. At an item level, the top 25 reasons for having sex were virtually identical across age groups. CONCLUSION Women aged 31-45 have more motives for engaging in sex than do women aged 18-30, but the primary reasons for engaging in sex do not differ within this age range. Women aged 18-45 have sex primarily for pleasure, and love and commitment. The implications for diagnosis and treatment of women with sexual dysfunctions were discussed.

Recreational Use of Erectile Dysfunction Medications and Its Adverse Effects on Erectile Function in Young Healthy Men: The Mediating Role of Confidence in Erectile Ability

INTRODUCTION Oral erectile dysfunction medications (EDMs) have become an increasingly popular drug of abuse among young men without a medical indication. In addition to being associated with increased sexual risk behaviors, recreational EDM use may adversely impact psychological aspects of sexual function, primarily by affecting ones confidence in pharmacologically unaided erectile ability. To date, these associations have not been investigated empirically. AIM This study examined the mediating role of confidence in erectile ability on the concurrent relationship between recreational EDM use and erectile function among young healthy men. A secondary aim was to examine erectile function characteristics among recreational users, prescribed users, and nonusers to control for the possibility that recreational users were using EDMs to treat ED. METHODS The sample comprised 1,207 sexually active men (mean age = 21.9 years; standard deviation = 4.48) who were recruited from undergraduate institutions within the United States. MAIN OUTCOME MEASURES Participants completed an online survey assessing frequency of EDM use, as well as levels of sexual function (erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall sexual satisfaction) and levels of confidence in ability to gain and maintain erection, as per the International Index of Erectile Function. RESULTS Recreational users (N = 72) reported similar erectile function levels compared with nonusers (N = 1,111), and both groups differed from prescribed users (N = 24). Recreational users also reported lower erectile confidence and lower overall satisfaction compared with nonusers. Results were consistent with mediation, in that more frequent EDM use was inversely associated with erectile confidence, which in turn showed negative relations with erectile function. CONCLUSIONS Confidence in erectile abilities mediates the inverse relationship between recreational EDM use and erectile function. Results underscore the possibility that recreational EDM use among healthy young men may lead to psychogenic ED. Additional longitudinal research is necessary to establish a causal link between these variables.

Smoking Status and Exercise in relation to PTSD Symptoms: A Test among Trauma-Exposed Adults

The present investigation examined the interactive effect of cigarette smoking status (i.e., regular smoking versus non-smoking) and weekly exercise (i.e., weekly metabolic equivalent) in terms of posttraumatic stress (PTSD) symptom severity among a community sample of trauma-exposed adults. Participants included 86 trauma-exposed adults (58.1% female; Mage = 24.3). Approximately 59.7% of participants reported regular (≥ 10 cigarettes per day) daily smoking over the past year. The interactive effect of smoking status by weekly exercise was significantly associated with hyperarousal and avoidance symptom cluster severity (p ≤ .05). These effects were evident above and beyond number of trauma types and gender, as well as the respective main effects of smoking status and weekly exercise. Follow-up tests indicated support for the moderating role of exercise on the association between smoking and PTSD symptoms, such that the highest levels of PTSD symptoms were observed among regular smokers reporting low weekly exercise levels. Theoretical and clinical implications of the findings are discussed.

Association Between Smoking and Heart Rate Variability Among Individuals with Depression

BackgroundBoth depression and smoking have been independently associated with lower heart rate variability (HRV), suggesting dysregulation of cardiac autonomic function. However, no studies have systematically explored the effects of smoking on HRV among depressed patients.PurposeThis study examined differences in HRV based on smoking status among depressed individuals.MethodsElectrophysiological data were examined among 77 adult outpatients without a history of myocardial infarction, who met criteria for major depressive disorder or dysthymia. Frequency domain [low frequency (LF), high frequency (HF), LF/HF ratio, respiratory sinus arrhythmia (RSA)] parameters of HRV, and heart rate and inter-beat interval (IBI) data were compared between depressed smokers (n = 34) and depressed nonsmokers (n = 44).ResultsAfter controlling for covariates, depressed smokers, compared to depressed nonsmokers, displayed significantly lower LF, HF, and RSA.ConclusionsAmong depressed patients, smoking is associated with significantly lower HRV, indicating dysregulated autonomic modulation of the heart.

Association Between Exercise and Posttraumatic Stress Symptoms Among Trauma-Exposed Adults

The present investigation examined associations between intensities of exercise involvement and posttraumatic stress (PTS) symptom cluster severity (reexperiencing, avoidance/numbing, and hyperarousal). The sample was comprised of 108 adults (54.6% women; M age = 23.9, SD = 10.22, range = 18–62), who endorsed exposure to a Diagnostic and Statistical Manual of Mental Disorders (Fourth edition, Text Revision) posttraumatic stress disorder Criterion A traumatic life event but did not meet criteria for any current Axis I psychopathology. After controlling for gender and lifetime number of trauma exposure types experienced, results indicated that vigorous-intensity exercise, but not light- or moderate-intensity exercise, was significantly inversely associated with hyperarousal symptom cluster severity. This study adds to the scarce, yet growing, body of exercise—PTS literature—by illuminating the inverse associations of vigorous-intensity exercise, specifically, and PTS hyperarousal symptom severity among trauma-exposed individuals.

Nicotine Acutely Inhibits Erectile Tumescence by Altering Heart Rate Variability

OBJECTIVE To examine potential mechanisms underlying nicotines 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.