title: Concurrent relations among cigarette smoking status, resting heart rate variability, and erectile response.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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.
  
  
  METHODS
  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.
authors.affiliation: Research Service, VA Boston Healthcare System, Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Harte
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D004562:Electrocardiography; D007172:Erectile Dysfunction / Q000209:etiology*; D004882:Erotica; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010410:Penile Erection / Q000502:physiology*; D010413:Penis / Q000294:innervation; D010991:Plethysmography; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology*; D055815:Young Adult
keywords: Cardiac Autonomic Function; Erectile Physiology; Erectile Tumescence; Heart Rate Variability; Nicotine; Sexual Arousal; Smoking