ORIGINAL ARTICLE Do motorcyclists have erectile dysfunction? A preliminary study A Ochiai 1 , Y Naya 2 , J Soh 1 , Y Ishida 1 , S Ushijima 1 , Y Mizutani 1 , A Kawauchi 1 and T Miki 1 1 Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan and 2 Department of Urology, Matsushita Memorial Hospital, Moriguchi, Osaka, Japan The aim of the present study was to evaluate the relationship between motorcycling and erectile dysfunction (ED). We investigated the relationship between motorcycling and erectile function using the 5-items version of the International Index of Erectile Function (IIEF5) in 234 motorcyclists (response rate 75%) and 752 healthy controls (response rate 66%). In all, 161 (69%) of 234 motorcyclists were diagnosed as ED based on IIEF5. The prevalence of ED in the motorcycle group increased by age as: 58, 63, 76 and 93%, for motorcyclists in 20–29, 30–39, 40–49 and 50–59 years, respectively. There was a significant difference in the prevalence of ED between the motorcycle group and the control group in all age groups. On stepwise logistic regression analysis, motorcycling was the strongest risk factor for ED. Although the severity of ED in motorcyclists was not so severe, motorcycling may be one of risk factors for ED. International Journal of Impotence Research (2006) 18, 396–399. doi:10.1038/sj.ijir.3901445; published online 2 February 2006 Keywords: erectile dysfunction; motorcyclists; Japanese male Introduction Several authors have suggested that bicycling may induce erectile dysfunction (ED) among some riders. 1–4 Perineal compression by the saddle during bicycling is thought to cause the ischemic neuro- pathy of penis and be responsible for ED. 5 Motorcy- cling is similar to bicycling, to astride the saddle. Motorcycling differs from bicycling, in the engine with vibration and saddle design. The compression and vibration by the saddle during motorcycling may affect perineal neurovasculature and cause ED. Therefore, a question is raised regarding the rela- tionship between motorcycling and ED. There is no report whether motorcycling may introduce ED or not, however. In the present study, we studied the prevalence of ED in members of an amateur motorcycle club in Japan, using the five-item version of the International Index of Erectile Func- tion (IIEF5). Methods Annual meetings of amateur large-sized motorcycle members and their families took place at several districts in Japan (approximately, over 8 thousands). Of the 325 motorcyclists whom we gave a self- completion questionnaire concerning ED, 244 mo- torcyclists had responded (response rate 75%). These 325 motorcyclists joined this annual meeting and they belonged to some motorcyclist clubs at Kansai district in Japan. They had approximately 3 h driving each every Saturday and Sunday. This questionnaire consisted of age, history of motor- cycle, type of motorcycle, survey on health status (age, present illness, and previous history of medication and hospitalization) and Japanese ver- sion of IIEF5, as described previously. 6 Of the 244 motorcyclists, 10 men who were were o20 years of age or over 60 years were excluded from our analysis, leaving 234 who were evaluable motorcy- clists. Of the 234 men, 113 had chronic diseases as follows: lumbar pain in 72 patients (31%), hemor- rhoid in 29 (12%), hypertension in 17 (7%), diabetes mellitus in 10 (4%) and other diseases in six (3%). Of the 113 men, 17 had more than one disease. There were no men who had coronary artery disease and hyperlipidemia. Erectile dysfunction was diag- nosed when the IIEF5 score was o22. 7 The 5-items version of the International Index of Erectile Func- tion was given to 2311 men who were employees of Received 11 June 2005; revised 30 November 2005; accepted 1 December 2005; published online 2 February 2006 Correspondence: Dr Y Naya, Department of Urology, Matsushita Memorial Hospital, 5-55 Sotojimacho, Mor- iguchi, Osaka 570-8540, Japan. E-mail: naya.yoshio@jp.panasonic.com International Journal of Impotence Research (2006) 18, 396–399 & 2006 Nature Publishing Group All rights reserved 0955-9930/06 $30.00 www.nature.com/ijir