Insight on pathogenesis of lifelong premature ejaculation: inverse relationship between lifelong premature ejaculation and obesity

Although both biological and psychological factors are important in the etiology, the exact pathogenesis of lifelong premature ejaculation (PE) remains to be clarified. Obesity is a worldwide epidemic that contributes to many chronic diseases. Obesity is associated with erectile dysfunction, but the relationship between obesity and PE has not yet been specifically investigated. The aim of this study was to evaluate the relationships of these two conditions. Between January 2008 and December 2009, we evaluated consecutive patients with lifelong PE in the urology outpatient clinic. Control cases without lifelong PE were selected randomly among cases attending the department of internal medicine for a checkup procedure. The age and sex of control group were matched with that of the study group. Body mass index (BMI) of each case was calculated using the World Health Organization criteria by the measurements of the physician instead of relying on verbal expressions. The mean (±s.d.) age of the premature ejaculators was 31.7±5.7 (range 21–51) years and in the control cases it was 32.3±6.7 (range 22–54) years. The comparison of the mean (±s.d.) weight between the study (74.1±11.2 kg) and control groups (81.9±6.4 kg) revealed a significant difference (P<0.001). The mean BMI of premature ejaculators (24.9±3.4 kg m–2) was lower than the mean BMI of control (27.5±3.6 kg m–2; P<0.001). As the BMI increased, the number of patients decreased in the PE group. The number of the obese cases in the control group (n=26, 24.1%) was three times greater than the obese premature ejaculators (P<0.005), and the number of PE patients were approximately two times greater than the control cases in the normal-weight class (P<0.001). This is the first prospective study that investigated the relationship between lifelong PE and obesity, and we found that patients with lifelong PE were leaner than the healthy control cases.