Abstract
BACKGROUND: In a previous report, we investigated whether the size of male genitalia similarly exposed to serum testosterone during aging could change with age and found that penile length almost stopped increasing during adolescence and decreased in older males. In this report, to determine what factors other than age are related to penile length, we performed a multivariate analysis of the relationships between stretched penile length (SPL) and other measurements of genital organs, nose size, height and body weight in 126 adults in their 30s-50s. RESULTS: The most highly correlated factor with SPL was flaccid penile length (r = 0.565, P < 0.0001). The next highest correlation was nose size (r = 0.564, P < 0.0001). The penile stretched rate correlated with FPL (r = - 0.690, P < 0.0001) but not with SPL or penile circumference. CONCLUSIONS: The fact that nose size is related to SPL indicates that penile length may not be determined by age, height or body weight but has already been determined before birth.