There has been no studies to date comparing two different voiding practices (voiding through the zipper vs. pants down) in males. The aim of this study is to evaluate if voiding through the zipper or voiding pants down would make any difference with regard to uroflowmetry parameters and post voiding residual urine (PVR) volumes in healthy males with no lower urinary tract symptoms (LUTS). (Figure 1)

Healthy males over 18 years of age with no LUTS were prospectively evaluated using a uroflowmetry test. Each individual was asked to void through the zipper (group 1) and pants down (group 2) at different times. Uroflowmery test was repeated if voided volume did not exceed 150 ml. Uroflowmetry results such as voided volume, maximum flow rate (Qmax), average flow rate (Qave) and duration of voiding were noted. PVR volume was assessed using ultrasonography. Electromyography was not used. Data were shown as mean ± standard deviation. For statistical analysis, paired t test was used to analyze parametric parameters.

A total of 44 males were enrolled. Median age of individuals was 24 (range 18 - 44 years). There were no statistically significant differences between two measurements in terms of voided volumes (307 ± 121ml vs. 325 ± 145ml, p=0.365) and duration of voiding (25 ± 11 s vs 23.8 ± 11.6 s, p=0.526). However, there was statistically significant differences in Qmax (26.6 ± 6.7 ml/s vs. 30.0 ± 8.2 ml/s, p=0.001), Qave (14.4 ± 3.6 ml/s vs.16.2 ± 5.1ml/s, p=0.009) and PVR volumes (23.9 ± 19.4 ml vs. 3.9 ± 9.6 ml, p=0.0001). Table 1 summarizes comparative results.

Results of our preliminary prospective trial indicated a statistically significant PVR rise when healthy males with no LUTS void through the zipper when compared to pants down. In addition, a significant decrease in Qmax and Qave values were observed. Median age of our cohort was 24 years of age, nevertheless simple voiding practices were shown to alter uroflowmetry parameters. Clinical impact of this change remains unclear in this age group, though, in males with mild symptoms, practice of voiding might be questionned. Even more, this might have a prominent clinical utility in older patients.

A change in practice of voiding may influence male uroflowmetry parameters significantly in individuals with no LUTS. Future studies with increased number of individuals (including those with LUTS) and a broader age range cohort is required for solid conclusions.