Lower urinary tract symptoms (LUTS) include storage dysfunction and voiding dysfunction. The prevalence of overactive bladder is high in women with storage symptoms. Some of these patients present detrusor overactivity (DO) with or without dysfunctional voiding (DV) during urodynamic studies. The management of DV is crucial in the management of DO because the presence of bladder outlet obstruction could aggravate OAB symptoms. Although video urodynamic study provides accurate diagnosis, its utilization is limited by the invasive nature and the radiation exposure. The development of surrogate biomarkers is still lacking for female LUTS. Our aim is to investigate whether women of DO with or without DV have different urinary protein compositions that could become potential biomarkers.

Women who visited our institute for the management of LUTS were included for the prospective study. Urine samples were collected before VUDS. Urinary proteins including 8-OHdG, PGE-2, IL-1β, IL-2, IL-6, IL-8, TNFα, and VEGF were quantified using enzyme-linked immunosorbent assay (ELISA). VUDS was performed under fluoroscopy and multichannel urodynamic equipment. Patients with DO with or without DV were included for analysis. Patients who had SUI without bladder dysfunction were included as a control group. Urinary protein levels were compared between DO, DO with DV, and the control group. ANOVA was used to compare the 3 groups, and t-test was used for post-hoc analysis between each group.

There were 30, 24, 20 in the DO, DO with DV, and the control group, respectively. Basic VUDS parameters are shown in Table 1. Patients of DO with or without DV were different from the control group in most VUDS parameters. Patients with DV had higher Pdet and AG number than patients without DV. Ages were similar between the groups. Among all the inflammatory proteins, 8-OHdG and IL-2 were significantly different between the groups. The 8-OHdG level was increased, and the IL-2 level was decreased, compared to the control group. However, they were not significantly different between group 1 and group 2 in post-hoc analysis (Table 2).

Among the inflammatory proteins including 8-OHdG, PGE-2, IL-1β, IL-2, IL-6, IL-8, TNFα, and VEGF, we found that 8-OHdG and IL-2 were significantly different from the control group, indicating that DO is associated with increased bladder inflammation through the induction of reactive-oxidative stress (ROS). The decrease in IL-2 could be the result of negative feedback in chronic inflammation. The inflammation could be either the cause of DO or the response to DO. However, 8-OHdG and IL-2 were not significantly between DO patients with and without DV, indicating that transient sphincter dysfunction during voiding phase has limited effect on the inflammatory process in addition to DO itself.

ROS-induced inflammation can be detected by urinary biomarkers in women with DO. The presence of DV does not alter the composition of urine inflammatory proteins in women with DO.