Effect of aging on urodynamic parameters in women with stress urinary incontinence

Purpose: Stress urinary incontinence (SUI) is one of the most common lower urinary tract symptoms in women. We analyzed age-associated changes in urodynamic parameters in women with SUI. Materials and Methods: We analyzed the urodynamic study (UDS) results of patients with urodynamically proven SUI between March 2008 and July 2014. In uroflowmetry, maximal flow rate (Qmax), time to Qmax, voided volume, and postvoid residual urine volume (PVR) and filling cystometry data including first, strong desire to void and Valsalva leak point pressure (VLPP) were measured. Also, Qmax and detrusor pressure at Qmax (Pdet@Qmax) of voiding cystometry data were analyzed. Results: The subjects included 776 patients. Among the patients, 151 were withdrawn because of incomplete UDS data or because they met the exclusion criteria. A total of 625 patients enrolled in our study. The mean age of the population was 57.3 years. The mean Qmax, voided volume, voiding time, and PVR were 26.2 mL/s, 292.1 mL, 25.7 s, and 31.7 mL, respectively. Qmax (p=0.001) in uroflowmetry, PVR (p=0.042), first desire to void (p=0.042), Pdet@Qmax (p=0.016), and the bladder contractility index (p=0.046) were significantly different between the age groups. Qmax and Pdet@Qmax were decreased and PVR was increased significantly with age after 60 years. Conclusions: Older women with SUI also have worsened voiding function with age as the results of urodynamic parameters. Specifically, detrusor contractility decreased with age after 60 years.