Influence of bladder outlet obstruction on age-related changes in male bladder contractility

Purpose: Changes in bladder contractility due to aging are among the important causes of lower urinary tract symptoms (LUTS) in elderly males. The purpose of this study was to observe changes in bladder contractility due to aging in male patients taking medi-cations commonly used to treat LUTS in clinical practice. Materials and Methods: Male patients aged over 40 years who underwent urodynamic studies for LUTS from January 2012 to December 2024 were included. The bladder outlet obstruction (BOO) index was used to distinguish between males with BOO and those without BOO. Changes in bladder contractility according to age in each group were analyzed using the bladder contractility index. The Pearson correlation coefficient (r) was used to calculate the strength of the linear relationship between age and the vari-ables. Results: A total of 449 male patients who underwent urodynamic studies for LUTS were eligible for this study (311 in the BOO group and 138 in the BOO group). Age and the maximum flow rate were inversely related in both groups. Age and bladder con-tractility were significantly correlated in the non-BOO group (p=0.021) but not in the BOO group (p=0.057). Conclusions: This study revealed that BOO might act as a confounding variable in measuring the contractility of an aged bladder. Excluding the effect of BOO, bladder contractility significantly decreases with age. Therefore, when male LUTS are treated, changes in bladder contractility due to aging vary depending on BOO.