Abstract
Aim: To identify the effect of aging on urinary bladder function, the maximal volume, post-voiding residual of the urinary bladder, mean urine flow rate, and urine volume were examined during micturition after drinking water (500-700 ml).
Methods: Bladder volume, post-voiding residual, mean urine flow rate, and urine volume during micturition were measured in young (22±3 yr, n=12) and elderly women (64±3 yr, n=6).
Results: The maximal urinary bladder volume was not significantly different (P>0.05) between young and elderly women (576±158 vs. 505±119 ml). In contrast, post-voiding residual volume was greater (88±52 ml, P<0.05) in elderly than in 34±40 ml in young women. Accordingly, urine volume was decreased to 418±155 ml in elderly compared to the volume in young women (556±141 ml). Although mean urine flow rate of 16 ml/s was equivalent between young and elderly women, the time period necessary for voiding was 27±6 s in elderly women, shorter (p<0.05) than the period for 43±24 s in young women.
Conclusion: It is suggested that contraction of the urinary bladder in elderly women is not so sustained as in young women, causing a greater post-voiding residual volume of the urinary bladder.
