Characterisation of detrusor contractile function in relation to old age.

This report describes an age-related clinical study of detrusor muscle function using urodynamic data obtained from 1391 women and 324 men of different age groups who were free from overt neurological disease and diabetes. Isometric detrusor function during unstable activity was assessed by integrating the calculated force of unstable detrusor activity during filling of the bladder. Isotonic voiding activity was measured by calculating the velocity constant Q*, which reflects the speed of detrusor muscle shortening. In addition, the change in detrusor pressure on initiation of voiding and the post-micturition residual urine volume were recorded. Older patients of both sexes had higher residual urine volumes. Older women showed lower detrusor shortening velocities. There were no age-related differences in isometric detrusor function. Older women showed a tendency for the detrusor contraction to fail on initiation of voiding, whereas older men did not demonstrate this difference. Voiding dysfunction in late life was more marked amongst women and seemed to be related to a failure of isotonic detrusor function with no related changes in isometric function.