THE AGING LOWER URINARY-TRACT - A COMPARATIVE URODYNAMIC STUDY OF MENAND WOMEN

Objectives. The fact that aging women report similar voiding symptoms as age-matched men prompted us to compare age-related changes of urody namic parameters in both sexes. Methods. Four hundred thirty-six patie nts (253 men and 183 women) 40 years of age or older underwent the fol lowing investigations: free uroflowmetry, measurement of postvoid resi dual volume, and full urodynamic testing, including a pressure-flow st udy (pQs). Additional investigations were a urethral pressure profile in women and quantification of prostate volume by transrectal ultrason ography in men. All men were referred for lower urinary tract symptoms suspicious of bladder outflow obstruction and women predominantly for urinary incontinence. Patients with previous surgery of the lower uri nary tract (prostate, bladder, urethra) and those taking medication wi th a major effect on voiding function (alpha-receptor blockers, 5 alph a-reductase inhibitors, anticholinergic agents) were excluded. Results . The mean +/- standard deviation (SD) age in the female (f) populatio n (n = 183) was 59 +/- 16 years (range 40 to 93), in the male populati on (m) (n = 253) 67 +/- 9 years (range 40 to 90). In both sexes, we ob served a statistically significant increase of postvoid residual volum e (f: P = 0.0001; m: P = 0.02) and a decrease of peak flow rate (f: P = 0.019; m: P = 0.014), average flow rate (f: P = 0.007; m: P = 0.04), voided volume (f: P = 0.007; m: P = 0.002), and bladder capacity dete rmined by urodynamics (f: P = 0.003; m: P = 0.0004) with progressing a ge. In both sexes, there were no age-related changes (P > 0.05), demon strable for maximum detrusor pressure and detrusor pressure at peak fl ow rate. In women, there was a significant decrease of functional uret hral length (P = 0.012) and maximum urethral closing pressure (P = 0.0 001) with higher age; in men, the prostate volume increased significan tly with age (P = 0.0001). With respect to detrusor instability, we ob served an increase in men from 25.4% (40 to 60 years) to 46.7% (more t han 80 years) (P = 0.004), whereas in women no significant age-related changes were present (P > 0.05). Conclusions. These data show that ag e-associated urodynamic changes in both sexes are comparable for a num ber of parameters. They provide an explanation for the fact that aging women report comparable voiding symptoms as men and suggest a primary , non-sex-specific aging process of the urinary bladder. (C) 1998, Els evier Science Inc. All rights reserved.