PURPOSE
To investigate age related changes in urodynamic parameters in two large cohorts of women planning stress urinary incontinence (SUI) surgery.
MATERIALS AND METHODS
Using a standardized protocol, urodynamic parameters were obtained from participants in the SISTEr and TOMUS trials undergoing baseline non-invasive flow (NIF), followed by filling cystometrogram (CMG) and pressure flow study (PFS). Bladder Contractility Index (BCI=PdetQmax+5Qmax) and detrusor hypocontractility (defined as detrusor pressure @ maximum flow (Pdet@Qmax) <10 cm H2O) were also characterized. Excluded patients had prior SUI surgery or prolapse stage >2. Propensity score analysis controlled for potential bias of combining participants from 2 clinical trials. Regression analysis (linear and logistic) adjusting for propensity score quintile assessed the association of age and an age cutoff value(<65 vs >65 years) with urodynamic parameters.
RESULTS
945 women (SISTER 468, TOMUS 477) were included. Mean age was 50 in SISTEr (27-75 years) and 51 in TOMUS (24-82 years). NIF Qmax significantly decreased with age (26.2 ml/sec vs. 22 ml/sec, p=0.002); NIF voiding time increased 2.7 seconds for every 10 year age increment and Pdet@Qmax decreased 2.1 cm H20 for each 10 year increase in age (p =0.003 for both). Hypocontractility was more likely in women ≥ 65 years (OR 2.89, 95% CI 1.59, 5.27). BCI and age were inversely related with BCI decreasing by 7.68 (1.96) cm H2O for every 10 year age increase (p <0.001).
CONCLUSIONS
In these two cohorts, the changes in voiding parameters observed suggest that detrusor contractility and efficiency decrease with age.