Inflammatory and tissue remodeling urinary biomarkers before and after mid urethral sling surgery for stress urinary incontinence.

OBJECTIVE

Urinary biomarkers were measured in women at baseline and 1 year after surgery for stress urinary incontinence, and associations with clinicodemographic covariates and outcomes were analyzed.

METHODS

Preoperative and postoperative urine specimens from 150 women were assayed for inflammatory biomarkers (tumor necrosis factor-α, interferon-γ, interleukin-1β, interleukin-6, interleukin-10, interleukin-12p70, interleukin-17 and nerve growth factor) and tissue remodeling biomarkers (collagenase activity, matrix metalloproteinases-1, 2, 9 and 13, and NTx [N-telopeptide cross-linked collagen], epidermal growth factor and heparin-binding epidermal growth factor-like growth factor). Paired t-tests were used to compare changes in biomarkers during 1 year (significance p <0.05). Linear regression models correlated baseline and changes in biomarker levels with covariates (significance p ≤ 0.001). Logistic regression models, controlling for age, were used to analyze associations of baseline and changes in biomarker levels with surgical failure (significance p <0.05).

RESULTS

During 1 year interleukin-12p70 decreased (mean ± SD 0.53 ± 1.4 to 0.28 ± 0.62 pg/mg creatinine, p = 0.04) and nerve growth factor increased (0.034 ± 0.046 to 0.044 ± 0.060 pg/ml/mOsm, p = 0.03). Baseline NTx level per mg creatinine was positively associated with age and postmenopausal status (p = 0.001), and negatively associated with current estrogen use (p = 0.0001). Baseline collagenase activity per mg creatinine was positively associated with age (p = 0.001). Epidermal growth factor per mOsm, NTx per mOsm and interferon-γ per mOsm were negatively correlated with age, current estrogen use and UDI (Urogenital Distress Inventory)-irritative subscale score, respectively (p ≤ 0.001). Subjects with lower baseline NTx per mg creatinine were less likely to experience surgical failure (OR 0.49, 95% CI 0.26-0.93, p = 0.03). Changes in biomarker levels were not associated with any covariates or surgical failure.

CONCLUSIONS

Stress urinary incontinence surgery was significantly less likely to fail in women with lower baseline NTx levels. Studies are needed to validate NTx as a possible independent biomarker for stress urinary incontinence surgery outcomes.