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

Abstract

Purpose: 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.

Materials and 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.

Keywords: biological markers; operative; prognosis; stress; surgical procedures; treatment outcome; urinary incontinence.