Urinary Biomarkers in Women with Refractory Urgency Urinary Incontinence Randomized to Sacral Neuromodulation versus OnabotulinumtoxinA Compared to Controls

Urinary Biomarkers and Overactive Bladder Symptoms Before and After Prolapse Surgery

IMPORTANCE

Women with pelvic organ prolapse (POP) have increased prevalence of overactive bladder (OAB) and the evaluation of urinary biomarkers associated with OAB in the setting of POP is limited.

OBJECTIVE

The objective is to determine whether associations exist between urinary biomarkers measured before POP surgery with postoperative OAB symptoms.

STUDY DESIGN

In this prospective cohort study, women with anterior and/or apical POP beyond the hymen undergoing POP surgery were assessed using the OAB Questionnaire Short Form (OAB-q SF) and the Urogenital Distress Inventory 6 (UDI-6) preoperatively and 3 months postoperatively. A first morning voided urine specimen was collected preoperatively and 3 months postoperatively. Urinary biomarkers for inflammation, neuroinflammation, and tissue remodeling were measured. Univariate generalized linear models measured the relationship between biomarkers and symptoms. Between- and within-cohort assessments were made using 2-sample paired and unpaired t tests, respectively.

RESULTS

Seventy-seven participants with OAB (n = 67, 87.0%) and without OAB (n = 10, 13.0%) were enrolled. Seventy-four participants (96%) completed 3-month follow up. The OAB-q SF and UDI-6 scores significantly improved between preoperative and postoperative measures. Preoperative urinary biomarkers did not demonstrate significant correlations with postoperative OAB-q SF or UDI-6 scores. No significant differences were measured in preoperative biomarkers between patients with and without OAB or when comparing preoperative and postoperative biomarkers in patients with OAB.

CONCLUSIONS

Urinary biomarkers for tissue remodeling, inflammation, and neuroinflammation were not significantly correlated with OAB symptoms in a population of patients with OAB and POP.

Feasibility of Real-Time Conditional Sacral Neuromodulation Using Wireless Bladder Pressure Sensor

Continuous sacral neuromodulation (SNM) is used to treat overactive bladder, reducing urine leakage and increasing capacity. Conditional SNM applies stimulation in response to changing bladder conditions, and is an opportunity to study neuromodulation effects in various disease states. A key advantage of this approach is saving power consumed by stimulation pulses. This study demonstrated feasibility of automatically applying neuromodulation using a wireless bladder pressure sensor, a real-time control algorithm, and the Medtronic Summit™ RC+S neurostimulation research system. This study tested feasibility of four conditional SNM paradigms over five days in 4 female sheep. Primary outcomes assessed proof of concept of closed-loop system function. While the bladder pressure sensor correlated only weakly to simultaneous catheter-based pressure measurement (correlation 0.26-0.89, median r=0.52), the sensor and algorithm were accurate enough to automatically trigger SNM appropriately. The neurostimulator executed 98.5% of transmitted stimulation commands with a median latency of 72 ms (n=1,206), suggesting that rapid decision-making and control is feasible with this platform. On average, bladder capacity increased for continuous SNM and algorithm-controlled paradigms. Some animals responded more strongly to conditional SNM, suggesting that treatment could be individualized. Future research in conditional SNM may elucidate the physiologic underpinnings of differential response and enable clinical translation.

Genetic variants and expression changes in urgency urinary incontinence: A systematic review

Aim

To perform a systematic review summarizing the knowledge of genetic variants, gene, and protein expression changes in humans and animals associated with urgency urinary incontinence (UUI) and to provide an overview of the known molecular mechanisms related to UUI.

Methods

A systematic search was performed on March 2, 2020, in PubMed, Embase, Web of Science, and the Cochrane library. Retrieved studies were screened for eligibility. The risk of bias was assessed using the ROBINS‐I (human) and SYRCLE (animal) tool. Data were presented in a structured manner and in the case of greater than five studies on a homogeneous outcome, a meta‐analysis was performed.

Results

Altogether, a total of 10,785 records were screened of which 37 studies met the inclusion criteria. Notably, 24/37 studies scored medium‐high to high on risk of bias, affecting the value of the included studies. The analysis of 70 unique genes and proteins and three genome‐wide association studies showed that specific signal transduction pathways and inflammation are associated with UUI. A meta‐analysis on the predictive value of urinary nerve growth factor (NGF) levels showed that increased urinary NGF levels correlate with UUI.

Conclusion

The collective evidence showed the involvement of two molecular mechanisms (signal transduction and inflammation) and NGF in UUI, enhancing our understanding of the pathophysiology of UUI. Unfortunately, the risk of bias was medium‐high to high for most studies and the value of many observations remains unclear. Future studies should focus on elucidating how deficits in the two identified molecular mechanisms contribute to UUI and should avoid bias.

Sacral Neuromodulation: Determining Predictors of Success

OBJECTIVE

To determine predictors of success for sacral neuromodulation in women with overactive bladder, urinary retention, and fecal incontinence.

METHODS

A retrospective chart review was performed on women who underwent a staged sacral neuromodulation implantation between 2007 and 2018. Clinical and procedural characteristics were recorded. Presence of intraoperative motor responses in either all 4 or <4 electrodes were used to group women. Endpoints included completion of stage II implant, tined lead revision, and patient-reported success.

RESULTS

In 198 women with a mean age of 62.9 years (SD+/- 14.7), completion of stage II implant occurred in 92.4% of women, and 83.3% of these women reported success at the first postoperative visit. Continued success at 6 months was reported in 70.3%. Lead revision was noted in 23.0%. Age >65 years (odds ratio [OR] = 0.2, 95% confidence interval [CI] = 0.06-0.8) and prior onabotulinumtoxinA (onaBoNT-A) (OR = 0.2, 95% CI = 0.06-0.9) were negative predictors for completion of stage II implant on multivariable analysis. Also, prior pelvic floor physical therapy was a significant negative predictor of postoperative patient-reported success on multivariable analysis (OR = 0.25, 95% CI = 0.1-0.6). There were no differences seen in women who had motor responses with either all 4 electrodes or <4 electrodes in any endpoint (P > .05).

CONCLUSION

Patient age >65 and history of prior onaBoNT-A were associated with failure to complete stage II implant. Women with prior pelvic floor physical therapy were less likely to report success after sacral neuromodulation. Motor responses in <4 electrodes during lead testing did not impact patient-reported success.

Biomarkers Implicated in Lower Urinary Tract Symptoms: Systematic Review and Pathway Analyses

PURPOSE

Lower urinary tract symptoms are prevalent and burdensome, yet methods to enhance diagnosis and appropriately guide therapies are lacking. We systematically reviewed the literature for human studies of biomarkers associated with lower urinary tract symptoms.

MATERIALS AND METHODS

PubMed®, EMBASE® and Web of Science® were searched from inception to February 13, 2018. Articles were included if they were in English, performed in benign urological populations without neurological disorders or interstitial cystitis/bladder pain syndrome, and assessed a biomarker's association with or ability to predict specific lower urinary tract symptoms or urological conditions. Bioinformatic pathway analyses were conducted to determine whether individual biomarkers associated with symptoms are present in unifying pathways.

RESULTS

Of 6,150 citations identified 125 met the inclusion criteria. Most studies (93.6%) assessed biomarkers at 1 time point and were cross-sectional in nature. Few studies adjusted for potentially confounding clinical variables or assessed biomarkers in an individual over time. No individual biomarkers are currently validated as diagnostic tools for lower urinary tract symptoms. Compared to controls, pathway analyses identified multiple immune response pathways that were enriched in overactive bladder syndrome and cell migration/cytoskeleton remodeling pathways that were enriched in female stress incontinence.

CONCLUSIONS

Major deficiencies in the existing biomarker literature include poor reproducibility of laboratory data, unclear classification of patients with lower urinary tract symptoms and lack of adjustment for clinical covariates. Despite these limitations we identified multiple putative pathways in which panels of biological markers need further research.

Urinary nerve growth factor can predict therapeutic efficacy in children with monosymptomatic nocturnal enuresis

AIM

To determine the urinary levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in children with monosymptomatic nocturnal enuresis (MNE) and evaluate whether these factors can be used as biomarkers for the treatment outcome.

METHODS

NGF and BDNF levels were measured and compared in 38 children (28 boys and 10 girls) with MNE and 25 children (18 boys and 7 girls) with no urinary symptoms were assessed. The mean ages in the patient and control groups were 9 and 10 years, respectively (P = .49). The patients were treated with either alarm or desmopressin therapy.

RESULTS

The urinary NGF/creatinine and BDNF/creatinine ratios were significantly higher in the patient group than in the control group (P = .0003 and P = .0095, respectively). NGF and BDNF levels showed a significant positive correlation (P = .0020, r = 0.40). With respect to the degree of response, 19 patients (50%) showed complete response (CR) or partial response (PR), and 19 patients (50%) showed nonresponse (NR). The urinary NGF/creatinine and BDNF/creatinine ratios were significantly higher in the NR group than in the CR and PR groups (P = .0003 and P = .0003, respectively).

CONCLUSIONS

Urinary NGF/creatinine and BDNF/creatinine ratios were significantly higher in children with MNE than in healthy controls. Urinary NGF/creatinine can be predictive factors of a poor treatment outcome in children with MNE.

Evaluation of Urine Choline Levels in Women With and Without Overactive Bladder Syndrome

OBJECTIVE

The objective of this study was to determine whether levels of choline (Ch) differ in women with and without overactive bladder (OAB) symptoms.

METHODS

New patients were evaluated using the overactive bladder symptom score; Medical, Epidemiologic, and Social Aspects of Aging (MESA) urgency incontinence questionnaire; and Impact Questionnaire 7 and provided a urine sample. Patients were stratified into asymptomatic controls, scoring 0 on overactive bladder symptom score and the MESA questionnaire, and patients with OAB and urgency incontinence (OAB-wet). Patients with conditions predisposing to OAB or had a history of OAB treatment were excluded. Choline detection was accomplished using a commercially available kit. Wilcoxon rank sum test and Fisher exact test were used to express differences between groups. Spearman ρ correlation was used to determine the relationship between Ch and questionnaire scores. Logistic regression was used to identify significant variables associated with OAB.

RESULTS

Sixty-three women were included in the final analysis. Patients with OAB-wet were older (P = 0.001), more likely to be obese (P = 0.04), had greater apical descent (P = 0.02), were more likely to be postmenopausal (P = 0.01), and were more likely to have stress incontinence (P = 0.005). Choline was 34.8% lower in OAB compared with the controls (P = 0.014). Lower Ch levels were associated with higher MESA (Spearman ρ = -0.311, P = 0.03). After logistic regression, lower Ch (adjusted odds ratio [aOR], 0.97; 95% confidence interval [CI], 0.96-0.98), age (aOR, 1.12; 95% CI, 1.08-1.18), and body mass index (aOR, 1.09; 95% CI, 1.01-1.18) were significantly associated with OAB-wet.

CONCLUSIONS

Choline levels are significantly decreased in women complaining of OAB with urgency incontinence, and lower levels are associated with higher MESA scores.

Urinary biomarkers in patients with detrusor underactivity with and without bladder function recovery

PURPOSE

Detrusor underactivity (DU) is frequently encountered in elderly patients. Part of patients with DU might have bladder function recovery after treatment. This study investigated urinary proteins in these DU patients with and without bladder function recovery.

METHODS

A total of 37 patients with chronic urinary retention and urodynamically proven DU were enrolled. After treatment, 24 DU patients had bladder function recovery whereas 13 had not, after 1-year follow-up. Urine collection at baseline was performed, and the urinary protein including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and prostaglandin E2 (PGE2) were measured by ELISA. Twenty urodynamically normal, 34 detrusor overactivity (DO) and 15 detrusor hyperactivity and inadequate contractility (DHIC) patients served as comparative groups.

RESULTS

Urinary NGF levels were significantly higher than normal in patients with DU (9.2 ± 20.3 vs 1.85 ± 2.9 pg/ml, p = 0.037). Urinary BDNF level was only significantly higher in patients with DU than that of the control group (153 ± 199 vs 77.4 ± 47.7 pg/ml, p = 0.033) but not in patients with DHIC or DO. Compared with the control group, the urinary BDNF level was significantly higher in DU patients with bladder function recovery (190 ± 239 pg/ml, p = 0.033) but not in patients without recovery (85.8 ± 43.7 pg/ml, p = 0.612). The PGE2 level was significantly higher than the control group in DU patients with bladder function recovery (1290 ± 836 pg/ml, p < 0.0001) but not in patients without recovery (383 ± 237 pg/ml, p = 0.130).

CONCLUSION

Patients with DU and higher urinary PGE2 and BDNF levels might have a chance to recover bladder function than those with a lower protein level.