Overactive Bladder Syndrome: Evaluation and Management

Asiatic Acid, a Natural Compound that Exerts Beneficial Effects on the Cystometric and Biochemical Parameters in the Retinyl Acetate-Induced Model of Detrusor Overactivity

Scientists have been constantly looking for new synthetic and natural compounds that could have beneficial effects in bladder overactivity. Our attention was drawn by asiatic acid that influences a number of molecules and signaling pathways relevant for the proper functioning of the urinary tracts in humans. In the present project we wanted to check whether asiatic acid would have positive effects in the confirmed animal model of detrusor overactivity (DO) and whether it would affect the bladder blood flow, urothelium thickness, inflammatory and oxidative stress markers, neurotrophic and growth factors, and other parameters important for the activity of the urinary bladder. The outcomes of our study showed that a 14-day administration of asiatic acid (30 mg/kg/day) by oral gavage normalizes the cystometric parameters corresponding to DO and reduces the accompanying oxidative stress (measured by the levels of malondialdehyde-61,344 ± 24,908 pg/ml vs. 33,668 ± 5,071 pg/ml, 3-nitrotyrosine-64,615 ± 25,433 pg/ml vs. 6,563 ± 1,736 pg/ml, and NOS2-2,506 ± 411.7 vs. 3,824 ± 470.1 pg/ml). Moreover, it decreases the urinary secretion of neurotrophins (BDNF-304.4 ± 33.21 pg/ml vs. 119.3 ± 11.49 pg/ml and NGF-205.5 ± 18.50 vs. 109.7 ± 15.94 pg/ml) and prevents the changes in a range of biomarkers indicating the dysfunction of the urinary bladder, CGRP (421.1 ± 56.64 vs. 108.1 ± 11.73 pg/ml), E-Cadherin (773.5 ± 177.5 pg/ml vs. 1,560 ± 154.5 pg/ml), OCT3 (3,943 ± 814.6 vs. 1,018 ± 97.07 pg/ml), SNAP-23 (6,763 ± 808.9 pg/ml vs. 3,455 ± 554.5 pg/ml), SNAP-25 (2,038 ± 162.7 pg/ml vs. 833.3 ± 65.48), substance P (171.7 ± 16.86 pg/ml vs. 65.07 ± 8.250 pg/ml), SV2A (1,927 ± 175.3 pg/ml vs. 1,154 ± 254.9 pg/ml), tight junction protein 1 (360.1 ± 95.05 pg/ml vs. 563.4 ± 65.43 pg/ml), VAChT (16,470 ± 2,419 pg/ml vs. 7,072 ± 1,339 pg/ml), VEGFA (318.3 ± 37.89 pg/ml vs. 201.5 ± 22.91 pg/ml). The mentioned parameters are associated with smooth muscle contractions, urothelial barrier, transportation and release of transmitters, or bladder compensation. Thus, the presented findings allow to suggest a possible future role of asiatic acid in the prevention of conditions accompanied by DO, such as overactive bladder.

Isoprostanes evoke contraction of the murine and human detrusor muscle via activation of the thromboxane prostanoid TP receptor and Rho kinase

Local or systemic inflammation can severely impair urinary bladder functions and contribute to the development of voiding disorders in millions of people worldwide. Isoprostanes are inflammatory lipid mediators that are upregulated in the blood and urine by oxidative stress and may potentially induce detrusor overactivity. The aim of the present study was to investigate the effects and signal transduction of isoprostanes in human and murine urinary bladders in order to provide potential pharmacological targets in detrusor overactivity. Contraction force was measured with a myograph in murine and human urinary bladder smooth muscle (UBSM) ex vivo. Isoprostane 8-iso-PGE₂ and 8-iso-PGF_2α evoked dose-dependent contraction in the murine UBSM, which was abolished in mice deficient in the thromboxane prostanoid (TP) receptor. The responses remained unaltered after removal of the mucosa or incubation with tetrodotoxin. Smooth muscle-specific deletion of Gα_12/13 protein or inhibition of Rho kinase by Y-27632 decreased the contractions. In Gα_q/11-knockout mice, responses were reduced and in the presence of Y-27632 abolished completely. In human UBSM, the TP agonist U-46619 evoked dose-dependent contractions. Neither atropine nor the purinergic receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid decreased the effect, indicating that TP receptors directly mediate detrusor muscle contraction. 8-iso-PGE₂ and 8-iso-PGF_2α evoked dose-dependent contraction in the human UBSM, and these responses were abolished by the TP antagonist SQ-29548 and were decreased by Y-27632. Our results indicate that isoprostanes evoke contraction in murine and human urinary bladders, an effect mediated by the TP receptor. The G_12/13-Rho-Rho kinase pathway plays a significant role in mediating the contraction and therefore may be a potential therapeutic target in detrusor overactivity.NEW & NOTEWORTHY Voiding disorders affect millions of people worldwide. Inflammation can impair urinary bladder functions and contribute to the development of detrusor overactivity. The effects and signal transduction of inflammatory lipid mediator isoprostanes were studied in human and murine urinary bladders ex vivo. We found that isoprostanes evoke contraction, an effect mediated by thromboxane prostanoid receptors. The G_12/13-Rho-Rho kinase signaling pathway plays a significant role in mediating the contraction and therefore may be a potential therapeutic target.

Bladder overactivity induced by psychological stress in female mice is associated with enhanced bladder contractility

AIMS

To investigates the effects of water avoidance stress on voiding behaviour and functional bladder responses in mice.

MAIN METHODS

Mice in the Stress group were exposed to water avoidance stress (WAS) for 1 h/day for 10 days, Controls were age-matched and housed normally. Voiding behaviour was measured periodically throughout the stress protocol and bladders were isolated 24-h after final stress exposure to measure bladder compliance, spontaneous phasic activity, contractile responses, and release of urothelial mediators.

KEY FINDINGS

Repeated stress exposure induced a significant increase in plasma corticosterone levels in the WAS group compared to control. An overactive bladder phenotype was observed in WAS mice, causing a significant increase in the number of voiding events observed from as early as day-3, and a 7-fold increase following 10-days' stress. This increase in voiding frequency was associated with a significant decrease in void size, an increase in the number of small voids, but no change in total voided volume. Bladders from stressed mice showed a significant increase in the maximum responses to the muscarinic agonist carbachol (p < 0.01), in addition to enhanced pressure responses to the purinergic agonists ATP (p < 0.05) and αβ-mATP (p < 0.05), and non-receptor mediated contractions to KCl (p < 0.05) compared to controls. Nerve-mediated bladder contractions to electric field stimulation were not significantly affected by stress, nor were spontaneous phasic contractions or release of urothelial ATP and acetylcholine.

SIGNIFICANCE

Repeated exposure to water avoidance stress produced an overactive bladder phenotype, confirmed by increased voiding frequency, and associated with enhanced bladder contractile responses.

A randomized controlled trial to assess the effectiveness and safety of acupuncture for overactive bladder: a study in Hong Kong population

BACKGROUND

Around 15% of the Hong Kong population was found to suffer from overactive bladder (OAB), but the current available treatments, such as medication, behavioral therapy and physical therapy are unsatisfactory. Previous studies have suggested that acupuncture may have promising effect for OAB, but some limitations on the study design render the evidence questionable. This study aimed to evaluate the effectiveness and safety of acupuncture treatment for patients with OAB in Hong Kong.

METHODS

One hundred patients with OAB were enrolled. The patients were randomized to receive either active acupuncture or sham needle intervention twice a week for 8 consecutive weeks, and had a follow-up consultation 12 weeks after the completion of acupuncture intervention. The primary outcome assessment was the 3-Day Voiding Diary, which records daytime and night-time urinary frequency and symptoms, at the baseline, the end of the 8-week intervention and 12 weeks after acupuncture intervention. Secondary outcomes included Urine NGF level, Incontinence Impact Questionnaire (IIQ-7) and Urogenital Distress Inventory (UDI-6), as well as Overactive Bladder Symptom Score (OABSS).

RESULTS

After 16 sessions of treatment, when compared with the baseline, both active and sham acupuncture significantly reduced the frequency of urgency urinary incontinence (UUI), daytime and night-time urinary frequency as well as the scores of IIQ-7, UDI-6 and OABSS. Moreover, the treatment effects could last for at least 3 months. However, no significant difference in frequency of UUI and daytime urinary frequency was found between the active and sham acupuncture groups. On the other hand, the night-time urinary frequency decreased more significantly during the treatment and follow-up in the active acupuncture group than in the sham control group after controlling baseline night-time urinary frequency. Urine NGF level could not be detected by ELISA method in our experiments.

CONCLUSION

This study suggests a beneficial effect of acupuncture on improving OAB symptoms. Both active and sham acupuncture treatment were able to improve the symptoms of frequency of urgency urinary incontinence, and the daytime and night-time urinary frequency, while only mild adverse effects were found. This project was unable to establish the specific effect of acupuncture for OAB.Trial registration Chinese Clinical Trial Registry, ChiCTR-INR-16010048. Registered on 29 Nov 2016.

Electroacupuncture for post-stroke overactive bladder: a multi-centre pilot randomized controlled trial

BACKGROUND

Although acupuncture has been shown to be effective at treating overactive bladder (OAB) following stroke, to our knowledge, no randomized controlled trial (RCT) examining the effects of acupuncture on patients with post-stroke OAB has been conducted. The aim of this preliminary study was to explore the effects of electroacupuncture (EA) in the treatment of post-stroke OAB.

METHODS

This study was a multi-site randomized, assessor-blind, controlled pilot trial of patients with post-stroke OAB. In all, 34 post-stroke subjects (mean age: 71.0 years; 32.4% female) with OAB symptoms were randomly assigned to the treatment group or control group in a 1:1 ratio. The subjects in the treatment group were treated with six sessions of EA for 4 weeks, while the subjects in the control group received usual care. The primary outcome measure was the overactive bladder symptom scale (OABSS). Secondary outcome measures included a three day bladder diary and the stroke-specific quality-of-life scale (SSQoL).

RESULTS

EA showed a moderate effect size (ES) on the perceived severity of OAB symptoms as measured by the OABSS at week 5 (one week post-treatment, ES 0.57; p = 0.034) and week 8 (three weeks post-treatment, ES 0.60; p = 0.021), although the results did not remain statistically significant after Bonferroni correction for multiple testing. No significant differences in bladder diary parameters or SSQoL score were found. The EA treatment was well tolerated by the post-stroke subjects.

CONCLUSION

A six-session EA treatment was feasible and appeared to reduce OAB symptoms in post-stroke patients. Further fully powered trials are warranted to confirm the efficacy of EA for those with post-stroke OAB.

O-1602, an Agonist of Atypical Cannabinoid Receptors GPR55, Reverses the Symptoms of Depression and Detrusor Overactivity in Rats Subjected to Corticosterone Treatment

In view of the fact that GPR55 receptors are localized in brain areas implicated in the pathophysiology of depression, GPR55 gene expression is reduced in the dorsolateral prefrontal cortex of suicide victims, and GPR55 receptor agonism exerts an anxiolytic-like effect, GPR55 receptors have drawn our attention as a potential target in the treatment of mood disorders. Therefore, in the present study, we wanted to check whether a 7-day intravenous administration of O-1602 (0.25 mg/kg/day) – a phytocannabinoid-like analogue of cannabidiol that belongs to the agonists of GPR55 receptors, was able to reverse the corticosterone-induced depressive-like behavior accompanied by detrusor overactivity in female Wistar rats. Additionally, we tried to determine the influence of GPR55 stimulation on the bladder, hippocampal and urine levels of several biomarkers that play a role in the functioning of the urinary bladder and/or the pathophysiology of depression. Our experiments showed that O-1602 therapy improved signs of depression (measured by the forced swim test) and detrusor contractility (measured by conscious cystometry) in animals exposed to the corticosterone treatment. Moreover, the treatment reduced the oxidative damage in the urinary bladder and neuroinflammation (observed as the reduction of elevated levels of 3-NIT, MAL, and IL-1β, TNF-α, CRF, respectively). The O-1602 treatment also reversed the abnormal changes in the bladder, hippocampal or urine values of CGRP, OCT3, VAChT, BDNF, and NGF. The above-mentioned findings allow to suggest that in the future the modulation of atypical cannabinoid receptors GPR55 could have a potential role in the treatment of depression and overactive bladder.

Altered gut microbiome associated with overactive bladder and daily urinary urgency

PURPOSE

To explore associations between the gut microbiome and overactive bladder (OAB) with daily urinary urgency among individuals reporting this diagnosis within a single community.

METHODS

This cross-sectional study surveyed 1113 individuals who participated in the Iwaki Health Promotion Project in Japan. OAB was defined as urinary urgency at least once per week and an Overactive Bladder Symptom Score (OABSS) of ≥ 3. OAB with urinary urgency at least once a day was defined as daily urgency. The gut microbiomes were assessed by next-generation sequencing of 16S rRNA genes extracted from fecal samples. The participants were divided into two groups: OAB-daily urgency and non-OAB. Cases were selected for inclusion on the basis of 1:1 propensity score matching; we assigned 58 individuals to each group (23 men and 35 women) for our analysis.

RESULTS

Individuals reporting OAB with daily urinary urgency demonstrated a lower bacterial diversity between individuals (Bray-Curtis distance 0.48 vs. 0.53, P < 0.001); the results cluster differently in the non-OAB groups. The relative abundance of genus Bifidobacterium was significantly lower among those reporting daily urgency (2.41% vs. 4.23%, P = 0.014). By contrast, the relative abundance of genus Faecalibacterium (9.25% vs. 6.26%, P = 0.006) was significantly higher in this group.

CONCLUSION

We observed significant differences in gut microbial contents and specific bacterial genera in association with OAB with daily urgency. Further study will be necessary to assess causal relationships between the gut microbiome and OAB.

The association between serum serotonin levels and overactive bladder: results from a community-based cross-sectional study in Japan

PURPOSE

To investigate the association between serum serotonin (5-HT) levels and overactive bladder (OAB) in a community-dwelling population.

METHODS

This cross-sectional study analyzed 1024 subjects who participated in the Iwaki Health Promotion Project in 2015 in Hirosaki, Japan. OAB was assessed using the Overactive Bladder Symptom Score (OABSS). OAB was defined as an occurrence of urinary urgency at least once a week and an OABSS of ≥ 3. We assessed serum 5-HT levels, laboratory data, and comorbidities of each participants. Participants' mental health status was evaluated using the Center for Epidemiologic Studies Depression (CES-D) scale. The association of serum 5-HT levels and OAB was analyzed by multivariable logistic regression analysis.

RESULTS

This study included 394 men and 630 women. Of those, 118 (44 male and 74 female) were OAB sufferers. There were significant group differences in age, history of cardiovascular disease, chronic kidney disease, hypertension, diabetes mellitus, and CES-D score. Participants' serum 5-HT levels in the OAB group were significantly lower than those in the non-OAB group (100 vs. 127 ng/mL, P < 0.001). Multivariable analysis showed that age (odds ratio [OR]; 1.06, 95% confidence interval [CI]; 1.04-1.08, P < 0.001) and log serum 5-HT level (OR; 0.25, 95% CI; 0.10-0.68, P = 0.006) were independently associated with OAB.

CONCLUSIONS

Lower serum 5-HT levels could independently be associated with the presence of OAB. Further study is necessary to elucidate a possible causal relationship between serum 5-HT levels and OAB.

Efficacy of trospium for prevention of catheter-related bladder discomfort: a prospective, randomized, placebo-controlled, double-blind study

Background

Catheter-related bladder discomfort (CRBD) is a frequent complaint after awakening from anesthesia in patients receiving perioperative bladder catheterization. Overactive bladder (OAB) and CRBD show similar symptoms; thus, drugs used for the management of OAB influence symptoms of CRBD. Trospium chloride has been found effective in managing resistant cases of OAB. We evaluated the efficacy of oral trospium on CRBD in the postoperative period.

Methods

Sixty-four male and female adult patients, with planned spinal surgery and requiring urinary bladder catheterization, were randomly divided into two groups of 32 each. Group T patients received 60 mg extended-release oral trospium (extended-release) 1 h before induction of anesthesia and Group C patients received a similar-looking placebo. The anesthetic technique was identical in both groups. The CRBD score was evaluated in the postoperative ward using a 4-point scale (1 = no discomfort, 2 = mild, 3 = moderate, 4 = severe). Readings were recorded on arrival (0 h), and 1 h, 2 h, and 6 h postoperatively. All patients received fentanyl for postoperative pain relief.

Results

The incidence of CRBD was significantly higher in Group C than in Group T at 0 h (66% vs. 22%, P = 0.001) and 1 h postoperatively (72% vs. 28%, P = 0.001). The incidence of moderate to severe CRBD was higher in Group C at postoperative 2 h (82% vs. 14%, P = 0.004). There was no significant difference in postoperative fentanyl requirements.

Conclusions

Pretreatment with 60 mg extended release trospium reduced the incidence and severity of CRBD in the early postoperative period.

Future Considerations in Nocturia and Nocturnal Polyuria

Nocturnal polyuria (NP), the most common etiology of nocturia, can be caused by various medical conditions, including cardiovascular disease, obstructive sleep apnea, renal tubular dysfunction, as well as medications (eg, diuretics) and/or behavioral patterns. NP in the absence of underlying medical conditions has been described as NP syndrome and is thought be the result of impaired circadian release of endogenous arginine vasopressin. Desmopressin, a synthetic arginine vasopressin analog, has been shown to be an effective replacement therapy in adults with nocturia due to NP. Further studies on the subset of patients with NP syndrome are warranted to maximize benefit from antidiuretic treatment. In addition, a connection between the pathophysiological mechanisms underlying NP and essential hypertension has been suggested, and hypertension has been shown to be a significant risk factor for nocturia, while an association between NP and brain natriuretic peptide levels has also been reported in patients with nocturia. Hypertension is now viewed as a disorder of blood vessels and treatment is directed at the vasculature rather than the blood pressure, with the latter currently serving as a biomarker for arterial injury. Nocturia is thought to be associated with the beginning of this cardiovascular continuum as studies have reported a link between coronary heart disease and nocturia. Therefore, there is an increasing need to elucidate the complex mechanisms implicated in the association between nocturia and hypertension to promote the development of more individualized therapies for the treatment of nocturia.

Blebbistatin reveals beneficial effects on the cystometric parameters in an animal model of detrusor overactivity

The aims of the study were to determine the effectiveness of blebbistatin (BLEB) on detrusor overactivity (DO) in an animal model induced by retinyl acetate (RA) and, because of potential urothelial permeability, to evaluate the degenerative impact of BLEB on the urothelium. Three days after RA instillation into the urinary bladder, BLEB was administered into the bladder and immediately after cystometric assessment was performed. Furthermore, Evans Blue extravasation into bladder tissue and urothelium thickness were measured. Sixty female Wistar rats were used and randomly assigned to one of four groups (n = 15 in each group): (1) control, (2) RA, (3) BLEB, and (4) RA + BLEB. RA administration induced changes in cystometric parameters reflecting DO, as previously reported. Treatment with BLEB did not significantly alter cystometric parameters in rats which did not receive RA. Administration of BLEB to rats pretreated with RA reversed changes in cystometric parameters induced by RA in basal pressure, threshold pressure, detrusor overactivity index, amplitude of nonvoiding contractions, frequency of nonvoiding contractions, voided volume, volume threshold, intercontraction interval, bladder compliance, and volume threshold to elicit nonvoiding contractions. There were no significant differences in Evans Blue extravasation into bladder tissue or urothelium thickness between the groups. The current research provides new data on the possible utility of blebbistatin in the pharmacotherapy of DO, which is an important feature of overactive bladder (OAB). Further studies in human patients with DO/OAB are warranted to confirm these preclinical results.

Vitamin D and thiol-disulfide homeostasis levels in postmenopausal women with overactive bladder syndrome

Background

This study aimed to find a relationship between vitamin D concentration and thiol-disulfide homeostasis in the pathophysiology of overactive bladder (OAB) syndrome in postmenopausal women.

Methods

A total of 76 postmenopausal women, referred for routine controls, were recruited between January and March 2018 to participate in this study. Participants with an overactive bladder questionnaire (OAB-q) score of >11 (n = 34) were included in the OAB syndrome group, while those with a score of <5 (n = 42) were included in the control group. Serum total antioxidant capacity, ischemia-modified albumin, C-reactive protein, 25-hydroxy vitamin D levels, and thiol-disulfide homeostasis were measured.

Results

Patients with OAB syndrome had waist circumferences of 106 ± 11 cm, and their body mass indexes (BMIs) were 30.8 ± 4.8 kg/m2. The control groups' waist circumferences were 102 ± 11 cm and their BMIs were 28.9 ± 4.3 kg/m2 (p = 0.069 and p = 0.098, respectively). The level of vitamin D in the control group was 33.7 (IQR: 30.7) nmol/L and 27.0 (IQR: 27.5) nmol/L (p = 0.081) in the OAB syndrome group.

Conclusions

We were not able to demonstrate with certainty any significant relationships between serum 25-hydroxy vitamin D levels and thiol-disulfide homeostasis parameters and OAB syndrome.

Nociceptin/Orphanin FQ and Urinary Bladder

Following identification as the endogenous ligand for the NOP receptor, nociceptin/orphanin FQ (N/OFQ) has been shown to control several biological functions including the micturition reflex. N/OFQ elicits a robust inhibitory effect on rat micturition by reducing the excitability of the afferent fibers. After intravesical administration N/OFQ increases urodynamic bladder capacity and volume threshold in overactive bladder patients but not in normal subjects. Moreover daily treatment with intravesical N/OFQ for 10 days significantly reduced urine leakage episodes. Different chemical modifications were combined into the N/OFQ sequence to generate Rec 0438 (aka UFP-112), a peptide NOP full agonist with high potency and selectivity and long-lasting duration of action. Rec 0438 mimicked the robust inhibitory effects of N/OFQ on rat micturition reflex; its action is solely due to NOP receptor stimulation, does not show tolerance liability after 2 weeks of treatment, and can be elicited by intravesical administration. Collectively the evidence summarized and discussed in this chapter strongly suggests that NOP agonists are promising innovative drugs to treat overactive bladder.