Melatonin Increases Bladder Capacity via GABAergic System and Decreases Urine Volume in Rats

Adjustment to an Appropriate Bedtime Improves Nocturia in Older Adults: A Crossover Study

PURPOSE

We examined whether nocturia could be improved by adhering to an appropriate bedtime as determined using a wearable device that measures sleep-wake activity.

MATERIALS AND METHODS

We enrolled patients aged 65 years or older with nocturia at our institution and associated hospital, for whom medical therapy was either not indicated or ineffective. We conducted a prospective crossover comparative study with alternate 4-week intervention and non-intervention periods with a 2-week washout period. During the intervention, participants were instructed to go to bed at a personalized bedtime determined via the steepest descent method, using the data of bedtime and mid-wake time from an Actiwatch Spectrum (Philips Respironics). A frequency volume chart was administered before and after each period. Sleep quality was evaluated using the Pittsburgh sleep quality index (PSQI).

RESULTS

The analysis included 24 patients enrolled for the study. The mean age was 79.7 years. The mean bedtime changed from 21:30 to 22:11 after intervention (p < 0.01). During the intervention and non-intervention periods, the mean changes were as follows: nocturnal urinary frequency (-0.90 vs. -0.01 times, p < 0.01), nocturnal urine volume (NUV) (-105.6 vs. +4.4 mL, p = 0.04), hours to undisturbed sleep (HUS) (62.8 vs. 12.7 min, p < 0.01), NUV per hour during HUS (-28.4 vs. -0.17 mL/h, p = 0.04), and PSQI scores (-2.4 vs. 1.2, p = 0.022).

CONCLUSIONS

In older patients with nocturia, going to bed at appropriate times, determined using a wearable device that measures sleep-wake activity, might potentially prolong HUS, decrease NUV, specifically NUV/h during HUS, and consequently improve nocturia and sleep quality.

From nocturnal awakenings to nocturnal voiding: the relationship between insomnia and nocturia - a systematic review

INTRODUCTION

The aim of this study was to systematically evaluate relevant literature regarding 1) the prevalence of nocturia in patients with insomnia; 2) sleep characteristics of insomniacs with and without nocturia; 3) interventions for the treatment of insomnia and their effect on nocturia.

EVIDENCE ACQUISITION

A systematic review of literature was performed through EMBASE, MEDLINE, CLINICALTRIALS.GOV and CENTRAL databases up until November 2022 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. From the identified reports, 11 studies were retained, of which 7 were eligible for meta-analysis. Bias assessment was performed using the ROBINS tools as per the Cochrane collaboration guidelines.

EVIDENCE SYNTHESIS

A total of 5396 older adults were included in the meta-analysis. The pooled estimate of the OR was 1.958 (95% CI: 1.609-2.384) for nocturia in patients with insomnia based on 7 studies in a random effects model with nonsignificant heterogeneity (I2=50.83%, P=0.06). Wake after sleep onset (WASO) was longer in people with insomnia and nocturia compared to those without and sleep efficiency (SE) declined. Interventions with melatonin, diet and behavioral therapy were beneficial on nocturia frequency in insomniacs. A limiting factor of our analysis was the scarcity of available data, potentially causing an important selection bias.

CONCLUSIONS

The overall odds for nocturia in older adults is higher in patients with insomnia than those without and is associated with worse sleep outcomes. Interventions for treating insomnia such as melatonin, behavioral therapy and diet show beneficial results on nocturnal voiding frequency. We advocate for further research in which uniform definitions and questionnaires are used. Routine screening for nocturia in patients with insomnia could be beneficial to maximize sleep quality improvement.

Melatonin induces urethral contraction and increases intraurethral pressure via MT1 receptor activation in female rats

Melatonin is released by the pineal gland and exerts numerous physiological effects via specific G protein-coupled receptors named MT1 and MT2 receptors. It is well known that melatonin acts as a key regulator of circadian rhythm through the activation of these receptors on the central nervous system. However, the expression and function of melatonin receptors in the lower urinary tract remain unclear. This study aimed to investigate the expression and function of melatonin receptors in female urethra. mRNA expression analysis exhibited high expression of MT1 and MT2 receptor mRNA in human and rat female urethra. A study of isolated female rat urethral tissue strips using melatonin receptor agonists and an antagonist strongly revealed that stimulation of melatonin MT1 receptor induced urethral smooth muscle contraction. Further investigation of the mechanism underlying this melatonin MT1 receptor-related urethral contraction demonstrated that stimulation of MT1 receptors in urethra activates intracellular Ca2+ mobilization via Gq protein-dependent pathways, resulting in smooth muscle contraction. In vivo studies also revealed that melatonin receptor agonists induced an increase in urethral perfusion pressure in female rats. This is the first study to clearly demonstrate the expression and function of melatonin receptors in the urethra. These findings suggested that activation of MT1 receptors could be a potential pharmacological target for modulation of urethral function.

Disruption of circadian rhythm as a potential pathogenesis of nocturia

Increasing evidence suggested the multifactorial nature of nocturia, but the true pathogenesis of this condition still remains to be elucidated. Contemporary clinical medications are mostly symptom based, aimed at either reducing nocturnal urine volume or targeting autonomic receptors within the bladder to facilitate urine storage. The day-night switch of the micturition pattern is controlled by circadian clocks located both in the central nervous system and in the peripheral organs. Arousal threshold and secretion of melatonin and vasopressin increase at night-time to achieve high-quality sleep and minimize nocturnal urine production. In response to the increased vasopressin, the kidney reduces the glomerular filtration rate and facilitates the reabsorption of water. Synchronously, in the bladder, circadian oscillation of crucial molecules occurs to reduce afferent sensory input and maintain sufficient bladder capacity during the night sleep period. Thus, nocturia might occur as a result of desynchronization in one or more of these circadian regulatory mechanisms. Disrupted rhythmicity of the central nervous system, kidney and bladder (known as the brain-kidney-bladder circadian axis) contributes to the pathogenesis of nocturia. Novel insights into the chronobiological nature of nocturia will be crucial to promote a revolutionary shift towards effective therapeutics targeting the realignment of the circadian rhythm.

PDE5 inhibitor potentially improves polyuria and bladder storage and voiding dysfunctions in type 2 diabetic rats

PURPOSE

Bladder dysfunction associated with type 2 diabetes mellitus (T2DM) includes urine storage and voiding disorders. We examined pathological conditions of the bladder wall in a rat T2DM model and evaluated the effects of the phosphodiesterase-5 (PDE-5) inhibitor tadalafil.

MATERIALS AND METHODS

Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and Long-Evans Tokushima Otsuka (LETO) rats were used as the T2DM and control groups, respectively. Tadalafil was orally administered for 12 weeks. Micturition behavior was monitored using metabolic cages, and bladder function was evaluated by cystometry. Bladder blood flow was evaluated by laser speckle imaging, and an organ bath bladder distention test was used to measure adenosine triphosphate (ATP) release from the bladder urothelium. The expression levels of vesicular nucleotide transporter (VNUT), hypoxia markers, pro-inflammatory cytokines and growth factors in the bladder wall were measured using real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Bladder wall contractions in response to KCl and carbachol were monitored using bladder-strip tests.

RESULTS

With aging, OLETF rats had higher micturition frequency and greater urine volume than LETO rats. Although bladder capacity was not significantly different, non-voiding bladder contraction occurred more frequently in OLETF rats than in LETO rats. Bladder blood flow was decreased and ATP release was increased with higher VNUT expression in OLETF rats than in LETO rats. These effects were suppressed by tadalafil administration, with accompanying decreased HIF-1α, 8-OHdG, IL-6, TNF-α, IGF-1, and bFGF expression. The impaired contractile responses of bladder strips to KCl and carbachol in OLETF rats with aging were restored by tadalafil administration.

CONCLUSIONS

The T2DM rats had polyuria, increased ATP release induced by decreased bladder blood flow and impaired contractile function. PDE5 inhibition improved these changes and may prevent T2DM-associated urinary frequency and bladder storage and voiding dysfunctions.

Diurnal differences in urine flow in healthy young men in a light-controlled environment: a randomized crossover design

BACKGROUND

Older men often experience nocturnal urination difficulties, reflected by diurnal differences in maximum urine flow (Qmax). Since lower urinary tract symptoms and pathological comorbidities are frequent in older men, it remains unclear whether this diurnal variation is a physiological or pathological phenomenon. Our aim was to quantify the diurnal variability of Qmax in healthy young participants under varying daylight conditions in a stable environment to discern potential underlying causes of nocturnal urination difficulties.

METHODS

Twenty-one healthy young men were recruited in a 4-day study utilizing daytime (08:00-18:00) exposure with two light conditions in randomized order: dim (< 50 lx) or bright (~2500 lx). Day 1 was for acclimation, and urine flow was assessed from day 2. The participants urinated ad libitum during day 2 and then at fixed 3-4-h intervals thereafter (days 3-4). Regular urination Qmax at late night (04:00) on day 4 was compared with the nearest voided volume during daytime of day 3 (mDay).

RESULTS

Morning Qmax scores (after bed-11:00) on day 2 were significantly lower than evening (17:00-before pre-sleep) in bright conditions and those of daytime (11:00-17:00), evening (17:00-before pre-sleep), and pre-sleep in dim conditions. Pre-sleep Qmax during the ad libitum period was significantly higher in dim than bright conditions. Late-night Qmax values (04:00) on day 4 were significantly lower than Qmax scores of mDay on day 3 in both light conditions.

CONCLUSIONS

Healthy young men had a clear diurnal Qmax difference that decreased during late night and morning. In addition, the pre-sleep Qmax values in dim daylight were significantly higher than in bright daylight. Taken together, we conclude that late-night and morning decreases in Qmax are an instinctive physiological phenomenon in humans, and the diurnal difference of Qmax can be influenced by daylight conditions.

'Nocturomics': transition to omics-driven biomarkers of nocturia, a systematic review and future prospects

OBJECTIVE

To systematically review studies that investigated different biomarkers of nocturia, including omics-driven biomarkers or 'Nocturomics'.

MATERIALS AND METHODS

PubMed® , Scopus® , and Embase® were searched systematically in May 2022 for research papers on biomarkers in physiological fluids and tissues from patients with nocturia. A distinction was made between biomarkers or candidates discovered by omics techniques, referred to as omics-driven biomarkers, and classical biomarkers, measured by standard laboratory techniques and mostly thought from pathophysiological hypothesis.

RESULTS

A total of 13 studies with 18 881 patients in total were included, eight of which focused on classical biomarkers including: atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), C-reactive protein (CRP), aldosterone, and melatonin. Five were 'Nocturomics', including one that assessed the microbiome and identified 27 faecal and eight urinary bacteria correlated with nocturia; and four studies that identified candidate metabolomic biomarkers, including fatty acid metabolites, serotonin, glycerol, lauric acid, thiaproline, and imidazolelactic acid among others. To date, no biomarker is recommended in clinical practice. Nocturomics are in an embryonic phase of conception but are developing quickly. Although candidate biomarkers are being identified, none of them are yet validated on a large sample, although some preclinical studies have shown a probable role of fatty acid metabolites as a possible biomarker of circadian rhythm and chronotherapy.

CONCLUSION

Further research is needed to validate biomarkers for nocturia within the framework of a diagnostic and therapeutic precision medicine perspective. We hope this study provides a summary of the current biomarker discoveries associated with nocturia and details future prospects for omics-driven biomarkers.

Traumatic Brain Injury, Sleep, and Melatonin-Intrinsic Changes with Therapeutic Potential

Traumatic brain injury (TBI) is one of the most prevalent causes of morbidity in the United States and is associated with numerous chronic sequelae long after the point of injury. One of the most common long-term complaints in patients with TBI is sleep dysfunction. It is reported that alterations in melatonin follow TBI and may be linked with various sleep and circadian disorders directly (via cellular signaling) or indirectly (via free radicals and inflammatory signaling). Work over the past two decades has contributed to our understanding of the role of melatonin as a sleep regulator and neuroprotective anti-inflammatory agent. Although there is increasing interest in the treatment of insomnia following TBI, a lack of standardization and rigor in melatonin research has left behind a trail of non-generalizable data and ambiguous treatment recommendations. This narrative review describes the underlying biochemical properties of melatonin as they are relevant to TBI. We also discuss potential benefits and a path forward regarding the therapeutic management of TBI with melatonin treatment, including its role as a neuroprotectant, a somnogen, and a modulator of the circadian rhythm.

Role of circadian rhythms and melatonin in bladder function in heath and diseases

The circadian system modulates all visceral organ physiological processes including urine storage and voiding. The "master clock" of the circadian system lies within suprachiasmatic nucleus of the hypothalamus while "peripheral clocks" are found in most peripheral tissue and organs, including the urinary bladder. Disruptions of circadian rhythms can cause organ malfunction and disorder or exacerbate pre-existing ones. It has been suggested that nocturia, which develops mostly in the elderly, could be a circadian-related disorder of the bladder. In the bladder, many types of gap junctions and ion channels in the detrusor, urothelium and sensory nerves are likely under strict local peripheral circadian control. The pineal hormone, melatonin, is a circadian rhythm synchroniser capable of controlling a variety of physiological processes in the body. Melatonin predominantly acts via the melatonin 1 and melatonin 2 G-protein coupled receptors expressed in the central nervous system, and many peripheral organs and tissues. Melatonin could be beneficial in the treatment of nocturia and other common bladder disorders. The ameliorating action of melatonin on bladder function is likely due to multiple mechanisms which include central effects on voiding and peripheral effects on the detrusor and bladder afferents. More studies are warranted to determine the precise mechanisms of circadian rhythm coordination of the bladder function and melatonin influences on the bladder in health and diseases.

Sleep Disorders, Comorbidities, Actions, Lower Urinary Tract Dysfunction, and Medications ("Sleep C.A.L.M.") in the evaluation and management of nocturia: A simple approach to a complex diagnosis

INTRODUCTION

Nocturia arises from a fundamental mismatch between nocturnal urine production, storage capacity, and sleep architecture, which may be driven by abnormalities of the genitourinary tract, but also by sleep disorders, medical diseases, patient actions/lifestyle factors, or medications. This article introduces a novel system for organizing the complex differential diagnosis for nocturia, as proposed by an international collective of practicing urologists, physician specialists, and sleep experts: "Sleep CALM"-Sleep Disorders, Comorbidities, Actions, Lower Urinary Tract Dysfunction, and Medications.

METHODS

Narrative review of current evidence regarding the relevance of each "Sleep CALM" factor to nocturia pathogenesis, evaluation, and management.

RESULTS

Nocturia and sleep disorders are highly intertwined and often bidirectional, such that nocturnal awakenings for reasons other than a sensation of bladder fullness should not be used as grounds for exclusion from nocturia treatment, but rather leveraged to broaden therapeutic options for nocturia. Nocturia is an important potential harbinger of several serious medical conditions beyond the genitourinary tract. Urologists should have a low threshold for primary care and medical specialty referral for medical optimization, which carries the potential to significantly improve nocturnal voiding frequency in addition to overall health status. Adverse patient actions/lifestyle factors, lower urinary tract dysfunction, and medication use commonly coexist with disordered sleep and comorbid medical conditions, and may be the primary mediators of nocturia severity and treatment response, or further exacerbate nocturia severity and complicate treatment.

CONCLUSION

"Sleep CALM" provides a memorable and clinically relevant means by which to structure the initial patient history, physical exam, and clinical testing in accordance with current best-practice guidelines for nocturia. Although not intended as an all-encompassing diagnostic tool, the "Sleep CALM" schema may also be useful in guiding individualized ancillary testing, identifying the need for specialty referral and multidisciplinary care, and uncovering first-line treatment targets.

Melatonin inhibits muscular-mucosal stretch-sensitive bladder afferents via the MT2 receptors

Melatonin is a circadian rhythm regulator capable of controlling a variety of physiological processes in the body. It predominantly acts via the melatonin 1 (MT1) and MT2 receptors expressed in the CNS neurons and peripheral organs and tissues. Melatonin can modulate urinary bladder function, however, to date it is not known if melatonin can regulate activity of sensory neurons innervating the bladder. Bladder afferents play an important role in urine storage and voiding. Therefore, this study aims to determine if melatonin can regulate mechanosensitivity of 2 major classes of sensory neurons in the guinea pig bladder: stretch-insensitive mucosal and low threshold stretch-sensitive muscular-mucosal afferents. The effects of melatonin on the mechanosensitivity of mucosal and muscular-mucosal afferents were measured ex vivo using single unit extracellular recording. Melatonin did not affect the responses of mucosal afferents to stroking of their receptive fields but did concentration-dependently, significantly inhibit 69% of muscular-mucosal afferents responses to stroking and bladder stretch. This inhibitory effect was not affected by the MT1 receptor antagonist, S26131 but was blocked by the selective MT2 receptor antagonists, K-185 and 4-P-PDOT. Forskolin significantly potentiated the responses of muscular-mucosal afferents to stroking and stretch, which were prevented by melatonin. These findings demonstrate a direct inhibitory effect of melatonin on the mechanosensitivity of low threshold stretch-sensitive muscular-mucosal bladder afferents acting via MT2 receptors, which is independent from its action on detrusor muscle. This may have important clinical implications for the treatment of many common bladder disorders including nocturia.

Predictive Values of Nocturia and Its Voiding Frequency on the Aging Males' Symptoms

BACKGROUND

The link between nocturia and aging male symptoms (AMS) has not been scientifically established. This study aimed to measure the degree of severity of AMS that impacts health-related quality of life (HRQoL) in adult males living with nocturia and to determine the predictive values of nocturnal factors on AMS.

METHODS

This is an extended analysis of new data collected by using the Hong Kong Traditional AMS (HK-AMS) scale and the Cantonese version of the Pittsburgh Sleep Quality Index (PSQI) in a recently published cross-sectional population-based survey.

RESULTS

Of the 781 respondents that completed the set of questionnaires, 68% and 61% of men living with nocturia reported clinically significant (at moderate-to-severe levels) somato-vegetative and sexual AMS; the prevalence and severity were increased with advancing nighttime voiding frequency. Age, the Global PSQI score, certain metabolic diseases, the nocturia-specific QoL (NQoL) score and bedtime voiding frequency were found to be significant predictive factors for composite somato-vegetative and sexual AMS.

CONCLUSIONS

The current findings suggested the inclusion of nocturia when measuring male-specific HRQoL related to aging.

Serotonin Discharge Regulation by Additional Neurotransmitters of Rat Hippocampus Associated With the Continence Central Circuit

Purpose

The lower urinary tract is believed to be centrally regulated with the involvement of a range of neurotransmitters. The parasympathetic excitatory input to the urinary bladder is suppressed when the serotonergic system is activated, and thereby voiding is blocked. In healthy people, continence is usually underpinned by hippocampal formation (circuit 3). In order to advance knowledge of how serotoninergic neurons and additional nerve fibers were correlated, the purpose of the present work was to research how the discharge of serotonin from hippocampal slices was affected by different neurotransmitters in rat models.

Methods

The adopted procedure involved administration of the central neurotransmitters acetylcholine, norepinephrine, dopamine, N-methyl-D-aspartate (NMDA), gamma-aminobutyric acid (GABA), glycine, and neuropeptide Y as well as monitoring of the alterations in the discharge of [³H]5-hydroxytryptamine (5-HT). Furthermore, to determine whether the effect of the neurotransmitters was influenced by interneuron, tetrodotoxin was also employed.

Results

Acetylcholine (10^-5M) did not alter [³H]5-HT discharge, whereas more 5-HT was discharged from the hippocampal slices of rats under stimulation by norepinephrine (10^-5M) as well as dopamine (10^-5M) and tetrodotoxin (10^-6M) did not inhibit the discharge. By contrast, tetrodotoxin inhibited the discharge of [³H]5-HT that was exacerbated by NMDA (10^-4M). Meanwhile, compared to control, GABA (10^-5M), glycine (10^-5M), or neuropeptide Y (10^-6M) did not alter the [³H]5-HT discharge.

Conclusions

From the research findings, it can be concluded that 5-HT discharge from rat hippocampus is enhanced by norepinephrine and dopamine through direct effect on the 5-HT neuronal terminal. By contrast, 5-HT discharge is intensified by NMDA by activating interneurons.

Psychological/mental stress-induced effects on urinary function: Possible brain molecules related to psychological/mental stress-induced effects on urinary function

Exposure to psychological/mental stress can affect urinary function, and lead to and exacerbate lower urinary tract dysfunctions. There is increasing evidence showing stress-induced changes not only at phenomenological levels in micturition, but also at multiple levels, lower urinary tract tissues, and peripheral and central nervous systems. The brain plays crucial roles in the regulation of the body's responses to stress; however, it is still unclear how the brain integrates stress-related information to induce changes at these multiple levels, thereby affecting urinary function and lower urinary tract dysfunctions. In this review, we introduce recent urological studies investigating the effects of stress exposure on urinary function and lower urinary tract dysfunctions, and our recent studies exploring "pro-micturition" and "anti-micturition" brain molecules related to stress responses. Based on evidence from these studies, we discuss the future directions of central neurourological research investigating how stress exposure-induced changes at peripheral and central levels affect urinary function and lower urinary tract dysfunctions. Brain molecules that we explored might be entry points into dissecting the stress-mediated process for modulating micturition.

Exploratory pilot study of exogenous sustained-release melatonin on nocturia in Parkinson's disease

INTRODUCTION

Nocturia is one of the commonest non-motor symptoms in Parkinson's disease (PD). Nocturia has evolved from being understood as a symptom of urological disorders or neurogenic bladder dysfunction to being considered as a form of circadian dysregulation. Exogenous melatonin is known to help circadian function and can be an effective strategy for nocturia in PD.

METHODS

In this open-label, single-site, exploratory, phase 2 pilot study, adults with PD and nocturia underwent assessments using standardized questionnaires, urodynamics studies and a bladder scan. This was followed by completion of a frequency volume chart (FVC) and 2-week sleep diary. Sustained-release melatonin 2 mg was then administered once-nightly for 6 weeks. A repeat assessment using questionnaires, the FVC and sleep diary was performed whilst on treatment with melatonin. Companion or bed partners filled in sleep questionnaires to assess their sleep during the intervention.

RESULTS

Twenty patients (12 males; mean age 68.2 [SD = 7.8] years; mean PD duration 8.0 [±5.5] years) with PD reporting nocturia were included. Administration of melatonin was associated with a significant reduction in the primary outcome bother related to nocturia measured using the International Consultation on Incontinence Questionnaire Nocturia (ICIQ-N) (p = 0.01), number of episodes of nocturia per night (p = 0.013) and average urine volume voided at night (p = 0.013). No serious adverse events were reported. No significant improvement was noted in bed partner sleep scores.

CONCLUSIONS

In this preliminary open-label study, administration of sustained-release melatonin 2 mg was found to be safe for clinical use and was associated with significant improvements in night-time frequency and nocturnal voided volumes in PD patients.

Therapeutic Effects of Prolonged Release Melatonin (Circadin®) in Patients with Overactive Bladder and Chronic Insomnia in More Than 55 Years Old

Objectives Bladder storage symptoms including nocturia is the most common cause of sleep disturbance in all age groups. Sleep disturbance is also a main cause of nocturia so that sleep recovery can clinically improve nocturia. Melatonin has main action to induce sleep and additional effects of smooth muscle relaxation, free radical scavenging, anti-inflammation, et cetera. This study was evaluated the improvement of sleep quality after administrating prolonged-release melatonin in elderly patients with overactive bladder and chronic insomnia. Methods This clinical trial was performed with a randomized single open study. Thirty-seven patients with overactive bladder and chronic insomnia were initially enrolled in this study. After 4 or 12 weeks treating with 2 mg of prolonged-release melatonin, clinical outcomes were evaluated with OABSS, IPSS, PSQI and WHO 5 well-being index. Results Of the 37 patients, 34 (91.9%) were included in the ITT group and 26 (76.5%) in the PP group. In the primary outcome of PP group, significant improvements were observed in total OABSS and nocturia frequencies at 12 weeks, respectively. Secondary outcome measurement including in voiding, storage symptoms, and total IPSS scores showed the improvement at 4 and 12 weeks and in total and sleep quality PSQI scores at 12 weeks, and in quality of life scores of the WHO 5 well-being index at 12 weeks. Only one (3.8%) adverse event was observed. Conclusions These results suggest clearly that prolonged-release melatonin in elderly patients with overactive bladder and chronic insomnia has the potential to control concomitant voiding and sleep difficulty.

Meta-Analysis of the Efficacy and Safety of Imidafenacin for Overactive Bladder Induced by Benign Prostatic Hyperplasia in Men Receiving Alpha-Blocker Therapy

PURPOSE

The aim of this meta-analysis was to evaluate the efficacy and safety of imidafenacin for overactive bladder (OAB) induced by benign prostatic hyperplasia (BPH) in men receiving alpha-blocker monotherapy.

METHODS

We performed a systematic research of the PubMed, Embase, and Cochrane Library databases, and searched for studies about alpha-blocker with or without imidafenacin treatment for OAB in patients with BPH. We also investigated the original references of the included texts.

RESULTS

Four randomized controlled trials including 779 participants with BPH (389 in the alpha-blocker+imidafenacin group and 390 in the alpha-blocker only group) were studied. The main efficacy endpoint was the Overactive Bladder Symptom Score, which showed a mean difference of -1.88 (95% confidence interval, -2.32 to -1.44; P<0.00001), suggesting that alpha-blocker and imidafenacin treatment was effective in treating men with OAB. As other primary efficacy end points, the International Prostate Symptom Score (IPSS) total score (P=0.47), the IPSS storage symptom score (P=0.07), the IPSS voiding symptom score (P=0.60), and the IPSS quality of life score (P=0.18) indicated that 2 methods had no significant differences in treating men with OAB. In terms of safety, which was assessed using postvoid residual volume (P=0.05) and maximum flow rate (P=0.53), the analysis suggested that combination treatment was very well tolerated.

CONCLUSION

This study suggested that imidafenacin plus alpha-blocker was an efficacious and safe treatment for OAB symptoms in BPH patients.

Altered metabolic and hormonal responses in male rats exposed to acute bright light-at-night associated with global DNA hypo-methylation

The association between light pollution and disruption of daily rhythms, metabolic and hormonal disorders, as well as cancer progression is well-recognized. These adverse effects could be due to nocturnal melatonin suppression. The signaling pathway by which light pollution affects metabolism and endocrine responses is unclear. We studied the effects of artificial light at night (ALAN¹) on body mass, food and water intake, daily rhythms of body temperature, serum glucose and insulin in male rats. Daily rhythms of urine production and urinary 6-sulfatoxymelatonin (6-SMT²), as well as global DNA methylation in pancreas and liver tissues were also assessed. Mass gain was higher in ALAN rats compared with controls. Food intake, water consumption, glucose, insulin, and 6-SMT levels markedly lessened in response to ALAN. Conversely, urine production and body temperature were elevated in ALAN rats compared with controls. Significant 24-h rhythms were detected for all variables that were altered in mesor, amplitude, and acrophase occurrences under ALAN conditions. DNA hypo-methylation was detected in ALAN pancreatic tissue compared with controls, but not in hepatic tissue. Overall, ALAN affects metabolic and hormonal physiology in different levels in which flexible crosstalk between melatonin and both epigenetics and metabolic levels expressed as body temperature rhythm, is suggested to mediate the environmental exposure at the molecular level and subsequently physiology is altered. The flexibility of epigenetic modifications provides a potential therapeutic target for rectifying ALAN adverse effects by epigenetic markers such as melatonin and behavioral lifestyle interventions for confining ALAN exposures as much as possible.

Melatonin as a Treatment after Traumatic Brain Injury: A Systematic Review and Meta-Analysis of the Pre-Clinical and Clinical Literature

Traumatic brain injury (TBI) is common; however, effective treatments of the secondary brain injury are scarce. Melatonin is a potent, nonselective neuroprotective and anti-inflammatory agent that is showing promising results in neonatal brain injury. The aim of this study was to systematically evaluate the pre-clinical and clinical literature on the effectiveness of melatonin in improving outcome after TBI. Using the systematic review protocol for animal intervention studies (SYRCLE) and Cochrane methodology for clinical studies, a search of English-language articles was performed. Eligible studies were identified and data were extracted. Quality assessment was performed using the SYRCLE risk of bias tool. Meta-analyses were performed using standardized mean differences (SMD). Seventeen studies (15 pre-clinical, 2 clinical) met inclusion criteria. There was heterogeneity in the studies, and all had moderate-to-low risk of bias. Meta-analysis of pre-clinical data revealed an overall positive effect on neurobehavioural outcome with SMD of 1.51 (95% CI: 1.06-1.96). Melatonin treatment had a favorable effect on neurological status, by an SMD of 1.35 (95% CI: 0.83-1.88), and on cognition by an SMD of 1.16 (95% CI: 0.4-1.92). Melatonin decreased the size of the contusion by an SMD of 2.22 (95% CI: 0.8--3.59) and of cerebral edema by an SMD of 1.91 (95% CI: 1.08-2.74). Only two clinical studies were identified. They were of low quality, were used for symptom management, and were of uncertain significance. In conclusion, there is evidence that melatonin treatment after TBI significantly improves both behavioral outcomes and pathological outcomes; however, significant research gaps exist, especially in clinical populations.

Angiotensin II, a stress-related neuropeptide in the CNS, facilitates micturition reflex in rats

BACKGROUND AND PURPOSE

We investigated the effects of centrally administered stress-related neuropeptide, angiotensin II, on the micturition reflex and the downstream signalling pathways in rats.

EXPERIMENTAL APPROACH

Male Wistar rats were anaesthetized with urethane for cystometry before and after i.c.v. administration of vehicle or angiotensin II (30 pmol). Muscimol (a GABA_A receptor agonist) or baclofen (a GABA_B receptor agonist) was i.c.v. administered 30 min before or 15 min after central angiotensin II administration. Telmisartan [an angiotensin II type 1 (AT₁ ) receptor antagonist], valsartan (an AT₁ receptor antagonist), PD123319 (an AT₂ receptor antagonist), U-73122 (a PLC inhibitor), chelerythrine chloride (a PKC inhibitor), apocynin (a NADPH oxidase inhibitor) or tempol (an antioxidant) was centrally administered 30 min before central angiotensin II administration.

KEY RESULTS

Centrally administered angiotensin II significantly shortened the intercontraction interval and decreased the voided volume and bladder capacity without altering the maximum voiding pressure, post-voiding residual urine volume or voiding efficacy. Muscimol, baclofen, telmisartan, valsartan, U-73122, chelerythrine chloride, apocynin or tempol pretreatment significantly suppressed the reduction in intercontraction interval induced by central angiotensin II. Post-treatment with muscimol or baclofen also ameliorated the decrease in intercontraction interval induced by central angiotensin II.

CONCLUSIONS AND IMPLICATIONS

Angiotensin II in the CNS facilitates micturition reflex by inhibiting central GABAergic activity and activating the AT₁ receptor/PLC/PKC/NADPH oxidase/superoxide anion pathway.

Psychological and Physical Environmental Factors in the Development of Incontinence in Adults and Children: A Comprehensive Review

The aim of this review was to identify etiological environmental factors related to incontinence in children and adults. A variety of etiological environmental factors for the development of incontinence were identified. In children, these encompass stressful life events and trauma, family dysfunction, parental psychopathology, school-related stressors, toilet or "potty" training, fluid consumption habits, housing conditions, and the availability of toilets. In adults, physical exercise, obesity, working conditions, fluid intake, and the availability of toilets play a role. Intervening variables such as hormonal variations due to work shifts have also been identified as influencing the likelihood of incontinence. Current research suggests that environmental factors influence the development of incontinence in children and adults. The interactions between biological factors, the immediate environment, and intervening variables need to be explored in greater detail. Practical solutions to reduce barriers to adequate fluid intake and healthy toileting habits should be implemented in school and work settings.

Nocturia in Parkinson's Disease: Why Does It Occur and How to Manage?

BACKGROUND

Nocturia is one of the commonest nonmotor symptoms in Parkinson's disease (PD) and has a significant impact on quality of life both for patients and their carers. There exists a relation between nocturia and poor sleep quality, falls, and institutionalization. Nocturia may manifest as a result of reduced functional bladder capacity or nocturnal polyuria; however, most often the cause is multifactorial. Disorders of circadian rhythm regulation are known to occur with sleep disturbances in PD may also contribute to nocturia.

METHODS AND RESULTS

In this review, an overview of the assessment and management of nocturia in patients with PD is presented. History taking, medication review, and a bladder diary form the cornerstone of the evaluation. Urinalysis, ultrasonography, and urodynamic studies help to assess the cause for lower urinary tract symptoms and exclude concomitant pathologies, such as bladder outlet obstruction. Antimuscarinic medications are the first-line treatment for the overactive bladder; however, caution is needed when using these medications in individuals predisposed to cognitive impairment. Desmopressin is effective for managing nocturnal polyuria.

CONCLUSIONS

An individualized approach is recommended to optimize the management of nocturia in PD.

Melatonin and Its Role in Lower Urinary Tract Function: An Article Review

This article reviewed the results of studies done on animals that assessed effects of melatonin on bladder function. Melatonin does not change strip relaxation on its own. However, pre-treatment with melatonin decreases contractile responses induced by phenylephrine, acetylcholine, bethanechol and KCl in a dose-dependent manner. The contractile responses induced by the direct calcium channel openers are significantly decreased by melatonin pre-treatment. It also binds to Ca(2+)-activated calmodulin, and prevents it from activating myosin light-chain kinase. It may have direct effects on ion channels which are responsible for regulating bladder contraction. Its other mode of action on bladder occurs via the brain GABAA receptor. Melatonin is an antioxidant. In bladder, treatment with melatonin prevents elevations in malondialdehyde levels, reverses changes in glutathione levels, and decreases myeloperoxidase levels compared with oxidative injury. It can normalize age induced bladder dysfunction through its antioxidant effects, inhibiting smooth muscle contractility directly and restoring impaired contractility via normalization of Ca(2+) handling and sensitizations pathways. It attenuates the severity of cystitis and inflammation. Mast cell proliferation and activation are increased in cystitis, but decrease by melatonin treatment. Also, there is a decrease in expression levels of pro-inflammatory cytokines after melatonin treatment.

Neural control of the lower urinary tract

This article summarizes anatomical, neurophysiological, pharmacological, and brain imaging studies in humans and animals that have provided insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract. The functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. The neural control of micturition is organized as a hierarchical system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brain stem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brain stem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary micturition, leading to urinary incontinence. Neuroplasticity underlying these developmental and pathological changes in voiding function is discussed.

Relationship between asymmetric dimethylarginine and nocturia in the general elderly population: The HEIJO-KYO cohort

AIMS

To evaluate the relationship between asymmetric dimethylarginine (ADMA) and nocturia.

METHODS

A total of 862 community-based elderly individuals were examined in this cross-sectional study (mean age, 72.1 years). We measured nocturnal void frequency and serum ADMA levels. Nocturia was ascertained for a frequency of two or more nocturnal voids.

RESULTS

Nocturia was observed in 262 (30.4%) participants. Univariate logistic regression models revealed a significant association between prevalent nocturia and ADMA levels (crude odds ratio [OR], 1.556 [2nd vs. 1st tertile]; 95% confidence interval [CI], 1.066-2.270; P = 0.022; crude OR, 2.114 [3rd vs. 1st tertile]; 95% CI, 1.453-3.072; P < 0.001). Univariate logistic regression models also revealed marginal to significant associations between prevalent nocturia and age, gender, calcium channel blocker use, nitric oxide-related drug use, diabetes, estimated glomerular filtration rate, insomnia, benign prostatic hyperplasia, overnight urine volume, and endogenous melatonin levels. In the multivariate model simultaneously adjusted for the former variables, higher ADMA levels were significantly associated with higher OR for nocturia (adjusted OR, 1.556 [3rd vs. 1st tertiles]; 95% CI, 1.010-2.397; P = 0.045).

CONCLUSION

Serum ADMA levels, an endogenous inhibitor of nitric oxide synthase, are significantly associated with prevalent nocturia in the general elderly population.

Role of spinal GABAA receptors in pudendal inhibition of nociceptive and nonnociceptive bladder reflexes in cats

Picrotoxin, an antagonist for γ-aminobutyric acid receptor subtype A (GABAA), was used to investigate the role of GABAA receptors in nociceptive and nonnociceptive reflex bladder activities and pudendal inhibition of these activities in cats under α-chloralose anesthesia. Acetic acid (AA; 0.25%) was used to irritate the bladder and induce nociceptive bladder overactivity, while saline was used to distend the bladder and induce nonnociceptive bladder activity. To modulate the bladder reflex, pudendal nerve stimulation (PNS) was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. AA irritation significantly (P < 0.01) reduced bladder capacity to 34.3 ± 7.1% of the saline control capacity, while PNS at 2T and 4T significantly (P < 0.01) increased AA bladder capacity to 84.0 ± 7.8 and 93.2 ± 15.0%, respectively, of the saline control. Picrotoxin (0.4 mg it) did not change AA bladder capacity but completely removed PNS inhibition of AA-induced bladder overactivity. Picrotoxin (iv) only increased AA bladder capacity at a high dose (0.3 mg/kg) but significantly (P < 0.05) reduced 2T PNS inhibition at low doses (0.01-0.1 mg/kg). During saline cystometry, PNS significantly (P < 0.01) increased bladder capacity to 147.0 ± 7.6% at 2T and 172.7 ± 8.9% at 4T of control capacity, and picrotoxin (0.4 mg it or 0.03-0.3 mg/kg iv) also significantly (P < 0.05) increased bladder capacity. However, picrotoxin treatment did not alter PNS inhibition during saline infusion. These results indicate that spinal GABAA receptors have different roles in controlling nociceptive and nonnociceptive reflex bladder activities and in PNS inhibition of these activities.

Incontinence in individuals with Angelman syndrome: a comparative study

Frequency and type of incontinence and variables associated with incontinence were assessed in individuals with Angelman syndrome (AS; n=71) and in a matched control group (n=69) consisting of individuals with non-specific intellectual disability (ID). A Dutch version of the "Parental Questionnaire: Enuresis/Urinary Incontinence" (Beetz, von Gontard, & Lettgen, 1994) was administered and information on primary caretakers' perspectives regarding each individual's incontinence was gathered. Results show that diurnal incontinence and fecal incontinence during the day more frequently occurred in the control group than in the AS group. In both groups, nocturnal enuresis was the most common form of incontinence. More incontinence was seen in individuals with AS who were younger, had a lower level of adaptive functioning and/or had epilepsy. Individuals with AS were able to stay dry for longer periods of time than the controls and often showed both in-toilet urination and urinary accidents during the day, whereas accidents and correct voids during the day were more set apart in the control group. Also, persons with AS had a lower micturition frequency implying possible voiding postponement. Both groups showed high rates of LUTS (lower urinary tract symptoms) possibly indicative of functional bladder disorders such as voiding postponement, dysfunctional voiding, or even an underactive bladder. In general, most primary caretakers reported severe intellectual disability as the main cause for urinary incontinence. Based on these results incontinence does not appear to be part of the behavioral phenotype of Angelman syndrome. Therefore, pediatric or urologic diagnostics and treatment are recommended for all persons with incontinence and intellectual disability. Further implications for practice and research are given.

Antidiuretic effect of antimuscarinic agents in rat model depends on C-fibre afferent nerves in the bladder

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Antichollnergic agents are anticipated to diminish storage symptoms, as well as nocturia. Nevertheless, the effect of this treatment on polyuria related to nocturia is not clear. By subgroup analysis of the data set from a phase III clinical trial of antimuscarinic agent for OAB patients in Japan, imidafenacin was found to improve nocturia with a reduction in nocturnal polyuria. This study adds the effects and underlying mechanism of antimuscarinic agents decreasing urine production through inhibition of C-fibre in the bladder of water-leaded rats.

OBJECTIVE

To evaluate the effects and underlying mechanisms of antimuscarinic agents used to decrease in urine production in water-loaded rats.

SUBJECTS AND METHODS

Urine production was measured using a cystostomy catheter in female Sprague-Dawley rats every 2 h. The effect of the antimuscarinic agents atropine, tolterodine and imidafenacin on urine production was investigated under water-loaded conditions, which were induced by i.p. injection of 15 mL saline. Blood samples were collected to determine the levels of antidiuretic hormone (ADH), aldosterone (ALD), atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) before, and 2 and 8 h after, antimuscarinic agent administration. To induce desensitization of C-fibre afferent nerves, resiniferatoxin (RTX)was injected s.c. or intravesically 2 days before experiments.

RESULTS

Urine production increased and reached its maximum 2 h after 15 mL saline injection. Imidafenacin and tolterodine decreased urine production in water-loaded rats, but ADH, ALD, ANP and BNP levels were not different between imidafenacin-treated and vehicle-treated rats. The inhibitory effect on urine production was not found in RTX-treated rats. Atropine did not reduce urine production.

CONCLUSION

These results suggest that antimuscarinic agents decrease urine volume through C-fibres in the bladder; thus, antimuscarinics with inhibitory effects on C-fibres could be beneficial for nocturia with nocturnal polyuria.

Efficacy of Ramelteon in Patients with Insomnia and Nocturia

OBJECTIVES

To study the efficacy of ramelteon for patients with insomnia and nocturia.

METHODS

Forty-nine patients experiencing insomnia and two or more nocturnal voids were included. The degree of lower urinary tract symptoms and sleep disorders was evaluated using the International Prostate Symptom Score (IPSS), Pittsburg Sleep Quality Index (PSQI)(1) score, and frequency/volume chart (FVC). The patients were treated with ramelteon (8 mg) for four weeks and then reexamined by questionnaire and FVC to evaluate the therapeutic efficacies.

RESULTS

The mean IPSS score was 16.1 ± 6.9 at baseline and 12.4 ± 7.1 at four weeks. The subject scores for the number of nocturnal voids also decreased significantly from 3.3 ± 0.9 to 2.9 ± 1.0. In addition, PSQI scores improved significantly from 7.4 ± 2.9 to 5.4 ± 2.8. According to the FVC, the number of nocturnal voids decreased significantly from 3.1 ± 1.2 at baseline to 2.2 ± 1.1 at four weeks, and nighttime bladder capacity improved significantly from 181.4 ± 79.9 to 201.1 ± 93.7 mL.

CONCLUSION

Ramelteon alleviated nocturia and disturbed sleep in patients with insomnia and nocturia and led to increased nighttime bladder capacity.

A novel pathway underlying the inhibitory effects of melatonin on isolated rat urinary bladder contraction

The aim of the present study was to elucidate the direct effects of melatonin on bladder activity and to determine the mechanisms responsible for the detrusor activity of melatonin in the isolated rat bladder. We evaluated the effects of melatonin on the contractions induced by phenylephrine (PE), acetylcholine (ACh), bethanechol (BCh), KCl, and electrical field stimulation (EFS) in 20 detrusor smooth muscle samples from Sprague-Dawley rats. To determine the mechanisms underlying the inhibitory responses to melatonin, melatonin-pretreated muscle strips were exposed to a calcium channel antagonist (verapamil), three potassium channel blockers [tetraethyl ammonium (TEA), 4-aminopyridine (4-AP), and glibenclamide], a direct voltage-dependent calcium channel opener (Bay K 8644), and a specific calcium/calmodulin-dependent kinase II (CaMKII) inhibitor (KN-93). Melatonin pretreatment (10^-8~10^-6 M) decreased the contractile responses induced by PE (10^-9~10^-4 M) and Ach (10^-9~10^-4 M) in a dose-dependent manner. Melatonin (10^-7 M) also blocked contraction induced by high KCl ([KCl]_ECF; 35 mM, 70 mM, 105 mM, and 140 mM) and EFS. Melatonin (10^-7 M) potentiated the relaxation response of the strips by verapamil, but other potassium channel blockers did not change melatonin activity. Melatonin pretreatment significantly decreased contractile responses induced by Bay K 8644 (10^-11~10^-7 M). KN-93 enhanced melatonin-induced relaxation. The present results suggest that melatonin can inhibit bladder smooth muscle contraction through a voltage-dependent, calcium-antagonistic mechanism and through the inhibition of the calmodulin/CaMKII system.