Efficacy of Tadalafil Therapy and Changes in Oxidative Stress Levels in Male Patients with Lower Urinary Tract Symptoms and Overactive Bladder

Tadalafil Ameliorates Chronic Ischemia-Associated Bladder Overactivity in Fructose-Fed Rats by Exerting Pelvic Angiogenesis and Enhancing p-eNOS Expression

Metabolic syndrome (MetS) can contribute to a chronic ischemia-relative overactive bladder (OAB). Using fructose-fed rats (FFRs), a rat model of MetS, we investigated the effects of tadalafil (a phosphodiesterase-5 inhibitor) on MetS-associated chronic bladder ischemia and bladder overactivity. Phenotypes of the OAB, including increased micturition frequency and a shortened intercontractile interval in cystometry, were observed in FFRs, together with reduced bladder blood perfusion (in empty bladders) via laser color Doppler imaging and elevated serum nitrite levels, suggesting chronic ischemia-related bladder dysfunction. Treatment with tadalafil (2 mg/kg) promoted pelvic angiogenesis, as shown by magnetic resonance imaging, and increased VEGF and p-eNOS overexpression in the bladder. This treatment restored bladder perfusion and alleviated bladder overactivity without significantly altering most MetS parameters. At the molecular level, FFRs exhibited increased ischemia markers (NGF, HIF-2α, and AMPK-α2) and decreased p-AMPK-α2, along with elevated proinflammatory mediators (ICAM-1, nuclear NF-κB, COX-2, IL-1β, IL-6, and TNF-α), enhanced mitochondria biogenesis (PGC-1α, TFAM, and mitochondria DNA copy number), oxidative stress (decreased nuclear NRF2, increase MnSOD and 8-OHdG staining), and tissue fibrosis (increased TGF-β1, collagen I, and fibronectin). Tadalafil treatment improved these effects. Together, these findings suggest that tadalafil may promote VEGF-associated angiogenesis, enhance p-eNOS staining in the bladder vasculature, normalize bladder perfusion in microcirculation, and reduce serum nitrite levels. Consequently, tadalafil mitigates the adverse effects of chronic ischemia/hypoxia, improving bladder overactivity. We elucidated the mechanisms underlying the tadalafil-mediated amelioration of MetS-associated OAB symptoms.

A Brief Overview of Cholinergic and Phosphodiesterase-5 Inhibitors in Diabetic Bladder Dysfunction

Diabetic bladder dysfunction (DBD) comprises a wide spectrum of lower urinary tract symptoms that impact diabetic patients' lives, including urinary frequency, urgency, incontinence, and incomplete bladder emptying. To relieve symptoms, anticholinergics have been widely prescribed and are considered an effective treatment. There is increasing evidence that diabetic patients may benefit from the use of phosphodiesterase 5 (PDE5) inhibitors. This narrative review aims to provide a brief overview of the pathophysiology of DBD along with a focus on cholinergic and phosphodiesterase inhibitors as therapies that benefit DBD. An examination of the literature suggests compelling avenues of research and underscores critical gaps in understanding the mechanisms underlying DBD. New tools and models, especially rodent models, are required to further elucidate the mechanisms of action of current therapies in the treatment of DBS.

Preliminary evidence for therapeutic impact of intravesical glucosamine on protamine sulfate and potassium chloride-induced bladder overactivity in rat model

PURPOSE

To investigate the protective effect of intravesical glucosamine in treating overactive bladder (OAB).

METHODS

Ninety-two female Sprague-Dawley (SD) rats were divided into 4 groups i.e. protamine sulfate (PS), N-acetylcysteine (NAC), and glucosamine-treated PS (GPS), and normal saline control (NC) were used. We induced hyperactivity in rats via intravesical infusion of PS and potassium chloride (KCl), whereas the NC group underwent a sustained intravesical saline infusion for 1 h. N-acetylcysteine (NAC), a potential antioxidant as well as anti-inflammatory agent was employed as positive control. Cystometrography (CMG) was then conducted to determine urodynamic parameters, i.e., leak point pressure (LPP, n = 48) and inter-contractile interval, the duration between two voids (ICI, n = 32).

RESULTS

LPP was significantly elevated in the GPS group (mean ± SD: 110.9 ± 6.2 mmHg) compared to the NC (81.0 ± 32.5 mmHg), PS (40.3 ± 10.9 mmHg), and NAC group (70.3 ± 19.4 mmHg). The cystometrogram data also reveals a prolonged ICI in the GPS group (241.3 ± 40.2 s) compared to the NC group (216.0 ± 41.7 s), PS group (128.8 ± 23.6 s), and NAC group (193.8 ± 28.3 s).

CONCLUSION

This preliminary study implies the ameliorative impact of GPS treatment on OAB in terms of improved urodynamic parameters, including LPP and ICI.

Current and Emerging Pharmacological Targets and Treatments of Urinary Incontinence and Related Disorders

Overactive bladder syndrome with and without urinary incontinence and related conditions, signs, and disorders such as detrusor overactivity, neurogenic lower urinary tract dysfunction, underactive bladder, stress urinary incontinence, and nocturia are common in the general population and have a major impact on the quality of life of the affected patients and their partners. Based on the deliberations of the subcommittee on pharmacological treatments of the 7th International Consultation on Incontinence, we present a comprehensive review of established drug targets in the treatment of overactive bladder syndrome and the aforementioned related conditions and the approved drugs used in its treatment. Investigational drug targets and compounds are also reviewed. We conclude that, despite a range of available medical treatment options, a considerable medical need continues to exist. This is largely because the existing treatments are symptomatic and have limited efficacy and/or tolerability, which leads to poor long-term adherence. SIGNIFICANCE STATEMENT: Urinary incontinence and related disorders are prevalent in the general population. While many treatments have been approved, few patients stay on long-term treatment despite none of them being curative. This paper provides a comprehensive discussion of existing and emerging treatment options for various types of incontinence and related disorders.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

The pressure flow study investigation of pathophysiology of post-micturition dribble in male patients

PURPOSE

In this study, we aimed to elucidate the pathophysiology of post-micturition dribble (PMD) through analyzing several variables including pressure flow study (PFS) findings and symptoms questionnaire.

METHODS

We retrospectively analyzed male patients who visited our department between 2010 and 2020. We used modified international prostate symptom score (m-IPSS), which consists of eight sub-score related to lower urinary tract symptoms (Incomplete Emptying, Frequency, Intermittency, Urgency, Weak Stream, Straining, Nocturia, and PMD) and one question related to quality of life (QOL). Multivariate regression analysis was conducted to evaluate the relationship between PMD and the variables, including age, prostate volume (PV), body mass index, bladder outlet obstruction index (BOOI), bladder contractility index, and bladder voiding efficiency, which were obtained by PFS.

RESULTS

A total of 143 male patients were analyzed. The patients with PMD showed significantly larger PV and higher BOOI, and worse IPSS total and QOL score than those without PMD. Multivariate regression analysis showed that large PV and BOOI were significantly associated with PMD. In Spearman's correlation analysis, PMD and each m-IPSS sub-score except nocturia had significant positive correlation. Furthermore, Spearman's correlation analysis showed that PMD and QOL had significant strong positive correlation.

CONCLUSION

PMD was significantly associated with large PV and BOO evaluated by PFS. Furthermore, PMD significantly exacerbated QOL. The severity of PMD and the other m-IPSS sub-score except nocturia could have intercorrelation with each other.

Established and emerging treatments for diabetes-associated lower urinary tract dysfunction

Dysfunction of the lower urinary tract (LUT) including urinary bladder and urethra (and prostate in men) is one of the most frequent complications of diabetes and can manifest as overactive bladder, underactive bladder, urinary incontinence, and as aggravated symptoms of benign prostate hyperplasia. We have performed a selective literature search to review existing evidence on efficacy of classic medications for the treatment of LUT dysfunction in diabetic patients and animals, i.e., α1-adrenoceptor and muscarinic receptor antagonists, β3-adrenoceptor agonists, and phosphodiesterase type 5 inhibitors. Generally, these agents appear to have comparable efficacy in patients and/or animals with and without diabetes. We also review effects of antidiabetic medications on LUT function. Such studies have largely been performed in animal models. In the streptozotocin-induced models of type 1 diabetes, insulin can prevent and reverse alterations of morphology, function, and gene expression patterns in bladder and prostate. Typical medications for the treatment of type 2 diabetes have been studied less often, and the reported findings are not yet sufficient to derive robust conclusions. Thereafter, we review animal studies with emerging medications perhaps targeting diabetes-associated LUT dysfunction. Data with myoinositol, daidzein, and with compounds that target oxidative stress, inflammation, Rac1, nerve growth factor, angiotensin II receptor, serotonin receptor, adenosine receptor, and soluble guanylyl cyclase are not conclusive yet, but some hold promise as potential treatments. Finally, we review nonpharmacological interventions in diabetic bladder dysfunction. These approaches are relatively new and give promising results in preclinical studies. In conclusion, the insulin data in rodent models of type 1 diabetes suggest that diabetes-associated LUT function can be mostly or partially reversed. However, we propose that considerable additional experimental and clinical studies are needed to target diabetes itself or pathophysiological changes induced by chronic hyperglycemia for the treatment of diabetic uropathy.

Drugs Currently Undergoing Preclinical or Clinical Trials for the Treatment of Overactive Bladder: A Review

Background

Overactive bladder (OAB) is a common clinical condition for which current drug treatment comprises drugs blocking the cholinergic nerve supply, or augmenting the adrenergic nerve supply, to the detrusor muscle of the urinary bladder. Current treatments have drawbacks, including lack of efficacy and the development of adverse effects in some patients. Hence, new and better drugs for treating OAB will be clinically useful.

Objective

This review is meant to provide information on drugs currently undergoing preclinical or clinical trials for the treatment of OAB published in journal articles or elsewhere.

Methods

The cited articles were retrieved from PubMed and Google Scholar from January 1, 1990, to December 31, 2021. The search terms used were contraction or contractility, detrusor, inhibition, isolated or in vitro, in vivo, overactive bladder, and relaxant effect or relaxation.

Results

There are 4 classes of new drugs under various stages of development for the treatment of OAB. These are drugs acting on the autonomic nerve supply to the detrusor muscle of the urinary bladder that include the anticholinergics tarafenacin and afacifenacin and the β₃ adrenoceptor agonists solabegron and ritobegron; drugs acting on ion channels in the detrusor muscle (eg, potassium channel openers and calcium channel blockers), drugs acting on cellular enzymes like phosphodiesterase-5 inhibitors and Rho kinase inhibitors, and drugs acting on miscellaneous targets (eg, pregabalin and trimetazidine).

Conclusions

Drugs currently used to treat OAB target only the cholinergic and adrenergic cellular signalling pathways. There are many other drugs under trial targeting other cellular pathways that may be useful for treating OAB. Their approval for clinical use might improve the treatment of patients with OAB. (Curr Ther Res Clin Exp. 2022; 83:XXX–XXX)

Serum Copper and Zinc Levels and Urinary Incontinence in Adult Women

Recent findings show that oxidative damage may contribute to lower urinary tract symptoms. Copper can induce oxidative stress while zinc is involved in the defense against oxidative stress. We examined the associations between serum copper and zinc levels and urinary incontinence (UI) in adult women. Data were retrieved from the 2011-2016 National Health and Nutrition Examination Surveys. Outcomes for multivariate logistic regression were any UI (AUI), urge UI (UUI), stress UI (SUI), mixed UI (MUI), and moderate/severe UI. Questions on urinary incontinence were asked by trained interviewers. The weighted UI prevalences were 44.89% for AUI, 28.12% for UUI, 41.64% for SUI, 17.27% for MUI, and 20.79% for moderate/severe UI in adult women. After adjusting for multiple factors, serum copper levels in the highest quartile were associated with UUI [odds ratios (95% confidence intervals): 1.74 (1.11-2.74)]. In women older than 50 years, serum copper levels in the highest quartile were associated with UUI [2.94 (1.57-5.49)], AUI [1.97 (1.19-3.27)], MUI [2.43 (1.19-4.97)], and moderate/severe UI [2.37 (1.06-5.31)]. Serum copper levels in the second quartile were also associated with MUI overall [1.75 (1.03-2.97)] and in young women (20-49 years) [2.29 (1.02-5.17)]. Positive associations were also found between serum copper levels and UUI in non-obese women. There were no associations between serum zinc levels and UI outcomes. Serum copper levels were associated with UUI, MUI, AUI, and moderate/severe UI in adult women, especially women older than 50 years. Causality deserves to be confirmed further.

Excessive accumulation of visceral fat is associated with lower urinary symptoms including overactive bladder in female patients

Objective

To assess the relationship between visceral fat accumulation and lower urinary tract symptoms in female patients.

Methods

In this single‐center study, we enrolled all women who underwent screening abdominal computed tomography 3 months before the study, irrespective of whether they experienced lower urinary tract symptoms. The Overactive Bladder Symptom Score was used to assess subjective symptoms. Uroflowmetry and ultrasound assessment of post‐void residual urine were carried out to assess objective signs. We analyzed the relationship between lower urinary tract symptoms and various body fat accumulation parameters, including visceral fat area, visceral fat volume and total abdominal fat volume, assessed using computed tomography scans.

Results

A total of 182 patients were divided into the overactive bladder (n = 71, 39.0%) and the non‐overactive bladder (n = 111, 61.0%) groups. The visceral fat area, visceral fat volume and visceral fat volume/total abdominal fat volume values were all significantly higher in the overactive bladder group than in the non‐overactive bladder group (P < 0.001). Of these parameters, the visceral fat volume/total abdominal fat volume ratio showed the strongest correlation with the total Overactive Bladder Symptom Score (r = 0.394, P < 0.001). The maximum urine flow rate correlated negatively with the visceral fat volume/total abdominal fat volume value (visceral fat volume/total abdominal fat volume r = –0.289, P < 0.001). Subsequent multivariate analysis showed that a high visceral fat volume/total abdominal fat volume value, age and metabolic syndrome‐related diseases were independent risk factors for the presence of overactive bladder.

Conclusions

Excessive accumulation of visceral fat is independently associated with overactive bladder in females.

Efficacy of Tadalafil Therapy and Changes in Oxidative Stress Levels in Male Patients with Lower Urinary Tract Symptoms and Overactive Bladder

Objective

To evaluate the effects of tadalafil monotherapy on lower urinary tract symptoms, urodynamic parameters, and oxidative stress levels in male patients.

Methods

This prospective study included 53 male patients with urinary symptoms, who met the criteria for overactive bladder (OAB) (≥ 2 points for Q3 [urgency] in the OAB symptom score [OABSS] assessment and ≥ 3 points for the total score). The patients received 5 mg tadalafil orally once daily, and their symptoms were assessed before and after the 12‐week treatment. The OABSS and international prostate symptom score (IPSS) were used to evaluate the subjective symptoms. The objective findings were assessed using uroflowmetry. Oxidative stress was assessed by determining urinary levels of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) levels with an adjustment for urinary creatinine (CR) concentration.

Results

After tadalafil administration, total and individual indices of the OABSS assessment showed significant improvement. In addition, total storage and voiding symptoms that contributed to the IPSS were also significantly improved. The voided volume was increased, and the maximum flow rate was improved after tadalafil treatment (P = .002 and < 0.001, respectively). Urinary 8‐OHdG/CR decreased from 12.4 ± 9.7 ng/mg CR to 7.6 ± 11.6 ng/mg CR (P < .001). In patients who showed OAB improvement and did not meet the criteria for OAB after the treatment (44 patients, 83.0%), the urinary 8‐OHdG/CR level was significantly decreased from 11.6 ± 8.4 ng/mg CR to 6.4 ± 10.3 ng/mg CR (P < .001).

Conclusions

Tadalafil treatment improves OAB symptoms and urodynamic parameters by decreasing oxidative stress level.