Metabolic syndrome, inflammation and lower urinary tract symptoms: possible translational links

Impact of Preoperative LUTS on Health-related Quality of Life Following Radical Prostatectomy: A Propensity Score Matched Longitudinal Study

OBJECTIVE

To assess the impact of preoperative lower urinary tract symptoms (LUTS) on long-term health-related quality of life (HRQOL) up to 10 years after radical prostatectomy (RP) for prostate cancer (PC).

METHODS

Within our prospective institutional database of 6487 patients treated with RP for PC (2008-2020), 2727 patients with preoperative LUTS (IPSS score of ≥8) were identified. A 1:1 propensity-score matched analysis of 3056 men (n = 1528 LUTS, n = 1528 no LUTS) was conducted. Primary endpoint was HRQOL (based on EORTC QLQ-C30 and PR25). Linear regression models tested the effect of preoperative LUTS on the net change in general HRQOL (P <.05).

RESULTS

Median follow-up was 48 months. Preoperative mean global health status (GHS) score (67.4 vs 75.7) was significantly lower in the LUTS cohort (P <.001). Post-RP the difference in general HRQOL between the LUTS cohort and the no-LUTS cohort became smaller (65.7 vs 67.8), however, remaining statistically significant (P = .037). In long-term follow-up, general HRQOL was comparable between both subcohorts (P-range 0.716-0.876). Multivariable linear regression analysis revealed increased preoperative IPSS as an independent predictor for increased perioperative improvement of IPSS (P <.001) CONCLUSION: For patients undergoing RP, preoperative LUTS were associated with a postoperative improvement of HRQOL outcomes. In long-term follow-up, HRQOL was comparable to patients without preoperative LUTS. Hence, RP is an efficient option to treat PC as well as LUTS in those patients.

Link between circadian rhythm and benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS)

BACKGROUND

Benign prostatic hyperplasia (BPH) is the most common urologic disease in aging males, affecting 50% of men over 50 and up to 80% of men over 80 years old. Its negative impact on health-related quality of life implores further investigation into its risk factors and strategies for effective management. Although the exact molecular mechanisms underlying pathophysiological onset of BPH are poorly defined, the current hypothesized contributors to BPH and lower urinary tract symptoms (LUTS) include aging, inflammation, metabolic syndrome, and hormonal changes. These processes are indirectly influenced by circadian rhythm disruption. In this article, we review the recent evidence on the potential association of light changes/circadian rhythm disruption and the onset of BPH and impact on treatment.

METHODS

A narrative literature review was conducted using PubMed and Google Scholar to identify supporting evidence. The articles referenced ranged from 1975 to 2023.

RESULTS

A clear relationship between BPH/LUTS and circadian rhythm disruption is yet to be established. However, common mediators influence both diseases, including proinflammatory states, metabolic syndrome, and hormonal regulation that can be asserted to circadian disruption. Some studies have identified a possible relationship between general LUTS and sleep disturbance, but little research has been done on the medical management of these diseases and how circadian rhythm disruption further affects treatment outcomes.

CONCLUSIONS

There is evidence to implicate a relationship between BPH/LUTS and circadian rhythm disruptions. However, there is scarce literature on potential specific link in medical management of the disease and treatment outcomes with circadian rhythm disruption. Further study is warranted to provide BPH patients with insights into circadian rhythm directed appropriate interventions.

Association between immune-inflammatory indexes and lower urinary tract symptoms: an analysis of cross-sectional data from the US National Health and Nutrition Examination Survey (2005-2008)

OBJECTIVE

This study aimed to systematically investigate the relationship between immune-inflammatory indexes with lower urinary tract symptoms (LUTSs).

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey (NHANES) (2005-2008).

PARTICIPANTS

A total of 2709 men with complete information for immune-inflammatory indexes and LUTSs were included from NHANES 2005-2008.

OUTCOMES AND ANALYSES

Automated haematology analysing devices are used to measure blood cell counts, and LUTSs were presented by standard questionnaires. Non-linear and logistic regression analyses were used to estimate their association after adjustment for confounders.

RESULTS

Multivariate logistic regression showed that pan-immune-inflammation value (OR (95% CI)=1.60 (1.14 to 2.23)), systemic inflammation response index (SIRI) (OR (95% CI)=1.82 (1.21 to 2.73)), neutrophil/lymphocyte ratio (NLR) (OR (95% CI)=1.81 (1.31 to 2.49)), derived NLR (dNLR) (OR (95% CI)=1.91 (1.35 to 2.70)) and C reactive protein (CRP) (OR (95% CI)=1.71 (1.05 to 2.79)) was positively associated with LUTS. Additionally, composite immune-inflammation markers exhibited a stronger association with LUTS than any single index, with the ORs for high SIRI+high CRP, high NLR+high CRP and high dNLR+high CRP being 2.26, 2.44 and 2.16, respectively (all p<0.05). Furthermore, subgroup analyses revealed that age, smoking status and hypertension have different effects on the relationship between immune-inflammatory markers and LUTS.

CONCLUSIONS

This study indicated that high levels of immune-inflammatory markers were associated with an increased risk of clinical LUTS. The combination of CRP with SIRI, NLR and dNLR, respectively, showed a stronger positive correlation with clinical LUTS compared with any single index.

Do LUTS Predict Mortality? An Analysis Using Random Forest Algorithms

Purpose

To evaluate a random forest (RF) algorithm of lower urinary tract symptoms (LUTS) as a predictor of all-cause mortality in a population-based cohort.

Materials and Methods

A population-based cohort of 3143 men born in 1924, 1934, and 1944 was evaluated using a mailed questionnaire including the Danish Prostatic Symptom Score (DAN-PSS-1) to assess LUTS as well as questions on medical conditions and behavioral and sociodemographic factors. Surveys were repeated in 1994, 1999, 2004, 2009 and 2015. The cohort was followed-up for vital status until the end of 2018. RF uses an ensemble of classification trees for prediction with a good flexibility and without overfitting. RF algorithms were developed to predict the five-year mortality using LUTS, demographic, medical, and behavioral factors alone and in combinations.

Results

A total of 2663 men were included in the study, of whom 917 (34%) died during follow-up (median follow-up time 15.0 years). The LUTS-based RF algorithm showed an area under the curve (AUC) 0.60 (95% CI 0.52-0.69) for five-year mortality. An expanded RF algorithm, including LUTS, medical history, and behavioral and sociodemographic factors, yielded an AUC 0.73 (0.65-0.81), while an algorithm excluding LUTS yielded an AUC 0.71 (0.62-0.78).

Conclusion

An exploratory RF algorithm using LUTS can predict all-cause mortality with acceptable discrimination at the group level. In clinical practice, it is unlikely that LUTS will improve the accuracy to predict death if the patient's background is well known.

Pathophysiology of Overactive Bladder and Pharmacologic Treatments Including β3-Adrenoceptor Agonists -Basic Research Perspectives

Overactive bladder (OAB) is a symptom-based syndrome defined by urinary urgency, frequency, and nocturia with or without urge incontinence. The causative pathology is diverse; including bladder outlet obstruction (BOO), bladder ischemia, aging, metabolic syndrome, psychological stress, affective disorder, urinary microbiome, localized and systemic inflammatory responses, etc. Several hypotheses have been suggested as mechanisms of OAB generation; among them, neurogenic, myogenic, and urothelial mechanisms are well-known hypotheses. Also, a series of local signals called autonomous myogenic contraction, micromotion, or afferent noises, which can occur during bladder filling, may be induced by the leak of acetylcholine (ACh) or urothelial release of adenosine triphosphate (ATP). They can be transmitted to the central nervous system through afferent fibers to trigger coordinated urgency-related detrusor contractions. Antimuscarinics, commonly known to induce smooth muscle relaxation by competitive blockage of muscarinic receptors in the parasympathetic postganglionic nerve, have a minimal effect on detrusor contraction within therapeutic doses. In fact, they have a predominant role in preventing signals in the afferent nerve transmission process. β3-adrenergic receptor (AR) agonists inhibit afferent signals by predominant inhibition of mechanosensitive Aδ-fibers in the normal bladder. However, in pathologic conditions such as spinal cord injury, it seems to inhibit capsaicin-sensitive C-fibers. Particularly, mirabegron, a β3-agonist, prevents ACh release in the BOO-induced detrusor overactivity model by parasympathetic prejunctional mechanisms. A recent study also revealed that vibegron may have 2 mechanisms of action: inhibition of ACh from cholinergic efferent nerves in the detrusor and afferent inhibition via urothelial β3-AR.

The association between the metabolic score for insulin resistance (METS-IR) index and urinary incontinence in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2001-2018

BACKGROUND

The association between insulin resistance and urinary incontinence (UI) has not been investigated widely. The purpose of this study is to assess the relationship between a novel indicator for assessing insulin resistance the metabolic score for insulin resistance (METS-IR) index and urinary incontinence (UI).

METHODS

This study utilized data from National Health and Nutrition Examination Survey (NHANES) 2001-2018. Weighted multivariable logistic regression models were conducted to explore the association of METS-IR index with three types of UI [stress UI (SUI), urgency UI (UUI), and mixed UI (MUI)]. Smooth curve fitting was utilized to investigate the linear relationship. Subgroup analysis was used to examine the stability of the connection between METS-IR index and UI in different stratifications.

RESULTS

A total of 17,474 participants were included in this study, of whom 23.76% had SUI, 20.05% had UUI, and 9.59% had MUI. METS-IR index was positively associated with three types of UI with full adjustment [SUI: odds ratio (OR) = 1.023, 95% confidence interval (CI) 1.019-1.027; UUI: OR = 1.015, 95% CI 1.011-1.019; MUI: OR = 1.020, 95% CI 1.016-1.025, all p < 0.001]. After transferring METS-IR index into a categorical variable by quartiles, the positive connection between METS-IR index and UI was still observed in the highest METS-IR group compared to the lowest METS-IR interval (SUI: OR = 2.266, 95% CI 1.947-2.637, p < 0.001; UUI: OR = 1.534, 95% CI 1.344-1.750, p < 0.001; MUI: OR = 2.044, 95% CI 1.707-2.448, p < 0.001). The analysis of smooth curves fitting showed that METS-IR index was positively linearly related to three types of UI. Moreover, the association between METS-IR index and SUI was more significant in females compared to males (p for interaction < 0.05).

CONCLUSION

An elevated METS-IR index was related to increased risks of three types of UI (SUI, UUI, and MUI) in the United States population. METS-IR index was more significantly connected to SUI in females than males. The association between insulin resistance and UI needs to be explored with more studies.

Chronic Prostatitis/Chronic Pain Pelvic Syndrome and Male Infertility

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is defined as urologic pain or discomfort in the pelvic region, associated with urinary symptoms and/or sexual dysfunction, lasting for at least 3 of the previous 6 months. The rate of symptoms related to prostatitis has a mean prevalence of 8-8.2%. CP/CPPS is most frequent in men younger than 50 years, among whom it is the most common urologic diagnosis. In the last decades, many studies have been published on CP/CPPS and its association with male infertility. The pathophysiologic relation between CP/CPPS and male infertility involves several aspects, which are not well studied yet. A reduction in semen parameters has been demonstrated in patients with CP/CPPS, and several mechanisms have been proposed to represent putative pathophysiological links between CP/CPPS and infertility, including male accessory gland inflammation, metabolic syndrome, inflammatory bowel disease, HPV co-infection and autoimmunity. In light of this evidence, a multidisciplinary approach is advocated for patients with known CP/CPPS, and particular attention is needed for male patients of infertile couples in order to evaluate male accessory glands correctly. In addition, it is advisable that future studies dealing with the treatment of CP/CPPS take into consideration all the different pathophysiological aspects implicated.

Effects of Concentrated Long-Chain Omega-3 Polyunsaturated Fatty Acid Supplementation on Quality of Life after Radical Prostatectomy: A Phase II Randomized Placebo-Controlled Trial (RCT-EPA)

Prostate cancer (PCa) and associated treatments incur symptoms that may impact patients’ quality of life. Studies have shown beneficial relationships between diet, especially omega-3 fatty acids, and these symptoms. Unfortunately, only few data describing the relationship between long-chain omega-3 fatty acids (LCn3) and PCa-related symptoms in patients are available. The purpose of this study was to evaluate the effects of LCn3 supplementation on PCa-specific quality of life in 130 men treated by radical prostatectomy. Men were randomized to receive a daily dose of either 3.75 g of fish oil or a placebo starting 7 weeks before surgery and for up to one-year post-surgery. Quality of life was assessed using the validated EPIC-26 and IPSS questionnaires at randomization, at surgery, and every 3 months following surgery. Between-group differences were assessed using linear mixed models. Intention-to-treat analyses showed no significant difference between the two groups. However, at 12-month follow-up, per-protocol analyses showed a significantly greater increase in the urinary irritation function score (better urinary function) (MD = 5.5, p = 0.03) for the LCn3 group compared to placebo. These results suggest that LCn3 supplementation may improve the urinary irritation function in men with PCa treated by radical prostatectomy and support to conduct of larger-scale studies.

Pathophysiological Mechanisms Involved in Overactive Bladder/Detrusor Overactivity

Purpose of Review

To examine the latest published findings on the pathophysiological mechanisms involved in the development of overactive bladder (OAB) and detrusor overactivity (DO), and to identify common pathways linked to the risk factors associated with these conditions.

Recent Findings

Evidence is accumulating, both clinical and experimental, that many of the factors linked to the development of OAB/DO, including ageing, bladder outlet obstruction, psychological stress, and obesity are associated with reduced bladder blood flow. This induces local tissue inflammation with cytokine release and enhanced oxidative stress, ultimately resulting in altered detrusor sensitivity, detrusor hypertrophy and fibrosis, together with afferent hypersensitivity. These mechanisms would explain the symptoms of urgency and frequency observed in OAB patients. Although not a characteristic of OAB, undetected low level bacterial infections of the bladder have been proposed to explain the OAB symptoms in patients resistant to standard treatments. In this condition, inflammatory responses without reductions in perfusion activate the inflammatory pathways.

Summary

Evidence is mounting that poor bladder perfusion and local inflammatory responses are central mechanisms involved in the development of OAB/DO. As our understanding of these pathophysiological mechanisms advances, new avenues for drug development will be identified and ultimately treatment may become more individualized depending on the particular pathway involved and the drugs available.

Antidiabetic drugs, glycemic control and risk of benign prostatic hyperplasia

BACKGROUND

Diabetes has been associated with an increased risk of benign prostatic hyperplasia (BPH). However, the role of antidiabetic drugs as a BPH risk factor is unclear. The objective of our study was to examine the risk of BPH by antidiabetic drug use and glycemic control in a large population-based cohort of Finnish men.

METHODS

A total of 74,754 men in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) free of BPH at baseline in 1996-1999 were linked to the national medication reimbursement database for information on physician-prescribed antidiabetic drug purchases. Information on recorded BPH procedures and diagnoses was obtained from the National Care Register for Health Care, and for a subgroup of 17,739 men, information on blood glucose levels (BGLs) from the Fimlab Laboratories database. Cox regression with antidiabetic drug use and BGL as time-dependent variables was used to analyze the risks for starting BPH medication, recorded BPH diagnosis, and undergoing BPH surgery. The analysis was adjusted for age, use of statins, antihypertensive medication, and nonsteroidal anti-inflammatory drugs.

RESULTS

Of the subjects, 14,012 men (18.7%) used antidiabetic medication. Of the subgroup with fasting blood glucose data available, 7487 (42.2%) had diabetic level. The risks for BPH diagnosis (HR: 1.08, 95% CI: 1.03-1.13) and surgery (HR: 1.16, 95% CI: 1.09-1.24) were slightly elevated among antidiabetic drug users compared to nonusers. The association was strongest for insulin use. Similarly, risk of BPH surgery was increased in men with diabetic blood glucose compared to normoglycemic men. The risk association was attenuated by use of antidiabetic drugs.

CONCLUSIONS

Diabetic BGL and antidiabetic medication use, especially insulin, are associated with an elevated risk of BPH surgery compared to nondiabetic men. These findings support the roles of insulin use and untreated hyperglycemia as possible BPH risk factors.

Mapping of Dietary Interventions Beneficial in the Prevention of Secondary Health Conditions in Spinal Cord Injured Population: A Systematic Review

OBJECTIVES

Individuals with spinal cord injury are at risk of secondary health conditions (SHC) that develop as a consequence of autonomic dysfunction, prolonged oxidative stress and inflammation, and physical inactivity coupled with inadequate energy and nutritional intake. SHC can be debilitating and even life-threatening, and its prevention remains one of the major challenges in the continuum of medical care of aging SCI population. An unhealthy diet is a major driver of inflammation, oxidative stress, and unfavourable metabolic status and may be a practical preventive target to tackle increased SHC risk post-injury.

AIMS

To provide a catalogue of dietary interventions beneficial in prevention of SHC among individuals with SCI by conducting a systematic review of the literature on dietary interventions and dietary supplementation in promoting health and well-being after the injury. In addition, we aimed to provide a summary of observational studies exploring the association between habitual diet (macro- and micronutrients intake and dietary patterns) and health patterns following the injury.

METHOD

This review was registered at PROSPERO (University of York) with registration number CRD42022373773. Four medical databases (EMBASE.com, MEDLINE [Ovid], Cochrane CENTRAL, and Web of Science Core Collection) and Google Scholar were searched from inception until 11th July 2022. Studies were included if they were clinical trials or observational studies conducted in adult individuals with SCI and provided information of interest. Based on strength of the study design and risk of bias assessment (using the NIH tool), we classified studies from Level 1 (most reliable studies) to Level 4 (least reliable studies).

RESULTS

Of 12,313 unique citations, 47 articles (based on 43 original studies) comprising 32 interventional (22 RCTs, 3 NRCT, and 7 pre-post studies) and 11 observational studies (2 cohort studies, 2 case-control, 1 post-intervention follow-up study, and 6 cross-sectional studies) were included in the present systematic review. Twenty studies (46.5%) were classified as Level 1 or 2, indicating high/moderate methodological quality. Based on those studies, dietary strategies including high protein diet, intermittent fasting, balanced diet in combination with physical conditioning and electrical stimulation, and dietary supplementation including alpha-lipoic acid, creatine, vitamin D, and cranberry-derived supplements and probiotics were mapped as the most promising in prevention of SHC among individuals with SCI.

CONCLUSIONS

To develop timely and effective preventive strategies targeting major SHC (e.g., cardiometabolic diseases, urinary tract infections) in SCI, further research is warranted to confirm the effectiveness of dietary strategies/interventions identified through the current systematic review of the literature.

Longitudinal Associations between Concurrent Changes in Phenotypic Frailty and Lower Urinary Tract Symptoms among Older Men

BACKGROUND

Lower urinary tract symptoms (LUTS) are associated with prevalent frailty and functional impairment, but longitudinal associations remain unexplored.

OBJECTIVES

To assess the association of change in phenotypic frailty with concurrent worsening LUTS severity among older men without clinically significant LUTS at baseline.

DESIGN

Multicenter, prospective cohort study.

SETTING

Population-based.

PARTICIPANTS

Participants included community-dwelling men age ≥65 years at enrollment in the Osteoporotic Fractures in Men study.

MEASUREMENTS

Data were collected at 4 visits over 7 years. Phenotypic frailty score (range: 0-5) was defined at each visit using adapted Fried criterion and men were categorized at baseline as robust (0), pre-frail (1-2), or frail (3-5). Within-person change in frailty was calculated at each visit as the absolute difference in number of criteria met compared to baseline. LUTS severity was defined using the American Urologic Association Symptom Index (AUASI; range: 0-35) and men with AUASI ≥8 at baseline were excluded. Linear mixed effects models were adjusted for demographics, health-behaviors, and comorbidities to quantify the association between within-person change in frailty and AUASI.

RESULTS

Among 3235 men included in analysis, 48% were robust, 45% were pre-frail, and 7% were frail. Whereas baseline frailty status was not associated with change in LUTS severity, within-person increases in frailty were associated with greater LUTS severity (quadratic P<0.001). Among robust men at baseline, mean predicted AUASI during follow-up was 4.2 (95% CI 3.9, 4.5) among those meeting 0 frailty criteria, 4.6 (95% CI 4.3, 4.9) among those meeting 1 criterion increasing non-linearly to 11.2 (95% CI 9.8, 12.6) among those meeting 5 criteria.

CONCLUSIONS

Greater phenotypic frailty was associated with non-linear increases in LUTS severity in older men over time, independent of age and comorbidities. Results suggest LUTS and frailty share an underlying mechanism that is not targeted by existing LUTS interventions.

Metabolic Syndrome and Overactive Bladder Syndrome May Share Common Pathophysiologies

Metabolic syndrome (MetS) is defined by a group of cardiovascular risk factors, including impaired glucose tolerance, central obesity, hypertension, and dyslipidemia. Overactive bladder (OAB) syndrome consists of symptoms such as urinary urgency, frequency, and nocturia with or without urge incontinence. The high prevalences of metabolic syndrome (MetS) and overactive bladder (OAB) worldwide affect quality of life and cause profound negative impacts on the social economy. Accumulated evidence suggests that MetS might contribute to the underlying mechanisms for developing OAB, and MetS-associated OAB could be a subtype of OAB. However, how could these two syndromes interact with each other? Based on results of animal studies and observations in epidemiological studies, we summarized the common pathophysiologies existing between MetS and OAB, including autonomic and peripheral neuropathies, chronic ischemia, proinflammatory status, dysregulation of nutrient-sensing pathways (e.g., insulin resistance at the bladder mucosa and excessive succinate intake), and the probable role of dysbiosis. Since the MetS-associated OAB is a subtype of OAB with distinctive pathophysiologies, the regular and non-specific medications, such as antimuscarinics, beta-3 agonist, and botulinum toxin injection, might lead to unsatisfying results. Understanding the pathophysiologies of MetS-associated OAB might benefit future studies exploring novel biomarkers for diagnosis and therapeutic targets on both MetS and OAB.

The Potential Role of Urinary Microbiome in Benign Prostate Hyperplasia/Lower Urinary Tract Symptoms

Historically, urine in the urinary tract was considered “sterile” based primarily on culture-dependent methods of bacterial detection. Rapidly developing sequencing methods and analytical techniques have detected bacterial deoxyribonucleic acid and live bacteria in urine, improving our ability to understand the urinary tract microbiome. Recently, many studies have revealed evidence of a microbial presence in human urine in the absence of clinical infections. In women, fascinating evidence associates urinary tract microbiota with lower urinary tract symptoms (LUTS). However, the association between urinary tract microbiota and men with LUTS, particularly those with benign prostate hyperplasia (BPH), has not been established. In addition, the identification of the proinflammatory cytokines and pathogens responsible for the clinical progression of BPH is still underway. This review article aimed to address microbiome-related evidence for BPH. Further studies are required for a comprehensive understanding of the relationship between the urogenital microbiome and BPH pathogenesis to facilitate the development of preventive and therapeutic approaches for male LUTS.

Obesity and Voiding Parameters in a Community-Based Population of Okinawa, Japan: Kumejima Digital Health Project (KDHP)

(1) Background: Evidence has accumulated regarding the etiology of lower urinary tract symptoms associated with obesity and metabolic syndrome. Therefore, the present study aimed to identify which subjectively and objectively measured voiding parameters were associated with obesity in a community-based population. (2) Methods: Voiding parameters on a self-administered questionnaire and a digital self-health monitoring system for urine excretion (s-HMSU) were compared between participants with and without obesity, defined as a body mass index ≥ 25 kg/m2 (n = 30 and 29, respectively), from a community in Okinawa, Japan. Logistic regression analysis was employed to calculate the odds ratios of abnormalities in voiding parameters for the obese group, with the non-obese group serving as a reference. (3) Results: The obese group had odds ratios of 5.17 (95% confidence interval: 1.33−20.0) for shortened hours of undisturbed sleep (<302 min) by s-HMSU and 7.65 (1.88−31.1) for nighttime urinary frequency by a questionnaire after adjusting for age and sex. In addition, the obese group had an adjusted odds ratio of 2.27 (0.76−6.78) for decreased maximum bladder capacity (<212 mL) by s-HMSU. (4) Conclusion: the results of the present study suggest that nocturia and shortened hours of undisturbed sleep are signs of obesity.

Oxidative Stress: A Putative Link Between Lower Urinary Tract Symptoms and Aging and Major Chronic Diseases

Aging and major chronic diseases are risk factors for lower urinary tract symptoms (LUTS). On the other hand, oxidative stress (OS) is one of the fundamental mechanisms of aging and the development of chronic diseases. Therefore, OS might be a candidate mechanism linking these two clinical entities. This article aims to summarize the studies on the prevalence of LUTS, the role of OS in aging and chronic diseases, and the potential mechanisms supporting the putative link. A comprehensive literature search was performed to identify recent reports investigating LUTS and OS in major chronic diseases. In addition, studies on the impact of OS on the lower urinary tract, including bladder, urethra, and prostate, were collected and summarized. Many studies showed LUTS are prevalent in aging and major chronic diseases, including obesity, metabolic syndrome, diabetes, cardiovascular disease, hypertension, obstructive sleep apnea, autoimmune diseases, Alzheimer’s disease, and Parkinson’s disease. At the same time, OS is a key component in the pathogenesis of those chronic diseases and conditions. Recent studies also provided evidence that exacerbated OS can cause functional and/or structural changes in the bladder, urethra, and prostate, leading to LUTS. The reviewed data support the concept that OS is involved in multiple risk factors-associated LUTS, although further studies are needed to confirm the causative relationship. The specific ROS/RNS and corresponding reactions/pathways involved in chronic diseases and associated LUTS should be identified in the future and could serve as therapeutic targets.

Aescin Protects against Experimental Benign Prostatic Hyperplasia and Preserves Prostate Histomorphology in Rats via Suppression of Inflammatory Cytokines and COX-2

Background: Benign prostatic hyperplasia (BPH) is the most common urogenital condition in aging males, while inflammation and tissue proliferation constitute the main pathophysiological factors. The adverse effects of currently available BPH medications limit patient compliance. We tested the protective effect of aescin against the development of BPH in rats. Methods: A total of 18 male Wistar rats were divided into 3 groups: control (sesame oil 1 mL/kg, s.c.); BPH (testosterone oenanthate 3 mg/kg, s.c., in sesame oil), and BPH-aescin rats (testosterone oenanthate 3 mg/kg, s.c. + aescin 10 mg/kg/day, p.o.). All treatments continued for 4 weeks. Serum and prostatic samples were harvested for biochemical and histopathological examination. Results: Induction of BPH by testosterone increased the prostate weight and prostate weight index, serum testosterone, prostate expression of inflammatory (IL-1β, TNF-α, and COX-2), and proliferative markers (PCNA and TGF-β1). Concurrent treatment with aescin decreased the testosterone-induced increase in prostatic IL-1β, TNF-α, and COX-2 expression by 47.9%, 71.2%, and 64.4%, respectively. Moreover, aescin reduced the prostatic proliferation markers TGF-β1 and PCNA by 58.3% and 71.9%, respectively, and normalized the prostate weight. Conclusion: The results of this study showed, for the first time, that aescin protected against the development of experimental BPH in rats via its anti-inflammatory and antiproliferative effects. These findings warrant further studies to clinically repurpose aescin in the management of BPH.

Potential Targets for Overactive Bladder in Older Men Based on Urinary Analysis of Metabolomics

OBJECTIVE

We investigated the association between overactive bladder (OAB) and urinary metabolites in men.

METHODS

This prospective observational study included 42 men aged 65-80 years. The 3-day frequency volume chart (FVC), International Prostate Symptom Score (IPSS), and quality of life score were adapted to assess the micturition behavior. Participants with IPSS urgency score ≥2 were included in the OAB group, and those with IPSS urgency score <2 were included in the control group. We performed a comprehensive metabolomic analysis using urine samples. Metabolites were compared between the groups using an unpaired t test and Fisher's exact test in a nonadjusted analysis. Multivariable logistic regression analysis was performed to investigate the association between OAB and the metabolites.

RESULTS

Overall, 23 men were included in the OAB group and 19 in the control group. There were no differences in the background factors except age between the groups. FVC analysis demonstrated that nocturnal urine volume, 24-h micturition frequency, and nocturnal micturition frequency were significantly higher, and the maximum voided volume was significantly lower in the OAB group than in the controls. Metabolomic analysis revealed 14 metabolites that were differentially expressed between the groups. Multivariate analysis indicated that an increase in the levels of 5-iso prostaglandin F2α-VI (5-iPF2a-VI) and 5-methoxyindoleacetic acid was associated with OAB.

CONCLUSION

Abnormal urinary metabolites, including metabolites in the tryptophan (5-methoxyindoleacetic acid, 3-indoleacetonitrile, and 3-hydroxyanthranilic acid) and arachidonic acid (5-iPF2a-VI) pathways, play a role in the pathogenesis of OAB in older men.

Prostatic artery embolization for giant prostatic hyperplasia: a single-center experience

Objective

To describe the safety and efficacy of prostatic artery embolization (PAE) in patients with a markedly enlarged prostate.

Materials and Methods

This was a retrospective study including 18 consecutive patients (mean age, 74 years) with benign prostatic hyperplasia, all with a prostate volume ≥ 200 cm³, who were enrolled to receive PAE for the treatment of moderate-to-severe lower urinary tract symptoms.

Results

The PAE procedure was technically successful in 17 patients (94.4%). During follow-up, clinical failure (defined as an International Prostate Symptom Score [IPSS] ≥ 8) was observed in two (11.1%) of those 18 patients. At 3 months of follow-up, there was significant improvement over baseline in all relevant outcome measures: total IPSS (from 15.7 to 2.9); IPSS quality of life score (from 5.2 to 1.0); prostate specific antigen (from 11.4 to 1.82 ng/mL); peak urinary flow rate (from 7.45 to 18.6 mL/s); prostate volume (from 252.4 to 151.6 cm³); and post-void residual volume (from 143.7 to 28.3 mL)-p < 0.05 for all. Of the 18 patients, one (5.6%) presented detachment of prostate tissue and self-limited hematuria, which did not require specific treatment.

Conclusion

In patients with a markedly enlarged prostate, PAE proved to be safe and effective, resulting in significant improvements in clinical, imaging, and urodynamic parameters.

Bladder Hyperactivity Induced by Oxidative Stress and Bladder Ischemia: A Review of Treatment Strategies with Antioxidants

Overactive bladder (OAB) syndrome, including frequency, urgency, nocturia and urgency incontinence, has a significantly negative impact on the quality-of-life scale (QoL) and can cause sufferer withdrawal from social activities. The occurrence of OAB can result from an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidant-induced oxidative stress. Several animal models, such as bladder ischemia/reperfusion (I/R), partial bladder outlet obstruction (PBOO) and ovarian hormone deficiency (OHD), have suggested that cyclic I/R during the micturition cycle induces oxidative stress, leading to bladder denervation, bladder afferent pathway sensitization and overexpression of bladder-damaging molecules, and finally resulting in bladder hyperactivity. Based on the results of previous animal experiments, the present review specifically focuses on four issues: (1) oxidative stress and antioxidant defense system; (2) oxidative stress in OAB and biomarkers of OAB; (3) OAB animal model; (4) potential nature/plant antioxidant treatment strategies for urinary dysfunction with OAB. Moreover, we organized the relationships between urinary dysfunction and oxidative stress biomarkers in urine, blood and bladder tissue. Reviewed information also revealed the summary of research findings for the effects of various antioxidants for treatment strategies for OAB.

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.

The Urinary Tract Microbiome in Male Genitourinary Diseases: Focusing on Benign Prostate Hyperplasia and Lower Urinary Tract Symptoms

The human body is sterile during gestation; however, but during and after birth, the entire body surface becomes host to an enormous variety of microorganisms. Urine in the urinary tract was once considered sterile based on the lack of cultured microorganisms. Many recent studies have revealed evidence of microorganisms in human urine in the absence of clinical infection. Sequencing methods and analytical techniques are rapidly evolving to improve the ability to detect bacterial DNA and living bacteria and to understand the microbiota of the urinary tract. In women, fascinating evidence associates urinary tract microbiota with lower urinary tract symptoms. However, in men, the relevance of urinary tract microbiota in low urinary tract symptoms and prostate disease has not been established. In this review, we highlight a recent study that increases our ability to understand the urinary tract microbiota in men with lower urinary tract symptoms.

Association Between Obesity and Lower Urinary Tract Symptoms Among Children and Adolescents: A Community-Based Study

Introduction: Obesity is associated with lower urinary tract symptoms (LUTSs) and dysfunction in adults while its impact on children and adolescents remains unknown. This study aimed to explore the impact of obesity on LUTSs among children and adolescents through a large-scale community-based study. Methods: From July 2004 to April 2017, children and adolescents aged 5-15 years-old in Xin-Dian District, New Taipei City were invited to participate in our study. The exclusion criteria were a history of congenital genitourinary tract anomalies, neurological anomalies, or a presence of urinary tract infection. After providing informed consent the participant completed a questionnaire, which included their baseline characteristics and dysfunctional voiding symptom score (DVSS); a parent completed the questionnaire with the younger children. Urgency and daytime incontinence were defined as having positive statement for DVSS questions 7 and 1, respectively. Multivariate regression analysis was used to evaluate the predictors of urgency, daytime incontinence and enuresis. A p-value of <0.05 was considered statistically significant. Results: A total of 2,371 participants were enrolled in the study, and 1,599 were ultimately eligible for analysis. The prevalence of urgency, daytime incontinence, constipation, and enuresis were 37.6, 6.4, 26.1, and 7.7%, respectively. Multivariate analysis revealed that younger age (p = 0.01) and obesity (p = 0.04) were independent predictors for urgency. Younger age (p < 0.01) and constipation (p = 0.04) were independent predictors for daytime incontinence but obesity was not. Younger children were more likely to have nocturnal enuresis (95% CI = 0.77-0.88) and obesity did not have a significant impact on enuresis. Conclusion: Obesity was significantly associated with urgency but it was not significantly associated with daytime incontinence and enuresis in community dwelling children and adolescents.

Review of the Roles and Interaction of Androgen and Inflammation in Benign Prostatic Hyperplasia

The lower urinary tract symptoms (LUTSs) and acute urinary retention (AUR) caused by benign prostatic hyperplasia (BPH) can seriously affect the quality of life of elderly men. Studies suggest that both androgens and inflammation greatly influence the occurrence and development of BPH in most patients. These two factors combined can also affect each other, leading to pathological changes in the stromal and epithelial tissue of the prostate transition zone in BPH patients. DHT in the prostate tissue of BPH patients may activate a chronic inflammatory response in the prostate, amplifying the expression of inflammatory factors and upregulating the proliferation ability of prostate tissue.

Insulin exacerbated high glucose-induced epithelial-mesenchymal transition in prostatic epithelial cells BPH-1 and prostate cancer cells PC-3 via MEK/ERK signaling pathway

As two most common progressive diseases of aging, type 2 diabetes mellitus (T2DM) and benign prostatic hyperplasia (BPH) were all characterized by endocrine and metabolic disorders. Here, our clinical study showed that there were significant differences in fasting blood glucose (FBG), fasting insulin (FINS), insulin resistance index (HOMA-IR) and prostate volume (PV) between simple BPH patients and BPH complicated with T2DM patients. Further analysis showed that HOMA-IR was positively correlated with PV in BPH complicated with T2DM patients. The in vitro experiment results showed that high glucose (HG) promoted EMT process in a glucose-dependent manner in human prostate hyperplasia cells (BPH-1) and prostate cancer cells (PC-3), and this pathological process was exacerbated by co-culture with insulin. Mechanistically, insulin-induced exacerbation of EMT was depended on the activation of MEK/ERK signaling pathway, and we suggested that insulin and its analogs should be used very carefully for the clinical antihyperglycemic treatment of BPH complicated with T2DM patients.

The underlying mechanism of metabolic syndrome on benign prostatic hyperplasia and prostate volume

OBJECTIVE

To investigate the potential mechanism of the effect of metabolic syndrome (MetS) on prostate volume (PV) and the risk of benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) and the relationships of MetS and the major pathogenic factors of MetS with the clinical progression of BPH/LUTS in older Chinese men.

SUBJECTS AND METHODS

We analyzed clinical data obtained from 506 ostensibly healthy men who underwent routine health check-ups and recruited 415 subjects from a group of previously studied men after 4 years. We evaluated the associations of major pathological factors of MetS, including insulin resistance, subclinical inflammatory state, and sex hormone changes, with PV, the risk of BPH and the clinical progression of BPH/LUTS by using multiple linear regression and logistic regression.

RESULTS

After adjustment for age, insulin, HOMA (homeostatic model assessment) index, leptin, resistin, adiponectin, C-reactive protein, tumor necrosis factor-α (TNF-α), sex hormone-binding globulin, and testosterone levels were significantly associated with PV (all P < .05), and in the age-adjusted logistic regression model, positive associations of resistin and TNF-α with BPH/LUTS were found (OR, 1.662, P = .007 and OR, 1.044, P < .001, respectively). Predictors of BPH/LUTS clinical progression were significantly correlated with MetS and TNF-α. The group with higher TNF-α levels had a higher rate of newly diagnosed BPH (9.5% vs 19.1%, P = .006) and a greater increase in PV levels (0.61 ± 0.08 vs 1.09 ± 0.35 cm³ , P <.001) after 4 years.

CONCLUSIONS

MetS and its pathological factors were associated with an increased PV and an increased risk of BPH/LUTS that is more prone to clinical progression. TNF-α may serve as an early biological indicator to identify which patients with BPH/LUTS are at higher risk of unfavorable outcomes.

Inflammation is a target of medical treatment for lower urinary tract symptoms associated with benign prostatic hyperplasia

Purpose

To review the role of a persistent prostatic inflammatory status (PIS) in the development and progression of benign prostatic hyperplasia (BPH) associated with lower urinary tract symptoms (LUTS) and which medical therapies approved for LUTS/BPH may reduce persistent PIS.

Methods

Literature search in PubMed up to July 2019.

Results

The cause of histologically defined persistent PIS or chronic prostatic inflammation is multifactorial. It is evident in many men with LUTS/BPH, particularly in older men and in men with a large prostate volume or more severe (storage) LUTS. Additionally, persistent PIS is associated with an increased risk of acute urinary retention and symptom worsening. Of medical therapies approved for LUTS/BPH, the current evidence for a reduction of persistent PIS is greatest for the hexanic extract of Serenoa repens (HESr). This treatment relieves LUTS to the same extent as α₁-adrenoceptor antagonists and short-term 5α-reductase inhibitors. Limited evidence is available on the effect of other mainstream LUTS/BPH treatments on persistent PIS.

Conclusions

Persistent PIS plays a central role in both the development and progression of LUTS/BPH. In men with LUTS/BPH who have a high chance of harbouring persistent PIS, HESr will not only improve LUTS, but also reduce (underlying) inflammation. Well-designed clinical studies, with a good level of evidence, are required to better evaluate the impact of BPH/LUTS medical therapies on persistent PIS.

Electronic supplementary material

The online version of this article (10.1007/s00345-020-03106-1) contains supplementary material, which is available to authorized users.

Urinary biomarkers profiles in patients with neurogenic detrusor overactivity according to their neurological condition

OBJECTIVES

The aim of this study was to investigate the disease-specific urinary levels variations of neurotrophins (NGF, BDNF), mediators of inflammation (TGFβ-1, PGE-2) and markers of extracellular matrix alterations (TIMP-2) in patients with multiple sclerosis (MS) spinal cord injury (SCI), or spina bifida (SB), and neurogenic detrusor overactivity (NDO).

METHODS

A prospective single-center study was conducted between March 2015 and March 2017. Patients aged over 18 years old, with neurological disease, with a urodynamic diagnosis of NDO were included. The urinary levels of NGF, BDNF, TIMP-2, PGE 2, and TGF-β1 were measured using dedicated ELISA kits.

RESULTS

Forty-one patients were included: 6 with MS, 20 with SCI, and 15 with spina bifida. The average urinary level of NGF/Cr was significantly higher in MS patients compared to other neurologic populations (8 vs. 0.56 vs. 1.25 pg/mg of creatinine; p = 0.001) as well for the average urinary level of BDNF (88.3 vs. 5 vs. 4.8 pg/mg of creatinine; p < 0.0001). SCI patients had a significantly lower level of TGFβ-1 than SB patients (p = 0.04). The urinary level of PGE2 was significantly correlated with the Body Mass Index (r = 0.61; p = 0.0002).

CONCLUSION

All NDO may not be created equal from the molecular standpoint. Multiple sclerosis patients had higher urinary levels of neurotrophins than in other neurologic populations with NDO. Urinary TGFβ-1, a strong determinant of extracellular matrix, was significantly higher in spina bifida patients compared to SCI patients. These findings underscore the importance of using and interpreting those possible urinary markers in a disease-specific fashion.

Statin use and longitudinal changes in prostate volume; results from the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial

OBJECTIVE

To test the association between statin use and prostate volume (PV) change over time using data from the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial, a 4-year randomised controlled trial testing dutasteride for prostate cancer chemoprevention.

SUBJECTS/PATIENTS AND METHODS

We identified men with a baseline negative prostate biopsy from REDUCE who did not undergo prostate surgery or develop prostate cancer over the trial period. Men reported statin use at baseline. PV was determined from transrectal ultrasonography performed to guide prostate biopsy at baseline, and 2- and 4-years after randomisation. Multivariable generalised estimating equations tested differences in PV change over time by statin use, overall and stratified by treatment arm. We tested for interactions between statins and time in association with PV using the Wald test.

RESULTS

Of 4106 men, 17% used statins at baseline. Baseline PV did not differ by statin use. Relative to non-users, statin users had decreasing PVs over the trial period (P = 0.027). Similar patterns were seen in the dutasteride and placebo arms, although neither reached statistical significance. The mean estimated PV was modestly but significantly lower in statin users relative to non-users in the dutasteride arm at 2-years (4.5%, P = 0.032) and 4-years (4.0%, P = 0.033), with similar (3-3.3%) but non-significant effects in the placebo arm.

CONCLUSION

If confirmed, our present findings support a role for statins in modestly attenuating PV growth, with a magnitude of effect in line with previously reported prostate-specific antigen-lowering effects of statins (~4%). Future studies are needed to assess whether this putative role for statins in PV growth could impact lower urinary tract symptom development or progression.

Can Botulinum Toxin A Still Have a Role in Treatment of Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia Through Inhibition of Chronic Prostatic Inflammation?

Patients with benign prostatic hyperplasia (BPH) can exhibit various lower urinary tract symptoms (LUTS) owing to bladder outlet obstruction (BOO), prostatic inflammation, and bladder response to BOO. The pathogenesis of BPH involves an imbalance of internal hormones and chronic prostatic inflammation, possibly triggered by prostatic infection, autoimmune responses, neurogenic inflammation, oxidative stress, and autonomic dysfunction. Botulinum toxin A (BoNT-A) is well recognized for its ability to block acetylcholine release at the neuromuscular junction by cleaving synaptosomal-associated proteins. Although current large clinical trials have shown no clinical benefits of BoNT-A for the management of LUTS due to BPH, BoNT-A has demonstrated beneficial effects in certain subsets of BPH patients with LUTS, especially in males with concomitant chronic prostatitis/chronic pelvic pain syndrome and smaller prostate. We conducted a review of published literature in Pubmed, using Botulinum toxin, BPH, BOO, inflammation, LUTS, and prostatitis as the key words. This article reviewed the mechanisms of BPH pathogenesis and anti-inflammatory effects of BoNT-A. The results suggested that to achieve effectiveness, the treatment of BPH with BoNT-A should be tailored according to more detailed clinical information and reliable biomarkers.

Urinary Metabolomic and Proteomic Analyses in a Mouse Model of Prostatic Inflammation

Lower urinary tract symptoms (LUTS) are common among aging men. Since prostatic inflammation is one of its etiologies, it is plausible that urinary metabolite and protein biomarkers could be identified and used to diagnose inflammation-induced LUTS. We characterized the urine metabolome and proteome in a mouse model of bacterial-induced prostatic inflammation. Mass Spectrometry (MS)-based multi-omics analysis was employed to discover urinary protein and metabolite-based biomarkers. The investigation of isobaric dimethylated leucine (DiLeu) labeling on metabolites allowed metabolomics and proteomics analysis on the same liquid chromatography (LC)-MS platform. In total, 143 amine-containing metabolites and 1058 urinary proteins were identified and quantified (data are available via ProteomeXchange with identifier PXD018023); among them, 14 metabolites and 168 proteins were significantly changed by prostatic inflammation. Five metabolic pathways and four inflammation-related biological processes were potentially disrupted. By comparing our findings with urinary biomarkers identified in a mouse model of genetic-induced prostate inflammation and with those previously found to be associated with LUTS in older men, we identified creatine, haptoglobin, immunoglobulin kappa constant and polymeric Ig receptor as conserved biomarkers for prostatic inflammation associated with LUTS. These data suggest that these putative biomarkers could be used to identify men in which prostate inflammation is present and contributing to LUTS.

[Impact of body mass index on lower urinary tract disorders in multiple sclerosis]

INTRODUCTION

Lower urinary tract symptoms (LUTS), and principally overactive bladder, are common in multiple sclerosis (MS). However, their origin is not necessarily unique. Obesity is widely recognized as a risk factor for stress urinary incontinence (SUI) and overactive bladder (OAB) in the general population. We wanted to evaluate the influence of body mass index (BMI) on LUTS in the MS population.

MATERIALS AND METHODS

We conducted an uncontrolled monocentric retrospective study in 260 subjects classified into 4 BMI groups: underweight, normal weight, overweight, obese people. Comparisons by Mann-Whitney test were made between different BMI groups, in the overall population and then by gender. LUTS (SUI, OAB, BOO (bladder outlet obstruction) were assessed using USP questionnaire.

RESULTS

In women, the mean OAB score was higher for obese women, 10.27 (SD=4.5) than for normal weight women, 7.96 (SD=4.58), P=0.024. The SUI score was lower for normal weight, 1.69 (SD=2.38) than for overweight, 3.19 (SD=2.91), P=0.002 and obese subjects, 3.80 (SD=3.23), P=0.0005. As in the overall population, the BOO score was higher in subjects with normal weight, 4.09 (SD=3.33) than in subjects with overweight, 1.91 (SD=2.03), P=0.0003 and in obese subjects, 2.33 (SD=2.37), P=0.013. The same comparisons in men were not significant.

CONCLUSION

In this series, increased BMI was associated with higher OAB and SUI USP questionnaire scores, in women presenting with MS.

LEVEL OF EVIDENCE

4.

A Comprehensive Review of Overactive Bladder Pathophysiology: On the Way to Tailored Treatment

CONTEXT

Current literature suggests that several pathophysiological factors and mechanisms might be responsible for the nonspecific symptom complex of overactive bladder (OAB).

OBJECTIVE

To provide a comprehensive analysis of the potential pathophysiology underlying detrusor overactivity (DO) and OAB.

EVIDENCE ACQUISITION

A PubMed-based literature search was conducted in April 2018, to identify randomised controlled trials, prospective and retrospective series, animal model studies, and reviews.

EVIDENCE SYNTHESIS

OAB is a nonspecific storage symptom complex with poorly defined pathophysiology. OAB was historically thought to be caused by DO, which was either "myogenic" (urgency initiated from autonomous contraction of the detrusor muscle) or "neurogenic" (urgency signalled from the central nervous system, which initiates a detrusor contraction). Patients with OAB are often found to not have objective evidence of DO on urodynamic studies; therefore, alternative mechanisms for the development of OAB have been postulated. Increasing evidence on the role of urothelium/suburothelium and bladder afferent signalling arose in the early 2000s, emphasising an afferent "urotheliogenic" hypothesis, namely, that urgency is initiated from the urothelium/suburothelium. The urethra has also recently been regarded as a possible afferent origin of OAB-the "urethrogenic" hypothesis. Several other pathophysiological factors have been implicated, including metabolic syndrome, affective disorders, sex hormone deficiency, urinary microbiota, gastrointestinal functional disorders, and subclinical autonomic nervous system dysfunctions. These various possible mechanisms should be considered as contributing to diagnostic and treatment algorithms.

CONCLUSIONS

There is a temptation to label OAB as "idiopathic" without obvious causation, given the poorly understood nature of its pathophysiology. OAB should be seen as a complex, multifactorial symptom syndrome, resulting from multiple potential pathophysiological mechanisms. Identification of the underlying causes on an individual basis may lead to the definition of OAB phenotypes, paving the way for personalised medical care.

PATIENT SUMMARY

Overactive bladder (OAB) is a storage symptom syndrome with multiple possible causes. Identification of the mechanisms causing a patient to experience OAB symptoms may help tailor treatment to individual patients and improve outcomes.

Impact of lower urinary tract symptoms on mortality: a 21-year follow-up among middle-aged and elderly Finnish men

BACKGROUND

The usefulness of lower urinary tract symptoms (LUTS) as mortality risk factors remains unclear. Repeated assessments are required to take into account symptom fluctuation and de novo symptom appearance. The study objective was to evaluate mortality in relation to three urinary storage symptoms-urgency, daytime frequency, and nocturia-in middle-aged and elderly men, considering also other time-varying factors during follow-up.

METHODS

A mail survey of a population-based cohort of men initially aged 50, 60, and 70 years was conducted in Finland in 1994, 1999, 2004, and 2009. The questionnaire included assessments of LUTS based on the Danish Prostatic Symptom Score and comorbidities. The men were followed up for mortality through the population registry through 2014. LUTS-related hazard ratios (HR) were analyzed with time-dependent Cox regression adjusted for the year of birth and comorbidities using variable values updated every 5 years. Sensitivity analyses were conducted using values of all variables fixed to the baseline assessment of 1994.

RESULTS

Of the 1332 eligible men with data on LUTS from each preceding survey, 514 (38.6%) died during the 21-year follow-up. In time-dependent analyses, daytime frequency, and nocturia were significantly associated with increased mortality: the adjusted HR was 1.42 (95% CI 1.11-1.83) for daytime frequency, 1.38 (1.07-1.79) for nocturia and 1.19 (0.94-1.50) for urgency. In sensitivity analyses with fixed baseline characteristics, only nocturia was suggestively associated with an increased risk of death: the adjusted HR was 1.09 (0.84-1.42) for daytime frequency, 1.41 (0.99-2.02) for nocturia and 0.94 (0.52-1.68) for urgency.

CONCLUSIONS

Among aging men, LUTS are more accurate predictors of short-term than longer-term mortality risk. Repeated assessments are needed to detect clinically relevant and persistent symptoms, often associated with ill health. Accordingly, men with daytime frequency or nocturia exhibit a 1.4-fold risk of death and therefore, should be evaluated for underlying comorbidity.

Inflammatory mediators in the development and progression of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is the most common urological disease in elderly men. Epidemiological data suggest a causal link between this condition and prostatic inflammation. The prostate is an immune-competent organ characterized by the presence of a complex immune system. Several stimuli, including infectious agents, urinary reflux, metabolic syndrome, the ageing process, and autoimmune response, have been described as triggers for the dysregulation of the prostatic immune system via different molecular pathways involving the development of inflammatory infiltrates. From a pathophysiological standpoint, subsequent tissue damage and chronic tissue healing could result in the development of BPH nodules.

Beta-3 Adrenoceptor Signaling Pathways in Urothelial and Smooth Muscle Cells in the Presence of Succinate

Succinate, an intermediate metabolite of the Krebs cycle, can alter the metabolomics response to certain drugs and controls an array of molecular responses in the urothelium through activation of its receptor, G-protein coupled receptor 91 (GPR91). Mirabegron, a β3-adrenergic receptor (β3-AR) agonist used to treat overactive bladder syndrome (OAB), increases intracellular cAMP in the detrusor smooth muscle cells (SMC), leading to relaxation. We have previously shown that succinate inhibits forskolin-stimulated cAMP production in urothelium. To determine whether succinate interferes with mirabegron-mediated bladder relaxation, we examined their individual and synergistic effect in urothelial-cell and SMC signaling. We first confirmed β3-AR involvement in the mirabegron response by quantifying receptor abundance by immunoblotting in cultured urothelial cells and SMC and cellular localization by immunohistochemistry in rat bladder tissue. Mirabegron increased cAMP levels in SMC but not in urothelial cells, an increase that was inhibited by succinate, suggesting that it impairs cAMP-mediated bladder relaxation by mirabegron. Succinate and mirabegron increased inducible nitric oxide synthesis and nitric oxide secretion only in urothelial cells, suggesting that its release can indirectly induces SMC relaxation. Succinate exposure decreased the expression of β3-AR protein in whole bladder in vivo and in SMC in vitro, indicating that this metabolite may lead to impaired pharmacodynamics of the bladder. Together, our results demonstrate that increased levels of succinate in settings of metabolic stress (e.g., the metabolic syndrome) may lead to impaired mirabegron and β3-AR interaction, inhibition of cAMP production, and ultimately requiring mirabegron dose adjustment for its treatment of OAB related to these conditions.

Aquablation: a novel and minimally invasive surgery for benign prostate enlargement

Aquablation is a minimally invasive surgical technology for benign prostate enlargement, which uses high-pressure saline to remove parenchymal tissue through a heat-free mechanism of hydrodissection. Early results show this to be a promising surgical strategy with a strong morbidity profile and reduced resection time. This review serves to provide an overview of the technique and evaluate its safety and efficacy.

Preliminary assessment of Neck Circumference in Benign Prostatic Hyperplasia in Patients with Metabolic Syndrome

OBJECTIVES

To investigate the impact of neck circumference (NC) in the treatment of bening prostatic hyperplasia (BPH) patients with metabolic syndrome (MtS). Additionally, we determined dose response to alpha-blockers and cut-off values for NC and waist circumference (WC), in these patients.

MATERIALS AND METHODS

Non-randomized, open-labelled, and multi-centre study was conducted between March 2014 and September 2015. The BPH patients were enrolled and were divided into 2 groups: with MtS (Group 1; n=94) and without MtS (Group 2; n=103). Demographic data, anthropometric measurements, blood analyses, uroflowmetric parameters, post voiding residual urine (PVR), prostate volume, quality of life (QoL) index, NC and WC were recorded. Both groups were administered oral alphablockers and response to treatment was evaluated. Receiver-operating characteristic (ROC) curves were obtained and significant p was p<0.05.

RESULTS

In total, 197 patients were enrolled with mean age of 60.5±8.1 years. Mean NC and WC were higher in MtS patients (p<0.001). Uroflowmetry parameters and QoL indexes were comparable between groups before treatment. International prostate symptom score, uroflowmetry parameters, and QoL significant improved in Group 2 than Group 1, at 1st and 6th months of treatment with alpha-blockers. Success rate of treatment was significant higher in Group 2 than Group 1 (p<0.001). Cut-off values were 42.5cm and 113.5cm for NC and WC respectively, for response to alpha-blockers in BPH patients with MtS.

CONCLUSIONS

MtS can be related with BPH and can negatively affect the response to alpha-blocker treatment. NC can be used for predicting response to alpha-blocker treatment in BPH patients with MtS.

Path of translational discovery of urological complications of obesity and diabetes

Diabetes mellitus (DM) is a prevalent chronic disease. Type 1 DM (T1DM) is a metabolic disorder that is characterized by hyperglycemia in the context of absolute lack of insulin, whereas type 2 DM (T2DM) is due to insulin resistance-related relative insulin deficiency. In comparison with T1DM, T2DM is more complex. The natural history of T2DM in most patients typically involves a course of obesity to impaired glucose tolerance, to insulin resistance, to hyperinsulinemia, to hyperglycemia, and finally to insulin deficiency. Obesity is a risk factor of T2DM. Diabetes causes some serious microvascular and macrovascular complications, such as retinopathy, nephropathy, neuropathy, angiopathy and stroke. Urological complications of obesity and diabetes (UCOD) affect quality of life, but are not well investigated. The urological complications in T1DM and T2DM are different. In addition, obesity itself affects the lower urinary tract. The aim of this perspective is to review the available data, combined with the experience of our research teams, who have spent a good part of last decade on studies of association between DM and lower urinary tract symptoms (LUTS) with the aim of bringing more focus to the future scientific exploration of UCOD. We focus on the most commonly seen urological complications, urinary incontinence, bladder dysfunction, and LUTS, in obesity and diabetes. Knowledge of these associations will lead to a better understanding of the pathophysiology underlying UCOD and hopefully assist urologists in the clinical management of obese or diabetic patients with LUTS.

In-Depth Characterization and Validation of Human Urine Metabolomes Reveal Novel Metabolic Signatures of Lower Urinary Tract Symptoms

Lower urinary tract symptoms (LUTS) are a range of irritative or obstructive symptoms that commonly afflict aging population. The diagnosis is mostly based on patient-reported symptoms, and current medication often fails to completely eliminate these symptoms. There is a pressing need for objective non-invasive approaches to measure symptoms and understand disease mechanisms. We developed an in-depth workflow combining urine metabolomics analysis and machine learning bioinformatics to characterize metabolic alterations and support objective diagnosis of LUTS. Machine learning feature selection and statistical tests were combined to identify candidate biomarkers, which were statistically validated with leave-one-patient-out cross-validation and absolutely quantified by selected reaction monitoring assay. Receiver operating characteristic analysis showed highly-accurate prediction power of candidate biomarkers to stratify patients into disease or non-diseased categories. The key metabolites and pathways may be possibly correlated with smooth muscle tone changes, increased collagen content, and inflammation, which have been identified as potential contributors to urinary dysfunction in humans and rodents. Periurethral tissue staining revealed a significant increase in collagen content and tissue stiffness in men with LUTS. Together, our study provides the first characterization and validation of LUTS urinary metabolites and pathways to support the future development of a urine-based diagnostic test for LUTS.

Prostate cancer outcomes for men who present with symptoms at diagnosis

OBJECTIVE

To compare clinical features, treatments and outcomes in men with non-metastatic prostate cancer (PCa) according to whether they were referred for symptoms or elevated prostate-specific antigen (PSA) level.

PATIENTS AND METHODS

This study used data from the South Australia Prostate Cancer Clinical Outcomes Collaborative database; a multi-institutional clinical registry covering both the public and private sectors. We included all non-metastatic cases from 1998 to 2013 referred for urinary/prostatic symptoms or elevated PSA level. Multivariate Poisson regression was used to identify characteristics associated with symptomatic presentation and compare treatments according to reason for referral. Outcomes (i.e. overall survival, PCa-specific survival, metastasis-free survival and disease-free survival) were compared using multivariate Cox proportional hazards and competing risk regression.

RESULTS

Our analytical cohort consisted of 4 841 men with localized PCa. Symptomatic men had lower-risk disease (incidence ratio [IR] 0.70, 95% confidence interval [CI] 0.61-0.81 for high vs low risk), fewer radical prostatectomies (IR 0.64, CI: 0.56-0.75) and less radiotherapy (IR 0.86, CI: 0.77-0.96) than men presenting with elevated PSA level. All-cause mortality (hazard ratio [HR] 1.31, CI: 1.16-1.47), disease-specific mortality (HR 1.42, CI: 1.13-1.77) and risk of metastases (HR 1.36, CI: 1.13-1.64) were higher for men presenting with symptoms, after adjustment for other clinical characteristics; however, risk of disease progression did not differ (HR 0.90, CI: 0.74-1.07) amongst those treated curatively. Subgroup analyses indicated poorer PCa survival for symptomatic referral among men undergoing radical prostatectomy (HR 3.4, CI: 1.3-8.8), those aged >70 years (HR 1.4, CI: 1.0-1.8), men receiving private treatment (HR 2.1, CI: 1.3-3.3), those diagnosed via biopsy (HR 1.3, CI: 1.0-1.7) and those diagnosed before 2006 (HR 1.6, CI: 1.2-2.7).

CONCLUSION

Our results suggest that symptomatic presentation may be an independent negative prognostic indicator for PCa survival. More complete assessment of disease grade and extent, more definitive treatment and increased post-treatment monitoring among symptomatic cases may improve outcomes. Further research to determine any pathophysiological basis for poor outcomes in symptomatic men is warranted.

Correlation between prostate volume and single nucleotide polymorphisms implicated in the steroid pathway

OBJECTIVES

A few preliminary studies have suggested a link between some genetics variants and benign prostatic hyperplasia (BPH). Our goal was to study the link between a set of single nucleotide polymorphisms (SNPs) implicated in the steroid pathway and accurate measurement of prostate volume in a cohort of men who underwent radical prostatectomy.

METHODS

Clinical and pathological data including prostate weight were obtained from 611 Caucasian patients with small volume, localized prostate cancer treated by radical prostatectomy. Patients were genotyped for 90 SNPs located inside or nearby genes implicated in the steroid pathway (Sequenom iPLEX). Correlation between prostate weight and genotypes from each SNP was studied by analysis of covariance, adjusted on age and tumor stage. A Bonferroni correction was applied, and the SNPs implicated were then incorporated in a multivariable model.

RESULTS AND LIMITATIONS

Seven SNPs located in or nearby genes implicated in steroid hormone metabolism were significantly associated with prostate volume: HSD17B2 (rs1119933), ESR2 (rs8006145), SULT2B1 (rs279451), NQO1 (rs2917670), ESR1 (rs1569788), GSTP1 (rs1138272), and CYP19A1 (rs17523880). Significant association was maintained after multivariate analysis for four SNPs, indicating their independent association with prostate volume. The power of the association of each SNP with prostate volume was comparable to the effect of age. The strongest associations were found with variants in ESR1, ESR2, HSD17B2, and CYP19A1 genes, indicating a potential role of the estrogen signaling pathway in genesis of BPH.

CONCLUSIONS

Our results are in favor of an implication of estrogen biotransformation and signaling pathways in the pathophysiology of BPH.

The Association Between Metabolic Syndrome and Characteristics of Benign Prostatic Hyperplasia: A Systematic Review and Meta-Analysis

The purpose of this systematic review was to examine the association of metabolic syndrome (MS) with measures of benign prostatic hyperplasia (BPH) including prostate growth rate, prostate volume, International Prostate Symptom Score (IPSS), prostate-specific antigen (PSA) level, and maximal flow rate.Medline, Cochrane CENTRAL, EMBASE, CBM, and Google Scholar databases were searched until March 23, 2015 using combinations of the keywords benign prostate hyperplasia/BPH, metabolic syndrome, total prostate volume, prostate growth rate, prostate specific antigen, International Prostate Symptom Score/IPSS, maximal flow rate. Cohort or case-control studies of patients with BPH and MS that reported quantitative outcomes were included. The pooled mean differences of the outcome measures were compared between patients with and without MS.A total of 158 potentially relevant studies were identified, and 8 were included in the meta-analysis. The 8 studies included in the meta-analysis contained a total of 3093 BPH patients, wherein 1241 had MS and 1852 did not have MS. BPH patients with MS had a significantly higher prostate growth rate (pooled mean difference = 0.67 mL/y, P < 0.001) and larger prostate volume (pooled mean difference = 6.8 mL, P = 0.010) than the BPH patients without MS. There was no significant difference in IPSS score (pooled mean difference = 1.58, P = 0.202) or maximal flow rate (pooled mean difference = -1.41 mL/s, P = .345) between BPH patients with and without MS. A borderline nonsignificant difference in PSA (pooled mean difference = 0.24 ng/mL, P = 0.056) was noted between BPH patients with and without MS.The results of this meta-analysis are consistent with literature indicating that BPH patients with MS have a higher prostate growth rate and larger prostate volume than those without MS; however, further study is necessary to determine the association of BPH and metabolic disorder elements and the potential risk of disease progression in BPH patients with MS.