Association of insulin resistance with overactive bladder in female patients

The Ketone Bridge Between the Heart and the Bladder: How Fast Should We Go?

Metabolic syndrome (MS) is associated with both cardiovascular and bladder dysfunction. Insulin resistance (IR) and central obesity, in particular, are the main risk factors. In these patients, vicious pathological cycles exacerbate abnormal carbohydrate metabolism and sustain an inflammatory state, with serious implications for both the heart and bladder. Ketone bodies serve as an alternative energy source in this context. They are considered a "super-fuel" because they generate adenosine triphosphate with less oxygen consumption per molecule, thus enhancing metabolic efficiency. Ketone bodies have a positive impact on all components of MS. They aid in weight loss and glycemic control, lower blood pressure, improve lipid profiles, and enhance endothelial function. Additionally, they possess direct anti-inflammatory, antioxidant, and vasodilatory properties. A shared key player in dysfunction of both the heart and bladder dysfunction is the formation of the NLRP3 inflammasome, which ketone bodies inhibit. Interventions that elevate ketone body levels-such as fasting, a ketogenic diet, ketone supplements, and sodium-glucose cotransporter 2 inhibitors-have been shown to directly affect cardiovascular outcomes and improve lower urinary tract symptoms derived from MS. This review explores the pathophysiological basis of the benefits of ketone bodies in cardiac and bladder dysfunction.

Correlation Between Insulin Resistance and Urinary Incontinence in Female Patients with Type 2 Diabetes Mellitus

INTRODUCTION AND HYPOTHESIS

Patients with type 2 diabetes mellitus (T2DM) are at a high risk of developing urinary incontinence; however, its pathogenesis is unclear. The purpose of this study is to explore the relationship between insulin resistance and urinary incontinence and its severity in female patients with T2DM.

METHODS

A total of 366 women with T2DM aged ≥18 years were enrolled in this study. Insulin resistance was evaluated by the homeostasis model insulin resistance (HOMA-IR) index and urinary incontinence was assessed by the International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF). All subjects were divided into four groups according to HOMA-IR quartiles. Logistic regression analysis was performed to investigate the relationship between insulin resistance and urinary incontinence and its severity.

RESULTS

Among the 366 patients, 186 (50.8%) had urinary incontinence. The prevalence of urinary incontinence increased significantly with HOMA-IR quartiles (p < 0.001). Adjusted logistic regression analysis showed that compared with HOMA-IR ≤ 1.76, 2.81 ≤ HOMA-IR ≤ 4.27 was associated with a significantly increased risk of moderate incontinence (OR = 2.197, 95% CI 1.031-4.683, p = 0.041), and HOMA-IR ≥ 4.28 was associated with a significantly increased risk of severe incontinence (OR = 5.699, 95% CI 1.685-19.276, p = 0.005). Binary logistic regression analysis showed that HOMA-IR was the independent risk factor for urinary incontinence (p < 0.001).

CONCLUSIONS

Higher levels of insulin resistance are associated with urinary incontinence and its severity in female patients with type 2 diabetes mellitus.

Associations between exposure to organophosphate esters and overactive bladder in U.S. adults: a cross-sectional study

Background

The relationship between exposure to organophosphate esters (OPEs) and the risk of developing overactive bladder (OAB) is uncertain. The purpose of this study is to examine the potential link between urinary metabolites of organophosphate esters and OAB.

Method

Data from the National Health and Nutrition Examination Survey (NHANES) database of the 2011-2016 cycles were utilized. Four urinary metabolites of organophosphate esters: diphenyl phosphate (DPHP), bis (1,3-dichloro-2-propyl) phosphate (BDCPP), bis (2-chloroethyl) phosphate (BCEP), and dibutyl phosphate (DBUP) were included in the study. Multivariate logistic regression and restricted cubic spline (RCS) were used to evaluate the relationship between urinary OPEs metabolites and OAB. Interaction analysis was conducted on subgroups to confirm the findings.

Results

A total of 3,443 United States (US) adults aged 20 years or older were included in the study, of whom 597 participants were considered to have OAB. After adjusting for potential confounding factors, we found a positive association between DPHP and the risk of overactive bladder. The risk of overactive bladder increased with increasing DPHP concentrations compared with quartile 1 (quartile 2, OR = 1.19, 95% CI, 0.82-1.73, P = 0.34; quartile 3, OR = 1.67, 95% CI, 1.10-2.53, P = 0.02; Q4, OR = 1.75, 95% CI, 1.26-2.43, P = 0.002). However, after dividing the participants by gender, only the female group retained consistent results. Additionally, restricted cubic spline analysis revealed a nonlinear dose-response correlation between DPHP and OAB in female participants. In the subgroup analysis based on age, race, body mass index (BMI), recreational activity, smoking status, drinking status, hypertension, diabetes, and stroke, the interaction analysis revealed that the findings were uniform.

Conclusion

Our findings indicate that exposure to DPHP could elevate the risk of OAB in US adult females. Further experimental studies are needed to explore the underlying mechanism in the future.

Machine Learning Model Based on Insulin Resistance Metagenes Underpins Genetic Basis of Type 2 Diabetes

Insulin resistance (IR) is considered the precursor and the key pathophysiological mechanism of type 2 diabetes (T2D) and metabolic syndrome (MetS). However, the pathways that IR shares with T2D are not clearly understood. Meta-analysis of multiple DNA microarray datasets could provide a robust set of metagenes identified across multiple studies. These metagenes would likely include a subset of genes (key metagenes) shared by both IR and T2D, and possibly responsible for the transition between them. In this study, we attempted to find these key metagenes using a feature selection method, LASSO, and then used the expression profiles of these genes to train five machine learning models: LASSO, SVM, XGBoost, Random Forest, and ANN. Among them, ANN performed well, with an area under the curve (AUC) > 95%. It also demonstrated fairly good performance in differentiating diabetics from normal glucose tolerant (NGT) persons in the test dataset, with 73% accuracy across 64 human adipose tissue samples. Furthermore, these core metagenes were also enriched in diabetes-associated terms and were found in previous genome-wide association studies of T2D and its associated glycemic traits HOMA-IR and HOMA-B. Therefore, this metagenome deserves further investigation with regard to the cardinal molecular pathological defects/pathways underlying both IR and T2D.

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 Urobiome and Its Role in Overactive Bladder

Urine is no longer considered to be sterile. After the existence of the microbiome was revealed through metagenomic analysis using next-generation sequencing, the relationship between characteristics of the microbiome and diseases have been studied and published in various journals. A microbiome exists in the urinary tract and is associated with urinary tract infection, malignancy of the genitourinary tract, and lower urinary tract symptoms. Based on the urine sampling method, sampling site, culture method, and sex, the characteristics of the microbiome vary. Most of the Lactobacillus species are identified mainly in women, and various other species are identified in men. These microorganisms can cause or prevent various diseases. Variations in the microbiome are seen in those with and without disease, and an asymptomatic status does not indicate the absence of microbes. This microbiome has been implicated in a variety of lower urinary tract symptoms and diseases, in particular, overactive bladder. The microbiome differs between patients with urgency and urge urinary incontinence and healthy individuals. There are many aspects of the microbiome yet to be studied in relation to other lower urinary tract symptoms.

Diagnostic Potential of Low Serum Platelet, Albumin and Prolong PT-INR for Overactive Bladder and Nocturia in Chronic Hepatitis-Related Liver Cirrhosis

Overactive bladder (OAB) is defined as urgency, usually with frequency, nocturia, and incontinence. Patients with liver cirrhosis often present with urinary complaints. The possible reason for this is fluid redistribution, which may induce OAB resulting from portal hypertension and ascites. We conducted this study to investigate predictors of OAB in cirrhotic patients. A total of 164 patients with chronic viral hepatitis-related liver cirrhosis were enrolled and 158 (96.3%) completed the Overactive Bladder Symptoms Score (OABSS) questionnaire. Age, severity of liver cirrhosis, comorbidities, serum sodium level, use of diuretics, body mass index and renal function were also recorded. In the study cohort, the prevalence of OAB was 31.01% and the prevalence of urge incontinence (OAB wet) was 18.3%. Patients with an urgency score ≥2 in OABSS had a significantly lower platelet level (p = 0.025) regardless of the use of diuretics. In addition, 98 patients (62%) with nocturia and 29 patients (18%) with urge incontinence had significantly lower levels of serum albumin (p = 0.028 and 0.044, respectively). In conclusion, patients with liver cirrhosis have a high prevalence of overactive bladder. A low platelet and low serum albumin level in these patients may be predictors for overactive bladder. And longer PT-INR is also a possible biomarker for nocturia.

Urinary metabolomics predict the severity of overactive bladder syndrome in an aging female population

INTRODUCTION AND HYPOTHESIS

To identify urinary metabolites that can facilitate the diagnosis and the characterization of the underlying pathophysiology of the association between the overactive bladder syndrome (OAB) and metabolic syndrome.

METHODS

We used gas chromatography-mass spectrometry to compare the urinary metabolome of 20 females of 50-80 years of age with OAB to that of 20 controls of the same age group. We performed urinary metabolomic analysis and obtained serum markers of metabolic syndrome for each subject. Participants completed a clinical evaluation and validated self-reported questionnaires of lower urinary tract symptoms as well as a one-day voiding diary.

RESULTS

In the OAB subjects, we identified increased urinary levels of markers of mitochondrial dysfunction (itaconate, malate and fumarate), oxidative stress (L-pyroglutamate and α-hydroxyglutarate) and ketosis (α-hydroxybutyrate and α-hydroxyisobutyrate). The increased levels of these markers correlated significantly with the OAB symptoms score on questionnaires. We found, using a multiple linear regression model, that age, blood glucose and urine metabolites (malate, fumarate and α-hydroxyisobutyrate) were significant predictive factors of OAB severity. Fumarate had high sensitivity as a biomarker of OAB due to metabolic syndrome, based on a statistically significant receiver-operating characteristic (ROC) curve, indicating its potential as a diagnostic tool.

CONCLUSIONS

Altogether, these findings establish that urinary metabolites of mitochondrial dysfunction, ketosis and oxidative stress can be potential biomarkers of OAB severity and diagnosis.

Associations Between Risk Factors and Overactive Bladder: A Meta-analysis

Age and body mass index are associated with increased risks of overactive bladder, whereas employment status is associated with a decreased risk of overactive bladder.

Objective

The purpose of this study was to investigate the risk factors of overactive bladder (OAB).

Methods

The PubMed, Embase, and Cochrane Library databases were retrieved through May 2016. Odds ratios (OR) or standard mean differences (SMDs) with 95% confidence intervals (CIs) were used to evaluate the associations between risk factors and OAB. Heterogeneity among studies was examined using χ² test based on the Q and I² tests.

Results

A total of 28 articles were analyzed in our study. The results suggested that age and body mass index were significantly higher in OAB patients than in non-OAB controls (SMDs [95% CIs], 0.30 [0.19–0.41] and 0.39 [0.24–0.53]). A significant negative association was found between employment status and OAB (OR [95% CIs], 0.64 [0.46–0.90]). However, sex, educational level, parity, vaginal delivery, race, menopause, marital status, smoking, and alcohol consumption were not significantly different in OAB and non-OAB control patients (ORs [95% CIs], 0.95 [0.59–1.55], 1.04 [0.82, 1.33], 0.98 [0.56–1.70], 1.66 [0.90–3.07], 0.98 [0.75–1.28], 1.84 [0.23–14.70], 0.97 [0.78–1.19], 0.91 [0.77–1.08], and 0.88 [0.71–1.09], respectively). In addition, the number of parities and vaginal deliveries in OAB patients also showed no significant differences compared with non-OAB control patients (SMDs [95% CI], 0.05 [−0.27 to 0.38] and −0.16 [0.40 to 0.09]).

Conclusions

This meta-analysis suggests that age and body mass index are associated with increased risks of OAB, whereas employment status is associated with a decreased risk of OAB. Further prospective studies with large sample sizes are needed to confirm this conclusion.

Risk factors and factors affecting the severity of overactive bladder symptoms in Korean women who use public health centers

Objective

To investigate the prevalence, risk factors of overactive bladder (OAB) and the factors affecting the severity of OAB symptoms.

Methods

A total 822 interviews with women aged 18–80 years who visited public health centers were conducted between April 2014 and April 2015. The questionnaire was composed of 16 questions about urinary symptoms, 14 questions about self-treatment and the use of complementary and alternative medicine, and 21 questions about socio-demographic characteristics. The diagnostic criterion for OAB is a total OAB symptom score of 3 and more, with an urgency score of 2 or more. To know the risk factors and factors affecting the severity of OAB, the multivariate logistic regression analysis was performed.

Results

One hundred fifty-seven participants (19.3%) were diagnosed with OAB, of whom 10.7%, 8.1%, and 0.7% had mild, moderate, and severe OAB symptoms, respectively. In addition, the prevalence of OAB increased with age. Among all the participants, 39.1% had stress incontinence, among them 32.7% had OAB as well. The significant risk factors of OAB were identified as age, current smoking, hyperlipidemia, cardiovascular and renal disease, whereas, the factors affecting the severity of OAB were age, current smoking, and hyperlipidemia.

Conclusion

Those who have risk factors and factors affecting severity of OAB should be educated to increase OAB awareness and act of urinary health promotion.

Epigallocatechin-3-gallate alleviates bladder overactivity in a rat model with metabolic syndrome and ovarian hormone deficiency through mitochondria apoptosis pathways

Metabolic syndrome (MetS) and ovarian hormone deficiency could affect bladder storage dysfunction. Epigallocatechin-3-gallate (EGCG), a polyphenolic compound in green tea, has been shown to protect against ovarian hormone deficiency induced overactive bladder (OAB). The present study investigated oxidative stress induced by MetS and bilateral ovariectomy (OVX), and elucidated the mechanism underlying the protective effect of EGCG (10 umol/kg/day) on bladder overactivity. Rats were fed with high fat high sugar (HFHS) diet to induce MetS and received ovariectomy surgery to deprive ovarian hormone. By dieting with HFHS for 6 months, rats developed MetS and OAB. MetS + OVX deteriorated bladder storage dysfunction more profound than MetS alone. MetS and MetS + OVX rats showed over-expression of inflammatory and fibrosis markers (1.7~3.8-fold of control). EGCG pretreatment alleviated storage dysfunction, and protected the bladders from MetS and OVX - induced interstitial fibrosis changes. Moreover, OVX exacerbated MetS related bladder apoptosis (2.3~4.5-fold of control; 1.8~2.6-fold of Mets group), enhances oxidative stress markers (3.6~4.3-fold of control; 1.8~2.2-fold of Mets group) and mitochondrial enzyme complexes subunits (1.8~3.7-fold of control; 1.5~3.4-fold of Mets group). EGCG pretreatment alleviated bladder apoptosis, attenuated oxidative stress, and reduced the mitochondrial and endoplasmic reticulum apoptotic signals. In conclusions, HFHS feeding and ovarian hormone deficiency enhances the generation of oxidative stress mediated through mitochondrial pathway. EGCG reduced the generation of oxidative stress and lessened bladder overactivity.

Vascular risk factors for male and female urgency urinary incontinence at age 68 years from a British birth cohort study

Objective

To investigate the prevalence of urgency urinary incontinence (UUI) at age 68 years and the contribution of vascular risk factors to male and female UUI pathogenesis in addition to the associations with raised body mass index (BMI).

Subjects and methods

In all, 1 762 participants from the Medical Research Council (MRC) National Survey for Health and Development birth cohort who answered the International Consultation on Incontinence Questionnaire short form (ICIQ‐SF), at age 68 years, were included. Logistic regression was used to estimate associations between UUI and earlier life vascular risk factors including: lipid status, diabetes, hypertension, BMI, previous stroke or transient ischaemic attack (TIA) diagnosis; adjusting for smoking status, physical activity, co‐presentation of stress UI symptoms, educational attainment; and in women only, type of menopause, age at period cessation, and use of hormone replacement therapy (HRT).

Results

UUI was reported by 12% of men and 19% of women at age 68 years. Female sex, previous stroke or TIA diagnosis, increased BMI and hypertension (in men only) at age 60–64 years were independent risk factors for UUI. Female sex, increased BMI, and a previous diagnosis of stroke/TIA increased the relative risk of more severe UUI symptoms. Type and timing of menopause and HRT use did not alter the estimated associations between UUI and vascular risk factors in women.

Conclusion

Multifactorial mechanisms lead to UUI and vascular risk factors may contribute to the pathogenesis of bladder overactivity in addition to higher BMI. Severe UUI appears to be a distinct presentation with more specific contributory mechanisms than milder UUI.

Analysis of the prevalence of and factors associated with overactive bladder in adult Korean women

Background

Overactive bladder (OAB) is one of the most prevalent lower urinary tract conditions and has been suggested to be related to various factors. We assessed the prevalence of and factors associated with OAB in women based on a large cross-sectional, population-based study of adult Korean women.

Methods

The Korean community health survey (KCHS) of 2012 was reviewed, and 107,950 female participants aged 19 to 107 years were identified for inclusion in this study. The overactive bladder symptom score (OABSS) was used to define and classify OAB as mild, moderate, or severe. Numerous variables, including marital status; physical activity; education and income levels; type of occupation; body mass index (BMI); smoking; alcohol; sleep time; and medical history of hypertension, diabetes mellitus, hyperlipidemia, or cerebral stroke, were evaluated. The correlation of these variables with the prevalence of OAB was analyzed using simple and multiple logistic regression analyses with complex sampling.

Results

The results showed that 5.2% of adult women experienced OAB. Multiple regression analyses showed a significant correlation between the following variables and OAB: older age (adjusted odds ratio [AOR] = 1.44, 95% confidence interval [CI] = 1.39–1.50, P < 0.001 as 10 years older); married status (AOR = 0.83, 95%CI = 0.70–0.96, P = 0.016); lower level of income (AOR = 1.50, 95%CI = 1.34–1.68, P < 0.001); high BMI (AOR = 1.33, 95%CI = 1.23–1.44, P < 0.001); smoking (AOR = 1.24, 95%CI = 1.04–1.47, P < 0.001); long sleep time (AOR = 1.95, 95%CI = 1.69–2.26); and medical history of hypertension (AOR = 1.11, 95%CI = 1.03–1.21, P = 0.011), diabetes mellitus (AOR = 1.38, 95%CI = 1.25–1.53, P < 0.001), hyperlipidemia (AOR = 1.27, 95%CI = 1.16–1.39, P < 0.001), and cerebral stroke (AOR = 2.04, 95%CI = 1.73–2.41, P < 0.001). The level of stress showed a dose-dependent association with OAB (AOR [95%CI] = 3.28 [2.81–3.83] > 2.11 [1.91–2.33] >1.28 [1.16–1.41] for severe > moderate > some stress, respectively, P < 0.001).

Conclusion

The prevalence of OAB was approximately 5.2% among adult Korean women. Older age; high BMI; stress level; sleep duration; levels of income and education; marital status; smoking; and medical history of hypertension, diabetes mellitus, hyperlipidemia, and cerebral stroke were significantly related to OAB in women.

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

BACKGROUND

Epidemiological data suggest that lower urinary tract symptoms (LUTSs) may be associated with metabolic syndrome (MetS). Inflammation has been proposed as a candidate mechanism at the crossroad between these two clinical entities. The aim of this review article is to evaluate the role of MetS-induced inflammation in the pathogenesis and progression of LUTS.

METHODS

A systematic review was conducted using the keywords 'metabolic syndrome and lower urinary tract symptoms' within the title search engines including PubMed, Web of Science and the Cochrane Library for relevant research work published between 2000 and January 2015. The obtained literature was reviewed by the primary author (QH) and was assessed for eligibility and standard level of evidence.

RESULTS

Total of 52 articles met the eligibility criteria. On the basis of database search during the past 15 years and our systematic review of prospective and retrospective cohorts, case-control trials, observational studies and animal data identified a possible link between MetS-induced inflammation and LUTS including BPH, bladder outlet obstruction, overactive bladder, urinary incontinence and other possible urinary tract abnormalities.

CONCLUSIONS

There is convincing evidence to suggest that MetS and inflammation could be important contributors to LUTS in men, particularly in the development of BPH. However, the role of MetS-induced inflammation remains unclear in overactive bladder, urinary incontinence and etiology of LUTS progression.

Is there a link between overactive bladder and the metabolic syndrome in women? A systematic review of observational studies

OBJECTIVES

To conduct a systematic review to determine whether there is an association between metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) or overactive bladder (OAB) in women.

METHODS

We systematically reviewed English language observational studies on the effect of MetS (or component factors) on the presence of OAB or LUTS in women. We searched PubMed, Web of Science and The Cochrane Library with no date restrictions, checked reference lists and undertook citation searches in PubMed and Google Scholar. Studies were assessed for risk of bias. Because of heterogeneity, results were not pooled, but are reported narratively.

RESULTS

Of 27 included studies, only three looked at the link between MetS and OAB. The rest looked at links between OAB and components of MetS such as obesity or insulin resistance (n = 10), between MetS and urinary symptoms (n = 3) and between urinary symptoms and components of MetS, such as obesity (n = 14). Evidence is currently limited, but it does suggest that there may be important links between MetS and OAB and components of MetS such as obesity.

CONCLUSIONS

The literature on MetS and OAB or LUTS in women is limited, and poor quality. However, the evidence available on obesity appears to support MetS as a contributor and predictor of LUTS in women. Many of the women with LUTS will be overweight and will have features of the MetS, if looked for. This provides not only an opportunity to encourage weight loss as an adjunct to therapy for the OAB symptoms but also a window of opportunity to address cardiovascular risk factors and prevent future cardiovascular morbidity and mortality.

Gender differences in bladder control: from babies to elderly

In both sexes, there are anatomical and behavioral differences in dealing with bladder control, as well as voiding and incontinence. Despite intensive research within the last decades, the differences in physiology and pathophysiology as well as gender differences of bladder control and continence are still poorly understood and further research is highly needed. In babies, gender difference seems to be most likely caused by a difference in maturity rate of the bladder. After gaining bladder control, behavior starts to be influenced by socialization. During preschool and school, children experience a negative perception of school toilets. Especially girls crouch over the toilet seat and train to empty the bladder without relaxation of the pelvic floor. This posture may lead to bladder dysfunction. Often adult women continue this bad habit and bladder dysfunction may consolidate. From the fourth decade in both sexes lower urinary tract symptoms start to develop. However, men and women handle the problem variedly showing gender differences in coping strategies with better coping mechanisms in women. In general, gender difference in help seeking and receiving treatment increases with younger age. In elderly, urinary incontinence is only associated with a higher mortality in men, and elderly men seek more often professional help. Aim of the review is to provide an insight into gender differences of bladder control and bladder dysfunction.