Obesity-initiated metabolic syndrome promotes urinary voiding dysfunction in a mouse model

How do we make progress in phenotyping patients with LUT such as OAB and underactive detrusor, including using urine markers and microbiome data, in order to personalize therapy? ICI-RS 2023: Part 1

INTRODUCTION

Overactive bladder (OAB) and Underactive bladder (UAB) could be associated with metabolic syndrome, affective disorders, sex hormone deficiency, changes in urinary microbiota, functional gastrointestinal disorders, or autonomic nervous system dysfunction.

OBJECTIVES

The aim of this Think Tank was to provide a guide on how to investigate OAB and/or detrusor underactivity (DU) patients to better clarify the underlying pathophysiology and possibly personalize the treatment.

METHODS

A compendium of discussion based on the current evidence related to phenotyping patients with OAB or DU investigating metabolic, neurogical, psychological and gastrointestinal aspects with the aim to personalize the treatment.

RESULTS AND CONCLUSIONS

The article emphasizes the critical significance of adopting a comprehensive yet tailored approach to phenotyping patients with lower urinary tract symptoms, such as OAB and UAB. The intricate interplay between the lower urinary tract and various factors, metabolic, neurological, psychological, and gastrointestinal can define unique LUT profiles, enabling personalized therapies to replace the one-size-fits-all approach.

Methylglyoxal and Advanced Glycation End Products (AGEs): Targets for the Prevention and Treatment of Diabetes-Associated Bladder Dysfunction?

Methylglyoxal (MGO) is a highly reactive α-dicarbonyl compound formed endogenously from 3-carbon glycolytic intermediates. Methylglyoxal accumulated in plasma and urine of hyperglycemic and diabetic individuals acts as a potent peptide glycation molecule, giving rise to advanced glycation end products (AGEs) like arginine-derived hydroimidazolone (MG-H1) and carboxyethyl-lysine (CEL). Methylglyoxal-derived AGEs exert their effects mostly via activation of RAGE, a cell surface receptor that initiates multiple intracellular signaling pathways, favoring a pro-oxidant environment through NADPH oxidase activation and generation of high levels of reactive oxygen species (ROS). Diabetic bladder dysfunction is a bothersome urological complication in patients with poorly controlled diabetes mellitus and may comprise overactive bladder, urge incontinence, poor emptying, dribbling, incomplete emptying of the bladder, and urinary retention. Preclinical models of type 1 and type 2 diabetes have further confirmed the relationship between diabetes and voiding dysfunction. Interestingly, healthy mice supplemented with MGO for prolonged periods exhibit in vivo and in vitro bladder dysfunction, which is accompanied by increased AGE formation and RAGE expression, as well as by ROS overproduction in bladder tissues. Drugs reported to scavenge MGO and to inactivate AGEs like metformin, polyphenols, and alagebrium (ALT-711) have shown favorable outcomes on bladder dysfunction in diabetic obese leptin-deficient and MGO-exposed mice. Therefore, MGO, AGEs, and RAGE levels may be critically involved in the pathogenesis of bladder dysfunction in diabetic individuals. However, there are no clinical trials designed to test drugs that selectively inhibit the MGO-AGEs-RAGE signaling, aiming to reduce the manifestations of diabetes-associated bladder dysfunction. This review summarizes the current literature on the role of MGO-AGEs-RAGE-ROS axis in diabetes-associated bladder dysfunction. Drugs that directly inactivate MGO and ameliorate bladder dysfunction are also reviewed here.

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.

Dysfunction of the aging female mouse urethra is associated with striated muscle loss and increased fibrosis: an initial report

The decline of urethral function with advancing age plays a major role in urinary incontinence in women, impairing quality of life and economically burdening the health care system. However, none of the current urinary incontinence treatments address the declining urethral function with aging, and the mechanisms by which aging impacts urethra physiology remain little known or explored. Here, we have compared functional, morphometric, and global gene expression of urethral tissues between young and old female mice. Bladder leak point pressure (LPP) measurement showed that the aged female mice had 26.55% lower LPP compared to younger mice. Vectorized Scale-Invariant Pattern Recognition (VIPR) analysis of the relative abundance of different tissue components revealed that the mid-urethra of old female mice contains less striated muscle, more extracellular matrix/fibrosis, and diminished elastin fibers ratio compared to young mice. Gene expression profiling analysis (bulk RNA-seq of the whole urethra) showed more down-regulated genes in aged than young mice. Immune response and muscle-related (striated and smooth) pathways were predominantly enriched. In contrast, keratinization, skin development, and cell differentiation pathways were significantly downregulated in aged urethral tissues compared to those from young female mice. These results suggest that molecular pathways (i.e., ACVR1/FST signaling and CTGF/TGF-β signaling) leading to a decreased striated muscle mass and an increase in fibrous extracellular matrix in the process of aging deserve further investigation for their roles in the declined urethral function.

Fructooligosaccharide (FOS) and Galactooligosaccharide (GOS) Improve Neuroinflammation and Cognition By Up-regulating IRS/PI3K/AKT Signaling Pathway in Diet-induced Obese Mice

Increasing evidence has indicated that prebiotics as an alternative treatment for neuropsychiatric diseases. This study evaluated the prebiotics Fructooligosaccharides (FOS) and Galactooligosaccharides (GOS) on the modulation of neuroinflammation and cognition in an experimental model of mice high-fat diet fed. Initially, mice were distributed in the following groups: (A) control standard diet (n = 15) and (B) HFD for 18 weeks (n = 30). In the 13th week, the mice were later divided into the following experimental groups: (A) Control (n = 15); (B) HFD (n = 14); and (C) HFD + Prebiotics (n = 14). From the 13th week, the HFD + Prebiotics group received a high-fat diet and a combination of FOS and GOS. In the 18th week, all animals performed the T-maze and Barnes Maze, and were later euthanized. Biochemical and molecular analyzes were performed to assess neuroinflammation, neurogenesis, synaptic plasticity, and intestinal inflammation. Mice fed HFD had higher blood glucose, triglyceridemia, cholesterolemia, and higher serum IL-1β associated with impaired learning and memory. These obese mice also showed activation of microglia and astrocytes and significant immunoreactivity of neuroinflammatory and apoptosis markers, such as TNF-α, COX-2, and Caspase-3, in addition to lower expression of neurogenesis and synaptic plasticity markers, such as NeuN, KI-67, CREB-p, and BDNF. FOS and GOS treatment significantly improved the biochemistry profile and decreased serum IL-1β levels. Treatment with FOS and GOS also reduced TNF-α, COX-2, Caspase-3, Iba-1, and GFAP-positive cells in the dentate gyrus, decreasing neuroinflammation and neuronal death caused by chronic HFD consumption. In addition, FOS and GOS promoted synaptic plasticity by increasing NeuN, p-CREB, BDNF, and KI-67, restoring spatial learning ability and memory. Moreover, FOS and GOS on HFD modulated the insulin pathway, which was proved by up-regulating IRS/PI3K/AKT signaling pathway, followed by a decreasing Aβ plate and Tau phosphorylation. Furthermore, the prebiotic intervention reshaped the HFD-induced imbalanced gut microbiota by modulating the composition of the bacterial community, markedly increasing Bacteroidetes. In addition, prebiotics decreased intestinal inflammation and leaky gut. In conclusion, FOS and GOS significantly modulated the gut microbiota and IRS/PI3K/AKT signaling pathway, decreased neuroinflammation, and promoted neuroplasticity improving spatial learning and memory. Schematic summarizing of the pathways by FOS and GOS improves memory and learning through the gut-brain axis. FOS and GOS improve the microbial profile, reducing intestinal inflammation and leaky gut in the distal colon. Specifically, the administration of FOS and GOS decreases the expression of TLR4, TNF-α, IL-1β, and MMP9 and increases the expression of occludin and IL-10. Prebiotics inhibit neuroinflammation, neuronal apoptosis, and reactive gliosis in the hippocampus but restore synaptic plasticity, neuronal proliferation, and neurogenesis.

Correlation between sKL and Nrf2 plasma levels and calcium oxalate urolithiasis

OBJECTIVE

To investigate the relationship between plasma levels of sKL and Nrf2 and calcium oxalate calculi.

METHODS

The clinical data of 135 patients with calcium oxalate calculi treated in the Department of Urology of the second affiliated Hospital of Xinjiang Medical University from February 2019 to December 2022, and 125 healthy persons who underwent physical examination in the same period were collected and divided into healthy group and stone group. The levels of sKL and Nrf2 were measured by ELISA. Correlation test was used to analyze the risk factors of calcium oxalate stones, logistic regression analysis was used to analyze the risk factors of calcium oxalate stones, and ROC curve was used to evaluate the sensitivity and specificity of sKL and Nrf2 in predicting urinary calculi.

RESULTS

Compared with the healthy group, the plasma sKL level in the stone group decreased (111.53 ± 27.89 vs 130.68 ± 32.51), while the plasma Nrf2 level increased (300.74 ± 114.31 vs 246.74 ± 108.22). There was no significant difference in the distribution of age and sex between the healthy group and the stone group, but there were significant differences in plasma levels of WBC, NEUT, CRP, BUN, BUA, SCr, BMI, and eating habits. The results of correlation test showed that the level of plasma Nrf2 was positively correlated with SCr (r = 0.181, P < 0.05) and NEUT (r = 0.144 P < 0.05). Plasma sKL was not significantly correlated with Nrf2 (r = 0.047, P > 0.05), WBC (r = 0.108, P > 0.05), CRP (r = - 0.022, P > 0.05), BUN (r = - 0.115, P > 0.05), BUA (r = - 0.139, P > 0.05), SCr (r = 0.049, P > 0.05), and NEUT (r = 0.027, P > 0.05). Plasma Nrf2 was not significantly correlated with WBC (r = 0.097, P > 0.05), CRP (r = 0.045, P > 0.05), BUN (r = 0.122, P > 0.05), and BUA (r = 0.122, P > 0.05); (r = 0.078, P > 0.05) had no significant correlation. Logistic regression showed that elevated plasma sKL (OR 0.978, 95% CI 0.969 ~ 0.988, P < 0.05) was a protective factor for the occurrence of calcium oxalate stones, BMI (OR 1.122, 95% CI 1.045 ~ 1.206, P < 0.05), dietary habit score (OR 1.571, 95% CI 1.221 ~ 2.020, P < 0.05), and WBC (OR 1.551, 95% CI 1.423 ~ 1.424, P < 0.05). Increased NEUT (OR 1.539, 95% CI 1.391 ~ 1.395, P < 0.05) and CRP (OR 1.118, 95% CI: 1.066 ~ 1.098, P < 0.05) are risk factors for the occurrence of calcium oxalate stones.

CONCLUSION

Plasma sKL level decreased and Nrf2 level increased in patients with calcium oxalate calculi. Plasma sKL may play an antioxidant role in the pathogenesis of calcium oxalate stones through Nrf2 antioxidant pathway.

Detrusor underactivity is associated with metabolic syndrome in aged primates

Lower urinary tract (LUT) dysfunction is prevalent in the elderly population, and clinical manifestations include urinary retention, incontinence, and recurrent urinary tract infections. Age-associated LUT dysfunction is responsible for significant morbidity, compromised quality of life, and rising healthcare costs in older adults, but its pathophysiology is not well understood. We aimed to investigate the effects of aging on LUT function by urodynamic studies and metabolic markers in non-human primates. Adult (n = 27) and aged (n = 20) female rhesus macaques were evaluated by urodynamic and metabolic studies. Cystometry showed detrusor underactivity (DU) with increased bladder capacity and compliance in aged subjects. Metabolic syndrome indicators were present in the aged subjects, including increased weight, triglycerides, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and high sensitivity C-reactive protein (hsCRP), whereas aspartate aminotransferase (AST) was unaffected and the AST/ALT ratio reduced. Principal component analysis and paired correlations showed a strong association between DU and metabolic syndrome markers in aged primates with DU but not in aged primates without DU. The findings were unaffected by prior pregnancies, parity, and menopause. Our findings provide insights into possible mechanisms for age-associated DU and may guide new strategies to prevent and treat LUT dysfunction in older adults.

Effects of different diets used to induce obesity/metabolic syndrome on bladder function in rats

Preclinical and human studies on the relationship between obesity/metabolic syndrome (MetS) and lower urinary tract dysfunction (LUTD) are inconsistent. We compared the temporal effects of feeding four different diets used to induce obesity/MetS, including 60% fructose, 2% cholesterol +10% lard, 30% fructose + 20% lard, or 32.5% lard diet, up to 42 wk, on metabolic parameters and bladder function in male Sprague-Dawley rats. Rats fed a 30% fructose + 20% lard or 32.5% lard diet consumed less food (grams), but only the 32.5% lard diet group took in more calories. Feeding rats a 60% fructose or 30% fructose + 20% lard diet led to glucose intolerance and increased blood pressure. Higher body weight and increased cholesterol levels were observed in the rats maintained on a 2% cholesterol +10% lard diet, whereas exposure to a 32.5% lard diet affected most of the above parameters. Voiding behavior measurement showed that voiding frequency and the total voided volume were lower in the experimental diet groups except for the 30% fructose + 20% lard group. The mean voided volume was lower in the 30% fructose + 20% lard and 32.5% lard groups compared with the control group. Cystometric analysis revealed a decreased bladder capacity, mean voided volume, intermicturition interval, and compliance in the 32.5% lard diet group. In conclusion, experimental diets including 60% fructose, 30% fructose + 20% lard, or 2% cholesterol + 10% lard diet differently affected physiological and metabolic parameters and bladder function to a limited extent, while exposure to a 32.5% lard diet had a greater impact.

A pilot dynamic analysis of formative factors of nephrolithiasis related to metabolic syndrome: evidence in a rat model

Introduction and objective

To examine the dynamic changes in the formative factors of nephrolithiasis and the final micromorphological changes in an obesity-initiated metabolic syndrome (MS) rat model.

Methods

Forty five-week-old male Sprague–Dawley (SD) rats were randomly divided into four groups: the regular diet group (RD), high-fat diet group (HFD), regular diet with drug (ethylene glycol and ammonium chloride) group (RDD), and high-fat diet with drug group (HFDD). A dynamic assessment of MS components (body weight (BW), body length (BL), Lee’s index (LI), blood glucose (BG), total cholesterol (TC), and triglycerides (TGs)) and stone-forming factors (urinary pH, urinary calcium, and urinary oxalate acid) was carried out. In addition, the levels of oxidative stress (OS) markers (CAT, SOD, TAC, GSH-PX, and MDA) were measured, and histological analysis was carried out at the end of 16 weeks.

Results

MS-related parameters, such as BW, LI, BG, TC, and TG, were significantly higher in HFD-fed rats than in RD-fed rats (p < 0.001). In the HFDD group, significantly lower urinary pH, hyperoxaluria, and hypocalciuria were noted in the dynamic assessment of stone-forming factors (p < 0.001). CAT, TAC, and MDA were notably changed in the HFD-fed groups, particularly the HFDD rats. Histological analysis showed that the renal tubules of HFDD rats had the highest scores for both inflammation and renal crystallization deposition (p < 0.05).

Conclusions

Our results suggest that male SD rats with MS are prone to developing nephrolithiasis. Validation in an in vivo model may lead to an understanding of the underlying pathophysiological mechanisms of action of MS-related nephrolithiasis in humans.

Key messages

Male SD rats with metabolic syndrome are more prone to developing calcium oxalate nephrolithiasis after treatment with ethylene glycol and ammonium chloride compared to control lean rats.

MS-related nephrolithiasis in rats induced by ethylene glycol and ammonium chloride is mainly related to increased hyperoxaluria and inflammation and decreased antioxidant levels.

High-fat diet-fed SD rats treated with ethylene glycol and ammonium chloride are a stable and valid in vivo model for understanding the potential mechanism of action of MS-related nephrolithiasis.

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.

Longitudinal Changes in Adiposity and Lower Urinary Tract Symptoms Among Older Men

BACKGROUND

Adiposity increases risk for male lower urinary tract symptoms (LUTS), although longitudinal studies have produced conflicting results. No prior studies have evaluated longitudinal associations of changes in adiposity with concurrent LUTS severity among older men.

METHODS

We used repeated adiposity measurements from dual-energy x-ray absorptiometry (DXA), body mass index (BMI), and American Urological Association Symptom Index (AUASI) measured at four study visits over a 9-year period among 5949 men enrolled in the Osteoporotic Fractures in Men (MrOS) study. Linear mixed effect models adjusted for age, health-related behaviors, and comorbidities were created to evaluate the association between baseline and change in visceral adipose tissue (VAT) area, total fat mass, and BMI with change in LUTS severity measured by the AUASI.

RESULTS

A non-linear association was observed between baseline VAT area and change in AUASI: men in baseline VAT tertile (T) 2 had a lower annual increase in AUASI score compared to men in T1 and T3 (T2 versus T1: β=-0.07; 95% CI -0.12, -0.03; P= 0.008; T3 versus T1: NS) but differences were small. No significant associations were observed between change in VAT area and change in AUASI score. Neither baseline tertiles nor change in total fat mass or BMI were associated with change in AUASI score.

CONCLUSIONS

Changes in VAT area, total fat mass, and BMI were not associated with change in LUTS severity in this cohort. Thus, despite other health benefits, interventions targeting adiposity alone are unlikely to be effective for preventing or treating LUTS among older men.

Methylglyoxal, a Reactive Glucose Metabolite, Induces Bladder Overactivity in Addition to Inflammation in Mice

Diabetic bladder dysfunction (DBD) is one of the most common complication of diabetes. Methylglyoxal (MGO), a highly reactive dicarbonyl compound formed as a by-product of glycolysis, is found at high levels in plasma of diabetic patients. Here, we explored the effects of chronic administration of MGO on micturition pattern (cystometry) and bladder contractility in vitro in healthy male C57/BL6 mice. Methylglyoxal was given at 0.5% in drinking water for 4 weeks. Exposure to MGO led to bladder tissue disorganization, edema of lamina propria, partial loss of urothelium and multiple leukocyte infiltrates. Filling cystometry revealed significant increases of micturition frequency and number of non-voiding contractions (NVCs) in the MGO group, clearly indicating an overactive bladder profile. Bladder contractions induced by electrical-field stimulation (EFS) and carbachol were significantly higher in the MGO group, while the muscarinic M₂ and M₃ mRNA expressions remained unchanged between groups. Additionally, MGO exposure induced upregulation of TRPA1 and down-regulation of TRPV1 and TRPV4 in bladder tissues. Methylglyoxal did not change the mRNA expression of the advanced glycation end products receptor (RAGE), but markedly increased its downstream NF-κB - iNOS signaling. The mRNA expression of cyclooxygenase-2 (COX-2) and reactive-oxygen species (ROS) levels remained unchanged. Altogether, our data show that 4-week MGO intake in mice produces an overactive bladder phenotype in addition to bladder inflammation and increased NF-kB/iNOS signaling. TRPA1 up-regulation and TRPV1/TRPV4 down-regulation may account for the MGO-induced bladder overactivity. Scavengers of MGO could be an option to ameliorate bladder dysfunction in diabetic conditions.

Urological complications of obesity and diabetes in males and females of three mouse models: temporal manifestations

Diabetic bladder dysfunction is a frequent complication of diabetes. Although many mouse models of diabetes now exist, there has been little systematic effort to characterize them for the timing of onset and severity of bladder dysfunction. We monitored metabolic status and tested bladder function by void spot assay and limited anesthetized cystometry in both male and female mice of three models of obesity and diabetes: a type 1 diabetes model (the Akita mouse) and two type 2 diabetes models [the diet-induced obese (DIO) model and the ob/ob mouse]. Akita mice had insulin pellets implanted subcutaneously every 3 mo to mimic poorly controlled type 1 diabetes in humans. Mice were hyperglycemic by 48 days after implants. Female mice exhibited no bladder dysfunction at any age up to 20 mo and gained weight normally. In contrast, by 7 mo, male Akita mice developed a profound polyuria and failed to show normal weight gain. There were no observable signs of bladder dysfunction in either sex. DIO mice on high/low-fat diets for 16 mo exhibited mild hyperglycemia in female mice (not in male mice), mild weight gain, and no evidence of bladder dysfunction. Ob/ob mice were followed for 8 mo and became extremely obese. Male and female mice were glucose intolerant, insulin intolerant, and hyperinsulinemic at 4 mo. By 8 mo, their metabolic status had improved but was still abnormal. Urine volume increased in male mice but not in female mice. Bladder dysfunction was observed in the spotting patterns of female mice at 4 and 6 mo of age, resolving by 8 mo. We conclude there are dramatic sex-related differences in lower urinary tract function in these models. Male Akita mice may be a good model for polyuria-related bladder remodeling, whereas female ob/ob mice may better mimic storage problems related to loss of outlet control in a setting of type 2 diabetes complicated by obesity.

[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.

Chronic high-fat diet decreased detrusor mitochondrial respiration and increased nerve-mediated contractions

AIMS

To assess the impact of chronic high-fat diet (HFD) on behavioral voiding patterns, detrusor contractility, and smooth muscle mitochondrial function in male mice.

MATERIALS AND METHODS

Male C57BL/6J mice (6 weeks) were fed a control or HFD for 20 weeks. Bladder function was assessed by void spot assays. Bladders were collected and detrusor contractility to carbachol (10^-9 -10^-5  M), and electrical field stimulation (EFS, 0.5-32 Hz) in the presence and absence of atropine was measured. Homogenized detrusor samples were placed in oxygraphs to assess the rate of oxygen consumption of the mitochondria within the detrusor in the presence of different substrates. Mitochondrial hydrogen peroxide (H₂ O₂ ) emission was measured fluorometrically. Detrusor citrate synthase activity was measured via enzyme activity kit and Western blots assessed the electron transport chain (ETC) protein content.

RESULTS

HFD significantly increased body weight, adiposity, and blood glucose levels. HFD mice demonstrated increased voiding frequency and increased EFS-induced detrusor contractility. There were no changes in detrusor relaxation or cholinergic-medicated contraction. Mitochondrial respiration was decreased with HFD and H₂ O ₂ emission was increased. The relative amount of mitochondria in the detrusor was similar between groups. However, ETC complexes V and III were increased following HFD.

CONCLUSIONS

Chronic HFD increased adiposity, lead to more frequent voiding, and enhanced EFS-mediated detrusor contractions. Mitochondrial respiration was decreased and H₂ O ₂ emission increased following HFD. Further research is required to determine if alterations in mitochondrial function could play a role in the development of HFD-induced bladder dysfunction.

The relationship between prevalence and severity of lower urinary tract symptoms (LUTS), and body mass index and mid-abdominal circumference in men in a resource-poor community in Southeast Nigeria: a cross-sectional survey

Background

There is paucity of information on the community-based prevalence and severity of lower urinary tract symptoms (LUTS) in men who are 40 years and older in the southeast region of Nigeria. This study seeks to determine the community-based prevalence of LUTS and the relationship between LUTS, and body mass index (BMI) and mid-abdominal circumference (MAC) in men.

Methods

An interviewer-administered, questionnaire-based survey. Three of nine settlement clusters were randomly selected while systematic random sampling of 1 in 3 eligible subjects was used to select participants. Analysis was done using SPSS® version 20.

Results

One thousand three hundred and nineteen duly completed questionnaires were analyzed. The respondents are within ages 40-92 years with mean age 54.2 ± 10.2 years, mean BMI 25.97 ± 4.18Kg/m² and mean MAC 89.80 ± 12.43 cm. Overall prevalence of LUTS is 20.2%. Nocturia at a prevalence of 19.2% is the most prevalent lower urinary tract symptom and also the earliest to manifest. LUTS prevalence and severity increases with increasing age. About 9.6% report moderate LUTS while 2.3% report severe LUTS. Storage LUTS are reported more frequently than voiding LUTS. LUTS did not vary significantly with BMI, MAC or Wealth-Index.

Conclusion

LUTS prevalence and severity vary with age, but not with BMI, MAC or Wealth-Index.

Effects of Metformin Combined with Lactoferrin on Lipid Accumulation and Metabolism in Mice Fed with High-Fat Diet

Metformin (Met) and lactoferrin (Lf) both exhibit beneficial effects on body weight management and lipid accumulation. However, the synergistical action of Met and Lf remains unclear. In this study, 64 mice were divided into five groups, namely, the control group, high-fat diet (HFD group), HFD with Met (Met group), Lf (Lf group), and a combination of Met and Lf (Met + Lf group). Met (200 mg/kg body weight) and Lf (2 g/100 mL) were administrated in drinking water. The experiment lasted for 12 weeks. Body weight, serum, and hepatic lipids were determined. Histology of the liver and perirenal fat was observed. Protein expression related to hepatic lipid metabolism was also measured. HFD significantly increased body weight, visceral fat weight, and lipid profiles, which lead to obesity and dyslipidemia in mice. Compared with the HFD group, the treatments significantly decreased body weight and Lee’s index (body mass index of mice) with the lowest values in the Met + Lf group. The treatments also decreased the weight of visceral fat, and improved circulating lipid profile and the ability for regulating glucose intake. The adipocyte size and serum TC level were significantly lower in the Met + Lf group as compared with those in the Met or Lf group. The treatments alleviated hepatic lipid accumulation, especially in the Met + Lf group. For protein expression, the p-AMPK/AMPK ratio, a key kinase-regulating cellular energy homeostasis, was significantly higher in the Met + Lf group than the ratio in the HFD group. Similarly, the treatments significantly downregulated the protein expression of lipogenic enzymes (FAS, ACC, and SREBP-1) and upregulated the protein expression of lipolytic enzyme (ATGL). The protein expression of HMGCoAR, which is an important rate limiting enzyme in cholesterol biosynthesis, was only significantly lower in the Met + Lf group than in the HFD group. In conclusion, Met and Lf, either alone or in combination, prevented HFD-induced obesity and improved lipid metabolism.

Deciphering the Relationship between Obesity and Various Diseases from a Network Perspective

The number of obesity cases is rapidly increasing in developed and developing countries, thereby causing significant health problems worldwide. The pathologic factors of obesity at the molecular level are not fully characterized, although the imbalance between energy intake and consumption is widely recognized as the main reason for fat accumulation. Previous studies reported that obesity can be caused by the dysfunction of genes associated with other diseases, such as myocardial infarction, hence providing new insights into dissecting the pathogenesis of obesity by investigating its associations with other diseases. In this study, we investigated the relationship between obesity and diseases from Online Mendelian Inheritance in Man (OMIM) databases on the protein–protein interaction (PPI) network. The obesity genes and genes of one OMIM disease were mapped onto the network, and the interaction scores between the two gene sets were investigated on the basis of the PPI of individual gene pairs, thereby inferring the relationship between obesity and this disease. Results suggested that diseases related to nutrition and endocrine are the top two diseases that are closely associated with obesity. This finding is consistent with our general knowledge and indicates the reliability of our obtained results. Moreover, we inferred that diseases related to psychiatric factors and bone may also be highly related to obesity because the two diseases followed the diseases related to nutrition and endocrine according to our results. Numerous obesity–disease associations were identified in the literature to confirm the relationships between obesity and the aforementioned four diseases. These new results may help understand the underlying molecular mechanisms of obesity–disease co-occurrence and provide useful insights for disease prevention and intervention.

Metabolic syndrome and voiding dysfunction

PURPOSE OF REVIEW

The metabolic syndrome (MetS) is an ever growing pandemic consisting of a constellation of abnormalities. Many hypotheses have been put forth to establish a link between this syndrome and voiding dysfunction. We created a layout of the possible, probable, and proven relationships connecting the MetS with voiding dysfunction in men.

RECENT FINDINGS

There has been growing interest in the relationship linking MetS and voiding dysfunction, with or without benign prostatic hyperplasia, during the past several years. Different mechanisms have been proposed to establish the connection.

SUMMARY

A clear-cut association between MetS and voiding dysfunction is not clearly defined; rather, voiding dysfunction occurring in men with MetS has been shown to be related to numerous pathologies. MetS is a complex disease that includes numerous pathophysiological aspects that may contribute to the causation and advancement of voiding dysfunction. In light of this association, future research is needed to better define this relationship to enable therapy targeted against MetS in patients with voiding dysfunction.

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.