Genetic contributions to urgency urinary incontinence in women

Shared genetic architecture of hernias: A genome-wide association study with multivariable meta-analysis of multiple hernia phenotypes

Abdominal hernias are common and characterised by the abnormal protrusion of a viscus through the wall of the abdominal cavity. The global incidence is 18.5 million annually and there are limited non-surgical treatments. To improve understanding of common hernia aetiopathology, we performed a six-stage genome-wide association study (GWAS) of 62,637 UK Biobank participants with either single or multiple hernia phenotypes including inguinal, femoral, umbilical and hiatus hernia. Additionally, we performed multivariable meta-analysis with metaUSAT, to allow integration of summary data across traits to generate combined effect estimates. On individual hernia analysis, we identified 3404 variants across 38 genome-wide significant (p < 5×10-8) loci of which 11 are previously unreported. Robust evidence for five shared susceptibility loci was discovered: ZC3H11B, EFEMP1, MHC region, WT1 and CALD1. Combined hernia phenotype analyses with additional multivariable meta-analysis of summary statistics in metaUSAT revealed 28 independent (seven previously unreported) shared susceptibility loci. These clustered in functional categories related to connective tissue and elastic fibre homeostasis. Weighted genetic risk scores also correlated with disease severity suggesting a phenotypic-genotypic severity correlation, an important finding to inform future personalised therapeutic approaches to hernia.

The polymorphisms of extracellular matrix-remodeling genes are associated with pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Extracellular matrix (ECM) synthesis and metabolism abnormalities may influence the pelvic supporting system and lead to the occurrence and development of pelvic organ prolapse (POP). Genetic polymorphisms of such related genes have been increasingly studied. This study aims to explore the association between the single-nucleotide polymorphisms (SNPs) of genes encoding ECM processing enzymes (a disintegrin and metalloproteinase with thrombospondin motifs [ADAMTSs]), ECM degrading enzymes (matrix metalloproteinases [MMPs]) and their tissue inhibitors of metalloproteinase (TIMPs), and POP.

METHODS

We conducted an association study including 48 women with POP at stages III and IV and 48 women without prolapse in Chinese groups. SNPs were identified using the target region sequencing technique. We performed Fisher's exact tests to assess the association between SNPs and POP in the unadjusted model and logistic regression analysis in the adjusted model, adjusting for delivery and pregnancy.

RESULTS

There was a significant association between TIMP2 SNP rs2277698 (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.16-0.82; P = 0.015), ADAMTS13 SNP rs149586801 (OR, 0.18; 95% CI, 0.05-0.69; P = 0.012), and ADAMTS1 SNPs rs370850 and rs422803 (OR, 3.71; 95% CI, 1.35-10.15; P = 0.011 for both), rs402007, rs428785, rs434857, and rs445784 (OR, 2.18; 95% CI, 1.05-4.56; P = 0.038 for the four), and POP in the adjusted model.

CONCLUSION

TIMP2, ADAMTS13, and ADAMTS1 might be candidate genes for POP. Our results provide preliminarily new evidence for future investigation of these genes in the pathophysiology of POP.

Urinary Incontinence and Depressive Symptoms: The Mediating Role of Physical Activity and Social Engagement

OBJECTIVES

This study investigates longitudinal within-person associations between urinary incontinence (UI) and depressive symptoms among older women. Drawing on activity theory, this study also adds to limited knowledge about the mediating role of physical activity and social engagement in the association between UI and depressive symptoms.

METHOD

Using six waves of a nationally representative longitudinal study of older adults in Korea between 2008 and 2018, this study examined the relationship between UI and depressive symptoms among women aged 70 and over. Fixed effects models were estimated to account for unobserved time-invariant confounding factors. Sobel mediation tests were conducted to formally test for mediation.

RESULTS

Fixed effects estimates showed that, after adjusting for a wide array of time-varying covariates, having UI is positively associated with depressive symptoms among older women (b = 0.238, p < 0.05). Results revealed that individuals who begin to experience UI tend to have less frequent social interactions and participate in fewer social activities. UI, however, is only marginally associated with a decrease in physical activity. Reductions in physical activity, social connections, and social activities jointly explain about 22% of the association between UI and depressive symptoms, rendering it statistically insignificant.

DISCUSSION

UI poses a threat to psychological well-being among older women. This is partly explained by a decrease in physical activity and disruption in social engagement. This study reaffirms the significance of the programs that promote physical and social activity among older adults.

Genetic variants and expression changes in urgency urinary incontinence: A systematic review

Aim

To perform a systematic review summarizing the knowledge of genetic variants, gene, and protein expression changes in humans and animals associated with urgency urinary incontinence (UUI) and to provide an overview of the known molecular mechanisms related to UUI.

Methods

A systematic search was performed on March 2, 2020, in PubMed, Embase, Web of Science, and the Cochrane library. Retrieved studies were screened for eligibility. The risk of bias was assessed using the ROBINS‐I (human) and SYRCLE (animal) tool. Data were presented in a structured manner and in the case of greater than five studies on a homogeneous outcome, a meta‐analysis was performed.

Results

Altogether, a total of 10,785 records were screened of which 37 studies met the inclusion criteria. Notably, 24/37 studies scored medium‐high to high on risk of bias, affecting the value of the included studies. The analysis of 70 unique genes and proteins and three genome‐wide association studies showed that specific signal transduction pathways and inflammation are associated with UUI. A meta‐analysis on the predictive value of urinary nerve growth factor (NGF) levels showed that increased urinary NGF levels correlate with UUI.

Conclusion

The collective evidence showed the involvement of two molecular mechanisms (signal transduction and inflammation) and NGF in UUI, enhancing our understanding of the pathophysiology of UUI. Unfortunately, the risk of bias was medium‐high to high for most studies and the value of many observations remains unclear. Future studies should focus on elucidating how deficits in the two identified molecular mechanisms contribute to UUI and should avoid bias.

Genome-Wide Association Study for Urinary and Fecal Incontinence in Women

PURPOSE

Urinary incontinence and fecal incontinence are common disorders in women that negatively impact quality of life. In addition to known health and lifestyle risk factors, genetics may have a role in continence. Identification of genetic variants associated with urinary incontinence and fecal incontinence could result in a better understanding of etiologic pathways, and new interventions and treatments.

MATERIALS AND METHODS

We previously generated genome-wide single nucleotide polymorphism data from Nurses' Health Studies participants. The participants provided longitudinal urinary incontinence and fecal incontinence information via questionnaires. Cases of urinary incontinence (6,120) had at least weekly urinary incontinence reported on a majority of questionnaires (3 or 4 across 12 to 16 years) while controls (4,811) consistently had little to no urinary incontinence reported. We classified cases of urinary incontinence in women into stress (1,809), urgency (1,942) and mixed (2,036) subtypes. Cases of fecal incontinence (4,247) had at least monthly fecal incontinence reported on a majority of questionnaires while controls (11,634) consistently had no fecal incontinence reported. We performed a genome-wide association study for each incontinence outcome.

RESULTS

We identified 8 single nucleotide polymorphisms significantly associated (p <5×10^-8) with urinary incontinence located in 2 loci, chromosomes 8q23.3 and 1p32.2. There were no genome-wide significant findings for the urinary incontinence subtype analyses. However, the significant associations for overall urinary incontinence were stronger for the urgency and mixed subtypes than for stress. While no single nucleotide polymorphism reached genome-wide significance for fecal incontinence, 4 single nucleotide polymorphisms had p <10^-6.

CONCLUSIONS

Few studies have collected genetic data and detailed urinary incontinence and fecal incontinence information. This genome-wide association study provides initial evidence of genetic associations for urinary incontinence and merits further research to replicate our findings and identify additional risk variants.

ADAMTS proteins in human disorders

ADAMTS proteins are a superfamily of 26 secreted molecules comprising two related, but distinct families. ADAMTS proteases are zinc metalloendopeptidases, most of whose substrates are extracellular matrix (ECM) components, whereas ADAMTS-like proteins lack a metalloprotease domain, reside in the ECM and have regulatory roles vis-à-vis ECM assembly and/or ADAMTS activity. Evolutionary conservation and expansion of ADAMTS proteins in mammals is suggestive of crucial embryologic or physiological roles in humans. Indeed, Mendelian disorders or birth defects resulting from naturally occurring ADAMTS2, ADAMTS3, ADAMTS10, ADAMTS13, ADAMTS17, ADAMTS20, ADAMTSL2 and ADAMTSL4 mutations as well as numerous phenotypes identified in genetically engineered mice have revealed ADAMTS participation in major biological pathways. Important roles have been identified in a few acquired conditions. ADAMTS5 is unequivocally implicated in pathogenesis of osteoarthritis via degradation of aggrecan, a major structural proteoglycan in cartilage. ADAMTS7 is strongly associated with coronary artery disease and promotes atherosclerosis. Autoantibodies to ADAMTS13 lead to a platelet coagulopathy, thrombotic thrombocytopenic purpura, which is similar to that resulting from ADAMTS13 mutations. ADAMTS proteins have numerous potential connections to other human disorders that were identified by genome-wide association studies. Here, we review inherited and acquired human disorders in which ADAMTS proteins participate, and discuss progress and prospects in therapeutics.

Is there "brain OAB" and how can we recognize it? International Consultation on Incontinence-Research Society (ICI-RS) 2017

AIMS

In light of mounting evidence supporting the association of brain regions with the control of urine storage and voiding, the high placebo effect in OAB studies as well as certain anecdotal observations from clinical practice with OAB patients, the role of the brain in OAB was explored.

METHODS

At the ICI-RS 2017 meeting, a panel of Functional Urologists and Basic Scientists presented literature data generating a proposal to discuss whether there is "brain OAB" and how we could recognize it.

RESULTS

Existing data point toward organic brain causes of OAB, in particular concerning white matter disease (WMD) and aging, but with currently speculative mechanisms. Imaging techniques have revealed connectivity changes between brain regions which may explain brain-peripheral interactions in OAB patients, further to acknowledged structural and functional changes in the central nervous system (CNS). Furthermore, psychological disorders like stress and depression have been identified as causes of OAB, with animal and human studies proposing a neurochemical and neuroendocrine pathophysiological basis, involving either the serotoninergic system or the hypothalamic-pituitary-adrenal axis. Finally, childhood data suggest that OAB could be a developmental disorder involving the CNS, although childhood OAB could be a different condition than that of adults in many children.

CONCLUSIONS

Future research should aim to identify the pathogenesis of WMD and the aging processes affecting the brain and the bladder, with possible benefits in prevention strategies, as well as connectivity disorders within the CNS, the pathophysiology of OAB in childhood and the neurochemical pathways connecting affective disorders with OAB.

Engaging Undergraduate Kinesiology Students in Clinically-Based Research

Many undergraduate students in kinesiology are interested in clinical careers and seek research opportunities for advanced study and unique learning experiences. This paper describes a process of engaging undergraduate students in a multi-disciplinary, NIH-funded Program Project investigating factors that may affect pelvic floor support and symptoms in primiparous women during the first year postpartum. Students complete general and protocol-specific training prior to engagement, have specific tasks that reinforce skill development and require independence, and are invited to participate in additional opportunities with the investigative team. The topic of pelvic floor health is novel to most students and participation in this research expands their knowledge beyond a mainstream kinesiology curriculum. Institutionalizing this type of program could formalize undergraduate student research experiences and facilitate ongoing clinical research efforts with a kinesiology focus.

Urinary incontinence in women

Urinary incontinence symptoms are highly prevalent among women, have a substantial effect on health-related quality of life and are associated with considerable personal and societal expenditure. Two main types are described: stress urinary incontinence, in which urine leaks in association with physical exertion, and urgency urinary incontinence, in which urine leaks in association with a sudden compelling desire to void. Women who experience both symptoms are considered as having mixed urinary incontinence. Research has revealed overlapping potential causes of incontinence, including dysfunction of the detrusor muscle or muscles of the pelvic floor, dysfunction of the neural controls of storage and voiding, and perturbation of the local environment within the bladder. A full diagnostic evaluation of urinary incontinence requires a medical history, physical examination, urinalysis, assessment of quality of life and, when initial treatments fail, invasive urodynamics. Interventions can include non-surgical options (such as lifestyle modifications, pelvic floor muscle training and drugs) and surgical options to support the urethra or increase bladder capacity. Future directions in research may increasingly target primary prevention through understanding of environmental and genetic risks for incontinence.

Clinical epidemiological insights into urinary incontinence

INTRODUCTION AND HYPOTHESIS

Urinary incontinence (UI) is very common and heterogeneous among women with limited knowledge of progression or prognosis. Evidence based on clinical epidemiology can help to better understand the natural history of UI.

METHODS

We examine the challenges of UI definition and its subtypes, its impact on quality of life and health-seeking behavior. We review the proposed pathophysiology of UI subtypes and known risk factors as they relate to our current knowledge of the disease state. Finally, we emphasize the role of epidemiology in the process of acquiring new insight, improving knowledge, and translating this information into clinical practice.

RESULTS

Stress UI is most common overall, but mixed UI is most prevalent in older women. The three UI subtypes have some common risk factors, and others that are unique, but there remains a significant gap in our understanding of how they develop. Although the pathophysiology of stress UI is somewhat understood, urgency UI remains mostly idiopathic, whereas mixed UI is the least studied and most complex subtype. Moreover, there exists limited information on the progression of symptoms over time, and disproportionate UI health-seeking behavior. We identify areas of exploration (e.g., epigenetics, urinary microbiome), and offer new insights into a better understanding of the relationship among the UI subtypes and to develop an integrated construct of UI natural history.

CONCLUSION

Future epidemiological strategies using longitudinal study designs could play a pivotal role in better elucidating the controversies in UI natural history and the pathophysiology of its subtypes leading to improved clinical care.

Non-viral nucleic acid delivery methods

INTRODUCTION

Delivery of nucleic acid-based molecules in human cells is a highly studied approach for the treatment of several disorders including monogenic diseases and cancers. Non-viral vectors for DNA and RNA transfer, although in general less efficient than virus-based systems, are particularly well adapted mostly due to the absence of biosafety concerns. Non-viral methods could be classified in two main groups: physical and vector-assisted delivery systems. Both groups comprise several different methods, none of them universally applicable. The choice of the optimal method depends on the predefined objectives and the features of targeted micro-environment. Areas covered: In this review, the authors discuss non-viral techniques and present recent therapeutic achievements in ex vivo and in vivo nucleic acid delivery by most commonly used techniques while emphasizing the role of 'biological particles', namely peptide transduction domains, virus like particles, gesicles and exosomes. Expert opinion: The number of available non-viral transfection techniques used for human therapy increased rapidly, followed by still moderate success in efficacy. The prospects are to be found in design of multifunctional hybrid systems that reflect the viral efficiency. In this respect, biological particles are very promising.

Overactive bladder in children

Overactive bladder (OAB) is a ubiquitous syndrome that is defined by urinary urgency with, or without urinary incontinence. OAB is observed in all parts of the world, with a prevalence of 5-12% in children (5-10 years of age) and a prevalence of 0.5% in older adolescents (16-18 years of age). Published data indicate that around a third of children with OAB are likely to become adults with similar complaints. Studies in children and in adults with OAB indicate that these individuals are more likely to also have anxiety, depression and attention deficit problems, and that appropriate treatment of these comorbidities can often improve the patient's OAB symptoms. Furthermore, data from twin studies and familial surveys seem to indicate a genetic component of OAB. Pharmacological treatments of OAB in children have improved in the past 5 years, moving beyond anticholinergic agents and including the off-label use of α-blockers, β3-agonists and intravesical botulinum toxin. Use of several different electrical stimulation techniques is also effective, both as first-line treatments, and for patients with treatment-refractory symptoms. Overall the outlook of children with OAB seems to be improving, with a greater understanding of the pathophysiology of this syndrome. Treatment modalities that target the source of the underlying problem, especially in children, are likely to provide the best patient outcomes.