The genetic and environmental contribution to the occurrence of bladder pain syndrome: an empirical approach in a nationwide population sample

Preliminary Validation of a General Factor Model of Chronic Overlapping Pain Conditions

Chronic overlapping pain conditions (COPCs) by definition, frequently co-occur, perhaps reflecting their shared etiologies. Their overlapping nature presents a methodological challenge, possibly masking associations between COPCs and health outcomes attributable to either general or specific processes. To address this challenge, we used population-based cohort data to evaluate the predictive validity of a bifactor model of 9 self-reported COPCs by assessing its association with incident pain-related clinical diagnoses; pain-relevant pharmacotherapy; and other health outcomes. We obtained data from a 2005 to 2006 study of Swedish adult twins linked with health data from nationwide registers through 2016 (N = 25,418). We then fit a bifactor model comprising a general COPC factor and 2 independent specific factors measuring pain-related somatic symptoms and neck and shoulder pain. Accounting for age, biological sex, and cancer, the general factor was associated with increased risk of all pain-related outcomes (eg, COPC diagnosis adjusted odds ratio [aOR], 1.71; 95% confidence interval [1.62, 1.81]), most mental health-related outcomes (eg, depression aOR, 1.72 [1.60, 1.85]), and overdose and mortality (eg, all-cause mortality aOR, 1.25 [1.09, 1.43]). The somatic symptoms specific factor was associated with pain-relevant pharmacotherapy (eg, prescribed opioids aOR, 1.25 [1.15, 1.36]), most mental health-related outcomes (eg, depression aOR, 1.95 [1.70, 2.23]), and overdose (eg, nonfatal overdose aOR, 1.66 [1.31, 2.10]). The neck and shoulder pain-specific factor was weakly and inconsistently associated with the outcomes. Findings provide initial support for the validity and utility of a general-factor model of COPCs as a tool to strengthen understanding of co-occurrence, etiology, and consequences of chronic pain. PERSPECTIVE: This article presents associations between a novel measurement model of COPCs and various health outcomes. Findings provide support for measuring pain across multiple domains rather than only measuring pain specific to one physical location in both research and clinical contexts.

Cognitive Behavioral Therapy for Chronic Pelvic Pain: What Is It and Does It Work?

PURPOSE

Urologic chronic pelvic pain syndrome (UCPPS), which encompasses interstitial cystitis/bladder pain syndrome in women and men and chronic prostatitis/chronic pelvic pain syndrome in men, is a common, often disabling urological disorder that is neither well understood nor satisfactorily treated with medical treatments. The past 25 years have seen the development and validation of a number of behavioral pain treatments, of which cognitive behavioral therapy (CBT) is arguably the most effective. CBT combines strategies of behavior therapy, which teaches patients more effective ways of behaving, and cognitive therapy, which focuses on correcting faulty thinking patterns. As a skills-based treatment, CBT emphasizes "unlearning" maladaptive behaviors and thoughts, and replacing them with more adaptive ones that support symptom self-management.

MATERIALS AND METHODS

This review describes the rationale, technical procedures, and empirical basis of CBT.

RESULTS

While evidence supports CBT for treatment-refractory chronic pain disorders, there is limited understanding of why or how CBT might work, for whom it is most beneficial, or the specific UCPPS symptoms (eg, pain, urinary symptoms) it effectively targets. This is the focus of EPPIC (Easing Pelvic Pain Interventions Clinical Research Program), a landmark NIH trial examining the efficacy of low-intensity, home-based CBT for UCPPS relative to a nonspecific comparator featuring self-care recommendations of AUA guidelines.

CONCLUSIONS

Systematic efforts to increase both the efficiency of CBT and the way it is delivered (eg, home-based treatments) are critical to scaling up CBT, optimizing its therapeutic potential, and reducing the public health burden of UCPPS.

Genome-wide association study identifies risk loci within the major histocompatibility complex region for Hunner-type interstitial cystitis

Hunner-type interstitial cystitis (HIC) is a rare, chronic inflammatory disease of the urinary bladder with unknown etiology and genetic background. Here, we conduct a genome-wide association study of 144 patients with HIC and 41,516 controls of Japanese ancestry. The genetic variant, rs1794275, in the major histocompatibility complex (MHC) region (chromosome 6p21.3) is associated with HIC risk (odds ratio [OR] = 2.32; p = 3.4 × 10^-9). The association is confirmed in a replication set of 26 cases and 1,026 controls (p = 0.014). Fine mapping demonstrates the contribution to the disease risk of a completely linked haplotype of three human leukocyte antigen HLA-DQβ1 amino acid positions, 71, 74, and 75 (OR = 1.94; p = 5 × 10^-8) and of HLA-DPβ1 amino acid position 178, which tags HLA-DPB1∗04:02 (OR = 2.35; p = 7.5 × 10^-8). The three HLA-DQβ1 amino acid positions are located together at the peptide binding groove, suggesting their functional importance in antigen presentation. Our study reveals genetic contributions to HIC risk that may be associated with class II MHC molecule antigen presentation.

Chronic pain conditions and risk of suicidal behavior: a 10-year longitudinal co-twin control study

BACKGROUND

Understanding the relationship between chronic pain conditions and suicidal behavior-suicide attempt, other intentional self-harm, and death by suicide-is imperative for suicide prevention efforts. Although chronic pain conditions are associated with suicidal behaviors, these associations might be attributed to unmeasured confounding or mediated via pain comorbidity.

METHODS

We linked a population-based Swedish twin study (N=17,148 twins) with 10 years of longitudinal, nationwide records of suicidal behavior from health and mortality registers through 2016. To investigate whether pain comorbidity versus specific pain conditions were more important for later suicidal behavior, we modeled a general factor of pain and two independent specific pain factors (measuring pain-related somatic symptoms and neck-shoulder pain, respectively) based on 9 self-reported chronic pain conditions. To examine whether the pain-suicidal behavior associations were attributable to familial confounding, we applied a co-twin control model.

RESULTS

Individuals scoring one standard deviation above the mean on the general pain factor had a 51% higher risk of experiencing suicidal behavior (odds ratio (OR), 1.51; 95% confidence interval (CI), 1.34-1.72). The specific factor of somatic pain was also associated with increased risk for suicidal behavior (OR, 1.80; 95% CI, 1.45-2.22]). However, after adjustment for familial confounding, the associations were greatly attenuated and not statistically significant within monozygotic twin pairs (general pain factor OR, 0.89; 95% CI, 0.59-1.33; somatic pain factor OR, 1.02; 95% CI, 0.49-2.11) CONCLUSION: Clinicians might benefit from measuring not only specific types of pain, but also pain comorbidity; however, treating pain might not necessarily reduce future suicidal behavior, as the associations appeared attributable to familial confounding.

Chronic Spontaneous Urticaria in Patients With Interstitial Cystitis/Bladder Pain Syndrome: Insights From Big Data Analyses

OBJECTIVE

To examine the association between chronic spontaneous urticaria (CSU) and interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

A population-based retrospective cross-sectional study was performed using the Clalit Health Services medical database. The prevalence of CSU was compared between patients diagnosed with IC/BPS and age- and gender-matched controls. Univariate analysis was performed using Chi-square and Student t test and a multivariable analysis was performed using a logistic regression model.

RESULTS

The study included 681 patients with IC/BPS and 3376 demographically matched controls. The mean age of IC/BPS patients was 60 years old. The prevalence of CSU among patients with IC/BPS was higher as compared to the control group (20% vs 13.7%; P <.001). The adjusted OR for CSU in patients with IC/BPS was 1.58 (95% CI 1.28-1.97). Female gender and Jewish ethnicity were associated with the coexistence of these disorders (OR 1.7 95% CI 1.36-2.13, and 1.6 95% CI 1.28-2, respectively).

CONCLUSION

A significant association was found between IC/BPS and CSU. This finding may support the presence of allergic/immune components in the pathogenesis of IC/BPS.

[Interstitial cystitis: the latest findings on its aetiopathogenesis]

New findings provide progress in the understanding of the complicated aetiopathogenesis of interstitial cystitis/bladder pain syndrome (IC/BPS), whose causalities have only been deciphered in fragments so far. An increasingly complex network of pathomechanisms is emerging, in which the frequently mentioned mast cells and urothelial changes seem to be only a fragment of the pathological changes. The latest findings regarding a possible genetic and epigenetic predisposition are based on pedigree analyses, detection of single nucleotide polymorphisms and significant changes in differentially expressed genes. Multiple alterations can be detected at the molecular level. Platelet-activating factor, VEGF, corticotropin-releasing hormone and the inflammasome are important players in understanding the disease, but the pathomechanism underlying the "activation" of IC remains unclear. New starting points could be the detection of viruses (Epstein-Barr virus, BK polyomaviruses) or bacterial inflammation by pathogens that cannot be detected in standard cultures.

Biomarkers in the Light of the Etiopathology of IC/BPS

In this review, we focused on putatively interesting biomarkers of interstitial cystitis/bladder pain syndrome (IC/BPS) in relation to the etiopathology of this disease. Since its etiopathology is still under discussion, the development of novel biomarkers is critical for the correct classification of the patients in order to open personalized treatment options, on the one hand, and to separate true IC/BPS from the numerous confusable diseases with comparable symptom spectra on the other hand. There is growing evidence supporting the notion that the classical or Hunner-type IC (HIC) and the non-Hunner-type IC (NHIC) are different diseases with different etiopathologies and different pathophysiology at the full-blown state. While genetic alterations indicate close relationship to allergic and autoimmune diseases, at present, the genetic origin of IC/BPS could be identified. Disturbed angiogenesis and impairment of the microvessels could be linked to altered humoral signaling cascades leading to enhanced VEGF levels which in turn could enhance leucocyte and mast cell invasion. Recurrent or chronic urinary tract infection has been speculated to promote IC/BPS. New findings show that occult virus infections occurred in most IC/BPS patients and that the urinary microbiome was altered, supporting the hypothesis of infections as major players in IC/BPS. Environmental and nutritional factors may also influence IC/BPS, at least at a late state (e.g., cigarette smoking can enhance IC/BPS symptoms). The damage of the urothelial barrier could possibly be the result of many different causality chains and mark the final state of IC/BPS, the causes of this development having been introduced years ago. We conclude that the etiopathology of IC/BPS is complex, involving regulatory mechanisms at various levels. However, using novel molecular biologic techniques promise more sophisticated analysis of this pathophysiological network, resulting in a constantly improvement of our understanding of IC/BPS and related diseases.

Lifestyle and behavioral modifications made by patients with interstitial cystitis

Interstitial cystitis/bladder pain syndrome (IC/BPS) negatively affects the quality of life. In this study, we investigated the lifestyle behavioral changes patients with IC/BPS make to cope with their symptoms. This prospective study was conducted between August 2018 and June 2019. All patients had a primary symptom of suprapubic pain with a full bladder and other lower urinary tract symptoms for more than 6 weeks as well as cystoscopic findings. All participants completed our self-developed questionnaire, which included informations about their living and work environment, occupational garments, dietary habits, and personal habits. Continuous variables were compared using an independent sample t test, and categorical variables were compared using a chi-square test. We recruited 86 patients with IC/BPS and age-matched 86 controls without IC/BPS. In our study, patients with IC/BPS had more cranberry intake (45.34% vs. 5.81%, P < 0.05) than non-IC/BPS controls; the IC/BPS group had decreased consumption of coffee and spicy food; and wore less makeup or special work garments. In conclusion, patients with IC/BPS tend to make several lifestyle behavioral changes to cope with their symptoms.

Chronic postsurgical pain and cancer: the catch of surviving the unsurvivable

PURPOSE OF REVIEW

Chronic postsurgical pain (CPSP) is an important and well recognized cause of much long-term suffering, which in some cases may be preventable and affects many people living with cancer. Unfortunately, general consensus is lacking as to how best reduce the risk of developing CPSP.

RECENT FINDINGS

Cancer is now not always a short-lived, fatal disease and is now moving towards a chronic illness. Poorly managed perioperative pain is the greatest risk factor for CPSP. Recent trials have examined preventive strategies for CPSP associated with breast surgery and thoracotomy, two operations used in cancer treatment. Standard antinociceptive drugs, 5% lidocaine patches and ketamine do not prevent CPSP. The evidence for gabapentinoids is conflicting. Intravenous lidocaine and, separately, regional anaesthesia appear beneficial.

SUMMARY

Well-managed pain, irrespective of technique, reduces the risk of CPSP. The literature is inconclusive regarding an 'optimal approach.' Regional anaesthesia, intravenous lidocaine and the aggressive management of perioperative pain using multimodal analgesia including antineuropathic pain agents such as gabapentinoids and certain antidepressants are recommended. Clinicians should not rely on general anaesthesia, opioids, NSAIDs and ketamine to prevent CPSP. A blanket approach using gabapentinoids for all patients undergoing major surgery is not indicated. Instead, the presence of perioperative neuropathic pain should be checked for regularly.

Autonomic neurophysiologic implications of disorders comorbid with bladder pain syndrome vs myofascial pelvic pain

AIMS

The neuropathophysiology of a debilitating chronic urologic pain condition, bladder pain syndrome (BPS), remains unknown. Our recent data suggests withdrawal of cardiovagal modulation in subjects with BPS, in contrast to sympathetic nervous system dysfunction in another chronic pelvic pain syndrome, myofascial pelvic pain (MPP). We evaluated whether comorbid disorders differentially associated with BPS vs MPP shed additional light on these autonomic differences.

METHODS

We compared the presence and relative time of onset of 27 other medical conditions in women with BPS, MPP, both syndromes, and healthy subjects. Analysis included an adjustment for multiple comparisons.

RESULTS

Among 107 female subjects (BPS alone = 32; BPS with MPP = 36; MPP alone = 9; healthy controls = 30), comorbidities differentially associated with BPS included irritable bowel syndrome (IBS), dyspepsia, and chronic nausea, whereas those associated with MPP included migraine headache and dyspepsia, consistent with the distinct autonomic neurophysiologic signatures of the two disorders. PTSD (earliest), anxiety, depression, migraine headache, fibromyalgia, chronic fatigue, and IBS usually preceded BPS or MPP. PTSD and the presence of both pelvic pain disorders in the same subject correlated with significantly increased comorbid burden.

CONCLUSIONS

Our study suggests a distinct pattern of comorbid conditions in women with BPS. These findings further support our hypothesis of primary vagal defect in BPS as compared with primary sympathetic defect in MPP, suggesting a new model for chronic these pelvic pain syndromes. Chronologically, PTSD, migraine, dysmenorrhea, and IBS occurred early, supporting a role for PTSD or its trigger in the pathophysiology of chronic pelvic pain.

Health Education and Symptom Flare Management Using a Video-based m-Health System for Caring Women With IC/BPS

OBJECTIVE

To assess effectiveness of the video-based m-health system providing videos dictated by physicians for health education and symptom self-management for patients with Interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

An m-health system was designed to provide videos for weekly health education and symptom flare self-management. O'Leary-Sant index and visual analogue scale as well as SF-36 health survey were administrated to evaluate the disease severity and quality of life (QoL), respectively. A total of 60 IC/BPS patients were recruited and randomly assigned to either control group (30 patients) or study group (30 patients) in sequence depending on their orders to visit our urological clinic. Patients in both control and study groups received regular treatments, while those in the study group received additional video-based intervention. Statistical analyses were conducted to compare the outcomes between baseline and postintervention for both groups. The outcomes of video-based intervention were also compared with the text-based intervention conducted in our previous study.

RESULTS

After video-based intervention, patients in the study group exhibited significant effect manifested in all disease severity and QoL assessments except the pain visual analogue scale, while no significance was found in the control group. Moreover, the study group exhibited more significant net improvements than the control group in 7 SF-36 constructs, except the mental health. The limitations include short intervention duration (8 weeks) and different study periods between text-based and video-based interventions.

CONCLUSION

Video-based intervention is effective in improving the QoL of IC/BPS patients and outperforms the text-based intervention even in a short period of intervention.

Establishment of a Novel Autoimmune Experimental Model of Bladder Pain Syndrome/Interstitial Cystitis in C57BL/6 Mice

The aim of this study is to identify whether vaccinating twice with bladder homogenate can establish a new model of experimental autoimmune cystitis (EAC) in C57BL/6 strain mice. C57BL/6 mice were vaccinated with bladder homogenate in complete Freund's adjuvant (CFA) and boost immunized with bladder homogenate in incomplete Freund's adjuvant (IFA) after 2 weeks were used as the EAC model. Mice immunized with phosphate-buffered saline (PBS) in CFA or IFA were used as the control. Micturition habits and suprapubic-pelvic pain threshold were measured 4 weeks after primary immunization. Bladder to body weight ratios and expression of inflammatory cytokines and neurokinin 1 receptor (NK1R) were then examined. Histologic and immunohistochemical examination of the bladder was carried out, and IL-1β, IFN-γ, and TNF-α production by the kidneys, liver, and lungs was also tested. Double-immunized mice were extensively sensitive to pressure applied on the pelvic area (P < 0.001). Compared to single-immunized mice or controls, double-immunized mice showed more micturition frequency, lower urine output per micturition, higher bladder to body weight ratio, and significant elevation in the expression of inflammatory cytokines, including IL-1β, IL-4, IL-6, IL-10, IFN-γ, and TNF-α (all P < 0.05). NK1R gene expression was significantly increased in double-immunized mice compared to the other three groups (P < 0.001). A nonspecific immune response occurred in the liver but was much weaker than bladder inflammation. Our dual immunization EAC model in C57BL/6 mice can effectively mimic the symptoms and pathophysiologic characteristics of BPS/IC and thus can be widely used to investigate the pathogenesis and therapeutic strategies of BPS/IC.

Significant Linkage Evidence for Interstitial Cystitis/Painful Bladder Syndrome on Chromosome 3

PURPOSE

Interstitial cystitis/painful bladder syndrome is a chronic pelvic pain condition of unknown etiology. We hypothesized that related interstitial cystitis/painful bladder syndrome cases were more likely to have a genetic etiology. The purpose of this study was to perform a genetic linkage analysis.

MATERIALS AND METHODS

We identified interstitial cystitis/painful bladder syndrome cases using diagnostic codes linked to the Utah Population Database genealogy resource and to electronic medical records. For this analysis we used 13 high risk pedigrees, defined as having a statistical excess number of interstitial cystitis/painful bladder syndrome cases among descendants compared to matched hospital population rates. Case status was confirmed in medical records using natural language processing. DNA was obtained from stored, nonneoplastic, formalin fixed, paraffin embedded tissue blocks. Each pedigree had at least 2 cases with DNA available. Parametric linkage analysis was performed.

RESULTS

Pedigrees ranged in size from 2 to 12 genotyped cases for a total of 48 cases. Significant genome wide linkage evidence was found under a dominant model on chromosome 3p13-p12.3 (maximum heterogeneity θ logarithm of odds 3.56). Two pedigrees showed at least nominal linkage evidence in this region (logarithm of odds greater than 0.59). The most informative pedigree included 12 interstitial cystitis/painful bladder syndrome cases (pedigree θ logarithm of odds 2.1). Other regions with suggestive linkage evidence included 1p21-q25, 3p21.1-p14.3, 4q12-q13, 9p24-p22 and 14q24-q31, all under a dominant model.

CONCLUSIONS

While the etiology of interstitial cystitis/painful bladder syndrome is unknown, this study provides evidence that a genetic variant(s) on chromosome 3 and possibly on chromosomes 1, 4, 9 and 14 contribute to an interstitial cystitis/painful bladder syndrome predisposition. Sequence analysis of affected cases in identified pedigrees may provide insight into genes contributing to interstitial cystitis/painful bladder syndrome.

Heritability of Lower Urinary Tract Symptoms in Men: A Twin Study

PURPOSE

Symptoms of urinary irritation, urgency, frequency and obstruction, known as lower urinary tract symptoms, are common in urological practice. However, little is known about the etiology or pathogenesis of lower urinary tract symptoms, especially the relative contributions of genetic and environmental factors to the development of these symptoms. We used a classic twin study design to examine the relative contributions of genetic and environmental factors to the occurrence of lower urinary tract symptoms in middle-aged men.

MATERIALS AND METHODS

Twins were members of the Vietnam Era Twin Registry. We used a mail survey to collect data on lower urinary tract symptoms using the I-PSS (International Prostate Symptom Score) instrument. Twin correlations and biometric modeling were used to determine the relative genetic and environmental contributions to variance in I-PSS total score and individual items.

RESULTS

Participants were 1,002 monozygotic and 580 dizygotic middle-aged male twin pairs (mean age 50.2 years, SD 3.0). Nearly 25% of the sample had an I-PSS greater than 8, indicating at least moderate lower urinary tract symptoms. The heritability of the total I-PSS was 37% (95% CI 32-42). Heritability estimates ranged from 21% for nocturia to 40% for straining, with moderate heritability (34% to 36%) for urinary frequency and urgency.

CONCLUSIONS

Genetic factors provide a moderate contribution (20% to 40%) to lower urinary tract symptoms in middle-aged men, suggesting that environmental factors may also contribute substantially to lower urinary tract symptoms. Future research is needed to define specific genetic and environmental mechanisms that underlie the development of these symptoms and conditions associated with lower urinary tract symptoms.

Toll-like receptor 4 and comorbid pain in Interstitial Cystitis/Bladder Pain Syndrome: a multidisciplinary approach to the study of chronic pelvic pain research network study

BACKGROUND

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a condition characterized by pelvic pain and urinary symptoms. Some IC/BPS patients have pain confined to the pelvic region, while others suffer widespread pain. Inflammatory processes have previously been linked to pelvic pain in IC/BPS, but their association with widespread pain in IC/BPS has not been characterized.

METHODS

Sixty-six women meeting criteria for IC/BPS completed self-report measures of pain as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP), collected 3days of saliva for cortisol assays, and provided blood samples. Peripheral blood mononuclear cells (PBMCs) were stimulated with Toll-like Receptor (TLR) 2 and 4 agonists and cytokines were measured in supernatant; IL-6 was also measured in plasma. Associations between inflammatory variables and the likelihood of endorsing extra-pelvic pain, or the presence of a comorbid syndrome, were tested by logistic regression and General Linear Models, respectively. A subset of patients (n=32) completed Quantitative Sensory Testing.

RESULTS

A one standard deviation increase in TLR-4 inflammatory response was associated with a 1.59 greater likelihood of endorsing extra-pelvic pain (p=.019). Participants with comorbid syndromes also had higher inflammatory responses to TLR-4 stimulation in PBMCs (p=.016). Lower pressure pain thresholds were marginally associated with higher TLR-4 inflammatory responses (p=.062), and significantly associated with higher IL-6 in plasma (p=.031).

CONCLUSIONS

TLR-4 inflammatory responses in PBMCs are a marker of widespread pain in IC/BPS, and should be explored in other conditions characterized by medically unexplained pain.

Exploring Genetic Susceptibility to Fibromyalgia

Fibromyalgia (FM) affects 1% to 5% of the population, and approximately 90% of the affected individuals are women. FM patients experience impaired quality of life and the disorder places a considerable economic burden on the medical care system. With the recognition of FM as a major health problem, many recent studies have evaluated the pathophysiology of FM. Although the etiology of FM remains unknown, it is thought to involve some combination of genetic susceptibility and environmental exposure that triggers further alterations in gene expression. Because FM shows marked familial aggregation, most previous research has focused on genetic predisposition to FM and has revealed associations between genetic factors and the development of FM, including specific gene polymorphisms involved in the serotonergic, dopaminergic, and catecholaminergic pathways. The aim of this review was to discuss the current evidence regarding genetic factors that may play a role in the development and symptom severity of FM.

Development and evaluation of an E-health system to care for patients with bladder pain syndrome/interstitial cystitis

OBJECTIVES

Bladder pain syndrome/interstitial cystitis (BPS/IC) is a chronic disease that highly degrades the quality of life for patients. In the present study, Internet intervention was used to care for bladder pain syndrome/interstitial cystitis patients to alleviate their pain and bothering symptoms.

METHODS

Healthcare education was carried out through the Internet by asking the patients, who were randomly divided into study (40 patients) and control (40 patients) groups, to check possible sensitive foods, habits, and behaviors weekly to remind and consolidate important rules for promoting quality of life. The symptom flares consultation through short message service with the Internet used to elevate healthcare efficiency was undertaken. Questionnaires, including Short Form 36 health survey, O'Leary-Sant symptom and problem indices, as well as visual analog scales pain and urgency scales, were used to evaluate quality of life and disease severity improvements before and after information and communication technology intervention. The outcome was evaluated at week 8.

RESULTS

The quality of life of both the control and study groups was significantly improved. The quality of life and visual analog scales for the patients in the study group with information and communication technology intervention showed a much greater improvement compared with the patients in the control group (P < 0.05).

CONCLUSIONS

The E-health system was shown to be effective in improving quality of life of bladder pain syndrome/interstitial cystitis patients through intervention of Internet healthcare education and short message service for the consolidation of healthy behavior and lifestyle in the 8-week follow up.

Bladder pain syndrome/interstitial cystitis as a functional somatic syndrome

PURPOSE

To determine whether bladder pain syndrome/interstitial cystitis (BPS/IC) has the characteristics of a functional somatic syndrome (FSS).

MATERIALS AND METHODS

There is no accepted definition of an FSS. Consequently, this paper reviewed the literature for common FSS characteristics and for reports that BPS/IC has these characteristics.

RESULTS

Eleven articles met inclusion and exclusion criteria and yielded 18 FSS characteristics. BPS/IC patients manifest all but two: the exceptions were normal light microscopic anatomy (after hydrodistention under anesthesia, some BPS/IC bladders have Hunner's lesions and most have petechial hemorrhages) and normal laboratory tests (many BPS/IC patients have hematuria). Petechial hemorrhages and hematuria are probably related and may appear during naturally-occurring bladder distention. Without such distention, then, the 90% of BPS/IC patients without a Hunner's lesion have all the characteristics of an FSS. Comparisons in the opposite direction were consistent: several additional features of BPS/IC were found in FSSs.

CONCLUSIONS

This systematic but untested method is consistent with but does not test the hypothesis that BPS/IC in some patients might best be understood as an FSS. Like most conditions, BPS/IC is probably heterogeneous; hence only a proportion of BPS/IC cases are likely to be manifestations of an FSS. This hypothesis has several implications. Explorations of processes that connect the FSSs might contribute to understanding the pathogenesis of BPS/IC. Patients with FSSs are at risk for BPS/IC and may benefit from future preventive strategies. Therapies that are useful in FSSs also may be useful in some cases of BPS/IC.

From FUS to Pandora syndrome: where are we, how did we get here, and where to now?

NEW CONCEPTS: Ideas about the causes of lower urinary tract signs (LUTS) in cats have changed significantly in the past 40 years. Recent research is challenging the conventional view that the bladder is always the perpetrator of LUTS, and suggests that the bladder can also be one victim of a systemic process associated with a sensitized central stress response system.

AIM

In this article the authors provide their perspective on the implications of these findings for the diagnosis and treatment of cats with LUTS, provide some historical context, and suggest ways that the veterinary profession might work together to better understand the disorders underlying these signs, and possibly reduce their prevalence.

Urgency and pain in patients with overactive bladder and bladder pain syndrome. What are the differences?

BACKGROUND

The Overactive Bladder Syndrome (OAB) and the Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) are different urological conditions sharing 'urgency' as a common symptom. The aim of this review is to address our existing knowledge and establish how these symptoms are interrelated and to determine whether or not there is a common link between both symptoms complexes that help to distinguish one from the other.

METHODS

Pubmed was used to obtain references for this non-systematic review aiming to discuss differences between OAB and BPS/IC. Guidelines of several professional associations and discussions based on expert opinion from the authors were implemented.

RESULTS

Whilst in BPS the hallmark symptom is pain on bladder filling, urgency is the defining symptom of OAB. Whilst it is likely that the pain in BPS/IC arises from local inflammation in the bladder wall, the nature of urgency as a symptom, its origin, and the relationship between urgency and pain, as well as the different afferent mechanisms associated with the genesis of these sensory symptoms, remains unknown. Although the aetiology of both OAB and PBS/IC is unclear, the influence of environmental factors has been suggested. Both are chronic conditions with very variable symptom resolution and response to therapy. The relationship with voiding dysfunction, gynaecological causes of chronic pelvic pain or the possible alteration of the hypothalamic-pituitary-adrenal axis and psychological disorders has not been established. Inflammation has been suggested as the common link between OAB and BPS/IC.

CONCLUSIONS

OAB and BPS/IC are different symptoms complexes that share urgency as a common symptom. None of them have a specific symptom although pain on bladder filling is the hallmark symptom in BPS/IC. Bladder pain with urgency should be a trigger for referral to the provider with appropriate knowledge and expertise in this disease state, whereas the management of OAB should be part of normal routine care in the community.

Interstitial cystitis/bladder pain syndrome: diagnosis and management

INTRODUCTION AND HYPOTHESIS

The bladder pain syndrome (BPS) is a spectrum of urological symptoms characterised by bladder pain with typical cystoscopic features. Diagnosis and management of this syndrome may be difficult. There is no evidence-based management approach for the diagnosis or treatment of BPS. The objective of this study was to critically review and summarise the evidence relating to the diagnosis and treatment of the bladder pain syndrome.

METHODS

A review of published data on the diagnosis and treatment of the BPS was performed. Our search was limited to English-language articles, on the "diagnosis", and "management" or "treatment" of "interstitial cystitis" and the "bladder pain syndrome" in "humans."

RESULTS

Frequency, urgency and pain on bladder filling are the most common symptoms of BPS. All urodynamic volumes are reduced in patients with BPS. Associated conditions include psychological distress, depression, history of sexual assault, irritable bowel syndrome and fibromyalgia. Cystoscopy remains the test for definitive diagnosis, with visualisation of haemorrhage on cystoreduction. A multidisciplinary treatment approach is essential in the management of this condition. Orally administered amitriptyline is an efficacious medical treatment for BPS. Intravesical hyaluronic acid and local anaesthetic, with/without hydrodistension are among new treatment strategies. Sacral or pudendal neuromodulation is effective, minimally invasive and safe. Surgery is reserved for refractory cases.

CONCLUSIONS

There remains a paucity of evidence for the diagnosis and treatment of BPS. We encountered significant heterogeneity in the assessment of symptoms, duration of treatment and follow up of patients in our literature review.

The Swedish Twin Registry: establishment of a biobank and other recent developments

The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.

Epigenetics and the transition from acute to chronic pain

OBJECTIVE

The objective of this study was to review the epigenetic modifications involved in the transition from acute to chronic pain and to identify potential targets for the development of novel, individualized pain therapeutics.

BACKGROUND

Epigenetics is the study of heritable modifications in gene expression and phenotype that do not require a change in genetic sequence to manifest their effects. Environmental toxins, medications, diet, and psychological stresses can alter epigenetic processes such as DNA methylation, histone acetylation, and RNA interference. As epigenetic modifications potentially play an important role in inflammatory cytokine metabolism, steroid responsiveness, and opioid sensitivity, they are likely key factors in the development of chronic pain. Although our knowledge of the human genetic code and disease-associated polymorphisms has grown significantly in the past decade, we have not yet been able to elucidate the mechanisms that lead to the development of persistent pain after nerve injury or surgery.

DESIGN

This is a focused literature review of epigenetic science and its relationship to chronic pain.

RESULTS

Significant laboratory and clinical data support the notion that epigenetic modifications are affected by the environment and lead to differential gene expression. Similar to mechanisms involved in the development of cancer, neurodegenerative disease, and inflammatory disorders, the literature endorses an important potential role for epigenetics in chronic pain.

CONCLUSIONS

Epigenetic analysis may identify mechanisms critical to the development of chronic pain after injury, and may provide new pathways and target mechanisms for future drug development and individualized medicine.

Twin studies of pain

Twin studies provide a method for estimating the heritability of phenotypes and for examining genetic and environmental relationships between phenotypes. We conducted a systematic review of twin studies of pain, including both clinical and experimental pain phenotypes. Fifty-six papers were included, whereof 52 addressed clinical phenotypes. Of the most comprehensively studied phenotypes, available data indicates heritability around 50% for migraine, tension-type headache and chronic widespread pain, around 35% for back and neck pain, and around 25% for irritable bowel syndrome. However, differences in phenotype definitions make these results somewhat uncertain. All clinical studies relied on dichotomous outcomes and none used pain intensity as continuous phenotype. This is a major weakness of the reviewed studies and gives reason to question their validity with respect to pain mechanisms. Experimental pain studies indicate large differences in heritability across pain modalities. Whereas there is evidence for substantial common genetic risk across many clinical pain conditions, different experimental pain phenotypes appear to be associated with different genetic factors. Recommendations for future research include inclusion of pain intensity scaling and number of pain sites in phenotyping. Furthermore, studies examining the genetic relationships between pain phenotypes, in particular between clinical and experimental phenotypes, should be prioritized.

Pain genetics: past, present and future

Chronic pain is a classic example of gene × environment interaction: inflammatory and/or nerve injuries are known or suspected to be the etiology of most chronic pain syndromes, but only a small minority of those subjected to such injuries actually develop chronic pain. Once chronic pain has developed, pain severity and analgesic response are also highly variable among individuals. Although animal genetics studies have been ongoing for over two decades, only recently have comprehensive human twin studies and large-scale association studies been performed. Here, I review recent and accelerating progress in, and continuing challenges to, the identification of genes contributing to such variability. Success in this endeavor will hopefully lead to both better management of pain using currently available therapies and the development and/or prioritizing of new ones.

Bladder pain syndrome/interstitial cystitis in twin sisters

PURPOSE

We determined the genetic contribution of and associated factors for bladder pain syndrome using an identical twin model.

MATERIALS AND METHODS

Multiple questionnaires were administered to adult identical twin sister pairs. The O'Leary-Sant Interstitial Cystitis Symptom and Problem Index was administered to identify individuals at risk for bladder pain syndrome. Potential associated factors were modeled against the bladder pain syndrome score with the twin pair as a random effect of the factor on the bladder pain syndrome score. Variables that showed a significant relationship with the bladder pain syndrome score were entered into a multivariable model.

RESULTS

In this study 246 identical twin sister pairs (total 492) participated with a mean age (± SD) of 40.3 ± 17 years. Of these women 45 (9%) were identified as having a moderate or high risk of bladder pain syndrome (index score greater than 13). There were 5 twin sets (2%) in which both twins met the criteria. Correlation of bladder pain syndrome scores within twin pairs was estimated at 0.35, suggesting a genetic contribution to bladder pain syndrome. Multivariable analysis revealed that increasing age (estimate 0.46 [95% CI 0.2, 0.7]), irritable bowel syndrome (1.8 [0.6, 3.7]), physical abuse (2.5 [0.5, 4.1]), frequent headaches (1.6 [0.6, 2.8]), multiple drug allergies (1.5 [0.5, 2.7]) and number of self-reported urinary tract infections in the last year (8.2 [4.7, 10.9]) were significantly associated with bladder pain syndrome.

CONCLUSIONS

Bladder pain syndrome scores within twin pairs were moderately correlated, implying some genetic component. Increasing age, irritable bowel syndrome, frequent headaches, drug allergies, self-reported urinary tract infections and physical abuse were factors associated with higher bladder pain syndrome scores.