Age, Gender and Women's Health and the Patient

Functional Bowel Disorders: A Roadmap to Guide the Next Generation of Research

In June 2016, the National Institutes of Health hosted a workshop on functional bowel disorders (FBDs), particularly irritable bowel syndrome, with the objective of elucidating gaps in current knowledge and recommending strategies to address these gaps. The workshop aimed to provide a roadmap to help strategically guide research efforts during the next decade. Attendees were a diverse group of internationally recognized leaders in basic and clinical FBD research. This document summarizes the results of their deliberations, including the following general conclusions and recommendations. First, the high prevalence, economic burden, and impact on quality of life associated with FBDs necessitate an urgent need for improved understanding of FBDs. Second, preclinical discoveries are at a point that they can be realistically translated into novel diagnostic tests and treatments. Third, FBDs are broadly accepted as bidirectional disorders of the brain-gut axis, differentially affecting individuals throughout life. Research must integrate each component of the brain-gut axis and the influence of biological sex, early-life stressors, and genetic and epigenetic factors in individual patients. Fourth, research priorities to improve diagnostic and management paradigms include enhancement of the provider-patient relationship, longitudinal studies to identify risk and protective factors of FBDs, identification of biomarkers and endophenotypes in symptom severity and treatment response, and incorporation of emerging "-omics" discoveries. These paradigms can be applied by well-trained clinicians who are familiar with multimodal treatments. Fifth, essential components of a successful program will include the generation of a large, validated, broadly accessible database that is rigorously phenotyped; a parallel, linkable biorepository; dedicated resources to support peer-reviewed, hypothesis-driven research; access to dedicated bioinformatics expertise; and oversight by funding agencies to review priorities, progress, and potential synergies with relevant stakeholders.

The stress concept in gastroenterology: from Selye to today

More than eighty years after Hans Selye (1907-1982) first developed a concept describing how different types of environmental stressors affect physiological functions and promote disease development (called the "general adaptation syndrome") in 1936, we herein review advances in theoretical, mechanistic, and clinical knowledge in stress research, especially in the area of gastroenterology, and summarize progress and future perspectives arising from an interdisciplinary psychoneurobiological framework in which genetics, epigenetics, and other advanced ( omics) technologies in the last decade continue to refine knowledge about how stress affects the brain-gut axis in health and gastrointestinal disease. We demonstrate that neurobiological stress research continues to be a driving force for scientific progress in gastroenterology and related clinical areas, inspiring translational research from animal models to clinical applications, while highlighting some areas that remain incompletely understood, such as the roles of sex/gender and gut microbiota in health and disease. Future directions of research should include not only the genetics of the stress response and resilience but also epigenetic contributions.

Gender differences in ghrelin, nociception genes, psychological factors and quality of life in functional dyspepsia

AIM

to evaluate gender differences in the aspect of ghrelin, nociception-related genes and psychological aspects and the quality of life (QoL) in Korean functional dyspepsia (FD) patients.

METHODS

Total of 191 persons were prospectively enrolled between March 2013 and May 2016 in Seoul National Bundang Hospital, and classified into control and FD group based on ROME III criteria. Questionnaire included assessment for dyspepsia symptoms, QoL and anxiety or depression. Preproghrelin and nociception genes in the gastric mucosa and plasma acyl/des-acyl ghrelin were measured.

RESULTS

Lower level of plasma acyl ghrelin in FD patients compared to control was significant only in male (15.9 fmol/mL vs 10.4 fmol/mL, P = 0.017). Significantly higher mRNA expressions of nerve growth factor and transient receptor potential vanilloid receptor 1 were observed in male (P = 0.002 and P = 0.014, respectively) than in female. In contrast, female FD patients had a higher anxiety and depression score than male FD (P = 0.029), and anxiety score was correlated with epigastric pain only in female FD patients (female: Spearman rho = 0.420, P = 0.037). The impairment of overall QoL was more prominent in female FD patients than male patients (5.4 ± 0.3 vs 6.5 ± 0.3, P = 0.020).

CONCLUSION

Gender differences of ghrelin and nociception-related genes in male and psychological factors in female underlie FD symptoms. More careful assessment of psychological or emotional status is required particularly for the female FD patients.

Gender and Weight Influence Quality of Life in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by abdominal pain and bowel dysfunction in the absence of structural abnormality. Diagnosis can be challenging and often leads to extensive medical tests, non-effective therapeutic modalities, and reduced quality of life (QOL). Identifying factors associated with dysfunction have the potential to enhance outcomes. Participants with IBS (n = 41) and healthy volunteers (n = 74) were recruited into this cross-sectional, descriptive, natural history protocol at the National Institute of Health, Clinical Center. Demographic characteristics were self-reported. QOL was assessed with the Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire. Statistical analysis included descriptive statistics, factorial ANOVA, and multiple regression. Individuals with IBS reported lower QOL scores across all QOL-subscales compared to healthy controls. Normal-weight women and overweight men with IBS reported the greatest QOL impairment. Body fat percent had confounding effects on the relationship between IBS and QOL. The disparity between QOL scores in participants with IBS by both gender and weight groups may reflect different social pressures perceived by normal and overweight women and men. These findings enhance the recognition of the disparities in patients with chronic symptoms and thereby lead to personalized assessment and interventions to improve their QOL.

Why We Still Need To Speak About Sex Differences and Sex Hormones in Pain

In the world of pain, we must always consider the presence of gender. In nociception, as well as in pain, women are different from men in many, if not all, aspects of the system. Nociception is the sum of several events that occur from the periphery to the CNS, and there is much evidence that female nociception differs from male nociception. Moreover, it has to be considered that pain results from a male or a female cortex. Genetic, anatomical, physiological, hormonal, psychological, and social factors have been considered to explain the differences present at both levels. Notwithstanding all the evidence, it is still difficult to observe the application of this knowledge to the treatment of pain. Drugs are still given per kilogram, and clinical studies, albeit including women, often mix data from both sexes. Moreover, reports on these studies often fail to mention the women’s age and reproductive status, i.e., sex hormones. Hormone levels vary from hour to hour, from day to day, and, as repeatedly confirmed, are affected by several pain killers commonly used in pain therapy. All the data confirm the urgent need to include sex differences and sex hormones among the key factors that play an important role in pain and pain treatment.

Sex-Related Differences in GI Disorders

Epidemiological studies indicate sex-related differences among functional gastrointestinal disorders (FGIDs) wherein females are more likely to receive a diagnosis than their male counterparts. However, the mechanism by which females exhibit an increased vulnerability for development of these pathophysiologies remains largely unknown, and therapeutic treatments are limited. The current chapter focuses on clinical research outlining our current knowledge of factors that contribute to the female predominance among FGID patients such as the menstrual cycle and sex hormones. In addition, we will discuss progress in preclinical research, including animal models, which serve as valuable tools for the investigation of the development and long term manifestation of symptoms observed within the patient population. Although much progress has been made, additional longitudinal studies in both clinical and preclinical research are necessary to identify more specific mechanisms underlying sex-related differences in FGIDs as well as targets for improved therapeutic approaches.

Western Dietary Pattern Is Associated with Irritable Bowel Syndrome in the French NutriNet Cohort

Background: Diet appears to play a key role in the pathogenesis of the irritable bowel syndrome (IBS). Some dietary patterns (DP) could increase the risk of triggering or worsening IBS symptoms. This cross-sectional study aimed to assess the association between a posteriori derived DP and IBS in a large French population, the web-based NutriNet-Santé cohort. Methods: Study population included participants of the NutriNet-Santé study who completed a questionnaire based on Rome III criteria assessing IBS. A principal component analysis (PCA) was performed to identify major DPs based on 29 food groups' consumption. Associations between DP quintiles and IBS were investigated with multivariable logistic regressions. Results: 44,350 participants were included, with 2423 (5.5%) presenting IBS. Three major DP were extracted using PCA, "healthy," "western," and "traditional." After adjustments on confounders, the "western" DP was positively associated with IBS (OR _{Q5 vs. Q1} = 1.38, 95% CI 1.19-1.61, p trend < 0.0001) and the "traditional" DP was positively associated with IBS in women (OR _{Q5 vs. Q1} = 1.29 95% CI 1.08-1.54, p trend = 0.001). Conclusions: In this study, a "western" DP-highly correlated with the consumption of fatty and sugary products and snacks-was associated with a moderate increased risk of IBS.

The Increased Level of Depression and Anxiety in Irritable Bowel Syndrome Patients Compared with Healthy Controls: Systematic Review and Meta-analysis

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) patients commonly experience psychiatric disorders, such as depression and anxiety. This meta-analysis sought to compare depression and anxiety levels between IBS patients and healthy controls.

METHODS

We searched major electronic databases (PubMed, EMBASE, MEDLINE, and Cochrane library) to find comparative studies on IBS patients and healthy controls. The primary outcome was a standardized mean difference (SMD) of anxiety and depression levels; sub-group analyses were conducted according to IBS-subtypes.

RESULTS

In total, 2293 IBS patients and 4951 healthy controls from 27 studies were included. In random effect analysis, depression and anxiety levels were significantly higher in IBS patients (pooled SMD = 0.76; 95% CI, 0.62-0.90; P < 0.001; I2 = 77.2% and pooled SMD = 0.84; 95% CI, 0.67-1.01; P < 0.001; I2 = 85.6%, respectively). Both analyses' funnel plots showed symmetry. In meta-regression analysis, heterogeneity was due to the studied region and questionnaire type for both depression and anxiety. In sub-group analyses of IBS-subtype, the pooled SMDs of depression and anxiety levels (IBS with predominant constipation: 0.83 and 0.81, IBS with predominant diarrhea: 0.73 and 0.65, and IBS with mixed bowel habits: 0.62 and 0.75; P < 0.001, respectively) were significantly higher in all IBS-subtypes.

CONCLUSIONS

The present meta-analysis showed depression and anxiety levels to be higher in IBS patients than in healthy controls, regardless of IBS-subtype. However, the gender effect on psychological factors among IBS patients could not be determined and should be evaluated in prospective studies.

Mapping of Brain Activations to Rectal Balloon Distension Stimuli in Male Patients with Irritable Bowel Syndrome Using Functional Magnetic Resonance Imaging

Background/Aims

Irritable bowel syndrome (IBS) is associated with exaggerated cerebral response including emotional processing following visceral stimulation; though data on this issue is available in female IBS patients, it is scanty among males. Hence, we aimed to study brain response of male IBS patients following rectal balloon distension as compared to healthy controls using functional magnetic resonance imaging (fMRI). Data between diarrhea and constipation predominant IBS (IBS-D and IBS-C) were also compared.

Methods

Rectal balloon distension threshold was assessed in 20 male IBS patients (10 IBS-C and 10 IBS-D) and 10 age-matched male healthy controls. Subsequently, fMRI on all the participants was performed at their respective rectal pain threshold. The fMRI data were analysed using the Statistical Parametric Mapping software.

Results

IBS patients showed greater cerebral activations in insula, middle temporal gyrus, and cerebellum in the left hemisphere compared to healthy controls. Neural activation was found in bilateral precuneus/superior parietal lobules in controls but not in patients with IBS. The brain activation differed among IBS-C and IBS-D patients; while the right mid-cingulate cortex was activated in IBS-C, the left inferior orbito-frontal cortex, left calcarine, and bilateral fusiform gyri were activated among patients with IBS-D following rectal balloon distension.

Conclusions

Brain response to rectal balloon distension differed among male patients with IBS and controls and among patients with IBS-C and IBS-D. Differential activation among patients with IBS-C and IBS-D was seen in the brain regions controlling affective motivation, homeostatic emotions, and autonomic responses to pain.

Post-cholecystectomy syndrome and sphincter of Oddi dysfunction: past, present and future

Post-cholecystectomy syndrome and the concept of a causal relationship to sphincter of Oddi dysfunction, despite the controversy, has presented a clinically relevant conflict for decades. Historically surgeons, and now gastroenterologists have expended tremendous efforts towards trying to better understand the dilemma that is confounded by unique patient phenotypes. Areas covered: This review encompasses the literature from a century of experience on the topic of post-cholecystectomy syndrome. Relevant historical and anecdotal experiences are examined in the setting of insights from evaluation of recently available controlled data. Expert commentary: Historical observations and recent data suggest that patients with post-cholecystectomy syndrome can be categorized as follows. Patients with sphincter of Oddi stenosis will most often benefit from treatment with sphincterotomy. Patients with classic biliary pain and some objective evidence of biliary obstruction may have a sphincter of Oddi disorder and should be considered for endoscopic evaluation and therapy. Patients with atypical post-cholecystectomy pain, without any evidence consistent with biliary obstruction, and/or with evidence for another diagnosis or dysfunction should not undergo ERCP.

Corticotropin-releasing hormone receptor 1 (CRH-R1) polymorphisms are associated with irritable bowel syndrome and acoustic startle response

BACKGROUND

Corticotropin-releasing hormone receptor 1 (CRH-R1) in the amygdala and the stria terminalis plays an important role in the activation of central stress circuits. Genetic factors may contribute to the hyperresponsiveness of these circuits in irritable bowel syndrome (IBS).

AIMS

To determine if CRH-R1 SNPs are associated with: (1) a diagnosis of IBS, (2) gastrointestinal (GI) symptoms, and (3) acoustic startle response (ASR) to threat, which is mediated by the amygdala via CRH.

METHODS

Three CRH-R1 SNPS (rs110402, rs242924, and rs7209436) were genotyped using salivary DNA from IBS and healthy control subjects (HCs). Eye blink ASR was obtained during safe (no shock), anticipation (abdominal shock may soon occur) and threat (abdominal shock likely) conditions in a subset of subjects. Associations between each SNP with IBS status, clinical traits and ASR were measured.

RESULTS

235 IBS patients (mean age 37.5 yrs, 74% F) and 264 HCs (mean age 32.1 yrs, 70% F) were studied. Of these, 57 IBS and 41 HCs underwent the ASR protocol. The presence of IBS was associated with the major allele for all three CRH-R1 SNPs (p=0.009-0.025). Within IBS, the major allele for all three SNPs (p=0.017-0.065) was associated with GI symptom anxiety scores. Within subjects with at least one copy of the major allele for the CRH-R1 SNPs, IBS had significantly lower ASR compared to HCs during threat conditions (p=0.001-0.002). Within IBS, CRH-R1 SNPs were associated with a graded increase in ASR to threat (p=0.007-0.008).

CONCLUSION

These findings support that CRH-R1 contributes to the dysregulated stress responsiveness in IBS.