Irritable bowel symptoms and the development of common mental disorders and functional somatic syndromes identified in secondary care - a long-term, population-based study

Role of hippocampal circKcnk9 in visceral hypersensitivity and anxiety comorbidity of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by recurrent visceral pain and altered bowel habits (diarrhea or constipation). However, the molecular and pathological mechanisms are poorly understood. This study found neonatal colorectal distension to induce visceral hypersensitivity and anxiety. The expression of hippocampal circKcnk9, a novel circRNA, was significantly increased in IBS-like rats. Interestingly, CA1 shcircKcnk9 treatment inhibited long-term potentiation (LTP) and alleviated visceral hypersensitivity and anxiety in IBS-like rats, whereas overexpression of CA1 circKcnk9 induced LTP, visceral hypersensitivity, and anxiety in controls. Several experiments indicated that increased CA1 circKcnk9 acted as a miR-124-3p sponge, which resulted in the inhibitory effect of miR-124-3p on gene silencing. There was a negative correlation between circKcnk9 and miR-124-3p expression. As expected, CA1 administration of agomiR-124-3p decreased CA1 LTP, visceral hypersensitivity, and anxiety in the IBS-like rats. In contrast, CA1 treatment with antagomiR-124-3p induced LTP, visceral hypersensitivity, and anxiety in the controls. Furthermore, bioinformatic analysis and experimental data showed that EZH2 is a circKcnk9/miR-124-3p target gene, and increased EZH2 expression was involved in visceral hypersensitivity and anxiety in IBS-like rats by enhancing hippocampal synaptic plasticity. In conclusion, early life stress induces increased expression of circKcnk9 in the CA1 of IBS-like rats. Increased circKcnk9 expression regulates synaptic transmission and enhances LTP, leading to visceral hypersensitivity and anxiety in IBS-like rats. The underlying circKcnk9 signaling pathway is miR124-3p/EZH2. Increased circKcnk9 reinforces its sponging of miR124-3p and strongly suppresses miR124-3p activity, resulting in increased expression of the target gene EZH2. This study provides a new epigenetic mechanism for visceral hypersensitivity and anxiety in IBS-like rats.

Examine the public health impacts of functional somatic disorders using the DanFunD study

Background: Persistent physical symptoms (e.g. pain, fatigue) are prevalent in the population and some persons may develop a functional somatic disorder (FSD). We still need to explore the limits between general bodily sensations and FSD, and great controversies exist as regard delimitation, occurrence, risk factors, prognosis, and costs of FSD in the general population. This is mainly due to the lack of focused, sufficient powered, population-based epidemiological studies. Material and Methods: The DanFunD study is the largest focused population-based study on FSD and has the potential to answer these crucial questions regarding the FSD disorders. DanFunD has its origin in the Copenhagen area of Denmark and was initiated in 2009 by an interdisciplinary team of researchers including basic scientists, clinical researchers, epidemiologists, and public health researchers. A population-based cohort of nearly 10,000 people have filled in detailed questionnaires, gone through a thorough health examination, and a biobank is established. The cohort was re-examined after five years. Results:The prevalence of FSD in the Danish population is about 10-15% and is twice as common in women as in men. Persons with FSD report impaired daily activities and low self-perceived health, which qualifies FSD as a major public health problem. The research plan to unravel the risk factors for FSD employs a bio-psycho-social approach according to a detailed plan. Preliminary results are presented, and work is in progress. Likewise, plans for assessing prognosis and health care costs are provided. Conclusion: We invite researchers in the field to collaborate on this unique data material.

Extraintestinal manifestations in irritable bowel syndrome: A systematic review

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by abdominal pain and altered bowel habits. Further, IBS patients experience a high degree of extraintestinal symptoms.

OBJECTIVES

The aim of this review was to describe the relation between IBS and extraintestinal manifestations and mechanisms and treatments of these extraintestinal manifestations.

DESIGN

The study was performed as a systematic review.

DATA SOURCES AND METHODS

Search terms including extraintestinal manifestations or somatization and IBS were used to scrutinize for publications in Pubmed. In total, 630 publications were identified and 80 were finally included in this review.

RESULTS

About 50% of all IBS patients have extraintestinal manifestations in addition to gastrointestinal symptoms. Somatic pain, fatigue, and sleeping disturbances are most common, and most often described in women. Both extraintestinal manifestations and psychological distress are associated with exaggerated gastrointestinal symptoms, impaired quality of life, and difficulties to treat IBS symptoms. The extraintestinal manifestations render an excess of healthcare costs. Varying etiology and pathophysiology to IBS are discussed, and many patients express a general hypersensitivity. Extraintestinal symptoms are seldom documented at clinical healthcare or included in the assessment of treatment outcomes. A good patient-physician relationship and strengthening of coping mechanisms have rendered less gastrointestinal symptoms, psychological distress, and somatization. Altered lifestyle habits may improve both gastrointestinal and extraintestinal symptoms. Pharmacological treatment, including antidepressant drugs, should be considered when lifestyle advice fails. Teamwork between different specialists and healthcare providers may be of importance in the wide range of symptoms and extraintestinal manifestations.

CONCLUSION

Extraintestinal manifestations are common in IBS patients and is associated with worse suffering and difficulties to treat symptoms. Evaluation and treatment of IBS patients should consider also extraintestinal manifestations and their treatment outcome. Establishment of good relationship, strengthening of coping mechanisms, and education in healthier lifestyle habits are crucial in the management of these patients.

Irritable bowel syndrome in women: Association between decreased insular subregion volumes and gastrointestinal symptoms

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All insular subregions are smaller in IBS compared to healthy women.

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Insular volume associates with GI symptoms independent of psychiatric comorbidity.

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GI symptoms associate with anterior but not posterior insular volume.

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More nausea associated with smaller dorsal anterior insula bilaterally.

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Insula in major depression is not significantly smaller than in healthy women.

Objective

Irritable bowel syndrome (IBS) is a chronic pain disorder characterized by disturbed interactions between the gut and the brain with depression as a common comorbidity. In both IBS and depression, structural brain alterations of the insular cortices, key structures for pain processing and interoception, have been demonstrated but the specificity of these findings remains unclear. We compared the gray matter volume (GMV) of insular cortex (IC) subregions in IBS women and healthy controls (HC) and examined relations to gastrointestinal (GI) symptoms and glutamate + glutamine (Glx) concentrations. We further analyzed GMV of IC subregions in women with major depression (MDD) compared to HC and addressed possible differences between depression, IBS, IBS with depression and HC.

Design

Women with IBS (n = 75), MDD (n = 41) and their respective HC (n = 39 and n = 43) underwent structural brain MRI. IC subregion volumes were estimated using statistical parametric mapping software. General linear model approaches were applied to IC volumetric data and FDR-corrected partial correlation analyses assessed relations between GMV, GI symptoms and Glx concentrations.

Results

IBS patients had significantly smaller IC subregions than HC in both hemispheres but there was no significant difference between MDD compared with IBS and HC for any insular subregion. In IBS, the dorsal anterior insular volumes were negatively correlated with symptoms of nausea and pain, and the left ventral subregion showed a positive correlation with straining to defecate, while the posterior subregion volumes showed no relation to symptoms. In the anterior insula, concentration of Glx showed positive correlations with GMV bilaterally in HC and with GMV of the right anterior insula in IBS.

Conclusion

As the interoceptive cortex, the insula shows substantial and disease-specific structural differences in patients with chronic interoceptive visceral pain. Particularly changes in the anterior proportions might be related to chronic exposure to or enhanced salience towards adverse interoceptive visceral signals and could be linked to biochemical changes, calling for further multimodal and longitudinal work.

Leveraging 16S rRNA Microbiome Sequencing Data to Identify Bacterial Signatures for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain or discomfort. Previous studies have illustrated that the gut microbiota might play a critical role in IBS, but the conclusions of these studies, based on various methods, were almost impossible to compare, and reproducible microorganism signatures were still in question. To cope with this problem, previously published 16S rRNA gene sequencing data from 439 fecal samples, including 253 IBS samples and 186 control samples, were collected and processed with a uniform bioinformatic pipeline. Although we found no significant differences in community structures between IBS and healthy controls at the amplicon sequence variants (ASV) level, machine learning (ML) approaches enabled us to discriminate IBS from healthy controls at genus level. Linear discriminant analysis effect size (LEfSe) analysis was subsequently used to seek out 97 biomarkers across all studies. Then, we quantified the standardized mean difference (SMDs) for all significant genera identified by LEfSe and ML approaches. Pooled results showed that the SMDs of nine genera had statistical significance, in which the abundance of Lachnoclostridium, Dorea, Erysipelatoclostridium, Prevotella 9, and Clostridium sensu stricto 1 in IBS were higher, while the dominant abundance genera of healthy controls were Ruminococcaceae UCG-005, Holdemanella, Coprococcus 2, and Eubacterium coprostanoligenes group. In summary, based on six published studies, this study identified nine new microbiome biomarkers of IBS, which might be a basis for understanding the key gut microbes associated with IBS, and could be used as potential targets for microbiome-based diagnostics and therapeutics.

The impact of mental vulnerability on the relationship between cardiovascular disease and depression

Background.

The mechanisms linking cardiovascular disease (CVD) and depression are still not established. We investigated the impact of mental vulnerability on the relationship between CVD and depression.

Methods.

A total of 19,856 individuals from five cohorts of random samples of the background population in Copenhagen were followed from baseline (1983–2011) until 2017 in Danish registries. Additive hazard and Cox proportional hazard models were used to analyze the effects of confounding by mental vulnerability as well as interactions between mental vulnerability and CVD on the risk of depression.

Results.

During follow-up, 15.3% developed CVD, while 18.1% experienced depression. A strong positive association between CVD and depression (hazard ratio: 3.60 [95% confidence intervals (CI): 3.30; 3.92]) corresponding to 35.4 (95% CI: 31.7; 39.1) additional cases per 1,000 person-years was only slightly attenuated after adjustment for mental vulnerability in addition to other confounders. Synergistic interaction between CVD and mental vulnerability was identified in the additive hazard model. Due to interaction between CVD and mental vulnerability, CVD was associated with 50.9 more cases of depression per 1,000 person-years among individuals with high mental vulnerability compared with individuals with low mental vulnerability.

Conclusions.

Mental vulnerability did not explain the strong relationship between CVD and depression. CVD was associated with additional cases of depression among individuals with higher mental vulnerability indicating that this group holds the greatest potential for intervention, for example, in rehabilitation settings.

Symptom-based latent classes of persons with irritable bowel syndrome

A large amount of interindividual variability exists in symptom experiences of persons with irritable bowel syndrome (IBS). Thus, consideration of multiple symptoms to identify distinct symptom subgroups may be useful in directing personalized health strategies for symptom management. We aimed to identify latent classes (i.e., subgroups) of persons with IBS who share similar patterns of symptoms using symptom-related variables (six groups of daily diary symptoms, cognitive beliefs about IBS, and IBS quality of life [QOL]); and to examine how subgroups differed in patient characteristics. Data were derived from a baseline assessment of men and women enrolled in two cognitively-focused intervention trials (N = 332). Using latent class analysis, four latent classes were identified: Class 1 (low symptoms and good QOL, n = 153), Class 2 (low symptoms and moderate QOL, n = 106), Class 3 (high symptoms with diarrhea and poor QOL, n = 38), and Class 4 (high symptoms with low diarrhea and moderate QOL, n = 35). Diarrhea, being female, less formal education, unemployment, and previous history of major depressive disorder were associated with membership in Class 3. Using these distinct symptom profiles, the next step is to explore underlying mechanisms accounting for symptom burden with the goal of designing tailored interventions to reduce that burden.

Association of defecation disorders with suicidal ideation in young adult with chronic abdominal discomfort

BACKGROUND

The role of physical symptoms on suicidal ideation in adolescents is incompletely understood. The purpose of this study was to discover the potential physical symptoms predictors for suicidal ideation in college freshmen.

METHODS

This cross-sectional survey was conducted in a randomly selected freshmen population in Wuhan China (N = 2449). Questionnaire evaluated suicidal ideation as well as related psychosocial risks and gastrointestinal (GI) physical symptoms. The association between the suicidal ideation and potential predictors was analyzed by Mann-Whitney test and multiple logistic regression analysis.

RESULTS

A total of 2053 (83.8%) completed this survey and 64 (3.1%) was reported to have suicidal ideation. Anxiety (OR 5.44(2.40-12.35)), depression (OR 8.36(3.90-17.94)) and chronic abdominal discomfort (OR 2.06(1.07-3.94)) were independent predictors for suicidal ideation. In freshmen with chronic abdominal discomfort, interestingly, defecation disorder(P = 0.01) and low satisfaction of defecation (P = 0.04) was associated with high risk for suicidal ideation.

CONCLUSION

Defecation disorders were associated with high risk of suicidal intention in young adult with chronic abdominal discomfort. Our result implied that clinicians should be vigilant for suicidal ideation in chronic abdominal discomfort patients, especially those with defecation disorders.

Irritable bowel symptoms, use of healthcare, costs, sickness and disability pension benefits: A long-term population-based study

Objectives: Irritable bowel syndrome (IBS) is associated with increased healthcare use and work absenteeism. We aimed to investigate long-term use of healthcare services and social benefits across IBS symptom groups. Additionally, we estimated excess healthcare costs. Methods: A longitudinal population-based study comprising two 5-year follow-up studies: The Danish part of the Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (Dan-MONICA) 1 (1982-1987) and Inter99 (1999-2004) recruited from the western part of Copenhagen County. The total study population (n = 7278) was divided into symptom groups according to degree of IBS definition fulfillment at baseline and/or 5-year follow-up and was followed until 31 December 2013 in Danish central registries. Poisson regression was used for the analyses adjusting for age, sex, length of education, comorbidity, cohort membership and mental vulnerability. Results: IBS symptom groups compared to no IBS symptoms were associated with an increased number of contacts with primary and secondary healthcare, as well as weeks on sickness and disability benefits. Accounting for mental vulnerability decreased the estimates and all but two associations between IBS symptom groups and outcomes remained statistically significant. The two associations that became insignificant were contacts with psychiatric hospitals and weeks on disability pension. The excess unadjusted healthcare costs for IBS were 680 Euros per year and the overall association between symptom groups and total healthcare costs were statistically significant. Conclusions: IBS symptoms influence the long-term use and costs of healthcare, as well as the use of social benefits in the general population. Mental vulnerability explained some, but not all, of the use of healthcare and social benefits.