Stockholm university

Anna AndreassonAssociate Professor

About me

Anna investigates which factors influence how individuals perceive their own health from a psychoneuroimmunological perspective. Her focus lays on inflammatory markers that are released when the immune system is activated and the sickness behaviour with fatigue, increased pain sensitivity and low mood that follows and the relevance for functional gastrointestinal disorders such as irritable bowel syndrome and functional dyspepsia, ME/CFS (chronic fatigue syndrome) and chronic pain. Anna is associate professor in psychology at Stockholm University, associate professor in clinical epidemiology at Karolinska Institutet and Honorary Associate Professor, Macquarie University, NSW, Australia.

 

Education

Master in science, nutrition, Stockholm University

Bachelor in medicine, physiology, Karolinska Institutet

PhD in medical sciences, Karolinska Institutet

Research projects

Publications

A selection from Stockholm University publication database

  • Prevalence of Histological Gastritis in a Community Population and Association with Epigastric Pain

    2024. Rachael Zuzek (et al.). Digestive Diseases and Sciences

    Article

    Background and Aims Gastritis is a common histological diagnosis, although the prevalence is decreasing in developed populations, alongside decreasing prevalence of H. pylori infection. We sought to determine the prevalence of the etiology of gastritis in a Swedish population sample and to analyze any associations with symptoms, an area of clinical uncertainty. Methods Longitudinal population-based study based in osthammar, Sweden. A randomly sampled adult population completed a validated gastrointestinal symptom questionnaire (Abdominal Symptom Questionnaire, ASQ) in 2011 (N = 1175). Participants < 80 years of age and who were eligible were invited to undergo esophagogastroduodenoscopy (EGD) (N = 947); 402 accepted and 368 underwent EGD with antral and body biopsies (average 54.1 years, range 20-79 years; 47.8% male) with H. pylori serology. Results Gastritis was found in 40.2% (148/368; 95% CI 35.2-45.2%). By rank, the most common histological subtype was reactive (68/148; 45.9%), then H. pylori (44/148; 29.7%), chronic non-H. pylori (29/148; 19.6%), and autoimmune (4/148; 2.7%). Gastritis was significantly associated with older age and H. pylori status (p < 0.01). Gastritis subjects were divided into three histological categories: chronic inactive inflammation, autoimmune gastritis, and active inflammation; there was no difference in the presence of upper gastrointestinal symptoms when categories were compared to cases with no pathological changes. Functional dyspepsia or gastroesophageal reflux were reported in 25.7% (38/148) of those with gastritis (any type or location) versus 34.1% (75/220) with no pathological changes (p = 0.32). Epigastric pain was more common in chronic H. pylori negative gastritis in the gastric body (OR = 3.22, 95% CI 1.08-9.62). Conclusion Gastritis is common in the population with a prevalence of 40% and is usually asymptomatic. Chronic body gastritis may be associated with epigastric pain, but independent validation is required to confirm these findings. Clinicians should not generally ascribe symptoms to histological gastritis.

    Read more about Prevalence of Histological Gastritis in a Community Population and Association with Epigastric Pain
  • Assessing sickness behavior in the French: Validation of the French translation of the sickness questionnaire (SicknessQ) in a non-clinical French population

    2023. Anna Andreasson (et al.). Brain, Behavior, & Immunity - Health 34

    Article

    The Sickness Questionnaire (SicknessQ) is a questionnaire developed to assess symptoms of sickness behavior, including somatic, behavioral, and affective dimensions. To promote cross-cultural assessments of sickness behavior, we aim to expand the use of this questionnaire to other populations and languages. The aim of the present study was to evaluate the French translation of SicknessQ in a French-speaking general population during the COVID-19 pandemic. One hundred and thirty-nine individuals completed the SicknessQ online, along with the construct criteria measures of self-rated health, state anxiety (STAI-S), and depressive symptoms (PHQ-9). The principal component analyses revealed two components: the first component included seven items concerning mood, motivation and experiences of fatigue and pain; the second component included three items concerning somatic sickness symptoms. Higher scores on the total scale and the two component subscales were associated with poorer self-rated health and higher STAI-S and PHQ-9 scores. Since the associations with construct criteria variables were relatively similar between the single- and the two-dimensional solutions, both the total scale and the subscales of the two components of the French SicknessQ can be used in future studies to measure sickness behavior in French-speaking populations.

    Read more about Assessing sickness behavior in the French
  • Diverticulosis is not associated with altered gut microbiota nor is it predictive of future diverticulitis: a population-based colonoscopy study

    2023. Bjarki T. Alexandersson (et al.). Scandinavian Journal of Gastroenterology, 1-8

    Article

    Background: The etiopathogenesis of diverticular disease is unknown.

    Objective: To compare the fecal and mucosa-associated microbiota between participants with and without diverticulosis and participants who later developed diverticulitis versus those that did not from a population-based study.

    Methods: The PopCol study, conducted in Stockholm, Sweden, invited a random sample of 3556 adults to participate, of which 745 underwent colonoscopy. Overall, 130 participants (17.5%) had diverticulosis. 16S rRNA gene sequencing was conducted on available sigmoid biopsy samples from 529 and fecal samples from 251 individuals. We identified individuals who subsequently developed acute diverticulitis up to 13 years after sample collection. In a case-control design matching for gender, age (+/−5 years), smoking and antibiotic exposure, we compared taxonomic composition, richness and diversity of the microbiota between participants with or without diverticulosis, and between participants who later developed acute diverticulitis versus those who did not.

    Results: No differences in microbiota richness or diversity were observed between participants with or without diverticulosis, nor for those who developed diverticulitis compared with those who did not. No bacterial taxa were significantly different between participants with diverticulosis compared with those without diverticulosis. Individuals who later developed acute diverticulitis (2.8%) had a higher abundance of genus Comamonas than those who did not (p = .027).

    Conclusions: In a population-based cohort study the only significant difference was that those who later develop diverticulitis had more abundance of genus Comamonas. The significance of Comamonas is unclear, suggesting a limited role for the gut microbiota in the etiopathogenesis of diverticular disease.

    Read more about Diverticulosis is not associated with altered gut microbiota nor is it predictive of future diverticulitis
  • Disturbed sleep and patterns of psychiatric symptoms and function in a school-based sample of adolescents

    2023. Lie Åslund (et al.). Clinical Child Psychology and Psychiatry 28 (4), 1524-1535

    Article

    Background Sleep problems are common in adolescence and often related to psychopathology and impaired functioning. However, most studies have used summative scores, and little is known about how adolescents with disrupted sleep perceive their specific symptoms and dysfunctions. This study explored differences in levels of psychiatric symptoms and functional ability between Swedish adolescents with and without self-reported disturbed sleep in a school-based sample.

    Methods Swedish adolescents (n = 618, mean age 15.7+/-1.9yrs) answered the PROMIS pediatric measures for fatigue, anxiety, depression, pain interference, anger, physical activity and peer and family relationships. Logistic regression analyses were performed to assess differences between respondents with and without disturbed sleep.

    Results Disturbed sleep was associated with higher levels of symptoms of fatigue, anxiety, depression, anger and pain interference, as well as lower functional abilities in terms of physical activity and peer- and family relationships. Adolescents reporting disturbed sleep generally displayed a pattern of impaired executive functioning, internal emotional distress and school- and sleep related worry and dysfunction, as compared to physical disability, aggressive behavior, stress and generalized worry.

    Conclusions The present study adds to the understanding of how disturbed sleep and specific psychiatric symptoms and functional ability are interrelated, which may also have clinical implications.

    Read more about Disturbed sleep and patterns of psychiatric symptoms and function in a school-based sample of adolescents
  • Improved prediction of 10-year risk of severe liver disease in the general population using commonly available biomarkers

    2023. Hannes Hagström (et al.). Alimentary Pharmacology and Therapeutics 57 (4), 418-425

    Article

    Background: Estimating the risk for cirrhosis in the general population is complex. Existing prediction tools are in general unsatisfactory.

    Aims: To explore if using commonly available biomarkers can improve the commonly used FIB-4 score in the identification of subgroups at risk of cirrhosis.

    Methods: We used laboratory and clinical data on 126,925 individuals aged 35–79 years in Stockholm, Sweden, undergoing health examinations from 1985 to 1996. We used Swedish nationwide registries to ascertain 10-year cumulative incidence of severe liver disease, a composite of diagnoses corresponding to cirrhosis and its complications. We considered combinations of biomarkers associated with severe liver disease to identify subgroups with different risk profiles.

    Results: During an average follow-up of 9.3 years, we ascertained 630 incident cases of severe liver disease (0.5%). Age, the FIB-4 score, diabetes or impaired glucose and gamma-glutamyl transferase (gGT) were the most relevant characteristics for classifying risk profiles. Using these factors, we identified 24 groups with a cumulative incidence of severe liver disease at 10 years ranging from 0.2% (age 35–65, low FIB-4, no diabetes or impaired glucose and normal gGT) to 32.1% (age 35–65, high FIB-4, diabetes or impaired glucose and high gGT).

    Conclusions: Identification of subjects at increased risk of severe liver disease in the general population using the FIB-4 score can be substantially improved by adding age and specific biomarkers commonly available in the primary care setting. These parameters should be considered for inclusion in the development of future risk prediction models.

    Read more about Improved prediction of 10-year risk of severe liver disease in the general population using commonly available biomarkers
  • Inflammatory Bowel Disease Is not Linked to a Higher Rate of Adverse Events in Colonoscopy - a Nationwide Population-based Study in Sweden

    2023. Bjarki T. Alexandersson (et al.). Journal of Crohn's & Colitis

    Article

    Background and Aims

    Inflammatory bowel disease may cause long-standing inflammation and fibrosis and may increase the risk of adverse events in colonoscopy. We evaluated whether inflammatory bowel disease and other potential risk factors are associated with bleeding or perforation in a nationwide, population-based, Swedish study.

    Methods

    Data from 969 532 colonoscopies, including 164 012 [17%] on inflammatory bowel disease patients, between 2003 and 2019, were retrieved from the National Patient Registers. ICD-10 codes for bleeding [T810] and perforation [T812] within 30 days of the colonoscopy were recorded. Multivariable logistic regression was used to test if inflammatory bowel disease status, inpatient setting, time period, general anaesthesia, age, sex, endoscopic procedures, and antithrombotic treatment were associated with higher odds for bleeding and perforation.

    Results

    Bleeding and perforation were reported in 0.19% and 0.11% of all colonoscopies, respectively. Bleeding [odds ratio 0.66, p <0.001] and perforation [odds ratio 0.79, p <0.033] were less likely in colonoscopies in individuals with inflammatory bowel disease status. Bleeding and perforation were more common in inpatient than in outpatient inflammatory bowel disease colonoscopies. The odds for bleeding but not perforation increased between 2003 to 2019. General anaesthesia was associated with double the odds for perforation.

    Conclusions

    Individuals with inflammatory bowel disease did not have more adverse events compared with individuals without inflammatory bowel disease status. However, the inpatient setting was associated with more adverse events, particularly in inflammatory bowel disease status. General anaesthesia was associated with a greater risk of perforation.

    Read more about Inflammatory Bowel Disease Is not Linked to a Higher Rate of Adverse Events in Colonoscopy - a Nationwide Population-based Study in Sweden
  • Limited evidence of moderation of the association between gastrointestinal symptoms and prospective healthcare utilisation by quality of life

    2022. David T. McNaughton (et al.). Alimentary Pharmacology and Therapeutics 55 (3), 311-317

    Article

    Background: An individual’s drive to seek medical help remains a complex behavioural process, incorporating psychological, social and symptom-specific factors. Within irritable bowel syndrome (IBS), gastrointestinal symptoms only predict a small portion of the high healthcare-seeking experienced.

    Aim: To examine the moderating role of quality of life (QoL) domains on this relationship to help explain the variance observed.

    Methods: This is an analysis of a Swedish population-based prospective study of healthcare use over a 12-year period. At baseline, gastrointestinal symptoms were measured with the valid Gastrointestinal Symptom Rating Scale, and QoL via the SF-36. 1159 subjects (57% female; mean age 48.6 years) had their health records matched with the initial survey. 164 were classified as IBS by Rome II criteria. Negative binomial or logistic models were fit to evaluate the moderating effect of particular QoL domains on the relationship between gastrointestinal symptoms and prospective healthcare utilisation.

    Results: Gastrointestinal symptoms were associated with prospective healthcare use, but moderation in this relationship by particular QoL domains was not supported; most models did not reach statistical significance. Furthermore, the impact of IBS status did not alter the moderation hypotheses.

    Conclusions: Particular QoL domains did not impact the relationship between gastrointestinal symptoms on prospective healthcare seeking. Future research should continue to examine other psychological, social and symptom variables to identify predictors of high healthcare consumers in IBS.

    Read more about Limited evidence of moderation of the association between gastrointestinal symptoms and prospective healthcare utilisation by quality of life
  • Comorbidity of atopic diseases and gastro-oesophageal reflux evidence of a shared cause

    2022. Bronwyn K. Brew (et al.). Clinical and Experimental Allergy

    Article

    Introduction: Gastro-oesophageal reflux disease (GERD) is the most common non-allergic comorbidity in adults with asthma; however, comorbidity with other atopic diseases such as eczema and hay fever is unclear. The objective was to assess the comorbidity of GERD with asthma and atopic diseases and to investigate possible mechanisms, including genetic and/or affective factors.

    Methods: A co-twin control study harnessing 46 583 adult twins. Questionnaires on health status were linked to national patient and prescribed drug register data. Analyses tested associations of comorbidity between multiple definitions of atopic diseases (self-report and register-based) with GERD. Comparisons were made between unpaired, monozygotic (MZ) and dizygotic (DZ) twins to assess genetic liability. Affective traits (depression, anxiety and neuroticism) were added to models as possible explanatory factors.

    Results: The risk of GERD in those with asthma was OR (odds ratio) 1.52 (95% CI 1.38, 1.68), hay fever OR 1.22 (95%CI 1.12, 1.34) and eczema OR 1.23 (95%CI 1.10, 1.38). Adjusting for affective traits completely attenuated the comorbidity associations for hay fever and eczema with GERD, and partly for asthma with GERD. Co-twin control associations attenuated suggesting a shared cause for both GERD and atopic diseases. For example, all twins adjOR 1.32 (95%CI 1.00, 1.74), 0.97 (95% CI 0.76–1.23) and 1.11 (95%CI 0.85–1.45) for self-report asthma, hay fever and eczema with GERD respectively.

    Conclusions: GERD is a common comorbidity in adults with asthma, hay fever and/or eczema. We found evidence for shared mechanisms suggesting common underlying causes that may involve affective traits requiring further investigation.

    Read more about Comorbidity of atopic diseases and gastro-oesophageal reflux evidence of a shared cause
  • Evaluating the construct validity and internal consistency of the Sickness Questionnaire in a Swedish sample of adults with longstanding pain

    2022. Jenny Åström (et al.). Scandinavian Journal of Pain 22 (1), 88-96

    Article

    Objectives: Low-grade inflammation is a possible contributing factor in the development and persistence of chronic primary pain syndromes. Related to inflammatory activity is sickness behavior, a set of behavioral responses including increased pain sensitivity, fatigue, malaise, fever, loss of appetite, as well as depressive behavior and anhedonia. To capture these behavioral responses and their relation to longstanding pain, psychometrically sound self-report questionnaires are needed. The Sickness Questionnaire (SicknessQ) was developed to assess self-reported sickness behavior based on studies on acute immune activation while maintaining relevance for persistent conditions. The aim of the current study was to evaluate aspects of the validity and reliability of the SicknessQ in a Swedish sample of persons with longstanding pain.

    Methods: Aspects of construct validity were evaluated by means of performing a confirmatory factor analysis (CFA) (testing structural validity) and by relevant hypothesis testing i.e., that ratings of sickness behavior in combination with other related factors (e.g., depression and anxiety) would be significantly related to ratings of avoidance. Reliability was evaluated by means of analyzing the internal consistency of items.

    Results: Following the CFA, a non-significant Chi-Square test (chi(2) [32, N=190] = 42.95, p=0.094) indicated perfect model fit. Also, the relative fit indices supported adequate model fit (CFI = 0.978; TLI = 0.969; RMSEA = 0.0430). Sickness behavior (p<0.0001), depression (p<0.05) and pain duration (p<0.05) significantly contributed to the regression model, explaining 45% of the total variance in avoidance. Internal consistency was adequate, as indicated by a Cronbach's alpha value of 0.82 for the entire questionnaire.

    Conclusions: Results indicate that the SicknessQ has adequate structural validity as well as adequate internal consistency, and is significantly associated with avoidance. The SicknessQ appears to have utility as a self-report questionnaire to assess symptoms of sickness behavior for adults with longstanding pain.

    Read more about Evaluating the construct validity and internal consistency of the Sickness Questionnaire in a Swedish sample of adults with longstanding pain
  • GWAS of stool frequency provides insights into gastrointestinal motility and irritable bowel syndrome

    2021. Ferdinando Bonfiglio (et al.). Cell Genomics 1 (3)

    Article

    Gut dysmotility is associated with constipation, diarrhea, and functional gastrointestinal disorders like irritable bowel syndrome (IBS), although its molecular underpinnings are poorly characterized. We studied stool frequency (defined by the number of bowel movements per day, based on questionnaire data) as a proxy for gut motility in a GWAS meta-analysis including 167,875 individuals from UK Biobank and four smaller population-based cohorts. We identify 14 loci associated with stool frequency (p ≤ 5.0 × 10-8). Gene set and pathway analyses detected enrichment for genes involved in neurotransmitter/neuropeptide signaling and preferentially expressed in enteric motor neurons controlling peristalsis. PheWAS identified pleiotropic associations with dysmotility syndromes and the response to their pharmacological treatment. The genetic architecture of stool frequency correlates with that of IBS, and UK Biobank participants from the top 1% of stool frequency polygenic score distribution were associated with 5× higher risk of IBS with diarrhea. These findings pave the way for the identification of actionable pathological mechanisms in IBS and the dysmotility syndromes.

    Read more about GWAS of stool frequency provides insights into gastrointestinal motility and irritable bowel syndrome
  • An Increasing Incidence of Upper Gastrointestinal Disorders Over 23 Years

    2021. Anna Andreasson (et al.). American Journal of Gastroenterology 116 (1), 210-213

    Article

    INTRODUCTION: We hypothesized that the prevalence of functional dyspepsia and gastroesophageal reflux disease in the community may be increasing.

    METHODS: Randomly selected adults were surveyed on 4 occasions: 1988 (n = 1,151, 21–79 years, response rate [rr] = 90%), 1989 (n = 1,097, 22–80 years, rr = 87%), 1995 (n = 1,139, 20–85 years, rr = 76%), and 2011 (n = 1,175, 20–93 years, rr = 63%).

    RESULTS: In functional dyspepsia, the odds of postprandial distress syndrome tripled over 23 years' follow-up (odds ratio [OR]: 3.55; 95% confidence interval [CI]: 2.60–4.84, mixed-effect regression analysis), whereas a small decrease in epigastric pain syndrome was observed (OR: 0.65, 95% CI: 0.42–1.00). The odds of reporting gastroesophageal reflux disease doubled (OR: 2.02; 95% CI: 1.50–2.73).

    DISCUSSION: The underlying mechanisms behind the increase in postprandial distress syndrome and gastroesophageal reflux disease remain to be determined.

    Read more about An Increasing Incidence of Upper Gastrointestinal Disorders Over 23 Years
  • Clusters of community-dwelling individuals empirically derived from stool diaries correspond with clinically meaningful outcomes

    2021. Michael P. Jones (et al.). European Journal of Gastroenterology and Hepathology 33 (1S), e740-e745

    Article

    Background Functional gastrointestinal disorders (FGIDs) are diagnosed according to expert consensus criteria based on recall of symptoms over periods of 3 months or longer. Whether the expert opinion concords with underlying disease process and whether individual recall is accurate are both in doubt. This study aimed to identify naturally occurring clusters of individuals with respect to symptom pattern, evaluate their significance, compare cluster profiles with expert opinion and evaluate their temporal stability.

    Methods  As part of a random population study of FGID-related symptoms, we first explored the use of prospective stool and symptom diaries combined with empirical grouping of individuals into clusters using nonhierarchical cluster analysis.

    Results The analysis identified two clusters of individuals, one of which was characterized by elevated scores on all domains of symptoms (26% of the sample) and one that was low to average on all domains (74% of the sample). Cluster membership was found to be stable over a long interval. Clusters were found to differ on most domains of quality-of-life (d = 0.46–0.74), self-rated health (d = −0.42) and depression (d = −0.42) but not anxiety. Prevalence of clinically diagnosed irritable bowel syndrome (IBS) was higher in the more impacted cluster (33%) compared with the healthy cluster (13%; P < 0.0001).

    Conclusion A naturalistic classification of individuals challenges consensus criteria in showing that some IBS individuals have a symptom experience not unlike health. The proposed approach has demonstrated temporal stability over time, unlike consensus criteria. A naturalistic disease classification system may have practical advantages over consensus criteria when supported by a decision-analytic system.

    Read more about Clusters of community-dwelling individuals empirically derived from stool diaries correspond with clinically meaningful outcomes
  • Duodenal eosinophilia and the link to anxiety

    2021. Jukka Ronkainen (et al.). Neurogastroenterology and Motility 33 (10)

    Article

    Introduction: The concept of gut-to-brain communication via microbial or inflammatory pathways is gaining increased attention but genuine pathology directly linking gut perturbation to anxiety is lacking. We hypothesized that duodenal eosinophilia, as known to occur in functional dyspepsia (FD), may be an underlying cause of anxiety and may help explain the striking association between FD and anxiety.

    Methods: Randomly selected subjects from the national population register of Sweden completed the validated Abdominal Symptom Questionnaire; 1000 completed esophagogastroduodenoscopy and the Hospital Anxiety and Depression Scale questionnaire. Duodenal biopsies were obtained from 1(st) (D1) and 2(nd) portion (D2). Eligible subjects who underwent endoscopy (n = 887) were invited to participate in a 10-year follow-up study with the same questionnaires. Among endoscopy normal subjects, FD was identified by Rome criteria, and controls were symptom free. Duodenal eosinophilia was based on pre-defined cut-offs. Finding are reported as odds ratios (ORs) with 95% confidence interval and p-value.

    Results: The study population comprised 89 cases with FD and 124 healthy controls (mean age 62 years, SD 12, 34% male). Clinical anxiety at follow-up was elevated in those with D1 eosinophilia at baseline considering either new-onset anxiety (OR = 4.5, 95% CI 0.8, 23.8; p = 0.08) or follow-up anxiety adjusting for baseline anxiety (OR = 4.51 (95% CI 1.03, 19.81; p = 0.046).

    Conclusion: Duodenal eosinophilia may potentially be a mechanism linked to anxiety independent of FD.

    Read more about Duodenal eosinophilia and the link to anxiety
  • Ileocolonic Histopathological and Microbial Alterations in the Irritable Bowel Syndrome

    2021. Nicholas J. Talley (et al.). Clinical and Translational Gastroenterology 12 (1)

    Article

    INTRODUCTION: Histopathological alterations in the ileum and colon in irritable bowel syndrome (IBS) are controversial, and normal values are poorly established. We hypothesized that changes in mucosal immune cells characterize IBS and key changes in immune composition are associated with the mucosa-associated microbiota (MaM).

    METHODS: A nested case-control study (48 IBS and 106 controls included) from 745 colonoscopy participants in a random population sample. Intraepithelial lymphocytes (IELs)/100 enterocytes and eosinophils/5 nonoverlapping high-power fields counted; mast cells identified by immunocytochemistry (CD117)/5 high-power fields. Paneth cells quantified per 5 crypts. 16S rRNA gene amplicon sequencing performed on available sigmoid MaM, n = 55 and fecal microbiota, n = 20. Microbiota profiles compared between samples with high and low IEL counts.

    RESULTS: IBS had increased IELs in the terminal ileum (relative risk ratio = 1.70, 95% confidence interval 1.08–2.76, P = 0.022 adjusted for age, sex, and smoking). Cecal IELs were increased in IBS—diarrhea (relative risk ratio = 2.03, 95% confidence interval 1.13–3.63, P = 0.017). No difference was observed in alpha diversity of MaM or fecal microbiota based on IEL count. There was no difference in beta diversity of the MaM according to IEL count in the terminal ileal (TI) (P = 0.079). High TI IEL counts associated with a significant expansion of the genus Blautia (P = 0.024) and unclassified Clostridiales (P = 0.036) in colon MaM.

    DISCUSSION: A modest but significant increase in IELs was observed in IBS vs. controls in a population-based setting. Subtle TI and cecal inflammation may play a pathogenic role in IBS but needs confirmation. Modest but discernible differences in the colonic MaM were seen according to TI IEL count but not IBS status.

    Read more about Ileocolonic Histopathological and Microbial Alterations in the Irritable Bowel Syndrome
  • Large-scale association analyses identify host factors influencing human gut microbiome composition

    2021. Alexander Kurilshikov (et al.). Nature Genetics 53 (2), 156-165

    Article

    To study the effect of host genetics on gut microbiome composition, the MiBioGen consortium curated and analyzed genome-wide genotypes and 16S fecal microbiome data from 18,340 individuals (24 cohorts). Microbial composition showed high variability across cohorts: only 9 of 410 genera were detected in more than 95% of samples. A genome-wide association study of host genetic variation regarding microbial taxa identified 31 loci affecting the microbiome at a genome-wide significant (P < 5 × 10−8) threshold. One locus, the lactase (LCT) gene locus, reached study-wide significance (genome-wide association study signal: P = 1.28 × 10−20), and it showed an age-dependent association with Bifidobacterium abundance. Other associations were suggestive (1.95 × 10−10 < P < 5 × 10−8) but enriched for taxa showing high heritability and for genes expressed in the intestine and brain. A phenome-wide association study and Mendelian randomization identified enrichment of microbiome trait loci in the metabolic, nutrition and environment domains and suggested the microbiome might have causal effects in ulcerative colitis and rheumatoid arthritis.

    Read more about Large-scale association analyses identify host factors influencing human gut microbiome composition
  • Measuring the impact of gastrointestinal inconvenience and symptoms on perceived health in the general population - validation of the Short Health Scale for gastrointestinal symptoms (SHS-GI)

    2021. Susanna Walter (et al.). Scandinavian Journal of Gastroenterology 56 (12), 1406-1463

    Article

    Objectives Gastrointestinal (GI) symptoms are intimately related to our wellbeing. The Short Health Scale for GI symptoms (SHS-GI) is a simple questionnaire to measure the impact of GI inconvenience and symptoms on quality of life. The aim was to validate the SHS-GI in a general population sample and to compare it with SHS-data across different patient groups.

    Method A subsample of 170 participants from a population-based colonoscopy study completed the Rome II questionnaire, GI diaries, psychological questionnaire (hospital anxiety and depression scale) and SHS-GI at follow-up investigation. Psychometric properties of SHS-GI as an overall score were determined by performing a confirmatory factor analysis (CFA). Spearman correlation between SHS total score and symptoms was calculated in the general population sample. SHS-GI data was compared with SHS data from patients with inflammatory bowel disease (IBD) and fecal incontinence (FI).

    Results As expected, the general population rated their impact of GI inconvenience on quality of life as better than the patient populations in terms of all aspects of the SHS-GI. The CFA showed a good model fit meeting all fit criteria in the general population. Cronbach's alpha for the total scale was 0.80 in the general population sample and ranged from 0.72 in the FI sample to 0.88 and 0.89 in the IBD samples.

    Conclusions SHS-GI demonstrated appropriate psychometric properties in a sample of the normal population. We suggest that SHS-GI is a valid simple questionnaire suitable for measuring the impact of GI symptoms and inconvenience on quality of life in both general and patient populations.

    Read more about Measuring the impact of gastrointestinal inconvenience and symptoms on perceived health in the general population - validation of the Short Health Scale for gastrointestinal symptoms (SHS-GI)
  • Neutrophils, eosinophils, and intraepithelial lymphocytes in the squamous esophagus in subjects with and without gastroesophageal reflux symptoms

    2021. Mudar Zand Irani (et al.). Human Pathology 115, 112-122

    Article

    Whilst intraepithelial lymphocytes (IELs) are considered normal within the distal esophageal mucosa, they have an increasingly recognised role in the pathogenesis of reflux esophagitis, and IEL quantification establishes the diagnosis of lymphocytic esophagitis. Knowledge regarding the upper limit of a normal IEL count in health is lacking. We studied 117 non-healthcare seeking adult volunteers from a random community sample (the Kalixanda study) with esophageal biopsies 2 cm above the gastroesophageal junction. Subjects were divided into four groups based on the presence or absence of gastro-esophageal reflux symptoms and/or esophagitis on endoscopy. Asymptomatic subjects with no endoscopic esophagitis were selected as controls, and the cell counts in this group were used to define the upper limit of normal of IELs, eosinophils and neutrophils. The entire sample was used to identify independent predictors of increased cellular counts by logistic regression analysis. None of the healthy controls had an IEL count of more than three per five high power fields (HPF), and therefore this was considered as the upper limit of normal; no controls had eosinophils or neutrophils in esophageal biopsies. Independent predictors of an elevated IEL count were spongiosis on histology (OR 11.17, 95% CI 3.32–37.58, P < 0.01) and current smoking (OR 4.84, 95% CI 1.13–2.71, P = 0.03). A receiver operating characteristics analysis concluded that a threshold of 3 IELs/5HPFs performs best in predicting reflux symptoms when a normal esophageal mucosa is visualized on endoscopy (sensitivity = 100.0%, specificity = 35.2%). The healthy esophageal mucosa does not contain more than three IELs per five HPF in the distal esophagus.

    Read more about Neutrophils, eosinophils, and intraepithelial lymphocytes in the squamous esophagus in subjects with and without gastroesophageal reflux symptoms
  • Objective and Subjective Sleep in Rheumatoid Arthritis and Severe Seasonal Allergy

    2021. Sandra Tamm (et al.). Nature and Science of Sleep 13, 775-789

    Article

    Introduction: Disturbed sleep in inflammatory disorders such as allergy and rheumatoid arthritis (RA) is common and may be directly or indirectly related to disease processes, but has not been well characterized in these patient groups, especially not with objective methods.

    Aim: The present study aimed to characterize objective and subjective sleep in patients with allergy or RA using sleep diaries, one-channel EEG and actigraphy. It also aimed to investigate if sleep measures were associated with central immune activation, assessed using translocator protein (TSPO) positron emission tomography, as well as cytokine markers of peripheral inflammation and disease-specific symptoms or general symptoms of sickness.

    Methods: In total, 18 patients with seasonal pollen allergy, 18 patients with RA and 26 healthy controls were included in the study. Allergy patients and matched controls were assessed twice, in and out of pollen season, and RA patients and controls were assessed once. Sleep was recorded for approximately 1 week at each occasion.

    Results: Patients with allergy had increased levels of slow-wave sleep during pollen season. In contrast, patients with RA had less SWS compared to healthy controls, while no differences were observed in sleep duration or subjective sleep quality. Across groups, neither proinflammatory cytokines, grey matter TSPO levels nor general sickness symptoms were associated with objective or subjective measures of sleep. Rhinitis, but not conjunctivitis, was correlated to worse subjective sleep and more slow wave sleep in allergy. Functional status, but not disease activity, predicted lower subjective sleep in RA.

    Conclusion: This study tentatively indicates that both patients with allergy and RA display sleep alterations but does not support inflammation as an independent predictor of the sleep disturbance across these patient groups.

    Read more about Objective and Subjective Sleep in Rheumatoid Arthritis and Severe Seasonal Allergy
  • Poor sleep quality is associated with worse self-rated health in long sleep duration but not short sleep duration

    2021. Anna Andreasson (et al.). Sleep Medicine 88, 262-266

    Article

    Unhealthy sleep duration, either short or long, is associated with worse health and central subjective dimensions of sleep and health such as fatigue. It has been argued that the link between sleep duration and health may depend on the quality of the slept hours, and on its functional impact (ie, fatigue). The present study therefore assessed whether the relationship between last night's sleep duration and general self-rated health (SRH) differs as a function of sleep quality, and secondly, whether current fatigue and sleep quality are factors linking sleep duration and SRH. The present cross-sectional dataset involved 1304 individuals (57% female, M age = 28.8, range 18-79). Participants completed surveys for general SRH, previous night's sleep duration and sleep quality, and current fatigue. Results showed the expected inverted U-shaped (ie, quadratic) relation between last night's sleep duration and SRH and a linear relation between last night's sleep quality and SRH. However, long sleep duration was only associated with poorer SRH in individuals who also reported poor sleep quality. Further, the quadratic relationship between sleep duration and SRH was partially mediated by fatigue and sleep quality. The results of this multi-study analysis suggest that SRH is particularly poor in those who slept both long and with poor quality the night before, while good sleep quality may protect those with a long sleep duration from poor SRH. Thus, last night's long sleep does not seem to be associated with poor subjective health unless it is coupled with poor sleep quality. Furthermore, fatigue and sleep quality are potential pathways linking short and long sleep duration with SRH. Different dimensions of sleep interact in their association with health, and future research will benefit from an integrative approach. 

    Read more about Poor sleep quality is associated with worse self-rated health in long sleep duration but not short sleep duration
  • Role of smoking in functional dyspepsia and irritable bowel syndrome

    2021. Nicholas J. Talley (et al.). Alimentary Pharmacology and Therapeutics 54 (1), 32-42

    Article

    Background: It is uncertain if functional dyspepsia (FD) or irritable bowel syndrome (IBS) are linked to smoking, and smoking cessation is not part of the routine advice provided to these patients.

    Aim: To assess if smoking is an independent risk factor for FD and IBS.

    Methods: Three population-based endoscopy studies in Sweden with 2560 community individuals in total (mean age 51.5 years, 46% male). IBS (14.9%), FD (33.5%), and associated symptoms were assessed using the validated abdominal symptom questionnaire, and smoking (17.9%) was obtained from standardised questions during a clinic visit. The effect of smoking on symptom status was analysed in an individual person data meta-analysis using mixed effect logistic regression, adjusted for snuffing, age and sex.

    Results: Individuals smoking cigarettes reported significantly higher odds of postprandial distress syndrome (FD-PDS) (OR 10-19 cig/day = 1.42, 95% CI 1.04-1.98 P = 0.027, OR ≥20 cig/day = 2.16, 95% CI 1.38-3.38, P = 0.001) but not epigastric pain. Individuals smoking 20 or more cigarettes per day reported significantly higher odds of IBS-diarrhoea (OR = 2.40, 95% CI 1.12-5.16, P = 0.025), diarrhoea (OR = 2.01, 95%CI 1.28-3.16, P = 0.003), urgency (OR = 2.21, 95%CI 1.41-3.47, P = 0.001) and flatus (OR = 1.77, 95%CI 1.14-2.76, P = 0.012) than non-smokers. Smoking was not associated with IBS-constipation or IBS-mixed.

    Conclusion: Smoking is an important environmental risk factor for postprandial distress syndrome, the most common FD subgroup, with over a twofold increased odds of PDS in heavy smokers. The role of smoking in IBS-diarrhoea, but not constipation, is also likely important.

    Read more about Role of smoking in functional dyspepsia and irritable bowel syndrome

Show all publications by Anna Andreasson at Stockholm University