| 1. |
- Beyder, Arthur, et al.
(författare)
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Loss-of-Function of the Voltage-Gated Sodium Channel Na(V)1.5 (Channelopathies) in Patients With Irritable Bowel Syndrome
- 2014
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 146:7, s. 1659-1668
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: SCN5A encodes the a-subunit of the voltage-gated sodium channel Na(V)1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of Na(V)1.5. METHODS: We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls. RESULTS: Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted Na(V)1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-Na(V)1.5 had the greatest effect in reducing Na(V)1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS. CONCLUSIONS: About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt Na(V)1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.
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| 2. |
- Beyder, Arthur, et al.
(författare)
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Loss-of-function of the voltage-gated sodium channel NaV1.5 (channelopathies) in patients with irritable bowel syndrome.
- 2014
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 146:7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: SCN5A encodes the α-subunit of the voltage-gated sodium channel NaV1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of NaV1.5.METHODS: We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls.RESULTS: Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted NaV1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-NaV1.5 had the greatest effect in reducing NaV1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS.CONCLUSIONS: About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt NaV1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.
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| 4. |
- Aro, Pertti, et al.
(författare)
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Use of tobacco products and gastrointestinal morbidity : an endoscopic population-based study (the Kalixanda study)
- 2010
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 25:10, s. 741-750
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Tidskriftsartikel (refereegranskat)abstract
- The impact of snus (smokeless tobacco or snuff) on gastrointestinal symptoms and pathological findings is largely unknown. The authors aimed to investigate whether the exposure to different forms of tobacco influences upper gastrointestinal symptoms, histology and frequency of Helicobacter pylori infection. A random sample (n = 2,860) of the adult population of two northern Swedish municipalities Kalix and Haparanda (n = 21,610) was surveyed between December 1998 and June 2001 using a validated postal questionnaire assessing gastrointestinal symptoms (response rate 74.2%, n = 2,122) (The Kalixanda Study). A random sub-sample (n = 1,001) of the responders was invited to undergo an esophagogastroduodenoscopy (participation rate 73.3%) including biopsies, Helicobacter pylori culture and serology and symptom assessment and exploration of present and past use of tobacco products. No symptom groups were associated with snus use. Snus users had a significantly higher prevalence of macroscopic esophagitis univariately but snus use was not associated with esophagitis in multivariate analysis. Snus use was associated with basal cell hyperplasia (OR = 1.74, 95% CI: 1.02, 3.00) and with elongation of papillae (OR = 1.79, 95% CI: 1.05-3.05) of the squamous epithelium at the esophago-gastric junction. Current smoking cigarettes was associated with overall peptic ulcer disease (OR = 2.32, 95% CI: 1.04, 5.19) whereas snus use was not. There were no significant association between current Helicobacter pylori infection and different tobacco product user groups. Snus significantly alters the histology of the distal esophagus but does not impact on gastrointestinal symptoms or peptic ulcer disease.
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| 5. |
- Forsberg, Anna M., et al.
(författare)
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Prevalence of colonic neoplasia and advanced lesions in the normal population : a prospective population-based colonoscopy study
- 2012
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Ingår i: Scandinavian journal of gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 47:2, s. 184-90
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Tidskriftsartikel (refereegranskat)abstract
- Objective. There are few prospective studies of the prevalence of colonic neoplasia in the normal population. In order to properly evaluate screening-protocols for colorectal cancer in risk groups (e.g., older subjects or those with a family history), it is essential to know the prevalence of adenomas and cancer in the normal population. Methods. A prospective population-based colonoscopy study on 745 individuals born in Sweden aged 19-70 years was conducted (mean age 51.1 years). All polyps seen were retrieved and examined. Results. Out of the 745 individuals 27% had polyps, regardless of kind. Adenomas were found in 10% of the individuals and finding of adenomas was positively correlated to higher age. Men had adenomas in 15% and women in 6% of the cases. Women had a right-sided dominance of adenomas. Hyperplastic polyps were seen in 21% of the individuals. The presence of hyperplastic polyps was significantly positively correlated to the presence of adenomas. Advanced adenomas were seen in 2.8% of the study participants, but no cancers were detected. Conclusion. One in 10 healthy subjects had an adenoma but advanced adenomas were uncommon. Men and women have a different adenoma prevalence and localization. The results provide baseline European data for evaluating colonoscopy screening-protocols for colorectal cancer risk groups, and the findings may have implications for colon cancer screening in the normal, otherwise-healthy population.
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| 6. |
- Kjellström, Lars, et al.
(författare)
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A randomly selected population sample undergoing colonoscopy : prevalence of the irritable bowel syndrome and the impact of selection factors
- 2014
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Ingår i: European Journal of Gastroenterology and Hepathology. - 0954-691X .- 1473-5687. ; 26:3, s. 268-275
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo analyse the epidemiology of irritable bowel syndrome (IBS) symptoms in a random sample of the general population and in a subsample consenting to a colonoscopy, and to what extent this introduces symptom selection bias.Materials and methodsOverall, 3347 randomly selected Swedish adults aged 18-70 years were mailed the validated Abdominal Symptom Questionnaire (ASQ). Responders (n=2293; 68.5%) were contacted by phone, and 745 consented to a colonoscopy. All nonresponders were contacted by phone; 265 were reached and asked seven key ASQ questions. Colonoscopy participants also completed the Rome II Modular Questionnaire.ResultsThe prevalence of IBS on the basis of the mailed ASQ (troublesome abdominal pain and bowel disturbance in the past 3 months) was 26.2% [95% confidence interval (CI): 24.4-28.0] among the ASQ responders and 36.6% (95% CI: 33.2-40.1) among the colonoscopy participants (P<0.001). Nonresponders had a lower prevalence of IBS (15.8%; 95% CI: 11.4-20.3, P<0.001) than ASQ responders. Colonoscopy participants were slightly older than noncolonoscoped participants completing the ASQ (P<0.001), but men and women were equally represented and no significant socioeconomic differences were identified. The prevalence of IBS was 14.8% (95% CI: 12.2-17.5) on the basis of the Rome II Modular Questionnaire in colonoscopy participants and 14.5% (95% CI: 11.9-17.2) when visible inflammatory disease was excluded. Of the colonoscopy participants, 31.9% (95% CI: 28.5-35.3) were symptom free.ConclusionIBS symptoms are common and rarely explained by visible inflammatory disease or cancer. There was a modest selection bias by IBS in participants accepting a screening colonoscopy, but still, one-third were symptom free. Thus, conclusions for the general population can be made from findings in the study cohort.
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| 7. |
- Ludvigsson, Jonas F., et al.
(författare)
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Celiac disease, eosinophilic esophagitis and gastroesophageal reflux disease, an adult population-based study
- 2013
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 48:7, s. 808-814
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Celiac disease (CD) has been linked to gastroesophageal reflux disease (GORD) and eosinophilic esophagitis (EoE), but population-based studies of the prevalence of CD in these conditions are lacking, that is, the aim of this study. Materials and methods. An endoscopic study was carried out in 1000 randomly selected adults from the general population. CD was defined on the basis of positive serology in parallel with mucosal abnormalities of the small intestine. Any eosinophil infiltration of the esophageal epithelium was defined as esophageal eosinophilia and EoE was defined as having at least 15 eosinophils/high-power field in biopsies from the distal esophagus. We used Fisher's exact test to compare the prevalence of GORD, esophageal eosinophilia, and EoE in subjects with CD versus controls. Results. Four hundred subjects (40%) had gastroesophageal reflux symptoms (GORS), 155 (15.5%) had erosive esophagitis, 16 (1.6%) had Barrett's esophagus, 48 (4.8%) had esophageal eosinophilia, and 11 (1.1%) had EoE. CD was diagnosed in 8/400 (2.0%) individuals with GORS (vs. controls: 10/600 (1.7%), p = 0.81), in 3/155 (1.9%) with erosive esophagitis (vs. 15/845 controls (1.8%), p = 0.75), and in 2/48 (4.2%) individuals with esophageal eosinophilia (controls: 16/952 (1.7%), p = 0.21), but in none of those 16 with Barrett's esophagus (vs. 18/984 controls (1.8%), p = 1.0) or of the 11 individuals with EoE (controls: 18/989 (1.8%), p = 1.0). Conclusions. This population-based study found no increased risk of CD among individuals with GORD, esophageal eosinophilia, or EoE. CD screening of individuals with GORD or EoE of individuals with CD cannot be recommended.
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| 10. |
- Walter, Susanna A, et al.
(författare)
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Prospective Diary Evaluation of Unexplained Abdominal Pain and Bowel Dysfunction : A Population-Based Colonoscopy Study
- 2011
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Ingår i: Digestive Diseases and Sciences. - : Springer. - 0163-2116 .- 1573-2568. ; 56:5, s. 1444-1451
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Diagnostic criteria for irritable bowel syndrome (IBS) have not been validated by prospective symptom diary. We investigated the bowel patterns in community subjects with and without non-organic abdominal pain, and compared the symptoms with subjects fulfilling the Rome II criteria (IBS). METHODS: From the Swedish population register, a random sample completed an abdominal symptom questionnaire. Responders were subsequently invited for a clinical evaluation and offered a colonoscopy regardless of whether they had abdominal symptoms or not. A total of 268 subjects underwent colonoscopy, clinical evaluation by gastroenterologist, laboratory investigations, and completed the Rome questionnaire and prospective gastrointestinal (GI) symptom diaries for 1 week. Twenty-three subjects of 268 were excluded due to organic GI disease. RESULTS: Subjects recorded 2,194 bowel movements and 370 abdominal pain episodes on 1,504 days. Subjects with pain in the diary (n = 81) had higher stool frequency (P = 0.01), more urgency (P = 0.0002), feelings of incomplete evacuation (P = 0.0002), nausea (P = 0.0009), and abdominal bloating (P = 0.0005) than subjects without pain (n = 151). Twenty-eight subjects (12%) fulfilled the Rome II criteria for IBS. Together, they had 96 pain episodes but only 4% were improved by defecation; 29% of the pain episodes started or worsened after a meal. Subjects with IBS and other subjects with non-organic abdominal pain (n = 64) exhibited no differences in terms of the proportions of pain episodes improved by defecation, bloating, stool frequency, consistency, or defecatory symptoms. CONCLUSIONS: Current criteria for IBS that rely on recall of the relationship between abdominal pain and bowel disturbance may overcall this association when measured prospectively.
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