No robust cortical morphometry differences and limited morphometry-phenotype associations in a UK Biobank irritable bowel syndrome phenotype

NeuroImage, vol. 340, pp. 122207

Abstract

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction that has sparked interest in neural markers. Yet, previous neuroimaging findings remain inconsistent and often fail to replicate, likely due to small sample sizes that overestimate effects and overlook patient heterogeneity. Using normative modeling to quantify cortical deviations from MRI in a UK Biobank digestive health questionnaire (DHQ)-derived IBS phenotype and matched controls (N = 3,413 each) relative to a healthy reference sample (N = 8,661), we found no robust group differences. Further, equivalence tests provided evidence that both group and group × sex effects were statistically equivalent to negligible effect sizes across nearly all regions. Within IBS, negative associations between cortical gray matter deviations and symptom or pain severity were observed for some regions. However, no statistically meaningful IBS-specific effects and no sex moderation were detected. Overall, our findings challenge previously reported structural alterations in IBS, underscoring the need for replicability in adequately powered designs.

Authors 8

1. Hanbing Gao Aachen Department for Psychiatry, Psychotherapy and Psychosomatics Medical School

   Dalian University of Technology · RWTH Aachen University

   Affiliation as printed

   Department for Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany; School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian, China

2. Carolin V. Schneider Aachen Department of Internal Medicine III

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Internal Medicine III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany

3. Tobias Seibel Aachen Department of Internal Medicine III

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Internal Medicine III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany

4. Chi Zhang

   Dalian University of Technology

   Affiliation as printed

   School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian, China; Key Laboratory of Social Computing and Cognitive Intelligence, Ministry of Education, Dalian University of Technology, Dalian, China

5. Fengyu Cong

   Dalian University of Technology · University of Jyväskylä

   Affiliation as printed

   School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian, China; Faculty of Information Technology, University of Jyvaskyla, Jyvaskyla, Finland; Key Laboratory of Social Computing and Cognitive Intelligence, Ministry of Education, Dalian University of Technology, Dalian, China; School of Software Engineering, Dalian University, Dalian, China

6. Klaus Mathiak Aachen Department for Psychiatry, Psychotherapy and Psychosomatics Medical School

   RWTH Aachen University

   Affiliation as printed

   Department for Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany

7. Kai Markus Schneider Aachen Department of Internal Medicine III

   Universitätsklinikum Aachen · University Hospital Carl Gustav Carus · Center for Regenerative Therapies Dresden · Else Kröner Fresenius Center for Digital Health · Technische Universität Dresden · RWTH Aachen University

   Affiliation as printed

   Department of Internal Medicine III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany; Department of Medicine I, Department of Gastroenterology and Hepatology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany; Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany; Else Kroener Fresenius Center for Digital Health, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany

8. David M.A. Mehler corresponding Aachen Department for Psychiatry, Psychotherapy and Psychosomatics Medical School

   University of Münster · Cardiff University · RWTH Aachen University

   Affiliation as printed

   Department for Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany; Institute of Translational Psychiatry, Medical Faculty, University of Münster, Münster, Germany; School of Psychology, Cardiff University Brain Research Imaging Center (CUBRIC), Cardiff University, Cardiff, UK. Electronic address: dmehler@ukaachen.de