Christopher W P Hopkins1, Nick Powell2, Christine Norton3, Jonathan L Dumbrill4, Bu'Hussain Hayee5, Calum D Moulton6. 1. Oxford Health NHS Foundation Trust, Wallingford Community Hospital, Wallingford, Oxon, UK. 2. Faculty of Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK. 3. Florence Nightingale Faculty of Nursing, Midwifery and Palliative Care, King's College London, London, UK. 4. Faculty of Biology, Medicine and Health, University of Manchester, UK. 5. Department of Gastroenterology, King's College Hospital NHS Foundation Trust, London, UK. 6. Department of Psychological Medicine, King's College London, London, UK. Electronic address: calum.moulton@kcl.ac.uk.
Abstract
BACKGROUND: People living with inflammatory bowel disease (IBD) are exposed to multiple risk factors for cognitive impairment and frequently report cognitive difficulties. However, the presence of cognitive impairment in IBD has not been systematically reviewed. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we performed a systematic multidatabase search for cross-sectional and longitudinal studies comparing adults with IBD versus healthy controls for domain-specific cognitive function or scores on multidomain cognitive screening tools. For any domain reported by 3 or more studies, we conducted random-effects meta-analysis to calculate the standardized mean difference between groups; lower scores reflected poorer performance. Between-study heterogeneity was assessed using the I2 statistic and study quality assessed using an IBD-modified Newcastle-Ottawa scale. RESULTS: Of 8302 articles screened, 12 studies (n = 687) were included in the qualitative synthesis and 11 in meta-analyses. All studies were cross-sectional. Studies generally excluded people with active IBD and older adults. Despite no significant differences on multidomain screening tools such as the Mini Mental State Examination (-0.27 [95% confidence interval -0.68, 0.08], P = 0.14), people with IBD showed significant deficits compared with healthy controls in attention (standardized mean difference -0.36 [-0.60, -0.12], P = 0.003, I2 = 0%), executive function (standardized mean difference -0.45 [-0.77, -0.13, P = 0.005, I2 = 42.5%), and specifically in working memory (standardized mean difference -0.58 [-0.85, -0.30], P < 0.001, I2 = 0%). Deficits in learning and recall were nonsignificant (P = 0.089) and other domains insufficient for meta-analysis. CONCLUSIONS: People with IBD show deficits in attention and executive function, particularly in working memory, suggesting that cognitive impairment is a potential extraintestinal manifestation of IBD.
BACKGROUND: People living with inflammatory bowel disease (IBD) are exposed to multiple risk factors for cognitive impairment and frequently report cognitive difficulties. However, the presence of cognitive impairment in IBD has not been systematically reviewed. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we performed a systematic multidatabase search for cross-sectional and longitudinal studies comparing adults with IBD versus healthy controls for domain-specific cognitive function or scores on multidomain cognitive screening tools. For any domain reported by 3 or more studies, we conducted random-effects meta-analysis to calculate the standardized mean difference between groups; lower scores reflected poorer performance. Between-study heterogeneity was assessed using the I2 statistic and study quality assessed using an IBD-modified Newcastle-Ottawa scale. RESULTS: Of 8302 articles screened, 12 studies (n = 687) were included in the qualitative synthesis and 11 in meta-analyses. All studies were cross-sectional. Studies generally excluded people with active IBD and older adults. Despite no significant differences on multidomain screening tools such as the Mini Mental State Examination (-0.27 [95% confidence interval -0.68, 0.08], P = 0.14), people with IBD showed significant deficits compared with healthy controls in attention (standardized mean difference -0.36 [-0.60, -0.12], P = 0.003, I2 = 0%), executive function (standardized mean difference -0.45 [-0.77, -0.13, P = 0.005, I2 = 42.5%), and specifically in working memory (standardized mean difference -0.58 [-0.85, -0.30], P < 0.001, I2 = 0%). Deficits in learning and recall were nonsignificant (P = 0.089) and other domains insufficient for meta-analysis. CONCLUSIONS: People with IBD show deficits in attention and executive function, particularly in working memory, suggesting that cognitive impairment is a potential extraintestinal manifestation of IBD.