Vascular comorbidity is associated with decreased cognitive functioning in inflammatory bowel disease

Abstract

Background: Reports of cognitive impairment in inflammatory bowel disease (IBD) have been mixed. IBD and cardiovascular disease are often co-morbid, yet it remains unknown whether vascular comorbidity confers a risk for decreased cognitive functioning, as observed in other populations. Methods: Participants with IBD were recruited from a longitudinal study of immune-mediated disease. Participants were administered a standardized neuropsychological test protocol, evaluating information processing speed, verbal learning and memory, visual learning and memory, and verbal fluency/executive function. Cognitive test scores were standardized using local regression-based norms, adjusting for age, sex, and education. Vascular risk was calculated using a modified Framingham Risk Score (FRS). We tested the association between FRS and cognitive test scores using a quantile regression model, adjusting for IBD type. Results: Of 84 IBD participants, 54 had ulcerative colitis and 30 had Crohn’s disease; mean (SD) age was 53.36 (13.95) years, and a high proportion were females (n = 58). As the risk score (FRS) increased, participants demonstrated lower performance in information processing speed (β=-0.12; 95% CI: -0.24, -0.006) and verbal learning (β=-0.14; 95% CI: -0.28, -0.01) at the 50th percentile. After adjusting for IBD type, higher FRS remained associated with lower information processing speed (β=-0.13; 95% CI: -0.24, -0.03). Conclusion: Vascular comorbidity is associated with lower cognitive functioning in persons with IBD, particularly in the areas of information processing speed and verbal learning. These findings suggest that prevention, identification, and treatment of vascular comorbidity in IBD may play a critical role for improving functional outcomes in IBD.