Cognitive Function of Patients with Crohn's Disease is Associated with Intestinal Disease Activity

Abstract

Background: Systemic inflammation and nutritional deficiencies are characteristics of Crohn's disease (CD) and have been suggested to influence cognitive performance. This study assessed cognitive function in patients with CD. Methods: Participants were adult patients with CD arriving at routine follow-up. Subjective cognitive complaints, depression, anxiety, fatigue, and sleep were evaluated by validated questionnaires. CD characteristics, blood tests, and Crohn's disease activity index were obtained. Nutritional risk index was derived from serum albumin and change in body weight. Montreal cognitive assessment was used for screening. Patients with either subjective cognitive complaints or Montreal cognitive assessment score ≤26 were tested by a computerized cognitive testing battery, with analysis of scores in 7 cognitive domains (CogDs) and an average of the CogD scores-global cognitive score (GCS). Impaired CogD was defined as scoring more than 1 SD below age and education adjusted average. Results: A total of 105 patients were recruited and 61 were tested with computerized cognitive testing battery. Mean age was 39 ± 13 and mean education years were 14 ± 2. The most commonly impaired CogDs were information processing speed (33%) and verbal function (28%). Crohn's disease activity index, nutritional risk index, and hemoglobin were significantly correlated with GCS (r-0.34, 0.39, 0.33; P 0.007, 0.003, 0.01). Linear regression revealed significant correlations between Crohn's disease activity index, nutritional risk index, and GCS (β-0.3, 0.29; P 0.03, 0.04), independent of depression. This model explained 24% of the variance in GCS. Conclusions: Cognitive performance is related to CD activity and nutritional status. The results provide insight into potential influence of nutrition and inflammation on cognitive function. Further studies on cognitive function of patients with CD are warranted.