Malnutrition assessment in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) affects over 6.8 million people worldwide and is highly associated with the development of malnutrition. Malnutrition in patients with Crohn’s disease (CD) and ulcerative colitis (UC) is often due to the following: decreased oral intake; food avoidance; side effects of medications; malabsorption; chronic enteric losses; altered anatomy from luminal surgery; and increased nutritional needs in the setting of active inflammation and a high catabolic state. Approximately 20%-80% of patients with IBD are estimated to be malnourished at some point during their disease course; this wide range is likely secondary to significant heterogeneity in the definition of malnutrition in the literature, and due to the lack of robust, validated tools to identify individuals who are malnourished. While malnutrition is traditionally thought of as under- nutrition or protein calorie malnutrition, there are other nutrition phenotypes of significance in patients with IBD including micronutrient deficiencies, sarcopenia and obesity (over-nutrition). Malnutrition is associated with poor outcomes in patients with IBD, including a high number of disease flares; impaired response to biologics; increased surgical complications; hospitalizations; and impaired quality of life, independent of disease activity. Given the significant prevalence of malnutrition, the impact it can have in patients with IBD, and its responsiveness to therapeutic interventions, it is crucial to accurately assess the nutritional status of patients at the time of diagnosis and regularly thereafter.