The role of lipid metabolism and creeping fat in disease assessment and prediction for Crohn's disease.

Crohn's Disease (CD) is a chronic disease that often leads to disability. Effective monitoring of the disease is essential for delaying progression and improving outcomes. Traditional assessment methods have some limitations, such as invasiveness, delayed response, or inability to evaluate transmural lesions. This review focuses on lipid metabolism and creeping fat (CF) and explores their roles in disease prediction and assessment of CD. Through literature review, this study summarized the currently commonly used methods for assessing the condition, and also summarized the relationships among blood lipids, inflammation, and adipose tissue, as well as their effects during the disease activity period of CD. The methods for CD to assess the condition include endoscopy, radiological examination and endoscopic ultrasound and so on. During active phase, patients often show characteristic dyslipidemia. These lipid changes are closely related to systemic inflammation severity. As a unique feature in CD, CF consists of mesenteric fat expansion and bowel wrapping, contributing to intestinal inflammation, fibrosis, and stricture formation. Immune responses, microbial factors, and molecular pathways are involved in this process. Current imaging techniques enable the assessment of CF for predicting surgical risks and postoperative recurrence. Considering the close correlation between lipid levels and CF and the inflammation during the active phase of CD, there is potential for disease assessment. In the future, we should focus on the application of lipid levels and CF in assessing and predicting the activity of CD.