Investigation of Vascular Endothelial Dysfunction, Thromboembolism and Structural Arterial Disease in Paediatric and Adolescent Inflammatory Bowel Disease (IBD)

Plan of Investigation:

Patients: 130 children and adolescents (8-21y) with an expected ratio of 60% (n=78) Crohn's disease (CD), 35% (n=45) Ulcerative colitis (UC) 5% (n=6) Indeterminate colitis (IC). 78 age and sex-matched controls will be investigated. Sample size calculations are based on Circulating Endothelial Cells (CECs) as the primary end-point, as suggested by an on-going study by one of the co-applicants, on healthy children and children with Kawasaki disease (Brogan P et al, ref published).

40 subjects/ group are required to detect a doubling average of CECs in CD and UC vs. control with 90% power, significance 0.05 and this should be achievable by our initial recruitment. Non-normality and the need to use non-parametric or transform prior to analysis, increases the number to 47; hence we will aim to recruit 50 to the UC group. This will provide adequate power, and is feasible based on the clinical cohort available to us.

This patient cohort is an appropriate candidate group for the present investigation as

1. Evidence indicates that vascular changes that occur between 10-20 years of age are a critical determinant of future vasculature health;
2. Initiation into smoking habits is most likely in teenage years and
3. Other established traditional risk factors for atherosclerosis (such as hypertension, type II diabetes, or even fully established atherosclerotic disease) that would act as confounding variables, are not yet present in adolescence.