Improving quality of care in inflammatory bowel disease: treatment targets and body composition

Abstract

Introduction: Quality care for people with inflammatory bowel disease (IBD) aims to modify the course of disease and normalise quality of life (QoL). Treatment directed at objective inflammation has been shown to improve outcomes in IBD, yet represents a paradigm shift for clinicians trained to manage symptoms alone. Beyond conventional treatment targets, abnormal body composition is often overlooked in clinical practice, yet is likely to influence morbidity in IBD. Although seemingly unrelated aspects of management, both treatment targets and evaluation of body composition are important for the delivery of quality IBD care. Aims: The aims of this thesis were to: 1. Explore treatment targets in IBD 2. Determine the prevalence and impact of abnormal body composition in IBD. Methods: A systematic review of disease activity assessment indices in IBD was performed. Following this, a prospective observational study was undertaken to explore the concordance between and prognostic benefits of measures of remission in IBD, so as to help define the ‘optimal’ treatment target. Thereafter, a cross-sectional study assessed attainment of IBD treatment targets in routine clinical practice, alongside clinician perceptions and potential barriers. Prospective evaluation of body composition in patients with IBD was undertaken, so as to describe rates of abnormal body composition, evolution of body composition over time, influencing factors, and the impact of body composition on outcomes in IBD. Results: Multiple indices of disease activity assessment in IBD were identified, most of which were confounded by complexity and lack of validation. Measures of disease activity in IBD were observed to be distinct and discordant, with the greatest disparity between symptoms and objective assessments of mucosal inflammation. Histological remission was found to impart prognostic benefit beyond endoscopic remission in ulcerative colitis (UC), predicting lower rates of steroid usage and hospitalisation over 6 years of follow-up. In routine IBD practice, attainment of treatment targets was identified to be modest and limited by clinician-dependent practice behaviours, with only one-third of patients attaining combined clinical and endoscopic remission. There was a high prevalence of abnormal body composition in patients with IBD. Rising rates of obesity were exposed, with gains in BMI related to increases in adiposity, whilst lean mass declined over time. Accordingly, myopenia and sarcopenia were prevalent (21% and 12% respectively). Visceral adipose tissue, rather than overall adiposity, was associated with stricturing Crohn’s disease behaviour, as well as disease activity and QoL in a disease distribution-dependent manner. Metabolic bone disease was prevalent in patients with IBD (37%), despite protocolised management of bone health. Conclusions: Incorporation of objective treatment targets into routine practice stands to benefit patients with IBD, but further work is required to simplify disease activity indices, define optimal treatment targets, and assess feasibility in practice. Beyond conventional treatment targets, body composition is frequently abnormal in patients with IBD yet may go unrecognised and is important because it is associated with morbidity. Treatment targets and body composition are disparate but important aspects of the same challenge: to improve the quality of care in IBD.