Short summary

Inflammatory bowel diseases (IBD) - Mb. Crohn and Colitis ulcerosa - are autoimmune diseases of the gastrointestinal tract. In severe cases of IBD, TNF-a inhibitor is an option for treatment. However, one third of patients have no effect of the treatment or experience loss of response (LOR) over time. BMI has been hypothesised as a predictor of poor treatment response and decreased time to LOR.

The aim of this study is to determine whether obese patients treated with TNF-a inhibitors for inflammatory bowel disease have a decreased time to LOR, using a large retrospective cohort.

---

Rationale

Background
Use of TNF-a inhibitors in treatment of IBD is increasing. While TNF-a inhibitors have expanded therapy options and improved quality of life for patients who would otherwise risk either on-going corticosteroid- or surgical treatment, LOR has been observed in 25%-40% of patients in randomized controlled trials.
Studies have identified obesity as a predictor of poor treatment response to TNF-a inhibitors and of decreased time to LOR, in IBD and other diseases. These findings apply both to TNF-a inhibitors in which dosing is weight adjusted as well as for those TNF-a inhibitors in which dosing is weight independent.
Research in this field is sparse, especially in the case of IBD.

Objective

This study aims to further investigate the apparent weight-associated difference in treatment response among IBD patients and to address whether obese patients with IBD require a different
dose in treatment with TNF-a inhibitor.

Primary outcomes

Time to LOR defined as dose increase or reduced time between treatments, hospitalization due to IBD flare, discontinuation of therapy without remission, or surgical intervention. 

---

Description of the cohort

The study will include patients treated with TNF-a inhibitors for IBD at Odense University Hospital from 2003 and onwards. Patients will be identified via patient-administrative systems, followed by manual collection of clinical data from medical records. The collected information will be stored in the data management system Redcap via OPEN at Odense University Hospital and University of Southern Denmark.
Exclusion criteria: Former treatment with biological therapy on other indication than IBD. Patients treated with biological therapy due to pouchitis.

Data and biological material

Data to be collected from a retrospective chart review will include: Sex, age, smoking status, height, weight, time of treatment, type of treatment (infliximab/adalimumab), indication of treatment (crohns disease/ulcerative colitis/pouchitis), former surgery due to IBD, change of dose, change of treatment interval, discontinuation of biological treatment, discontinuation of treatment, hospitalization due to IBD flare, discontinuation due to lack of response.

Data on medication other than TNF-a inhibitors will be drawn from the Odense pharmacoepidemiological database (OPED) which is a complete database containing all prescription medicine for the inhabitants of the county of Funen.

Collaborating researchers and departments

Department of Medical Gastroenterology, Odense University Hospital

• Professor and Consultant Jens Kjeldsen, MD, PhD

Clinical Pharmacology, Institute of Public Health, University of Southern Denmark

• Professor Jesper Hallas, MD, DMSc
• Postdoc and Clinical Pharmacist Anton Pottegård, PhD