Prospective Study
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World J Gastroenterol. Sep 14, 2014; 20(34): 12269-12276
Published online Sep 14, 2014. doi: 10.3748/wjg.v20.i34.12269
Smoking increases the risk of extraintestinal manifestations in Crohn's disease
Claudia Ott, Angela Takses, Florian Obermeier, Elisabeth Schnoy, Martina Müller
Claudia Ott, Angela Takses, Florian Obermeier, Elisabeth Schnoy, Martina Müller, Department of Internal Medicine I, University of Regensburg, 93042 Regensburg, Germany
Author contributions: Ott C contributed to the conception and design of the study, acquisition of data and writing of the manuscript; Takses A contributed to the acquisition and analysis of data; Obermeier F and Schnoy E contributed to the acquisition of data and editing the manuscript; Müller M contributed to the providing financial support for this work, editing and revision of the manuscript.
Correspondence to: Claudia Ott, MD, Department of Internal Medicine I, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany. claudia.ott@ukr.de
Telephone: +49-941-9447003 Fax: +49-941-9447004
Received: November 12, 2013
Revised: January 22, 2014
Accepted: April 27, 2014
Published online: September 14, 2014
Abstract

AIM: To demonstrate a high prevalence of extraintestinal manifestations (EIMs) in a prospective population-based cohort of inflammatory bowel disease (IBD) patients at first diagnosis as well as during the early course of the disease.

METHODS: EIMs are common in patients with IBD. Data on the frequency of EIMs have mostly been assessed in patients from tertiary centers; however, data about the prevalence of EIMs at first diagnosis as well as factors influencing their incidence during the early course of disease from prospective population-based cohorts are scarce. We present data of patients of our population-based “Oberpfalz cohort” (Bavaria, Germany) from first diagnosis (up to 3 mo after first diagnosis) as well as during the early course of the disease. Possible risk factors were assessed by calculating the relative risk (RR) as well as using logistic regression analysis.

RESULTS: In total, data of 257 newly diagnosed patients with IBD were evaluated [161 Crohn’s disease (CD), 96 ulcerative colitis (UC)]. Median duration of follow-up was 50 mo after first diagnosis. In 63.4% of all patients (n = 163), an EIM was diagnosed at any point during the observation period. At first diagnosis, patients with CD had a significantly increased risk of an EIM [n = 69 (42.9%)] compared with UC patients [n = 21 (21.9%); P < 0.001; RR = 1.96; 95%CI: 1.30-2.98]. Active smoking increased the risk of CD patients developing an EIM during the early course of the disease, but notably not of UC patients (P = 0.046; RR = 1.96; 95%CI: 1.01-3.79). In addition, using logistic regression analysis, the need for IBD-related surgery and a young age at first diagnosis were identified as risk factors for the development of an EIM in CD patients. No association with EIMs was found for the factors sex, localization of the disease and positive family history of IBD. In contrast, no key factors which increased the risk of development of an EIM could be identified in UC patients.

CONCLUSION: We found a high prevalence of EIM in this cohort at first diagnosis and during the early course of the disease. In patients with CD, smoking, need for surgery and younger age at first diagnosis were risk factors for the development of an EIM.

Keywords: Extraintestinal manifestations, Crohn’s disease, Ulcerative colitis, Smoking, Surgery, Age at onset

Core tip: Owing to the high prevalence of extraintestinal manifestations (EIM) in patients with inflammatory bowel disease (IBD), Crohn’s disease (CD) and ulcerative colitis have to be considered as systemic diseases. However, prospective data on the prevalence of EIM at first diagnosis from population-based cohorts are lacking. We found a high prevalence of EIMs in our population-based cohort of IBD patients at first diagnosis, with an increased risk in patients with CD. More than 60% of patients developed an EIM during the early course of disease. Smoking, young age at disease onset and the need for IBD-related surgery were identified as risk factors for developing an EIM in CD.