Smoking increases the risk of extraintestinal manifestations in Crohn's disease.
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.
['Ott|Claudia|C|', 'Takses|Angela|A|', 'Obermeier|Florian|F|', 'Schnoy|Elisabeth|E|', 'Müller|Martina|M|']
D000328:Adult D000367:Age Factors D003093:Colitis, Ulcerative D003424:Crohn Disease D018450:Disease Progression D005260:Female D005858:Germany D006801:Humans D016015:Logistic Models D008297:Male D016017:Odds Ratio D011237:Predictive Value of Tests D015995:Prevalence D011379:Prognosis D011446:Prospective Studies D018570:Risk Assessment D012307:Risk Factors D012907:Smoking D013997:Time Factors
Smoking Extraintestinal manifestations Ulcerative colitis Surgery Age at onset Crohn’s disease