P772 Trends and risk factors of elderly-onset Crohn’s disease: A nationwide cohort study in South Korea

Abstract

Abstract Background The incidence of inflammatory bowel disease (IBD) is increasing in Asia. Numerous risk factors associated with IBD development have been investigated. This study aimed to demonstrate the risk factors of Crohn’s disease (CD) diagnosed in persons aged >40 years in South Korea and to specify any differences between age groups by using the National Health Insurance Service (NHIS) database. Methods Using the National Health Insurance Service (NHIS) database, a total of 14,060,821 persons aged >40 years who underwent national health screening in 2009 were followed up until December 2017. Patients with newly diagnosed CD were enrolled and compared with non-CD cohort. CD was identified according to the International Classification of Diseases 10th revision and the rare/intractable disease registration programme codes from the NHIS database. The mean follow-up periods were 7.39 years. Age and sex were adjusted for in the multivariate analysis model. Results During the follow-up, 1337 (1.33/100,000) patients developed CD. Men in the middle-aged group (40–64 years) had a higher risk than women (adjusted HR [aHR] 1.46, 95% CI 1.29–1.66); however, this difference tended to disappear as the age of onset increases. In the middle-aged group, patients with a history of smoking (adjusted hazard ratio [aHR] 1.29, 95% confidence interval [CI] 1.06–1.58) and anemia (aHR 1.99, 95% CI 1.67–2.36) had a significantly higher CD risk. In the elderly group (age, ³65 years), ex-smoking and anemia also increased the CD risk (aHR 1.58 [95% CI 1.16–2.18] and 1.91 [95% CI 1.53–2.38], respectively). Especially in the middle-aged group, those with chronic kidney disease (CKD) had a statistically elevated CD risk (aHR 1.38, 95% CI 1.06–1.79). Alcohol consumption and higher body mass index showed negative association trend with CD incidence in both of the age groups. (Middle-aged: aHR 0.76 [95%CI 0.65–0.87] and aHR 0.38 [95%CI 0.27–0.53], respectively) (elderly-group: aHR 0.57 [95%CI 0.42–0.77] and aHR 0.52 [95%CI 0.32-.83], respectively) For regular physical activity and dyslipidemia, negative correlation between CD incidences was proved only in the middle-aged group (aHR 0.85 [95%CI 0.74–0.96] and aHR 0. [95%CI 0.75 [95% CI 0.63–0.89], respectively). Conclusion This study demonstrated four risk factors (ex-smoking, anemia, CKD, and lower BMI) and three possible protective factors (alcohol consumption, physical activity, and dyslipidemia) for CD in Asians age >40 years. Individuals with potential risk factors need more cautious monitoring for CD.