Search in the Abstract Database

Search Abstracts 2015

* = Presenting author

P650 Age of onset is associated with disease seasonality in inflammatory bowel disease: A multi-center observational study by the Osaka Gut Forum

M. Araki*1, S. Shinzaki1, H. Iijima1, S. Hiyama1, T. Yamada2, S. Arimitsu3, M. Komori4, M. Ito5, A. Mukai6, S. Nakajima7, F. Terabe8, K. Kinoshita9, S. Kitamura10, Y. Murayama11, H. Ogawa12, Y. Yasunaga13, M. Oshita14, E. Masuda15, M. Tsujii1, T. Takehara1

1Osaka University Graduate School of Medicine, Department of Gastroenterology and Hepatology, 2-2 Yamadaoka, Suita, Japan, 2Osaka Medical Center, National Hospital Organization, Department of Gastroenterology, 2-1-14, Hoenzaka, Chuo-ku, Osaka, Japan, 3Kinshukai , Infusion Clinic, Osaka, Japan, 4Osaka Rosai Hospital, Department of Gastroenterology, 1179-3, Nagasone-cho, Kita-ku, Sakai, Osaka, Japan, 5NTT-west Hospital, Department of Gastroenterology, 2-6-40, Karasugatsuji, Tennoji-ku, Osaka, Japan, 6Sumitomo Hospital, Department of Gastroenterology, 5-3-20, Nakanoshima, Kita-ku, Osaka, Japan, 7Toyonaka Municipal Hospital, Department of Gastroenterology, 4-14-1, Shibahara-cho, Toyonaka, Osaka, Japan, 8Yao Municipal Hospital, Department of Gastroenterology, 1-3-1, Ryukacho, Yao, Osaka, Japan, 9Otemae Hospital, Department of Gastroenterology, 1-5-34, Otemae, Chuo-ku, Osaka, Japan, 10Sakai City Hospital, Department of Gastroenterology, 1-1-1, Minamiyasui-cho, Sakai-ku, Sakai, Osaka, Japan, 11Itami City Hospital, Department of Gastroenterology, 1-100, Koyaike, Itami, Hyogo, Japan, 12Nishinomiya Municipal Central Hospital, Department of Gastroenterology, 8-24, Hayashida-cho, Nishinomiya, Hyogo, Japan, 13Hyogo Prefectural Nishinomiya Hospital, Department of Gastroenterology, 13-9, Rokutanji-cho, Nishinomiya, Hyogo, Japan, 14Osaka Police Hospital, Department of Gastroenterology, 10-31, Kitayama-cho, Tennoji-ku, Osaka, Japan, 15Osaka Minami Medical Center, National Hospital Organization, Department of Gastroenterology, 2-1, Kidohigashimachi, Kawachinagano, Osaka, Japan

Background

Although environmental factors are suggested to affect the pathogenesis of inflammatory bowel disease (IBD), disease seasonality in IBD has not been well investigated. We aimed to clarify the disease seasonality and investigate the underlying characteristics in IBD patients.

Methods

This was a multi-center observational study conducted by Osaka Gut Forum (OGF) comprising 20 institutions in Japan. A total of 1,078 IBD patients (303 Crohn's disease [CD], 775 ulcerative colitis [UC]) were enrolled. All patients were Japanese and data were collected using survey forms from doctors and questionnaires from patients from November 2013 to August 2014. Association between disease seasonality and patient characteristics was investigated. Statistical analysis was performed using Pearson's chi-square test, and odds ratio (OR) and 95% confidence interval [CI]) were analyzed.

Results

Disease onset was significantly more frequent in spring-summer compared with autumn-winter in IBD, especially in CD (p = 0.037 and 0.030, respectively), but UC patients did not show seasonality of disease onset. When the patients were divided into two groups by age of onset (A1/2 and A3 in Montreal classification), the proportion of patients with spring-summer onset was larger than that with autumn-winter onset in A1/2 group of IBD, especially of CD (p = 0.014 and p = 0.019, respectively), whereas A3 group did not show onset seasonality. Disease exacerbation was significantly more frequent in autumn-winter than in spring-summer in IBD, especially in UC (p = 0.006 and 0.016, respectively), but CD patients did not show seasonality of disease exacerbation. A1/2 group had significant dominance in autumn-winter exacerbation in IBD, especially in UC (p = 0.013 and p = 0.038, respectively), whereas A3 group did not show exacerbation seasonality in both CD and UC. Multivariate analysis showed that age onset of A1/2 was the independent factor of seasonality for disease onset and exacerbation in IBD (OR 1.33, 95% CI 1.01 - 1.75, p = 0.042 and OR 1.62, 95% CI 1.21 - 2.16, p = 0.001, respectively).

Conclusion

Seasonality of disease onset and exacerbation was observed in young-onset IBD patients, suggesting that young and elderly-onset patients might have different pathophysiological triggers for disease initiation and exacerbation.