title: Factors associated with exacerbation of newly diagnosed mild ulcerative colitis based on a nationwide registry in Japan.
abstract: BACKGROUND
  The exacerbation of disease in patients with ulcerative colitis (UC) can greatly affect quality of life and can impose economic burdens. In Japan, a large nationwide registry for the medical reimbursement of UC patients has existed since 1975. We aimed to examine factors associated with UC exacerbation among patients newly diagnosed with mild UC using electronic data from the registry.
  
  
  METHODS
  We retrospectively reviewed the clinical data of patients (n = 8120) newly diagnosed with mild UC between 2003 and 2011, and examined the association of patient background, medications, clinical symptoms and laboratory data, and pathological findings with exacerbation of UC, using the Cox proportional hazards model.
  
  
  RESULTS
  The incidence of UC exacerbation was 94.6 per 1000 person-years (mean follow-up of 2.1 years). We found that male sex, age <17 years, an extensive lesion (left-sided colitis or pancolitis), overweight or obesity, hematochezia (mild or moderate-to-severe), mushy stools, frequency of bowel movements, and crypt architectural distortion were positively associated with UC exacerbation. On the other hand, age >40 years, high hemoglobin concentration, and high serum albumin levels were inversely associated with UC exacerbation among patients with mild UC in Japan.
  
  
  CONCLUSIONS
  Using data from the Japanese nationwide registry, we identified several factors, including body mass index and pathological findings, associated with disease exacerbation among patients with newly diagnosed mild UC. Our findings may lead to earlier recognition of exacerbation in patients with mild UC, thus enabling optimal care.
authors.affiliation: Department of Environmental and Occupational Health, School of Medicine, Toho University, 5-21-16 Omori-nishi, Ohta-ku, Tokyo, 143-8540, Japan. erika.kuwahara@med.toho-u.ac.jp.
authors.forename: Erika
authors.initials: E
authors.lastname: Kuwahara
authors.affiliation: Department of Medical Statistics, School of Medicine, Toho University, Tokyo, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Department of Environmental and Occupational Health, School of Medicine, Toho University, 5-21-16 Omori-nishi, Ohta-ku, Tokyo, 143-8540, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Center for Diagnostic and Therapeutic Endoscopy, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Nagamu
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Advanced Clinical Center for Inflammatory Bowel Disease, Medical Hospital, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nagahori
authors.affiliation: Department of Gastroenterology, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Matsui
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Environmental and Occupational Health, School of Medicine, Toho University, 5-21-16 Omori-nishi, Ohta-ku, Tokyo, 143-8540, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nishiwaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications*; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
keywords: Exacerbation; Severity; Ulcerative colitis