title: Clinical epidemiology of ulcerative colitis in Mexico: a single hospital-based study in a 20-year period (1987-2006).
abstract: BACKGROUND
  Ulcerative colitis (UC) is a chronic disease with a heterogeneous clinical evolution. The prevalence and incidence of UC vary widely and depend on multiple factors including ethnicity and geographic location.
  
  
  OBJECTIVE
  To determine the frequency of new cases of UC and their clinical characteristics in a large cohort from a referral hospital in Mexico City.
  
  
  METHODS
  Patients with confirmed diagnosis of UC were included during a period between January 1987 and December 2006. Demographic and clinical data were collected from medical records.
  
  
  RESULTS
  A total of 848 new cases of UC were diagnosed during a 20-year period. All the patients had endoscopic and histologic confirmation. The mean of annual new UC cases increased from 28.8 in the first period (1987 to 1996) to 76.1 in the second period (1997 to 2006) (P<0.00008). The incidence of new cases increased 2.6-fold comparing both periods of time. This study consisted of 467 females and 382 males, with a mean age at diagnosis of 31.3+/-12.3 years. The clinical manifestations were pancolitis (59.1%), and extraintestinal manifestations (41.5%). Most of the patients, 762 (89.8%) were taking sulfasalazine or 5-aminosalicylic acid, 282 (33.3%) used oral or systemic steroids, 237 (28%) were taking azathioprine.
  
  
  CONCLUSIONS
  The frequency of new UC cases has increased significantly in the last 10 years in Mexico, largely due to the unique genetic make-up and the environmental factors (infectious diseases including parasites) not found in other countries.
authors.affiliation: Inflammatory Bowel Disease Clinic, Department of Gastroenterology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. kazuofurusho@hotmail.com
authors.forename: Jesús K
authors.initials: JK
authors.lastname: Yamamoto-Furusho
mesh_terms: D000328:Adult; D017668:Age of Onset; D000636:Aminosalicylic Acids / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001379:Azathioprine / Q000627:therapeutic use; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015994:Incidence; D007411:Intestinal Diseases, Parasitic / Q000150:complications; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D012460:Sulfasalazine / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000636:Aminosalicylic Acids; D000894:Anti-Inflammatory Agents, Non-Steroidal; D007166:Immunosuppressive Agents; D012460:Sulfasalazine; D001379:Azathioprine