Background: Inflammatory bowel disease (IBD) is changing profile and surveys conducted in areas with homogenous population have shown important changes in incidence. Herein we present a large Greek population based study for IBD in a well-defined area of Greece.
Methods: A retrospective epidemiological survey was conducted for the years 1982–2015. Only cases that met the diagnostic criteria of IBD at least twice in a time span of six months or more were included in the study. Confidence intervals were calculated at the 95% level of significance using the form of the Poison distribution. The referral population was derived from the 2011 census. All numbers were calculated for every 105 inhabitants.
Results: In total we recorded 1647 patients with IBD, of whom 1018 were males and 619 were females. The mean age of the patients was 50.59±15.35. It was also found that the first peak regarding the number of patients per 5-year classes, located in the class of 45–50, with a constantly increasing number of patients under 25 years old. Men are more affected than women (2:1) and Ioannina patients have the most severe extraintestinal manifestations. The mean annual incidence of Crohn's disease was 2.36/100000 (1.16–3.56) and of ulcerative colitis was 7.31/100000 (4.85–9.75). We also recorded 97 patients with indeterminate colitis. In our previous epidemiological registry for the whole period 1981–1997 the mean annual incidence of CD was 0.5/100000 and of UC was 6.6/100000.
Conclusions: This recent population based IBD registry in our area shows that incidence of Crohn's disease is increasing more rapidly compared to UC (also increasing) and so the ratio gap of UC to CD is also decreasing, showing similarities in IBD epidemiology profiles like in Northern European countries. This changing profile of Crohn's disease strengthens the hypothesis of some environmental factor(s), which, probably in correlation with the genetic factor(s), are responsible for the expression of IBD