Background: There is a common impression that the incidence and prevalence of Crohn's disease (CD) in the Polish population have been rising in recent years. In 2005, a nationwide Crohn's disease registry in Poland was established to collect demographic and clinical data of patients diagnosed with Crohn's disease.
The aim of presented study was to characterise demographic and clinical features of Polish population with CD, based on national registry data.
Methods: In a collaborative, prospective registry of a consecutive CD patients conducted in 95 gastroenterology centers across the country 5942 adult patients have been enrolled. Patient's phenotype according to: Montreal classification, demographics, smoking, family history, comorbidity, extraintestinal manifestation, medical treatment and surgical interventions have been evaluated.
Results: The age of diagnosis of CD in polish population was under 40 in more than 77% of patients [22.8% <16 (A1), 55.2% 17–40 (A2)] and only in 22% over 40 (A3). Although there was no gender difference in the overall population (males/females ratio 1.025), males predominated among young patients (759/565 in <16 group and 1723/1474 in 17–40 group, p<0.001). Males more often sustain penetrating disease and localization in ileum and upper gastrointestinal tract. On the other hand females more often suffer from extraintestinal manifestations. The location of the disease was as follows: ileal (L1): 13.4%, colonic (L2): 30.3%, ileocolonic (L3): 56%, upper gastrointestinal tract (L4): 9.9%. The disease behaviour presented: non stricturing, non penetrating (B1): 58.6%, stricturing (B2): 28%, penetrating (B3): 19.8%, perianal disease (p): 26.4%. The disease was more common in urban areas and in patients with higher education. Family history was positive in 4.4%. Rheumatoid arthritis among women (2.6%) and ankylosing spondylitis among men (1.1%) were the most prevalent coexisting diseases. There were more smokers among men than women (15.6% vs. 11.0% p<0.001). Smoking was associated with a higher risk of strictures (36.4% vs 28.5%, p<0.001), abscesses (19.3% vs 15.3%, p=0.013) and overall need for surgery (41.8% vs 30.5%). However smokers less likely suffer from extraintestinal manifestations and localization in upper gastrointestinal tract. 31.6% of the patients had at least one surgery.
Conclusions: The prevalence of IBD in this cohort falls in the intermediate range of that reported for white populations in Europe and North America. Young age of diagnosis, smoking and male gender are the main risk factors for the complications, which will require surgery. Future studies are needed to examine more local risk factors and epidemiologic time trends.