Search

DOP47 The changing pattern of inflammatory bowel disease incidence in Northern France: A continuing increase in the young women (1988–2014)

T. CRETIN1, H. Sarter2, G. Savoye3, M. Fumery4, A. Leroyer2, L. Dauchet2, B. Pariente5, C. Gower-Rousseau2

1Hôpital Saint Philibert, Pathologie Digestive, Lomme, France, 2Epimad Registry- Maison de la Recherche CHU Lille, Public Health- Epidemiology, Lille, France, 3CHU Rouen, Service d’Hépato-Gastroentérologie et Oncologie Digestive, Rouen, France, 4CHU Amiens, Service d’Hépato-Gastroentérologie, Amiens, France, 5Hôpital Huriez- CHU Lille, Maladies de l’Appareil Digestif, Lille, France

Background

In industrialised countries, inflammatory bowel disease (IBD) incidence rates appear to have stabilised in adults but not in children. The objective was to describe changes in the incidence and phenotype of adult-onset IBD in northern France over a 27-year period.

Methods

We included all patients aged 17 or over at IBD diagnosis, recorded in the EPIMAD population-based registry between 1988 and 2014. Standardised incidence rates for Crohn’s disease (CD) and for ulcerative colitis (UC) were calculated in the population as a whole and by age and sex. Patients were divided into three age groups: 17–39, 40–59, and 60 and over. Disease locations were defined according to the Montreal classification.

Results

17,686 incident adult-onset IBD cases were recorded, including 10,206 cases of CD (58%), 6,839 cases of UC (38%) and 641 cases of IBD unclassified (IBDU; 4%). The mean [95% CI] annual incidences of adult-onset IBD, CD, UC, and IBDU were 13.5 per 105 [13.3–13.7], 7.5 per 105 [7.4–7.7], 5.4 per 105 [5.3–5.6] and 0.51 per 105 [0.47–0.55] respectively. The median [IQR] age at diagnosis was lower in CD (28 [22–40]) than in UC (36 [27–49]) (p < 0.0001). The median [IQR] age at diagnosis was lower in women than in men: 28 [21–39] vs. 29 [22–40] in CD (p < 0.0001), and 33 [26–45] vs. 39 [28–51] (p < 0.0001) in UC. The incidence of IBD rose from 11.5 per 105 in 1988–1990 to 12.9 per 105 in 2012–2014 (p = 0.053). The incidence of CD steadily increased from 5.5 to 7.9 per 105 (average percent change per year [APC] +1%; [0.5;1.4]; p < 0.0001), whilst that of UC was stable at 5.0 per 105. The largest increase was seen in young women: APC of +2.0% per year for CD (p < 0.0001) and +1.7% per year for UC (p < 0.0001) in the 17–39 age group, and APC of +1.1% per year for both disease (p = 0.019 for CD and p = 0.024 for UC) in the 40–59 age group. The sex ratio did not vary for CD but changed from 0.70 in 1988–1990 to 1.10 in 2012–2014 for UC (p = 0.001). Among CD patients having undergone a full assessment of the ileum and colon, ileal locations increased from 19% to 26% for L1 (p < 0.0001) and from 50% to 58% for L3 (p < 0.0001), while L2 locations decreased from 31% to 16% (p < 0.0001). In the UC group, the proportion of patients with E1 location decreased from 42% to 34%, whereas the proportion with E3 location increased from 19% to 28% (p < 0.0001).

Conclusion

In a large, population-based study over a period of 27 years, we found that the incidences of CD and UC in the young women in northern France are still rising quickly. Our present results suggest that one or more environmental factors may significantly predispose women to IBD in our region. Among patients with CD, we observed an increase in ileal involvement and a concomitant decrease in colonic involvement.

Portal