Rising Incidence of Inflammatory Bowel Disease Among Children

Abstract

Purpose: To assess the trends in the incidence of IBD in children over time and describe the clinical constellation and risk factors associated with IBD in children Methods: We conducted a retrospective clinical epidemiologic investigation by identifying a cohort of children diagnosed with IBD in the period 1991–2002 and registered in the IBD -Center at Texas Children's Hospital. This center in Houston, Texas sees approximately 500 children with IBD each year. We identified the following variables: the year of IBD diagnosis, age at diagnosis, gender, self-reported race/ethnicity, and the IBD subtypes; Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC). IBD was diagnosed based on clinical, radiological, endoscopic, and histological examinations. Results: A total of 272 children with first diagnosis of IBD were eligible for the analysis of the current study. Children were identified from the IBD registry in the period 1991–2002 (56% CD, 22% UC and 22% IC). The overall ratio of male to female patients was 1.2:1 in CD, 0.6:1 in UC and 0.8:1 in IC. The highest age-related occurrence for CD and UC was found among the10–14-year-old age group. The mean age of diagnosis of patients with CD was not statistically different from those with UC or IC (11.7 ± 3.4, 10.7 ± 4.1, 10.4 ± 4.4, respectively, P > 0.5 0). The overall incidence rate of IBD doubled between 1991 and 2002; from 1.1/100,000 per year (95% CI, 0.85–1.36) to 2.4/100/1000/year (95% CI: 2.10–2.77). This trend was valid for CD but not for UC. Significantly, more Caucasians had higher incidence rate of IBD than African-Americans or Hispanic children; 4.15/100,000/year (95%CI = 3.48, 4.82) vs. 1.83 /100,000/year (95%CI = 1.14, 2.51) and 0.61/100,000 (95% CI = 0.33, 0.89), respectively. Furthermore, we examined the ratio of CD:UC for each race/ethnic group separtely. Although CD was more diagnosed among the three groups, the CD:UC ratio differed among African Americans children as they predominantly had CD than UC. Conclusion: Our results demonstrate a clear evidence of the rising incidence of IBD among children in the United States with more clear evidence of CD than UC. These findings imply that the clinical field of IBD is evolving and affecting all races and ethnicities, all ages, and both boys and girls. Recognition of these results will have important implications for diagnosis and management of the disease. The childhood IBD registries are valuable tools for further epidemiologic and genetic research.