Anemia in a Population-based IBD Cohort (ICURE)

BACKGROUND: Prevalence of anemia in patients with inflammatory bowel disease (IBD) is uncertain because of scarcity of population-based studies. The aim of this study was to evaluate prevalence of anemia in a population-based cohort of newly diagnosed patients with IBD to identify risk factors for anemia and to describe contemporary anemia-specific treatment during the first year. METHODS: All patients with ulcerative colitis or Crohn's disease in the IBD Cohort of Uppsala Region cohort (n = 790) and hemoglobin levels at the time of diagnosis were eligible for inclusion. The WHO definition of anemia was used. RESULTS: Seven hundred forty-nine (95%) of the patients with IBD were included. Five hundred eighty of 749 (77%) patients had measured hemoglobin levels at 12-month follow-up. The prevalence of anemia at the time of diagnosis was 227/749 (30%). After 1 year, it was 102/580 (18%). Anemia was more common among newly diagnosed patients with Crohn's disease compared with ulcerative colitis (42% versus 24%, P < 0.0001), but after 1 year, there was no difference (18% versus 18%, P = NS). Children had more often anemia compared with adults, both at diagnosis and after 1 year (diagnosis: 55% versus 27%, P < 0.0001; follow-up: 28% versus 16%, P < 0.05). Anemia was associated with colonic engagement in Crohn's disease and the extent of inflammation in ulcerative colitis. Only 46% of patients with anemia were treated with iron supplementation or blood transfusion. CONCLUSIONS: The overall prevalence of anemia in patients with IBD at the time of diagnosis was high. A large proportion was still anemic after 1 year. Children were more at risk compared with adults. More efforts are needed to treat patients with anemia.