Impact of the age of diagnosis on the natural history of ulcerative colitis

Background: Ulcerative colitis (UC) has a recognized phenotypic heterogeneity. Some studies suggest that age at diagnosis may influence features and natural history of the disease. Aim: This study aimed to compare patients', disease's and treatment's features between Portuguese patients diagnosed before and after the age of 40-years-old. Methods: Retrospective single-center study that included 310 patients with UC, divided in two groups: Those diagnosed before the age of 40-years-old (early onset UC) and those diagnosed later than that (late onset UC). In each group features of the patients (gender, family history, smoking), of the disease (duration, extension, severity, clinical course, hospitalization, extraintestinal manifestations), and of treatment (oral aminosalicylates, systemic steroids or immunomodulators) were analyzed. Statistical analysis was performed using SPSSv22.0. Univariate and multivariate analyses were performed to assess factors associated with early and late onset UC. Results: From the analyzed patients, 207 had UC diagnosed before the age of 40 years old (43.5% men; mean age at diagnosis 29.4 +/- 6.9 years) and 103 were diagnosed after that age (61.2% men; mean age at diagnosis 51.8 +/- 8.1 years). In the group diagnosed before 40 years old, female gender (p = 0.003), severe disease (p = 0.002), chronic intermittent clinical course (p = 0.026), and hospitalizations (p = 0.001) were significantly more frequent. The use of oral aminosalicylates (p = 0.032), systemic steroids (p = 0.003) and immunomodulators (p = 0.012) were also more common in the early onset UC group. No differences between groups were found in family history, smoking, disease's extension, extraintestinal manifestations, and use of biological agents. Multivariate analysis pointed early onset UC to be significantly associated with female gender (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.08-2.91; p = 0.024), chronic intermittent symptoms (OR, 2.34; 95% CI, 1.17-4.70; p = 0.016), and need of hospitalization (OR, 2.89; 95% CI, 1.46-5.72; p = 0.002). Conclusions: When diagnosed before the age of 40-years-old, UC preferably affects women and manifests as a more severe disease, with more frequent hospitalizations and chronic intermittent symptoms. These facts might have implications in planning timely and individualized future therapeutic strategies.