Crohn's disease clinical course and severity in obese patients

Background and aims: Obesity is unusual in Crohn's disease and the particularities of the disease in obese patients have not been studied.

Methods: 2065 patients were studied retrospectively. Obesity was defined by a BMI value >25.0 at disease onset and >30.0 at any time during the course of the disease. Disease characteristics, therapeutic needs, and year-by-year disease activity were determined in patients with and without obesity.

Results: 62 patients (3%) were obese. When compared with non-obese patients, obese patients did not show differences regarding sex, intestinal disease location, and disease behavior, but at diagnosis they were older (32 vs 28 years, P = 0.01) and a larger proportion had anoperineal disease (35 vs 24%, P = 0.03). When the 62 obese patients were paired for sex, location of disease at onset, date of birth, and date of diagnosis with 124 non-obese patients, the disease severity assessed by the importance of medical therapy and excisional surgery did not differ in the two groups but time to development of anoperineal abscess or fistula was shorter in obese patients, and obese patients were more prone to develop an active disease (OR 1.50, 95% CI 1.07-2.11) and to require hospitalization (OR 2.35, 95% CI 1.56-3.52)

Conclusion: Obesity in Crohn's disease is associated with more frequent anoperineal complications and a more marked year-by-year disease activity, but does not alter significantly the long-term course of the disease.