HealthDay News — Obesity, as measured by body mass index (BMI), is associated with an increased risk for Crohn disease (CD) but not ulcerative colitis (UC), according to a study published in the May issue of Clinical Gastroenterology & Hepatology.
Simon S. M. Chan, M.B., B.Chir., Ph.D., from the Norfolk and Norwich University Hospital National Health Service Trust in the United Kingdom, and colleagues conducted pooled analyses of data from five prospective cohort studies with validated anthropometric measurements for BMI and waist-hip ratio and other lifestyle factors to examine the association between obesity and CD and UC risk.
The researchers confirmed 563 incident cases of CD and 1,047 incident cases of UC among 601,009 participants with 10,110,018 person-years of follow-up. Compared with normal BMI (18.5 to <25 kg/m2), obesity (baseline BMI ≥30 kg/m2) was associated with increased CD risk. Each 5-kg/m2 increment in early adulthood BMI (age 18 to 20 years) was associated with a significant increase in CD risk. An increase in waist-hip ratio was associated with increased CD risk, but the association was not statistically significant. There were no associations observed between measures of obesity and UC risk.
“Our data implies that the growing burden of obesity is likely contributing to the increasing incidence of CD worldwide,” the authors write. “Future work should consider examining the precise mechanisms through which obesity may influence the etiopathogenesis of CD.”