High childhood BMI raises risk for Crohn’s disease in adulthood
Higher body mass index (BMI) in childhood appears to be significantly associated with Crohn’s disease (CD) before 30 years of age, a recent study has shown.
Over 10 million person-years of follow-up, CD was diagnosed in 1,500 individuals, of whom 634 were male and 866 were female. Incidence rate by age showed two peaks: one at 20–30 years (2.2 cases per 10,000 person-years) and the other at 65–75 years (2.9 cases per 10,000 person-years).
Using BMI z-scores from 7–13 years of age, researchers showed that each unit increase was associated with a significant increase in the risk of being diagnosed with CD before the age of 30 years. The same effect was absent for CD diagnosis after 30 years of age.
On the other hand, ulcerative colitis (UC) had a significant but inverse correlation with BMI z-scores from ages 7–13 years. UC was diagnosed in 2,732 participants and similarly showed two incidence peaks according to age: at 20–30 years (2.8 cases per 10,000 person-years) and at 65–75 years (6.0 cases per 10,000 person-years).
Subsequent analysis stratified according to BMI categories showed that the risk was most apparent for obese children and only at specific ages. For instance, only obese children at age 11 (hazard ratio [HR], 1.31; 95 percent CI, 1.04–1.66; p=0.02), 12 (HR, 1.40; 1.12–1.77; p=0.01) and 13 (HR, 1.40; 1.12–1.76; p=0.002) years were at significantly elevated risks of CD development relative to normal weight children. The interaction with age of CD diagnosis was attenuated in this analysis.
Linking the Danish National Patient Register with the Copenhagen School Health Records Register, researchers identified 316,799 children, of whom 4,232 were diagnosed with inflammatory bowel diseases (IBD). Cox regression analysis was used to determine the relationship between childhood BMI with IBD risk.