Environmental factors trigger the onset of inflammatory bowel disease (IBD) in genetically predisposed individuals.
Exposure to seasonal external factors during the maturation of the immune system is suspected to be an inducing factor for IBD.
Some studies suggested an association between the month of birth and the later development of IBD.
|Being born in June significantly reduces the risk of developing Crohn's disease|
|Inflammatory Bowel Diseases|
Dr Van Ranst and colleagues studied this putative relationship in a large cohort of Belgian patients with Crohn's disease.
The investigators collected data from 1025 patients born between 1935 and 1990.
The team based the diagnosis of Crohn's disease on generally accepted clinical, endoscopic, and histologic criteria.
The investigative team used a control group that was a cohort of 5125 non-IBD patients seen at the same hospital matched for birth year and sex.
The team calculated odds ratios using multivariate unconditional logistic regression including the matching variables, and allowing for cyclic variation in risk with month of birth.
The investigators observed a cyclic pattern described by a 4-month periodic function with peaks in April and August.
Moreover, the research team observed that being born in June significantly reduced the risk of developing Crohn's disease later in life.
Dr Van Ranst's team concludes, “In this Belgian cohort, a significant association was found between the month of birth and later development of IBD.”
“A significant reduced risk to develop Crohn's disease was observed for people born in June.”
“Moreover, environmental yearly reoccurring factors during pregnancy or postpartum might be associated with the occurrence of Crohn's disease later in life.”