Birth-cohort patterns in Crohn's disease and ulcerative colitis

Area of Science:

• Gastroenterology
• Epidemiology
• Public Health

Background:

• Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), presents significant global health challenges.
• Understanding long-term mortality trends is crucial for effective public health strategies and disease management.

Purpose of the Study:

• To investigate long-term mortality trends for IBD, CD, and UC.
• To identify the presence of birth-cohort phenomena influencing IBD mortality patterns.

Main Methods:

• Analysis of mortality data from national statistical offices in Canada, England and Wales, Italy, the Netherlands, Switzerland, and the USA (60-80 years).
• Utilized period-age and cohort-age contour plotting to visualize age-specific mortality rates against period of death and birth period, respectively.

Main Results:

• A consistent birth-cohort pattern shaped IBD mortality trends across all six studied countries.
• Ulcerative colitis (UC) mortality rose in 19th-century birth cohorts, peaking near the turn of the century, then declining in subsequent 20th-century cohorts.
• Crohn's disease (CD) exhibited a similar birth-cohort pattern but was delayed by 30-50 years compared to UC.

Conclusions:

• The findings suggest at least two distinct early-life risk factors contribute to IBD, with one potentially specific to CD.
• These identified risk factors likely require exposure during early life to influence disease development and subsequent mortality.