Association between spring season of birth and Crohn's disease.
OBJECTIVE
As for many complex diseases, the incidence of inflammatory bowel disease (IBD) is higher among individuals born during certain seasons. This difference could arise from seasonal variations in many factors, including exposure to sunlight, antibiotics, or infectious agents. We investigated the relationship between season of birth, early childhood exposure to antibiotics, and incidence of IBD.


METHODS
We performed a nested case-control analysis using data from the University of Manitoba inflammatory bowel disease epidemiology database. We compared seasons of birth among 11,145 individuals with IBD (cases) and 108,633 controls using conditional logistic regression models. We collected data on use of antibiotics in the first year of life for cases and controls from the Manitoba Drug Program Information Network-a comprehensive database of all prescriptions given to residents of Manitoba since 1995.


RESULTS
Approximately 27.0% of cases were born from April through June, compared with 25.6% of controls (odds ratio, 1.07; 95% confidence interval, 1.02-1.12; P = .002). Comparisons made by sex (male vs female) and type of IBD (ulcerative colitis vs Crohn's disease) showed statistical significance only for men with Crohn's disease (odds ratio, 1.13; 95% confidence interval, 1.03-1.25; P = .009). At ages 6 months and older, cases and controls born from April through June received a significantly greater number of prescriptions for antibiotics than cases and controls born in other months.


CONCLUSIONS
Men with Crohn's disease are more likely to have been born in the months of April through June.
Inflammatory Bowel Disease Clinical and Research Centre, University of Manitoba, Manitoba, Canada; Department of Community Health Sciences, University of Manitoba, Manitoba, Canada.
Souradet Y
SY
Shaw
Inflammatory Bowel Disease Clinical and Research Centre, University of Manitoba, Manitoba, Canada.
Zoann
Z
Nugent
Inflammatory Bowel Disease Clinical and Research Centre, University of Manitoba, Manitoba, Canada; Department of Internal Medicine, University of Manitoba, Manitoba, Canada.
Laura E
LE
Targownik
Inflammatory Bowel Disease Clinical and Research Centre, University of Manitoba, Manitoba, Canada; Department of Community Health Sciences, University of Manitoba, Manitoba, Canada; Department of Internal Medicine, University of Manitoba, Manitoba, Canada.
Harminder
H
Singh
Inflammatory Bowel Disease Clinical and Research Centre, University of Manitoba, Manitoba, Canada; Department of Community Health Sciences, University of Manitoba, Manitoba, Canada.
James F
JF
Blanchard
Inflammatory Bowel Disease Clinical and Research Centre, University of Manitoba, Manitoba, Canada; Department of Internal Medicine, University of Manitoba, Manitoba, Canada. Electronic address: charles.bernstein@med.umanitoba.ca.
Charles N
CN
Bernstein
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000453:epidemiology; D003424:Crohn Disease / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D012621:Seasons; D055815:Young Adult
D000900:Anti-Bacterial Agents
Antibiotics; CD; CI; Crohn's Disease; Crohn's disease; DPIN; Drug Prescription Information Network; Etiology; FY; IBD; ICD-9-CM; International Classification of Diseases, 9th revision, Clinical Modification; MH; Manitoba Health; OR; Seasonality; UC; UMIBDED; Ulcerative Colitis; University of Manitoba Inflammatory Bowel Disease Epidemiology Database; confidence interval; fiscal year; inflammatory bowel disease; odds ratio; ulcerative colitis