Objectives
Caesarean-section (CS) delivery increases risk of childhood obesity, and is
associated with a distinct early-life gut microbiome, which may contribute to obesity.
Household pets may alter human gut microbiome composition. We examined if pet-keeping
modified the association of CS with obesity at age 2 years in 639 Wayne County Health,
Environment, Allergy and Asthma Longitudinal Study (WHEALS) birth cohort
participants.
Methods
Pet-keeping was defined as having a dog or cat (indoors ≥1 hour/day) at
child age 2 years. We used logistic regression to test for an interaction between CS and
pet-keeping with obesity (BMI≥95th percentile) at age 2 years,
adjusted for maternal obesity.
Results
A total of 328 (51.3%) children were male; 367 (57.4%) were
African American; 228 (35.7%) were born by CS; and 55 (8.6%) were obese.
After adjusting for maternal obesity, CS-born children had a non-significant
(P=0.25) but elevated 1.4 (95% CI: 0.8, 2.5) higher
odds of obesity compared to those born vaginally. There was evidence of effect
modification between current pet-keeping and delivery mode with obesity at age 2 years
(interaction P=0.054). Compared to children born vaginally
without a pet currently in the home, children born via CS without a pet currently in the
home had a statistically significant (P=0.043) higher odds
(odds ratio=2.00; 95% CI: 1.02, 3.93) of being obese at age 2 years.
Conclusions
Pets modified the CS-BMI relationship; whether the underlying mechanism is
through effects on environmental or gut microbiome requires specific investigation.