title: Does pet-keeping modify the association of delivery mode with offspring body size?
abstract: 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 birth cohort participants. Pet-keeping was defined as having a dog or cat (indoors ≥1 h/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. 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. Pets modified the CS-BMI relationship; whether the underlying mechanism is through effects on environmental or gut microbiome requires specific investigation.
authors.affiliation: Department of Public Health Sciences, Henry Ford Hospital, 1 Ford Place, 5C, Detroit, MI, 48202, USA, acassid1@hfhs.org.
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Cassidy-Bushrow
authors.forename: Ganesa
authors.initials: G
authors.lastname: Wegienka
authors.forename: Suzanne
authors.initials: S
authors.lastname: Havstad
authors.forename: Albert M
authors.initials: AM
authors.lastname: Levin
authors.forename: Susan V
authors.initials: SV
authors.lastname: Lynch
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Ownby
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Rundle
authors.forename: Kimberley J
authors.initials: KJ
authors.lastname: Woodcroft
authors.forename: Edward M
authors.initials: EM
authors.lastname: Zoratti
authors.forename: Christine Cole
authors.initials: CC
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000818:Animals; D049628:Body Size; D002415:Cats; D002585:Cesarean Section / Q000009:adverse effects / Q000706:statistics & numerical data; D002675:Child, Preschool; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D004285:Dogs; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063766:Pediatric Obesity / Q000209:etiology*; D057805:Pets; D011247:Pregnancy; D012307:Risk Factors; D055815:Young Adult