Repeated antibiotic exposure in early childhood is associated with higher mean body mass index (BMI) and an increased likelihood of obesity, a new study suggests.
A prospective cohort study, published in JAMA Network Open, recruited 6853 children antenatally; of which 93% had weight and height measured at the 54-month follow-up.
Community pharmacy antibiotic dispensing data was obtained for children whose parents consented.
Measurements included the World Health Organization’s BMI-for-age z scores and International Obesity Task Force overweight and obesity cut-off points.
Of the 5128 singletons (2622 [51%] male; mean [SD] birth weight of 3527  g), 4886 (95%) had an antibiotic prescription by age 48 months and 437 (9%) were obese at 54 months.
Adjusted mean (SE) BMI-for-age z scores increased significantly with the number of antibiotic dispensings for 4 to 6, 7 to 9, and more than 9 dispensings (unexposed, 0.87 [0.09]; 1-3 exposures, 0.92 [0.06] [P=0.57]; 4-6 exposures, 1.06 [0.06] [P=0.02]; 7-9 exposures, 1.06 [0.06] [P=0 .02]; >9 exposures, 1.08 [0.05] [P=0.01]).
Children whose antibiotic exposure began z score than those not exposed.
The study authors suggest future research could examine whether interventions such as antibiotic stewardship programmes also reduce early childhood obesity.