Pregnancy and childhood exposure to residential traffic noise and overweight at 7years of age.

BACKGROUND Exposure to road traffic noise has been associated with adiposity and diabetes in adults. The suggested pathways have been through sleep disturbance and stress. Children may be particularly susceptible to noise induced sleep disturbance and stress and the effects hereof. OBJECTIVES To examine the association between traffic noise exposure during pregnancy and early childhood and adiposity in children. METHODS We identified 40,974 singletons from the Danish National Birth Cohort with parentally given questionnaire information on weight and height at 7-years of age. Road and railway traffic noise were modeled at all historical addresses and expressed as time-weighted means for two exposure periods (pregnancy and childhood). Adiposity was assessed using BMI z-scores and a dichotomous measure of childhood overweight based on age and sex specific cut-offs. Associations were analyzed using linear regression for BMI z-scores and logistic regression for risk of childhood overweight, adjusting for socioeconomic position, maternal BMI, maternal smoking, maternal age, parity and degree of urbanization. RESULTS We found both pregnancy and childhood exposure to road traffic noise to be associated with a higher risk for childhood overweight (odds ratio (OR)=1.06 per 10dB, 95% confidence interval (CI): 1.00-1.12 for exposure during pregnancy and OR=1.06 per 10dB, 95% CI: 0.99-1.12 for childhood exposure). There were no associations between road traffic noise and BMI z-scores. We found no associations between railway noise and adiposity. CONCLUSIONS We found suggestions of a positive association between road traffic noise and risk of overweight in 7-years old children.