Intrauterine and Extrauterine Environmental PM_2.5 Exposure Is Associated with Overweight/Obesity (O/O) in Children Aged 6 to 59 Months from Lima, Peru: A Case-Control Study

There is evidence that PM_2.5 could be obesogenic. Lima is one of the most polluted cities in South America, with an increasing prevalence of childhood obesity. This study aimed to determine the association between PM_2.5 exposure of children aged 6 to 59 months and being overweight or obese (O/O) in a significant dataset survey. Cases were defined when weight for height Z-score (WHZ) was >2 standard deviations (SD) from the mean, for each sex. A control was defined when WHZ was between ±2 SD. We used a conditional logistic regression model to calculate the odds ratio (OR) between extrauterine and intrauterine PM_2.5 exposure and O/O. Extrauterine PM_2.5 exposure was evaluated as a 6-month PM_2.5 mean prior to the survey. We found a significant association between O/O and extrauterine (OR: 1.57, 1.51–1.63) and intrauterine (OR: 1.99, 1.88–2.12) PM_2.5 exposure for an increment of 10 μg/m³. The ORs increased as the quartile increased in both exposures. We observed a higher association in children aged 6–11 months (OR: 3.07, 2.84–3.31). In conclusion, higher levels of PM_2.5 in Lima and Callao were associated with cases of O/O in children from 6 to 59 months, with the association higher for prenatal exposure.