Association between environmental pollution by PM 2.5 exposure and childhood overweight/obesity in children from 6 to 59 months in Lima and Callao, Perú

Abstract

Background: Air pollution by PM2.5 is an important public health problem of considerable impact worldwide due to its deleterious effects in human beings. A recent report ranked Lima (Peru) as the second most polluted South American city by PM2.5. Recent evidences suggest that PM2.5 may be a obesogenic factor. Overweight and obesity in childhood is related with PM2.5 exposure by inflammation, methylation of adipogenic receptors and also associated to a fat consumption behavior. There is no time-series studies in Peru that associated PM2.5 with overweight/obesity in pre-school children (PSC). Methods: Average daily PM2.5 concentrations were calculated for 43 districts of Lima and Callao using an advanced machine learning model to estimate daily PM2.5 concentrations at a 1 km2 spatial resolution in Lima, Peru. Daily PM2.5 concentrations were attributed to overweight/obese PSC by day of medical control. Overweight/obesity cases were diagnosed when Z score of weight per stature were >2DS. The time-series study used Distributed Lag model and Poisson regression to estimate RR for daily overweight/obesity diagnoses with daily PM2.5, controlling by relative humidity, temperature, year and Lima area. Results: An increase of 10 ug/m3 of PM2.5 90 days before medical control was significantly associated with the development of overweight/obesity (RR 1.92, 95% CI: 1.90-1.94) in children aged 6 to 59 months when controlled by temperature, relative humidity, year and Lima area. The highest concentrations of PM2.5 were found in East Lima districts. Overweight/obesity risk was highest also in East Lima (RR 2.53, 95% CI: 2.49-2.57). Conclusions: Data in PSC children in Lima and Callao, Peru demonstrate that PM2.5 is obesogenic.