Prenatal Exposure to Air Pollution and Childhood Lipid Levels: The Rhea Birth Cohort (Greece)

Abstract

BACKGROUND AND AIM: Abnormal blood lipid profiles in childhood are an important precursor to atherosclerosis and cardiovascular disease. Air pollution has been associated with lipid levels in animal models; however, evidence from human studies remains insufficient and inconclusive. We evaluated the associations of pregnancy exposure to air pollution with serum lipid profiles during childhood in the Rhea birth cohort, Greece. METHODS: Residential exposure to particulate matter <10 μm (PM10) and <2.5 μm (PM2.5) during pregnancy was estimated with temporally adjusted land-use regression models. We measured triglycerides (TG), total cholesterol (TC), HDL- and LDL- cholesterol at 4, 6, and 11 years. Abnormal lipid levels in children were defined according to the US NHLBI guidelines. We assessed associations with multivariate regression models and effect modification by sex. RESULTS: Prenatal PM2.5 and PM10 levels ranged between 13.0 and 18.7 μg/m3 and 34.9 and 54.6 μg/m3, respectively. PM10 concentrations over the 4th quartile were associated with lower TG levels overall (β= -5.25 mg/dL, 95% CI: -10.38, -0.11) and lower TC and TG levels in girls (β= -6.87 mg/dL, 95% CI: -13.78, 0.05; β= -9.03 mg/dL, 95% CI: -17.05, -1.01 respectively) at 4 years. At 11 years, higher prenatal PM10 levels were associated with both higher levels of TC and LDL (β= 7.75 mg/dL, 95% CI: -0.17, 15.68; β= 7.40 mg/dL, 95% CI: 0.36, 14.45) but also higher risk for elevated TC and LDL. Associations at 11 years were stronger in girls, indicating a sex-dependent effect. Associations with PM2.5 were in the same direction but not significant. No associations were observed at 6 years. CONCLUSIONS: These results shed new light on the importance of controlling air pollution, which can contribute to abnormal blood lipid levels during childhood, an independent risk factor for adult cardiovascular disease. KEYWORDS: prenatal, air pollution, lipids, children