Early-Life Environmental Exposures and Blood Pressure in Children

Abstract

Background: Growing evidence exists about the fetal and environmental origins of hypertension, but mainly limited to single-exposure studies. The exposome has been proposed as a more holistic approach by studying many exposures simultaneously.

Objectives: This study aims to evaluate the association between a wide range of prenatal and postnatal exposures and blood pressure (BP) in children.

Methods: Systolic and diastolic BP were measured among 1,277 children from the European HELIX (Human Early-Life Exposome) cohort aged 6 to 11 years. Prenatal (n = 89) and postnatal (n = 128) exposures include air pollution, built environment, meteorology, natural spaces, traffic, noise, chemicals, and lifestyles. Two methods adjusted for confounders were applied: an exposome-wide association study considering the exposures independently, and the deletion-substitution-addition algorithm considering all the exposures simultaneously.

Results: Decreases in systolic BP were observed with facility density (β change for an interquartile-range increase in exposure: -1.7 mm Hg [95% confidence interval (CI): -2.5 to -0.8 mm Hg]), maternal concentrations of polychlorinated biphenyl 118 (-1.4 mm Hg [95% CI: -2.6 to -0.2 mm Hg]) and child concentrations of dichlorodiphenyldichloroethylene (DDE: -1.6 mm Hg [95% CI: -2.4 to -0.7 mm Hg]), hexachlorobenzene (-1.5 mm Hg [95% CI: -2.4 to -0.6 mm Hg]), and mono-benzyl phthalate (-0.7 mm Hg [95% CI: -1.3 to -0.1 mm Hg]), whereas increases in systolic BP were observed with outdoor temperature during pregnancy (1.6 mm Hg [95% CI: 0.2 to 2.9 mm Hg]), high fish intake during pregnancy (2.0 mm Hg [95% CI: 0.4 to 3.5 mm Hg]), maternal cotinine concentrations (1.2 mm Hg [95% CI: -0.3 to 2.8 mm Hg]), and child perfluorooctanoate concentrations (0.9 mm Hg [95% CI: 0.1 to 1.6 mm Hg]). Decreases in diastolic BP were observed with outdoor temperature at examination (-1.4 mm Hg [95% CI: -2.3 to -0.5 mm Hg]) and child DDE concentrations (-1.1 mm Hg [95% CI: -1.9 to -0.3 mm Hg]), whereas increases in diastolic BP were observed with maternal bisphenol-A concentrations (0.7 mm Hg [95% CI: 0.1 to 1.4 mm Hg]), high fish intake during pregnancy (1.2 mm Hg [95% CI: -0.2 to 2.7 mm Hg]), and child copper concentrations (0.9 mm Hg [95% CI: 0.3 to 1.6 mm Hg]).

Conclusions: This study suggests that early-life exposure to several chemicals, as well as built environment and meteorological factors, may affect BP in children.

Keywords: blood pressure; chemicals; children; cohort; environment; epidemiology; exposome.

Figure 1.. Environmental-wide association study between prenatal and postnatal exposome and systolic and diastolic blood pressure (n=1277 children).

Volcano plots showing the results of the environmental-wide association studies (ExWAS) between (A) prenatal exposome and systolic blood pressure, (B) prenatal exposome and diastolic blood pressure, (C) postnatal exposome and systolic blood pressure, and (D) postnatal exposome and diastolic blood pressure. All models are adjusted for cohort, maternal age, maternal education level, maternal pre-pregnancy body mass index, parity, parental country of birth, child age, child sex, child height. BPA, Bisphenol-A; BUPA, Butyl-paraben; DBPs, Disinfection-by-product; DDE, 4,4’dichlorodiphenyldichloroethylene; HCB, Hexachlorobenzene; MBzP, Mono benzyl phthalate; MEHP, Mono-2-ethylhexyl phthalate; MEP, Monoethyl phthalate; MnBP, Mono-n-butyl phthalate; OP, Organophosphate; PBDE, Polybrominated diphenyl ether; PCB, Polychlorobiphenyls; PFASs, Perfluoroalkyl substances; UV-Vit. D, Vitamin-D dose from ultraviolet; TEF, Threshold for effective number of tests (i.e., p-value correction for multiple testing).

Central illustration.. Early-life environmental exposures and blood pressure in children.

The illustration shows the overall framework of the exposome and summarizes the associations observed between early-life environmental exposures and blood pressure in 6–11 years old children. Within the longitudinal European HELIX mother-child cohort (n=1,277), this study covered a wide-range of environmental exposures assessed during pregnancy and in childhood including outdoor exposures, chemicals, and lifestyles. Decreases (green line) and increases (red line) in systolic or diastolic blood pressure have been observed in association with either prenatal (solid line) or postnatal (dotted line) exposures including several chemicals, as well as with fish intake, markers of the built environment, and meteorological factors. Using a unique and systematic exposome approach covering hundreds of exposures, this study highlights that early-life environmental exposures may affect blood pressure in children.