Prenatal urban environment and blood pressure trajectories from childhood to early adulthood

BackgroundPrenatal urban environmental exposures have been associated with blood pressure in children. The dynamic of these associations across childhood and later ages is unknown. ObjectivesTo assess associations of prenatal urban environmental exposures with blood pressure trajectories from childhood to early adulthood. MethodsRepeated measures of systolic (SBP) and diastolic blood pressure (DBP) were collected in up to 7,454 participants from a UK birth cohort. Prenatal urban exposures (n=42) covered measures of noise, air pollution, built environment, natural spaces, traffic, meteorology, and food environment. An exposome-wide association study approach was used. Linear spline mixed-effects models were used to model associations of each exposure with trajectories of blood pressure. Replication was sought in four independent European cohorts (N up to 9,261). ResultsIn discovery analyses, higher humidity was associated with a faster increase (mean yearly change in SBP for an interquartile range [IQR] increase in humidity: 0.29 mmHg/year, 95%CI 0.20; 0.39) and higher temperature with a slower increase (mean yearly change in SBP per IQR increase in temperature: -0.17 mmHg/year, 95%CI -0.28; -0.07) in SBP in childhood. Higher levels of humidity and air pollution were associated with faster increase in DBP in childhood and slower increase in adolescence. There was little evidence of an association of other exposures with change in SBP or DBP. Results for humidity and temperature, but not for air pollution, were replicated in other cohorts. ConclusionReplicated findings suggest that higher prenatal humidity and temperature could modulate blood pressure changes across childhood.