Existing studies mostly explored
the association between urban
environmental exposures and blood pressure (BP) in isolation, ignoring
correlations across exposures. This study aimed to systematically
evaluate the impact of a wide range of urban exposures on BP using
an exposome-wide approach. A multicenter cross-sectional study was
conducted in ten cities of China. For each enrolled participant, we
estimated their urban exposures, including air pollution, built environment,
surrounding natural space, and road traffic indicator. On the whole,
this study comprised three statistical analysis steps, that is, single
exposure analysis, multiple exposure analysis and a cluster analysis.
We also used deletion–substitution–addition algorithm
to conduct variable selection. After considering multiple exposures,
for hypertension risk, most significant associations in single exposure
model disappeared, with only neighborhood walkability remaining negatively
statistically significant. Besides, it was observed that SBP (systolic
BP) raised gradually with the increase in PM2.5, but such
rising pattern slowed down when PM2.5 concentration reached
a relatively high level. For surrounding natural spaces, significant
protective associations between green and blue spaces with BP were
found. This study also found that high population density and public
transport accessibility have beneficially significant association
with BP. Additionally, with the increase in the distance to the nearest
major road, DBP (diastolic BP) decreased rapidly. When the distance
was beyond around 200 m, however, there was no obvious change to DBP
anymore. By cluster analysis, six clusters of urban exposures were
identified. These findings reinforce the importance of improving urban
design, which help promote healthy urban environments to optimize
human BP health.