posted on 2023-12-29, 22:47authored byTongjun Guo, Wanzhou Wang, Xi Chen, Huaqi Guo, Kai Wang, Yating Ma, Hongyan Deng, Xianggui Li, Anqi Shan, Qian Wu, Yaoyan Li, Hongyu Li, Qisijing Liu, Juan Chen, Yang Lan, Jian Lei, Furong Deng, Zhiwei Sun, Xinbiao Guo, Yan Wang, Naijun Tang, Shaowei Wu
Previous
studies have shown that exposure to black carbon (BC,
a tracer of traffic-related air pollution) and psychosocial stress
are both associated with adverse cardiac effects, but whether psychosocial
stress could modify the cardiac effects of BC is unclear. To investigate
the potential modifying effect of psychosocial stress on the associations
between acute exposure to BC and typical cardiac health variables,
real-time personal 24 h measurements were conducted in a repeated-measure
study among adults with elevated blood pressure (high-risk group)
and a panel study among normal adults (low-risk group) in China. Measured
cardiac health variables included ST-segment depression events, heart
rate, and heart rate variability (HRV) variables. Perceived Stress
Scale, State Anxiety Inventory and Self-rating Depression Scale were
used to assess the recent psychosocial stress status of the participants,
and a composite stress index was established based on these scales.
Generalized linear mixed-effects model was used to analyze the associations
between BC exposure and cardiac health variables and potential effect
modification by psychosocial stress. A total of 97 24 h measurements
among 97 participants in the repeated-measure study and 202 24 h measurements
among 87 participants in the panel study were included in the final
analysis. Acute BC exposure was significantly associated with increased
ST-segment depression events and heart rate and decreases in HRV in
both studies. The marginal effects of acute BC exposure on most cardiac
health variables generally tended to be amplified under higher vs
low levels of psychosocial stress in both studies, with the composite
stress index apparently modifying the associations of BC exposure
with most ST-segment depression events and HRV variables. These findings
suggest that psychosocial stress may increase the participants’
cardiac susceptibility to BC exposure, which could be helpful for
the identification of susceptible individuals in the context of traffic-related
air pollution.