Department of Cardiology, The First Affiliated Hospital of Guangxi Medical University, No.6 Shuangyong Road, Nanning, 530021, China.
Guangxi Key Laboratory of Precision Medicine in Cardio-Cerebrovascular Diseases Control and Prevention, Nanning, China.
BMC Public Health. 2023 Oct 2;23(1):1897. doi: 10.1186/s12889-023-16815-0.
Hypertension caused by air pollution exposure is a growing concern in China. The association between air pollutant exposure and hypertension has been found to be potentiated by obesity, however, little is known about the processes mediating this association. This study investigated the association between fine particulate matter (aerodynamic equivalent diameter ≤ 2.5 microns, PM2.5) exposure and the prevalence of hypertension in a representative population in southern China and tested whether obesity mediated this association.
A total of 14,308 adults from 48 communities/villages in southern China were selected from January 2015 to December 2015 using a stratified multistage random sampling method. Hourly PM2.5 measurements were collected from the China National Environmental Monitoring Centre. Restricted cubic splines were used to analyze the nonlinear dose-response relationship between PM2.5 exposure and hypertension risk. The mediating effect mechanism of obesity on PM2.5-associated hypertension was tested in a causal inference framework following the approach proposed by Imai and Keele.
A total of 20.7% (2966/14,308) of participants in the present study were diagnosed with hypertension. Nonlinear exposure-response analysis revealed that exposure to an annual mean PM2.5 concentration above 41.8 µg/m was associated with increased hypertension risk at an incremental gradient. 9.1% of the hypertension burden could be attributed to exposure to elevated annual average concentrations of PM2.5. It is noteworthy that an increased body fat percentage positively mediated 59.3% of the association between PM2.5 exposure and hypertension risk, whereas body mass index mediated 34.3% of this association.
This study suggests that a significant portion of the estimated effect of exposure to PM2.5 on the risk of hypertension appears to be attributed to its effect on alterations in body composition and the development of obesity. These findings could inform intersectoral actions in future studies to protect populations with excessive fine particle exposure from developing hypertension.
空气污染暴露导致的高血压在中国是一个日益严重的问题。已有研究发现，空气污染暴露与高血压之间的关联在肥胖人群中更为显著，但对于介导这种关联的具体过程知之甚少。本研究旨在探讨中国南方一个代表性人群中细颗粒物（空气动力学等效直径≤2.5 微米，PM2.5）暴露与高血压患病率之间的关系，并检验肥胖是否介导了这种关联。
采用分层多阶段随机抽样方法，于 2015 年 1 月至 12 月从中国南方 48 个社区/村庄中选取了 14308 名成年人。从中国国家环境监测中心收集了每小时 PM2.5 测量值。采用受限立方样条分析 PM2.5 暴露与高血压风险之间的非线性剂量-反应关系。采用 Imai 和 Keele 提出的方法，在因果推理框架下检验肥胖对 PM2.5 相关高血压的中介效应机制。
本研究共纳入 20.7%（2966/14308）的参与者患有高血压。非线性暴露-反应分析显示，每年平均 PM2.5 浓度超过 41.8µg/m3 与高血压风险呈递增梯度相关。高血压负担的 9.1%可归因于暴露于升高的年平均 PM2.5 浓度。值得注意的是，体脂百分比的增加正向介导了 PM2.5 暴露与高血压风险之间关联的 59.3%，而体重指数介导了 34.3%的关联。
本研究表明，PM2.5 暴露对高血压风险的估计效应中，相当一部分可能归因于其对身体成分改变和肥胖发展的影响。这些发现可以为未来研究中保护暴露于过量细颗粒物的人群免受高血压影响的跨部门行动提供信息。
