Association between smoking and hypertension under different PM2.5 and green space exposure: A nationwide cross-sectional study

Abstract

BackgroundSmoking has been widely reported to have a significant relationship with hypertension, but the past description of this relationship has not been uniform. In addition, there has been a lack of research to discuss the impact of environmental exposure on the relationship between smoking and hypertension. Therefore, this study estimates the association between smoking and hypertension in middle aged and elderly people in China under different PM2.5 (fine particulate matter) concentrations and the green space exposure conditions.MethodsIndividual sample data from the China Health and Retirement Longitudinal Study in 2018 and the long-term average exposure concentration of fine particles and green space exposure for all participants were used with a multilevel binary logistic mixed effects model. Adjustments were made for sociodemographic characteristics and other health behaviors including drinking, physical activity, and social activity. The normalized difference vegetation index (NDVI) and PM2.5 concentration stratification were assigned with the median of the population exposure concentration as the dividing line, and the dual environmental factor stratification was assigned in combination with the two types of environmental exposure. The analysis was also stratified using age groups.ResultsA total of 10,600 participants over the age of 45 were included in the study. The effects of smoking on hypertension were diverse under different environmental exposure conditions. There was a significant relationship between smoking behavior and hypertension in the Low-NDVI group, and the effect value of this relationship was significantly different from that in the High-NDVI group. Furthermore, for respondents exposed to low green spaces and high PM2.5 environments at the same time (Low-NDVI/High-PM2.5 group), their smoking behavior may lead to an increase in the risk of hypertension. In addition, the risk of hypertension caused by smoking in the middle-aged (45–64) was significant under low green space exposure, but the effect difference between the different age groups was not significant.ConclusionsThe relationship between smoking and hypertension was different under different environmental exposure conditions. Exposure to low green spaces may strengthen the association between smoking and hypertension risk. When participants were exposed to both low green spaces and high PM2.5 concentrations, the risk of hypertension caused by smoking was significantly higher than that of those who were exposed to high green spaces and low PM2.5 concentrations.

The causal effect of air pollution on the risk of essential hypertension: a Mendelian randomization study

“…People with obesity have increased susceptibility to the cardiovascular damage effects of air pollutants ( 48 ). For other factors, the association between smoking behavior and hypertension differed based on different levels of air pollution ( 49 ). In areas with high PM2.5, smoking was associated with a higher risk of hypertension.…”

“…In areas with high PM2.5, smoking was associated with a higher risk of hypertension. While in areas with low PM2.5, this was not observed, indicating that smoking might also act synergistically with air pollutants on hypertension ( 49 ).…”

“…Besides, obesity could also amplify the negative cardiovascular effects of PM2.5 pollution, especially concerning blood pressure and hypertension rates (47). People with obesity have increased susceptibility to the cardiovascular damage effects of air pollutants (48). For other factors, the association between smoking behavior and hypertension differed based on different levels of air pollution (49).…”

Cigarette smoking and PM2.5 might jointly exacerbate the risk of metabolic syndrome

“…It is worth noting that the joint role of both exposures in MS pathogenesis has not received considerable attention. However, some studies investigated the joint role of PM and cigarette smoking on cardiovascular and pulmonary morbidity and mortality (59,(73)(74)(75). For instance, Turner and colleagues (59) reported an increased risk of cardiovascular mortality (i.e., about 32 extra deaths per 100,000 person-years) due to smoking-PM 2.5 interaction.…”

“…Moreover, determining the interaction between PM 2.5 and smoking could provide insightful knowledge regarding the susceptibility to PM 2.5 -related adverse health conditions in smokers and nonsmokers ( 59 ). High exposure to PM 2.5 among Chinese was recently associated with a higher risk of hypertension caused by smoking ( 60 ). However, robust studies have not been conducted to determine the combined effect of PM 2.5 and cigarette smoking on MS.…”