A longitudinal study on the effect of PM2.5 components on blood pressure in the hypertensive patients from 2011 to 2019.

Extensive research has established the link between PM2.5 exposure and blood pressure (BP) levels among normal individuals. However, the association between PM2.5 components and BP levels in hypertensive patients has not been fully explored. In this study, 12 971 hypertensive cases from Jinchang cohort (in Jinchang City, China) with nearly 9 years of follow-up were enrolled. Based on the linear mixed-effect model, the effects of fine particulate matter (PM2.5) and five major components [sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), black carbon (BC) and organic matter (OM)]on BP [systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP)]were evaluated by single-component model, component-joint model and component-residual model, respectively. A positive correlation was found between PM2.5 as well as its components (SO42-, NO3-, NH4+, BC and OM) exposure and BP levels. The effects of SO42-, BC and OM on BP were observed to be the most robust among the three models. Based on the results of interaction effects and stratified analysis, the effect of BC exposure on SBP, and the effect of PM2.5 and its five components on PP were greater in female than in males. Compared with elderly hypertensive patients, OM had more significant effects on SBP, DBP and MAP in young and (or) middle-aged hypertensive patients. During the heating season, the effect of PM2.5 and its components on BP was grater compared to the non-heating season. Meanwhile, PM2.5 and its components have a greater influence on BP in patients with hypertension combined with diabetes. Therefore, the findings suggested that both PM2.5 exposure and its components had a significant effect on BP in patients with hypertension. Women and young and middle-aged hypertensive patient were the sensitive population. The implementation of source control and reduction of PM2.5 emission (mainly for SO42-, BC and OM) may be of great significance to control BP level and could reduce the risk of cardiovascular disease in patients with hypertension.

A study of temperature variability on admissions and deaths for cardiovascular diseases in Northwestern China.

OBJECTIVE: To explore the effect of temperature variability (TV) on admissions and deaths for cardiovascular diseases (CVDs). METHOD: The admissions data of CVDs were collected in 4 general hospitals in Jinchang City, Gansu Province from 2013 to 2016. The monitoring data of death for CVDs from 2013 to 2017 were collected through the Jinchang City Center for Disease Control and Prevention. Distributed lag nonlinear model (DLNM) was combined to analyze the effects of TV (daily temperature variability (DTV) and hourly temperature variability (HTV)) on the admissions and deaths for CVDs after adjusting confounding effects. Stratified analysis was conducted by age and gender. Then the attribution risk of TV was evaluated. RESULTS: There was a broadly linear correlation between TV and the admissions and deaths for CVDs, but only the association between TV and outpatient and emergency room (O&ER) visits for CVDs have statistically significant. DTV and HTV have similar lag effect. Every 1 ℃ increase in DTV and HTV was associated with a 3.61% (95% CI: 1.19% ~ 6.08%), 3.03% (95% CI: 0.27% ~ 5.86%) increase in O&ER visits for CVDs, respectively. There were 22.75% and 14.15% O&ER visits for CVDs can attribute to DTV and HTV exposure during 2013-2016. Males and the elderly may be more sensitive to the changes of TV. Greater effect of TV was observed in non-heating season than in heating season. CONCLUSION: TV was an independent risk factor for the increase of O&ER visits for CVDs, suggesting effective guidance such as strengthening the timely prevention for vulnerable groups before or after exposure, which has important implications for risk management of CVDs.