Association study of long-term exposure to different particle sizes with cardiovascular disease risk in middle-aged and elderly patients with metabolic syndrome

Lei Kehang; Huang Ji

doi:10.3760/j.issn.1673-4777.2026.05.006

Abstract：Objective To evaluate the association between long-term exposure to different particle sizes[fine particulate matter(PM2.5),inhalable particulate matter(PM10)]and cardiovascular disease(CVD)risk in middle-aged and elderly individuals with metabolic syndrome(MS).Methods Based on the 2011-2018 data from the China Health and Retirement Longitudinal Study,1 959 participants aged ≥60 years were enrolled and divided into non-CVD group(1 445 cases)and CVD group(514 cases)according to CVD status.MS status was classified based on relevant metabolic indicators.Individual exposure levels were estimated using annual average concentrations of PM2.5 and PM10.Participants were divided into four groups(Q1-Q4)according to quartiles of particulate matter concentration,with Q,as the lowest exposure group(control)and Q4 as the highest exposure group,to compare risks at different exposure levels.Cox proportional hazards regression model was applied to assess the effects of PM2.5 and PM10 on CVD incidence risk,and restricted cubic spline was used to analyze the dose-response relationship between average particulate matter concentration and CVD incidence risk.Results High exposure to PM2.5 and PM10 was both significantly associated with elevated CVD incidence risk(both P＜0.05).After stepwise adjustment for sociodemographic factors,lifestyle,physiological indicators and past medical history in multiple models,the independent association of CVD risk remained significant in the Q4 group for PM2.5(hazard ratio=1.60,95％confidence interval:1.22-2.08);a consistent trend was observed for PM10,with significant dose-response relationships in both.Restricted cubic spline analysis showed that the associations of PM2.5 and PM10 concentrations with CVD were significant in non-MS individuals(P=0.009 6,0.001 5)but not significant in MS individuals(both P＞0.05).Conclusions Exposure to PM2.5 and PM10 is positively correlated with CVD incidence risk in middle-aged and elderly individuals.This association exhibits a"ceiling effect"in MS individuals and is more significant in non-MS individuals,suggesting that both may be independent risk factors for CVD.