Environmental lead exposure is associated with higher predicted 10-year atherosclerotic cardiovascular disease risk in chinese middle-aged and older adults: a cross-sectional study

Environmental lead exposure has emerged as a risk factor for cardiovascular disease (CVD). Studies have focused on the role of lead in promoting atherosclerosis. Nonetheless, its long-term impact on atherosclerotic cardiovascular disease (ASCVD) remains unclear. To investigate the relationship between environmental lead exposure and 10-year ASCVD risk among Chinese middle-aged and older adults, we conducted a cross-sectional study in rural southern China during 2019–2020. Data were collected through face-to-face surveys and physical examinations, and blood lead levels were measured by Inductively Coupled Plasma Mass Spectrometry. The 10-year ASCVD risk score was calculated using the Prediction for ASCVD Risk in China (China-PAR) equation and classified into low-risk (< 5.0%), intermediate-risk (5.0–9.9%), and high-risk (≥ 10%) categories. A generalized linear model (GLM) for ordinal logistic regression was used to estimate associations between blood lead and the 10-year ASCVD risk categories, both overall and in subgroups. The dose–response association between blood lead and 10-year ASCVD risk was assessed using multivariable-adjusted ordinal logistic regression with restricted cubic splines (RCS). A total of 803 participants (526 females, 65.5%) were included (mean age 58 ± 7 years). The median blood lead level was 1.79 μg/L, with an interquartile range (IQR) of 1.14–44.91 μg/L, and the median predicted 10-year ASCVD risk score was 3.20% (IQR 1.70–5.90%). Carotid intimal thickening or plaque was present in 59.4% of participants. In fully adjusted models, participants in Q3 of blood lead had an odds ratio (OR) of 2.64 with a 95% confidence interval (CI) of 1.05–6.61 ( P = 0.038) for 10-year ASCVD risk category compared with those in Q1. This significance was attenuated in Q4 of blood lead (OR = 2.05, 95% CI: 0.65–6.47, P = 0.220). Overall, blood lead levels showed a significant association with 10-year ASCVD risk ( P = 0.030), with a suggestive non-linear, J-shaped pattern ( P for non-linearity = 0.074). Subgroup analyses suggested that the OR was higher among males, younger individuals (below 60 years), smokers, and those with hypertension. Our findings suggested a nonlinear association between environmental lead exposure and the predicted 10-year ASCVD risk among rural southern Chinese adults, highlighting the potential importance of controlling environmental lead exposure to prevent ASCVD, particularly among susceptible subgroups.