Low-level exposure to lead and atherosclerosis in the carotid arteries: Results from the Swedish population-based cohort SCAPIS

Background:<bold> </bold>Lead exposure is associated with cardiovascular disease. Atherosclerosis has been hypothesized to be one of the underlying mechanisms behind this association.Aim:<bold> </bold>To investigate whether lead exposure is associated with an increased risk of atherosclerosis in the carotid arteries in a large Swedish population-based cohort.Methods:<bold> </bold>We performed a cross-sectional study using data from the population-based Swedish CardioPulmonary bioImage Study (SCAPIS), including 5622 middle-aged men and women, enrolled 2013-2018. Blood lead (B-Pb), measured by inductively coupled plasma mass spectrometry, was used as exposure biomarker. The presence of atherosclerotic plaque in the carotid arteries (yes/no), total plaque area (mm(2)) and the presence of large plaques (>25 mm(2)) were determined by ultrasonography. Associations between B-Pb and the different outcomes were analysed using Poisson and linear regression models, adjusted for potential confounders.Results:<bold> </bold>Atherosclerotic plaque was present in 57% of the individuals, for whom the median total plaque area was 16 mm(2) (range: 0.2-222). The median B-Pb concentration was 14 mu g/L (range: 0.75-203). After adjusting for potential confounders, individuals in the fourth quartile of B-Pb (Q4) had a prevalence ratio (PR) for plaque of 1.08 (95% CI: 1.01, 1.16) when compared with the first quartile (Q1). A 10 mu g/L increase in B-Pb concentrations was associated with an increase of 0.92 mm(2) (95% CI: 0.14, 1.71) in total plaque area. The PR for large plaque was 1.09 (95% CI: 0.84, 1.42 for Q4 vs Q1).Conclusions:<bold> </bold>This study shows an association between B-Pb and atherosclerosis in the carotid arteries providing some support for the hypothesis that atherosclerosis is one of the mechanisms underlying the association between lead exposure and cardiovascular disease.