Central hemodynamics in relation to blood lead in young men prior to chronic occupational exposure

Abstract

Background: Aortic pulse wave velocity (aPWV) predicts cardiovascular complications, but the association of central arterial properties with blood lead level (BL) is poorly documented. We therefore assessed their association with BL in 150 young men prior to occupational lead exposure, using baseline data of the Study for Promotion of Health in Recycling Lead (NCT02243904). Methods: Study nurses administered validated questionnaires and performed clinical measurements. Venous blood samples were obtained after 8-12h of fasting. The radial, carotid and femoral pulse waves were tonometrically recorded. We accounted for ethnicity, age, anthropometric characteristics, mean arterial pressure, heart rate, smoking and drinking, and total and high-density lipoprotein serum cholesterol, as appropriate. Results: Mean values were 4.14 mu g/dL for BL, 27 years for age, 108/79/28 mm Hg for central systolic/diastolic/pulse pressure, 100/10% for the augmentation ratio/index, 1.63 for pressure amplification, 5.94 m/s for a PWV, 27/11 mm Hg for the forward/backward pulse pressure height, and 43% for the reflection index. Per 10-fold BL increase, central diastolic pressure and the augmentation ratio were respectively 5.37 mm Hg (95% confidence interval [CI], 1.00-9.75) and 1.57 (CI, 0.20-2.94) greater, whereas central pulse pressure and the forward pulse pressure height were 3.74 mm Hg (CI, 0.60-6.88) and 3.37mm Hg (CI, 0.22-6.53) smaller (p <=.036 for all). The other hemodynamic measurements were unrelated to BL. The reflected pulse peak time was inversely correlated with diastolic pressure (r = -0.20; p <= .017). Conclusion: At the exposure levels observed in our current study, aPWV, the gold standard to assess arterial stiffness, was not associated with BL. Increased peripheral arterial resistance, as reflected by higher diastolic pressure, might bring reflection points closer to the heart, thereby moving the backward wave into systole and increasing the augmentation ratio in relation to BL.