Lead Exposure Is Related to Impairment of Aortic Elasticity Parameters

Analysis of lead distribution in avian organs by LA-ICP-MS: Study of experimentally lead-exposed ducks and kites

Lead poisoning of wild birds by ingestion of lead ammunition occurs worldwide. Histopathological changes in organs of lead-intoxicated birds are widely known, and lead concentration of each organ is measurable using mass spectrometry. However, detailed lead localization at the suborgan level has remained elusive in lead-exposed birds. Here we investigated the detailed lead localization in organs of experimentally lead-exposed ducks and kites by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In both the ducks and kites, lead accumulated diffusely in the liver, renal cortex, and brain. Lead accumulation was restricted to the red pulp in the spleen. With regard to species differences in lead distribution patterns, it is noteworthy that intensive lead accumulation was observed in the arterial walls only in the kites. In addition, the distribution of copper in the brain was altered in the lead-exposed ducks. Thus, the present study shows suborgan lead distribution in lead-exposed birds and its differences between avian species for the first time. These findings will provide fundamental information to understand the cellular processes of lead poisoning and the mechanisms of species differences in susceptibility to lead exposure.

Central hemodynamics in relation to low-level environmental lead exposure

Purpose: Arterial stiffness predicts cardiovascular complications. The association between arterial stiffness and blood lead (BL) remains poorly documented. We aimed to assess the association of central hemodynamic measurements, including pulse wave velocity (aPWV), with blood lead in a Flemish population.Materials and Methods: In this Flemish population study (mean age, 37.0 years; 48.3% women), 267 participants had their whole BL and 24-h urinary cadmium (UCd) measured by electrothermal atomic absorption spectrometry in 1985-2005. After 9.4 years (median), they underwent applanation tonometry to estimate central pulse pressure (cPP), the augmentation index (AI), pressure amplification (PA), and aPWV. The amplitudes of the forward (Pf) and backward (Pb) pulse waves and reflection index (RI) were derived by a pressure-based wave separation algorithm.Results: BL averaged 2.93 μg/dL (interquartile range, 1.80-4.70) and UCd 4.79 µg (2.91-7.85). Mean values were 45.0 ± 15.2 mm Hg for cPP, 24.4 ± 12.4% for AI, 1.34 ± 0.21 for PA, 7.65 ± 1.74 m/s for aPWV, 32.7 ± 9.9 mm Hg for Pf, 21.8 ± 8.4 mm Hg for Pb, and 66.9 ± 18.4% for RI. The multivariable-adjusted association sizes for a 2-fold higher BL were: +3.03% (95% confidence interval, 1.56, 4.50) for AI; -0.06 (-0.08, -0.04) for PA; 1.02 mm Hg (0.02, 2.02) for Pb; and 3.98% (1.71, 6.24) for RI (p ≤ .045). In 206 participants never on antihypertensive drug treatment, association sizes were +2.59 mm Hg (0.39, 4.79) for cPP and +0.26 m/s (0.03, 0.50) for aPWV. Analyses adjusted for co-exposure to cadmium were consistent.Conclusion: In conclusion, low-level environmental lead exposure possibly contributes to arterial stiffening and wave reflection from peripheral sites.

Relation Between Lead Exposure and Trends in Blood Pressure in Children

Obesity raises blood pressure (BP) in children and adults. Nevertheless, as obesity increased around the globe, population systolic and diastolic blood pressures were flat or fell. Examining children is insightful because pediatric trends are largely unconfounded by antihypertensive therapy. Decomposing BP into arterial types, large artery measures (pulse pressure) increased in concert with obesity while small artery measures (mean arterial pressure, [MAP]) decreased, suggesting small arteries are the locus of the countervailing temporal trends. Pediatric lead exposure decreased as pediatric obesity rose. Over the period of rising obesity, we examined the association between lead exposure and temporal trends in BP. We analyzed anthropometric, BP, and laboratory data on 8-17 year old children from the serial cross-sectional National Health and Nutrition Examination Surveys 1976 through 2008. Multivariable adjusted survey regression was used to examine temporal trends in blood pressure in relation to blood lead concentrations (N = 13,501). As obesity prevalence rose from 5.3% to 24.5%, age-sex adjusted systolic BP was flat (-0.01 [95% confidence interval (CI) -0.06, 0.04] mm Hg/yr, p = 0.8), diastolic BP and MAP decreased (respectively -0.28 [-0.32, -0.24] and -0.19 [CI -0.23, -0.15], both p<0.0001) while pulse pressure increased (0.28 [0.23, 0.32], p<0.001). Accounting for blood lead concentration attenuated the decreasing MAP trend by 67%. In conclusion, the contrary trends in pediatric BP during the rise of pediatric obesity may be substantially attributable to decreasing lead exposure acting on small resistance arteries. These results have implications for globally observed BP trends in youth and adults. Environmental policy altering lead levels may have long-lasting cardiovascular benefits.

Exome-wide association study identifies genetic polymorphisms of C12orf51, MYL2, and ALDH2 associated with blood lead levels in the general Korean population

BACKGROUND

Lead (Pb) is a ubiquitous toxic metal present in the environment that poses adverse health effects to humans. Inter-individual variation in blood Pb levels is affected by various factors, including genetic makeup. However, limited data are available on the association between genetic variation and blood Pb levels. The purpose of this study was to identify the genetic markers associated with blood Pb levels in the Korean population.

METHODS

The study subjects consisted of 1,483 healthy adults with no history of occupational exposure to Pb. We measured blood Pb levels and calculated probable daily intake of Pb according to dietary data collected using 24-hour recall. We conducted exome-wide association screening using Illumina Human Exome-12v1.2 platform (n = 500) and a replication analysis using VeraCode Goldengate assay (n = 1,483).

RESULTS

Among the 244,770 single nucleotide polymorphisms (SNPs) tested, 12 SNPs associated with blood Pb level were identified, with suggestive significance level (P < 1 × 10^-4). In the Goldengate assay for replication, three SNPs (C12orf51 rs11066280, MYL2 rs12229654, and ALDH2 rs671) were associated with statistically suggestively significant differences in blood Pb levels. When stratified by drinking status, a potential association of C12orf51 rs11066280, MYL2 rs12229654, and ALDH2 rs671 with blood Pb level was observed only in drinkers. A marginally significant gene-environment interaction between ALDH2 rs671 and alcohol consumption was observed in relation to blood Pb levels. The effects of the three suggestively significant SNPs on blood Pb levels was dependent on daily calcium intake amounts.

CONCLUSIONS

This exome-wide association study indicated that C12orf51 rs11066280, MYL2 rs12229654, and ALDH2 rs671 polymorphisms are linked to blood Pb levels in the Korean population. Our results suggest that these three SNPs are involved in the determination of Pb levels in Koreans via the regulation of alcohol drinking behavior, and that their negative effects may be compensated by appropriate calcium intake.

The aortic mechanical properties in patients with the essential hypertension environmentally exposed to cigaret smoke

CONTEXT

The impairment of the aortic mechanical features constitutes the independent predictor of all-cause and cardiovascular mortality and morbidity.

OBJECTIVE

The purpose of the present research has been the determination of the influence of the environmental exposure to cigaret smoke on the aortic mechanical properties, namely, the stiffness and elasticity of aorta, in patients with essential hypertension.

MATERIALS AND METHODS

The research has covered 128 people with essential hypertension: 64 nonsmokers, declaring the environmental exposure to cigaret smoke (group A) and 64 nonsmokers declaring the lack of environmental exposure to cigaret smoke selected on the case to case basis (group B). Aortic mechanical properties have been evaluated on the basis of the parameters: aortic stiffness index (AoSI), aortic strain (AoS) and aortic distensibility (AoD).

RESULTS

In group A, the average values of AoSI were significantly higher, and the average values of AoS and AoD significantly lower than in group B. It has been documented that the older age and environmental exposure to cigaret smoke form independent risk factors of increasing the aortic stiffness expressed by higher values of AoSI, whereas the older age, higher pulse pressure (PP) values and environmental exposure to cigaret smoke - independent risk factors of aortic elasticity reduction expressed for the age and "passive smoking" by lower values of AoS and AoD and for PP - lower values of AoD.

CONCLUSION

In patients with essential hypertension, the environmental exposure to cigaret smoke seems to result in impairment of the aortic mechanical properties.