Relation Between Lead Exposure and Trends in Blood Pressure in Children

Abstract

Obesity raises blood pressure(BP) in children and adults. Nevertheless, as obesity increased around the globe, population systolic(SBP) and diastolic blood pressures(DBP) 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, PP) increased in concert with obesity while small artery measures(mean arterial pressure, MAP) declined, suggesting small arteries are the locus of the countervailing temporal trends. Pediatric lead exposure declined 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 (NHANES) 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 SBP was flat (−0.01[95%CI −0.06,0.04]mmHg/yr,p=0.8), DBP and MAP declined (respectively −0.28[−0.32,−0.24] and −0.19 [CI −0.23, −0.15], both p<0.0001) while PP increased (0.28 [0.23, 0.32], p<0.001). Accounting for blood lead concentration attenuated the declining 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.

Central hemodynamics in relation to low-level environmental lead exposure

“…Few previous studies addressed the potential association of arterial stiffness with lead exposure [9][10][11][12][13][14][15][16][17][18][19]. Interpretation of these studies is difficult, because most focused on the occupational exposure to lead [15][16][17][18][19], applied a suboptimal method to assess central hemodynamics [15,16], had a small sample size [19], or case-control design [15,17,18].…”

“…In comparison with the literature on the possible association of arterial stiffness and exposure to lead [9][10][11][12][13][14][15][16][17][18][19], our current study moves the field forward; because it is population based, thereby excluding the healthy-worker effect [35]; because a large panel of central hemodynamic variables was assessed, including aPWV, the gold standard in measuring arterial stiffness [7], as well as the forward and backward pulse pressure waves; and because we evaluated coexposure to cadmium. Moreover, our study is representative for current day environmental exposure levels, which are substantially lower than in the cited worker studies [15][16][17][18][19].…”

“…Whereas there is an abundant, albeit contradictory, literature on the association of blood pressure with lead exposure, a PubMed search using as keywords "pulse pressure" OR "augmentation index" OR "pulse wave velocity" OR "arterial stiffness" combined with "exposure" or "lead exposure" revealed only ten articles of potential relevance to the research issue addressed in this article. These studies described the association of peripheral pulse pressure [9][10][11][12][13][14], the ambulatory arterial stiffness index [15], or central hemodynamic measurements [16][17][18][19] with the lead concentration in blood [9][10][11][12][13][14][15][16][17][18], urine [15], toenails [19], or bone [10,11,13]. Our objective was to address this knowledge gap.…”

Understanding the Link between Neighborhoods and Kidney Disease

“…Numerous pollutants are related to CKD (32)(33)(34). Further, environmental lead, for example, is associated with increases in BP and oxidative stress in endothelial cells and vascular smooth muscle cells (35,36), which intimately relate to kidney function and damage. Neighborhood food quality and availability, as another example, are linked to obesity and diabetes (26,37,38), and they are thought to be linked to CKD and ESKD (39).…”

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

“…Advancing age and higher blood pressure are the main drivers of arterial stiffening and increased aortic pulse wave velocity [5,11]. Whereas there is an abundant, but contradictory, literature on the association of blood pressure with lead exposure, a PubMed search using as keywords "pulse wave velocity" OR "augmentation index" OR "arterial stiffness" OR "pulse pressure" combined with "exposure" or "lead exposure" revealed only ten articles of potential relevance, describing the association of peripheral pulse pressure [12][13][14][15][16][17], the ambulatory arterial stiffness index [18], or central hemodynamic measurements [19][20][21] with the lead concentration in blood [12][13][14][15][16][17][18][19][20], urine [18], toenails [21] or bone [13,14,16]. We therefore assessed the association of central hemodynamic measurements, including central blood pressure, systolic augmentation, aortic pulse wave velocity and pulse wave reflection, with blood lead, using the first in-study assessment (2015)(2016)(2017) collected in the ongoing Study for Promotion of Health in Recycling Lead (SPHERL; NCT02243904).…”