The amount of lead found in a childï¿½s bloodstream during the early childhood can affect the way the cardiovascular system responds to stress and may later lead to hypertension, a new study has found.
The amount of lead found in a child’s bloodstream during the early childhood can affect the way the cardiovascular system responds to stress and may later lead to hypertension, a new study has found.
The research, done at the State University of New York, Oswego, found that even minimal levels of lead had an impact on the children’s cardiovascular systems. The greatest level of lead found in the children’s systems was 3.8 micrograms per deciliter. Ten micrograms of lead found in the bloodstream is the level at which the Centers for Disease Control and Prevention recommend that “public health actions be initiated.”
For the study, 140 children between nine and 11 years old were given a psychologically stressful computer task to work on. Cardiovascular function, which included total peripheral resistance (PR), was measured in the children at rest and during the computer task. The researchers found that there was a correlation between the child’s total PR response to the task. Increases in total PR response have been shown to possibly predispose individuals to hypertension later in life.
In addition, the researchers found that more exposure to lead resulted in lower circulating aldosterone levels, which makes it more difficult for the body to jump-start the sympathetic nervous system when needed.
A previous study showed that two-year-old children with higher levels of lead in their blood had an increased vascular response to stress at about 9.5 years of age, the researchers said, which is where the idea for this new study came from.
In investigating how the levels of lead impacted the cardiovascular system’s response to stress, the researchers discovered “increased sympathetic nervous system activity during rest and, paradoxically, a depressed sympathetic response during the stressful computer task.”
“We believe lead causes an increase in sympathetic nervous activity during rest which reduces the body’s ability to generate a response when stress comes along,” Dr. James A. MacKenzie, lead author of the study, said.
Though MacKenzie cautioned that these findings are preliminary, he said that “the issue deserves more study.”