Jan. 10, 2011 -- Parents who smoke around their preschool-aged children may increase their kids’ risk of having higher blood pressure at that young age compared to children who have parents who do not smoke, according to research published in Circulation: Journal of the American Heart Association.
The study, performed by German researchers from the University of Heidelberg in Germany, is the first to show that environmental nicotine exposure can increase the blood pressure of children as young as 4 and 5 years old. And researchers say smoke exposure is likely to have a similar effect on the blood pressure of children in the U.S.
The study included 4,236 preschool children, aged 4 to 7years old, from the Heidelberg Kindergarten Blood Pressure Project, who were examined from February 2007 to October 2008. Researchers gathered questionnaires from 4,185 parents on their smoking habits. Parents who smoked: 28.5% of fathers, 20.7% of mothers, and 11.9% for both parents.
Factors That Raise a Child’s Blood Pressure
Height, body mass index (BMI), sex, and prenatal risk factors affected children’s blood pressure, according to the study. Obese children were almost twice as likely to have a high-normal or elevated systolic (the top number) blood pressure.
Girls had lower systolic blood pressure than boys, research showed.
Children born preterm or with low birth weight had higher systolic blood pressure values than children born at term, and children whose mothers smoked during pregnancy had higher systolic blood pressure than those who were not exposed during pregnancy. The study confirms findings from previous studies that these factors independently are associated with higher blood pressure in early childhood.
However, the unique finding of this study was the new evidence that exposure to tobacco smoke from smoking parents may raise the blood pressure of kids as young as 4 and 5 years old. Kids exposed to nicotine and smoke at home had higher systolic and diastolic blood pressure than kids who were not exposed.
Children whose parents smoked had a 21% greater chance of having systolic blood pressure in the top 15%, even after researchers adjusted for the other risk factors mentioned above.
“Smoking adds to other risk factors,” Giacomo D. Simonetti, MD, says in a news release. “Average blood pressure increased in proportion to the cumulative number of risk factors present.”
The Argument for Smoke-Free Environments
The study suggests that implementing smoke-free environments, especially at home, may be necessary to preserve heart health for not only adults, but also for children. Researchers found that mothers smoking had a larger effect on kids’ blood pressure than fathers smoking. The difference may be that mothers were more likely to smoke at home while fathers smoked more while at work, researchers say.
“The prevention of adult diseases like stroke or heart attack begins during childhood,” Simonetti says. “Removing any avoidable risk factors as soon as possible will help reduce the risk for heart disease later on and improve the long-term health of children.”