MONDAY, May 2, 2011 (HealthDay News) -- Boys who are exposed to secondhand smoke tend to have higher blood pressure levels than other boys, placing them at increased risk of developing hypertension when they grow up, a new study has found. But the reverse was true for girls.
In the study, researchers analyzed statistics from four national studies conducted between 1999 and 2006, focusing on the exposure of 6,421 children to secondhand smoke. The children answered questions about whether they lived with a smoker and were also tested for cotinine, a chemical produced by the body when it is exposed to nicotine.
Compared to boys not exposed to secondhand smoke, boys aged 8 to 17 who were exposed had significantly higher levels of systolic blood pressure, the investigators found.
"While the increases in blood pressure observed among boys in our study may not be clinically meaningful for an individual child, they have large implications for populations. Over one-third of children in the U.S. and globally are exposed to secondhand smoke levels similar to those associated with adverse cardiovascular effects in our study," Jill Baumgartner, lead author of the study and research fellow at the University of Minnesota's Institute on the Environment, said in a news release from the American Academy of Pediatrics.
Girls who were exposed to secondhand smoke, however, had lower blood pressure readings than those who weren't, the study authors noted.
"These findings support several previous studies suggesting that something about female gender may provide protection from harmful vascular changes due to secondhand smoke exposure. An important next step is to understand why," Baumgartner said.
The study was scheduled for presentation May 1 at the Pediatric Academic Societies annual meeting in Denver.
Experts note that research presented at meetings has not been subjected to the same type of rigorous scrutiny given to research published in peer-reviewed medical journals.
For more about secondhand smoke, visit the U.S. National Library of Medicine.