Whether exposure to secondhand smoke increases the chance that children with a family history of cardiovascular disease will develop the disease themselves is under study at the Medical College of Georgia.
If those children also have a variation in at least one of four genes responsible for metabolizing nicotine, their risk may increase even more because nicotine might stay in the body longer and do more damage, an interdisciplinary research team says.
Researchers will study 585 children age 15-20 who have a parent, grandparent or both with essential hypertension and/or a heart attack by age 55.
"What I hope to take away from this is more information for parents and caregivers - to be able to share with them information about the risk of future disease that their behavior places on their child," says Dr. Martha Tingen, a nurse researcher at the Georgia Prevention Institute and principal investigator on the $220,000 National Institute of Nursing Research grant.
Researchers will look for adverse clinical cardiovascular measures, including reduced ability of arteries to dilate; the blood encountering increased resistance as it travels through vessels; higher blood pressure; and an increase in the size of the pumping chamber of the heart - a result of pumping against elevated pressure.
Exposure to the damaging effects of nicotine and other pathogens in smoke may also cause a vicious cycle in the body.
"It likely causes damage to cells on the inner wall lining of blood vessels, which results in less adaptive capacity of the vessels and arteries, which may then cause greater strain on the heart," says Dr. Tingen.
Children exposed to secondhand smoke who have a variation of one or more of the genes that metabolize nicotine - CYP1A1, GSTM1, GSTT1 and CYP2A6 - can experience cellular damage because the nicotine does not leave the body as quickly, she says.
"And if that's happening, they're going to have more of these adverse pre-clinical cardiovascular measures that predispose them to developing cardiovascular disease," she says.