When exposed to secondhand smoke at home, teenage girls tend to have lower levels of the "good" form of cholesterol that reduces heart disease risk, according to a recent study.

High-density lipoproteins (HDL) pick up excess cholesterol in the blood stream and take it to the liver where it can be broken down. Unlike low-density lipoproteins that can create a waxy build-up that blocks blood vessels, HDL cholesterol can play a key role in combatting heart disease risk.

"In our study, we found 17-year-old girls raised in households where passive smoking occurred were more likely to experience declines in HDL cholesterol levels," said the study`s lead author, Chi Le-Ha, MD, of the University of Western Australia.

"Secondhand smoke did not have the same impact on teenage boys of the same age, which suggests passive smoking exposure may be more harmful to girls. Considering cardiovascular disease is the leading cause of death in women in the western world, this is a serious concern," the researcher added.

Researchers studied a longitudinal birth cohort of 1,057 adolescents who were born between 1989 and 1992 in Perth, Australia. The study gathered information about smoking in the household beginning at 18 weeks gestation and leading up to when the children turned 17. During that time, 48 percent of the participants were exposed to secondhand smoke at home. Blood tests were performed to measure the teenagers` cholesterol levels.

"The findings indicate childhood passive smoke exposure may be a more significant cardiovascular risk factor for women than men," Le-Ha said.

The study has been accepted for publication in The Endocrine Society`s Journal of Clinical Endocrinology and Metabolism (JCEM).