Teenage girls exposed to secondhand tobacco smoke at home had lower levels of the "good" cholesterol known to reduce the risk of heart disease, Australian researchers reported this week.

However, the loss was not seen in boys, when compared to boys and girls who were not exposed to any secondhand smoke at home. Dr. Chi Le-Ha, of the University of Australia, led the study, which will be published in The Endocrine Society's Journal of Clinical Endocrinology and Metabolism.

Dr. Le-Ha said the finding is significant given that heart disease is the leading cause of death for women in the western hemisphere. So-called "good" cholesterol, also known as high-density lipoproteins, collects excess cholesterol in the bloodstream and transports it to the liver, where it is broken down. By contrast, low-density lipoproteins, sometimes referred to as "bad cholesterol", stick around in the bloodstream to create a waxy build-up that blocks blood vessels and arteries.

Thus, levels of good cholesterol in the body are seen as predictors of future cardiovascular health.

In the study, investigators examined a longitudinal birth cohort of 1,057 adolescents born between 1989 and 1992 in Perth, Australia, looking specifically at tobacco smoking within the household beginning at 18 weeks gestation until they turned 17-years-old. The researchers then took blood samples from the teenagers to measure cholesterol levels.

Forty-eight percent of the kids in the study had been exposed to secondhand smoke at home.

"The findings indicate childhood passive smoke exposure may be a more significant cardiovascular risk factor for women than me," Dr. Le-Ha said in a press release. The researchers said the work suggests a need to "redouble public health efforts to reduce young children's secondhand smoke exposure in the home," especially for the sake of girls.