Teenage girls exposed to passive smoking face a greater risk of heart disease than teenage boys, according to researchers at The University of Western Australia.
The study, published in the international Journal of Clinical Endocrinology & Metabolism, found girls exposed to second-hand smoke had less of the "good" cholesterol which reduces heart disease risk. Second-hand smoke did not appear to have the same impact on teenage boys.
High-density lipoproteins (HDL) pick up excess cholesterol in the blood and take it to the liver where it can be broken down. Unlike low-density lipoproteins that can create a waxy build-up blocking blood vessels, HDL cholesterol can play a key role in combatting heart disease risk.
Lead author Dr Chi Le-Ha, from UWA's School Medicine and Pharmacology and based at Royal Perth Hospital, said the researchers had surveyed more than 1000 adolescents using the Western Australian Pregnancy Cohort (Raine) Study, a Perth-based longitudinal cohort of children born in Western Australia between 1989 and 1992.
"In our study we found that 17-year-old girls raised in households where passive smoking occurred were more likely to experience declines in HDL cholesterol levels," Dr Le-Ha said.
"Second-hand 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."
Dr Le-Ha said the results suggested public health efforts needed to focus on reducing young children's second-hand smoke exposure in the home, and particularly for girls.