Although previous research has been conducted about the relationship between tobacco smoke and atherosclerosis in adults, a new study is one of the first about the correlation in children.
Adolescents who are frequently exposed to tobacco smoke but are otherwise healthy experience arterial changes, which are associated with preclinical atherosclerosis and increased apolipoprotein B (apoB) levels.
Lead researcher Dr. Katariina Kallio, of the University of Turku in Finland, and her team used high-resolution ultrasound to examine maximum carotid and aortic intima-media thickness (IMT) and brachial-artery flow-mediated dilation in 494 healthy 13-year-old children enrolled in the Special Turku Coronary Risk Factor Intervention Project; serum lipid, lipoprotein, and apoA-I and B concentrations were also measured. For the study, the adolescents were divided into three groups based on levels of tobacco exposure: high (163 participants), intermediate (171), and low (160).
The maximum IMT in both the carotid and the aorta increased as the level of exposure to tobacco smoke went up, and “endothelial function as measured by brachial artery flow-mediated dilation was decreased in the highest-exposure group compared with the lowest.” In addition, “poB and apoB/apoA-I ratio increased with increases in cotinine level.”
Previous studies have shown that passive smoking is associated with IMT in adults, according to the researchers. Although they do cite one earlier study that found an association between second-hand smoke exposure and endothelial dysfunction in 11-year-old children, the researchers conducted the study because no others “have previously examined the impact of exposure to tobacco smoke on IMT in healthy children or adolescents.” The new study provides some insight into the relationship between passive smoking and increased IMT in this age group.
"The present study suggests that even modest exposure to tobacco smoke is associated with increased IMT,” the researchers commented. “As thickness of the arterial wall is a marker of early atherosclerosis, our data suggest that exposure to tobacco smoke may play a role in the development of atherosclerosis."
Results of the study were also published in Circulation: Cardiovascular Quality and Outcomes.