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January 26th, 2009:

Decreased Aortic Elasticity In Children Exposed To Tobacco Smoke

Childhood exposure to tobacco smoke (verified with serum cotinine levels) decreases aortic elastic properties in healthy children…

Title: Decreased aortic elasticity in healthy 11-year-old children exposed to tobacco smoke

Authors: K Kallio, E Jokinen, M Hämäläinen, M Saarinen, et al.

Reference: Pediatrics 2009; 123: e267-273,

Reviewer: Joaquin Barnoya, MD, MPH, ProCor contributing editor, Director, Research and Education, Unidad de Cirugia Cardiovascular de Guatemala, Guatemala

Purpose of study: To assess the association of exposure to tobacco smoke with elastic properties of the aorta and carotid artery in children.

Location of study: Finland

Study design: Healthy young (age 11 years) children were selected from a randomized, prospective, atherosclerosis prevention trial (Special Turuk Coronary Risk Factor Intervention Project for Children [STRIP] trial). Smoking habits of all family members were assessed annually with a questionnaire. Aortic and carotid elasticities were determined by using M-mode ultrasound imaging based on measurements of blood pressure and arterial diameter changes during the cardiac cycle. The aortic stiffness index, Young’s elastic modulus (YEM), and distensibility and the respective studies for the carotid artery were calculated. Exposure to tobacco smoke was measured using serum cotinine and classified as no-exposure (undetectable levels), low exposure (cotinine levels 0.2-1.6 ng/ml), and high exposure (levels >=1.7 ng/ml).

Results: A total of 386 children were included in the analysis. A significant increase in aortic stiffness index, YEM and aortic disetensibility was observed across the cotinine levels. After adjustment for BMI and systolic blood pressure, cotinine levels remained a significant explanatory variable regarding all aortic elasticity indices. Carotid elasticity indices were not statistically significant across cotinine groups.

Comment: This study adds to the mounting evidence of the cardiovascular effects of secondhand smoke, this time in healthy young children. One of the strengths of this study is that they used three indices to assess the mechanical properties of elastic arteries and all were found to be associated with cotinine levels. The fact that they did not find an effect of tobacco smoke on carotic stiffness might be a result of the aorta being affected before the carotid artery. This biological data on children add to the mounting evidence to fight for smoke-free environments worldwide.