Cardiovascular effects of passive smoking in adults and children

Multiple sources of evidence have linked secondhand smoke to cardiovascular disease (CVD) in adults. While the prevalence of this exposure has decreased in the past 20 years, a substantial proportion of the population (43%) still remains exposed. The relative risk of CVD in passive smokers is approximately 1.25 when controlled for confounding variables. Potential mechanisms appear to be oxidant gas exposure, which leads to endothelial dysfunction, resulting in multiple abnormalities of the vascular system (arterial thickening, and the pro-inflammatory, pro-thrombotic, and pro-atherogenic state). Additional mechanisms accounting for the causal relationship between secondhand smoke exposure and CVD include mitochondrial damage leading to energy perturbations and alterations in autonomic function, leading to decreased heart rate variability, a risk factor for higher mortality rates in patients with chronic heart failure. Children are at high risk due to home exposure, but there is has been limited research in this area, with most research on the effects of tobacco smoke exposure in childhood focusing on the respiratory system. Non-invasive diagnostic research tools will be useful in determining the effects of tobacco smoke exposure during childhood on the developing cardiovascular system.