Passive smoking and how it relates to cardiovascular disease (CVD) is a widely debated topic. Many studies that discuss this topic address the specific issue of how passive smoking affects the development of CVD among the non-smoking relatives of smokers. The researchers who have studied the relationship of passive smoking and the risk of CVD in the non-smoking relatives of smokers, mostly differ in their interpretation of the results.
As will be discussed in the following, there is strong evidence to suggest a correlation between passive smoking and the development of CVD in the non-smoking relatives of smokers. However, the exact statistics of this correlation differ from study to study. Some studies suggest a substantial correlation and propose that passive smoking is a likely causal factor of CVD in the non-smoking relatives of smokers (He, Lam, Li, Li, Du, Jia, Huang & Zheng, 1994). Other studies find that there is a minimal correlation and that there is no statistical significance to the hypothesis that passive smoking leads to increased risk of CVD in the non-smoking relatives of smokers (Iso, Shimamoto, Sato, Koike, Iida & Komachi, 1996).
It has been suggested that increased risk of CVD due to passive smoking is the result of many separate components and effects of smoke (Glanz & Parmley, 1995). For example, passive smoking limits the amount of oxygen that the blood delivers to the heart (Glanz & Parmley, 1995:1048). This decreases the production of Adenosine Triphosphate (ATP). A reduction in ATP limits the ability of an individual to perform exercise and physical activity. Also, passive smoking results in increased activity of platelets (Glanz & Parmley, 1995:1048). Platelets are important for clotting (the formation of a thrombus) and involved in the formation of atheroscleritic plaque (Glanz & Parmley, 1995:1048). When the inhalation of smoke occurs, the platelets are stimulated to a high level and the blood "thickened", which lends to a greater degree of clotting and a greater chance of the formation of a thrombus (Glanz & parmley, 1995:1048).