a Adapted with permission from IARC (2004); Vineis et al. (2004).
bData from CDC (2008b).
cSynergistic interaction with alcohol use.
About one-third of smoking-related deaths in the United States result from cardiovascular disease (CDC, 2008b). Smoking causes 20% of cardiovascular deaths in the United States; it increases the risk of coronary heart disease, including acute myocardial infarction; sudden death; stroke; and peripheral vascular disease, including abdominal aortic aneurysm (Burns, 2003). Smoking accelerates atherosclerosis, causes endothelial injury and dysfunction, and increases blood coagulation, thereby promoting acute ischemic events (US Surgeon General, 2004). Smoking delivers CO to the blood, which reduces the amount of oxygen carried by the hemoglobin and impairs the release of oxygen from hemoglobin to body tissues; this results in functional anemia. Concentrations of carboxyhemoglobin, which binds to red blood cells and competes with oxygen, are typically 5–10% in smokers and 1% in nonsmokers. Reduction in oxygen delivery secondary to CO exposure reduces the maximal exercise capacity in otherwise healthy smokers and the exercise capacity is reduced even further in people who have