Smoking and Blood Pressure Phenotypes: New Perspective for an Old Problem

Smoking is a preventable cause of cardiovascular mortality across the world.1 Each year, over 5 million people die from smoke-related diseases.1 It is estimated that 20% of adults living in North America and Europe are currently smokers.2 Smoking is responsible for 1/5 of all deaths recorded yearly,3 and this number is expected to increase 10-fold during the 21st century.1 Since the number of smokers continues to increase, it is expected that there will be a boost in the number of smoking-related deaths.1 Cigarette smoking causes various adverse cardiovascular problems and acts synergistically with hypertension to increase the risk of coronary heart disease, myocardial infarction, sudden coronary death and stroke.4 Smoking can also cause an acute elevation of blood pressure by vasoconstriction and acceleration of heart rate.4 The nicotine present in cigarettes acts as an adrenergic agonist, enhances local and systemic catecholamine release, and it may also stimulate vasopressin release.4 Despite these observations, the precise effect of smoking on blood pressure remains unclear. Controversial epidemiological studies have reported that blood pressure levels among smokers were the same as,5 lower6 or higher7 than those of nonsmokers. These inconclusive results may be reflecting the differences in study designs and sample size, populations background, and adjusted factors used to control for confounding errors.8 In addition, most epidemiological smoking-blood pressure studies are designed around the general population and few studies have been focused on hypertensive patients, which may present a different pattern in the smoking-blood pressure relationship. Thus, a large well-designed study may clarify the relationship between smoking and blood pressure phenotypes among hypertensive patients.