The cardiovascular burden of light smoking

Abstract

The assumption that light cigarette smoking, meaning smoking one to five cigarettes per day, is not so harmful has been dissipated by several studies. Regardless of the quantity of tobacco cigarettes, smoking remains a leading risk factor for the development and progression of cardiovascular diseases. Smoke is a mixture of several toxic chemicals, such as nicotine, carbon monoxide, and oxidants, implicated in the pathogenesis of cardiovascular and pulmonary diseases. Despite anti-smoking campaigns, a misconception concerning "safe smoking" still exists. The purpose of this literature review is to highlight the deleterious effect of light cigarette smoking and claim the consensus that there is no safe smoking.

Keywords: cardiovascular disease; cardiovascular risk; light smoking.

Figure 1

Pathophysiological principles of cardiovascular disease development in the case of light cigarette smoking: The potential mechanisms include catecholamine release and ischaemia due to supply-demand mismatch, vasospasm, increased platelet reactivity, imbalance between prothrombotic and fibrinolytic activity, endothelial dysfunction, oxidative stress, activation of inflammation, and impaired autonomic function

Figure 2

The theoretical effect of smoking 1 to 5 cigarettes per day on 10-year risk of development of a fatal cardiovascular event (%) based on the SCORE risk prediction model and application of a relative risk value of 1.4–1.6, based on the respective relative risk values for this tobacco consumption category reported in recent studies and meta-analyses. A – Percentage risk of fatal cardiovascular event in a 50-year-old male smoker, as calculated by applying the SCORE model, by blood pressure and total cholesterol level category. B – Percentage risk for fatal cardiovascular event in a 50-year-old male light smoker (1–5 CPD), calculated by applying a relative risk value of 1.4–1.6 on the respective values for a non-smoker of the same gender and age (SCORE model). Colours: Green indicates a 0–1% 10-year risk of fatal cardiovascular event, yellow indicates a 2% 10-year risk, orange stands for a 3–4% 10-year risk, red indicates a 5–9% 10-year risk, and dark red stands for an absolute risk value of at least 10% (very-high-risk category). Blue squares in panel B demarcate reclassification to a lower-risk category, by applying a lower (1.4–1.6) relative risk value for consumption of 1–5 cigarettes per day, as opposed to smoking of unspecified intensity CV – cardiovascular, CPD – cigarettes per day.