Tobacco Harm Reduction Network (Thailand)

รวมบทความ ข่าวสาร งานวิจัย เกี่ยวกับเทคโนโลยีใหม่ๆ สำหรับผู้ที่ต้องการลดสารพิษจากการสูบบุหรี่แบบมวน และลดมลพิษให้กับคนรอบข้าง

Cardiologists and smoking alternatives: what we should know

It was not until 1958 that the first major epidemiologic study demonstrated a strong correlation between smoking and cardiovascular disease. The most effective approach for assisting smokers in their attempts to quit combines both pharmacotherapy and non-pharmacological interventions; however, our success continues to be suboptimal in the long term. New smoking alternatives, such as E-cigarettes and heat-not-burn devices, are now getting significant market shares. This article summarises actual scientific knowledge on these products since cardiologists will be asked by patients for their opinion on these.

In Europe, tobacco has been consumed in a variety of ways, but it was only at the start of the 20th century that cigarette smoking became very fashionable with the mass production of cigarettes [1,2]. Eventually, the potential health hazards of smoking were recognised by the US government – first, the association with lung cancer, and subsequently with other diseases. Early legislative attempts to ban cigarettes proved unsuccessful, however, as did heavy taxation.

Cigarette consumption has declined in recent years, but nevertheless an estimated 15,1% of US adults smoked in 2015. Worldwide, there are 1.3 billion smokers.

Tobacco is first mentioned around 600 BC in South America [3]. In Europe, it was first imported by Spanish explorers. They observed the local inhabitants inhaling the smoke of burning dried tobacco leaves and subsequently adopted the habit themselves.

The first actual cigarette seems to have been smoked in 1832 by a soldier during the war between Turkey and Egypt. At various points in history smoking was banned – in 1633 the Turkish sultan was said to have executed 18 people per day not respecting this ban and smoking.

Nicotine, which was first isolated from tobacco in 1828, constitutes between 0.3% and 5% of the dried tobacco plant. It is recognised as a potent psychoactive drug that induces euphoria, which makes it highly addictive [1,2]. A single cigarette contains, on average, 11 mg of nicotine, of which 0.8 mg is extracted by smoking. Nicotine in cigarette smoke is responsible for the addictive nature and enhanced cardiovascular disease risk. During World War I, cigarette smoking escalated and a sharp increase in the incidence of cardiovascular disease was noted. However, it was not until 1958 that the first major epidemiologic study demonstrated a strong correlation between smoking and cardiovascular disease [4]. The study found that the risk of dying from coronary artery disease (CAD) was 70% greater in smokers than in non-smokers. Although it did not provide definitive evidence that tobacco smoke was responsible for the increased coronary risk, the study prompted the first anti-smoking measures by the US Surgeon General in his 1964 report, followed by the 1979 report proposing a definite association between smoking and CAD [5].

The European Society of Cardiology in the latest prevention guidelines [6] reinforces the 5A smoking cessation strategy (ask, assess, advise, assist, arrange). This strategy has proved to be effective and patients rate it positively when asked about the help received from their doctor to stop smoking.

Brief advice on stopping smoking delivered by a physician has been seen to have a positive effect (although doctors generally do not feel the same way). The latest meta-analysis shows an increase in 6-month abstinence rates of 2.5% [7], which means that for every 40 smokers who receive short advice one will quit. Therefore, advice to stop smoking should be addressed to all smokers and not only to those who express an interest in quitting.

There is a dose-response relation between session length and abstinence rates.

All three session durations (minimal counselling – less than three minutes; low-intensity counselling – between 3 and 10 minutes; and higher intensity counselling – more than 10 minutes) significantly increased abstinence rates over those produced by no-contact conditions. However, there was a clear trend for abstinence rates to increase across these session lengths, with higher intensity counselling producing the highest rates.

Although we have quite successful medications for smoking cessation and good short-term results for smoking cessation at one year, the relapse rate is significant, which implies a high degree of psychological dependence.

Studies on varenicline showed that among subjects who received varenicline at the end of 12 weeks approximately 50% were successful in stopping smoking, while at 52 weeks after the initiation of the study drug (i.e., nine months after the drug was discontinued) the seven-day point-prevalence rates of abstinence from smoking were approximately 29% [8].

In addition to the prevention of smoking initiation and the promotion of smoking cessation, tobacco harm reduction is being recognised as a valuable and promising approach to accelerate further the decline in smoking prevalence and smoking-related harm [9]. Tobacco harm reduction is based on switching smokers to markedly less harmful alternative products, referred to by the Food and Drug Administration as modified-risk tobacco products (MRTP). The US Family Smoking Prevention and Tobacco Control Act defines an MRTP as “any tobacco product that is sold or distributed for use to reduce harm or the risk of tobacco-related disease associated with commercially marketed tobacco products”.

Importantly, to improve health at the population level, these substitutes for cigarettes must be acceptable to smokers, providing adequate nicotine delivery and satisfaction to prevent relapse to cigarette smoking.

Therefore, tobacco companies try to substitute cigarettes either with electronic cigarettes or with “heat not burn” (HNB) devices. In an era where regulatory pressures and public campaigns constantly reduce the number of smokers and consequently the number of cigarettes sold, the aim is to provide alternative, less harmful methods to satisfy the smoker’s addiction, reducing smoking-related health hazards.

In this fast-moving landscape with few solid scientific data, cardiologists are called on to express judgements on these products without real training or updating on the scientific level of evidence.

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