Cigarette smoking and perceived risk of cardiovascular disease in Iran

Cigarette smoking is a well-established risk factor for cardiovascular disease (CVD), contributing significantly to the global burden of cardiovascular morbidity and mortality. Numerous epidemiological studies have consistently demonstrated a strong link between cigarette smoking and an increased risk of CVD. For example, the Barua et al. study showed that smoking plays a major role in premature coronary atherosclerosis and in accelerating atherosclerosis by increasing the oxidation of low-density lipoprotein (LDL) and damaging coronary endothelial vasodilation [1]. Long-term cohort studies, such as the Framingham Heart Study, led by Dawber, Meadors, and Moore, have provided compelling evidence that smoking is associated with a higher incidence of coronary heart disease (CHD) and stroke [2]. The harmful effects of smoking on the cardiovascular system are mediated through various mechanisms. Smoking is known to induce endothelial dysfunction, inflammation, and oxidative stress which contribute to the development and progression of atherosclerosis [3, 4, 5].

Cigarette smoking has been identified as a significant modifiable risk factor for ischemic and hemorrhagic strokes. Some studies like the Jackson Heart Study [6], Framingham study [7] and study by Shah et al. [8] have consistently highlighted the elevated risk of stroke among smokers.

Cigarette smoking is a well-documented and significant risk factor for hypertension [9, 10, 11]. Hypertensive smokers are more likely to develop severe forms of hypertension, including malignant and renovascular hypertension, an effect likely due to accelerated atherosclerosis [12].

The results of a nationwide study that included 10,834 participants aged ≥ 15 years from Iran showed that the mean ± standard deviation of systolic blood pressure and history of cardiovascular symptoms in current smokers was higher than in nonsmokers [13]. The results of a cohort study,12 years follow-up in the capital city of Tehran, indicated that adjusted hazard ratios CVD in daily smoker men were 2.05 (95%CI: 1.57–2.67). In smokers with a history of using more than 21 cigarettes per day, the HR of CVD was 3.79 (95%CI: 2.25–6.37), with less risk observed in those who smoked fewer cigarettes per day [14]. The results of a study conducted by Ansari et al. in central parts of Iran revealed that the hypertension prevalence was 2.5 times higher in urban areas compared to rural areas with a significant difference as it increased to 3.5 times smoking factor was considered [15]. The findings of a population-based study of 3059 male individuals, aged ≥ 30 years, free of CVD at baseline, were evaluated for a median of 9.3 years and showed that being a past smoker significantly increased the risk of CVD events (HR = 2.42, CI = 1.28–0.56). Additionally, being a current smoker (more than 10 cigarettes a day) dramatically increased the risk of CVD/CHD events and total/CVD mortality. However, smoking less than 10 cigarettes per day only increased the risk of CVD and its mortality [16].The results of the Tehran Lipid and Glucose Study (TLGS) in the last two decades indicated that smoking in men was associated with an increased risk of hypertension (HR 1.26; CI 95% 0.98–1.63). Moreover, men, even smoking less than 10 cigarettes per day, were at increased risk for cardiovascular diseases by HR 2.12 (CI 95% 1.14–3.95) [17].

Understanding the relationship between perceived risk among cigarette smokers and cardiovascular disease (CVD) is crucial for developing effective public health interventions to reduce the burden of CVD. While research on this specific aspect is still ongoing, studies have explored the broader connection between perceived risk, smoking behavior, and cardiovascular health. Another study conducted by Weinstein et al. has investigated how individuals’ perception of the risks associated with smoking influences their smoking behavior [18]. For instance, a higher perceived risk of developing smoking-related health issues, including CVD, has been linked with increased motivation to quit and higher rates of smoking cessation attempts [19, 20].

Individuals with a lower perceived risk of CVD due to smoking may be less likely to adopt healthier behaviors or seek preventive measures [21]. This underlines the potential role of perceived risk in mediating the relationship between smoking and cardiovascular health [21, 22]. Despite the importance of increasing the studies on the perceived risk to reduce the burden of cigarette smoking, there is a dearth of studies in Iran addressing this topic. Therefore, this study was designed to assess the perceived risk of CVD among smokers, to enrich the existing body of knowledge.

Risk perception stands as a cornerstone within numerous health behavior theories. The perception of smoking risk encapsulates an individual’s thoughts and emotions concerning the detrimental health effects linked with smoking [32]. The present study was meticulously designed and implemented to ascertain the perceived risk of cardiovascular diseases among cigarette smokers in Golestan province, located in the northern province of Iran. There are numerous studies indicating that the impact of smoking on populations exposed to air pollution is different and extensive research has shown that air pollution is a recognized risk factor for mortality [33]. However, this study has not looked at air pollution as one of the contributing factors because this province is the only province in Iran with forests and green coverage, and air pollution is not a major issue like other big cities (e.g., Tehran, Mashhad, etc.). The findings of this study indicate a moderate overall perception of the risk of cardiovascular diseases resulting from smoking among the participants. The researchers posit that a lower perceived risk associated with smoking and other tobacco products correlates with an increased likelihood of initiation and decreased motivation for smoking cessation. Conversely, a heightened perceived risk may act as a deterrent factor to initiation or, if already engaged, encourage cessation [34, 35, 36, 37]. Overall, the findings of the studies confirm that smokers tend to underestimate their risk of developing diseases because of smoking [21, 37]. However, a more detailed measure of occupation beyond the broad categories provided could capture specific work-related exposures or stress on factors that influence perceived risk. Incorporating information on physical activity levels, including frequency, intensity, and type of activity, could provide insights into how physical activity influences perceived risk. Assessing dietary factors like fruit and vegetable consumption, processed food intake, and dietary quality could potentially contribute to explaining variance in perceived risk. Measures of stress levels and coping mechanisms, such as social support or relaxation techniques, could reveal their influence on perceived risk. Incorporating information about pre-existing medical conditions, even those unrelated to CVD, could help clarify the influence of overall health status on perceived risk. A family history of CVD could reveal the potential impact of genetic predisposition on perceived risk. Measures of access to healthcare services, such as insurance status, could contribute to understanding the role of healthcare availability in perceived risk. Measures of health literacy could reveal how individuals’ understanding of health information influences their perceptions. By including these additional factors, the model could potentially capture a wider range of influences on perceived risk and lead to a more robust and accurate explanation of the variation in the outcome variable. Overall, these are the factors that must be considered when conducting future studies.

The findings of the study revealed that smokers tend to underestimate their risk of developing cardiovascular diseases and lung cancer in comparison to non-smokers [38]. However, Iran has experienced some socio-cultural changes in the recent decade. These changes increased the young generation’s tendency to cigarette smoking which resulted in presenting smoking as a normal behavior. The results of a qualitative study conducted by Jafari et al. indicated that community predispositions like the normalization of smoking behavior, easy access and lower price of cigarettes than other entertainments, and selling cigarettes to under-age groups, were the main factors influencing women to smoke [39].

It must be noted that the actual ratio of male to female smokers in Iran is around 25.9% in men vs. 4.4% in women in 2021 [40]. However, since we aimed to investigate gender differences between smokers’ perceived risk, we aimed to recruit more females (22.9% female and 77.1% male participants. This means the percentage of female participants in this study (22.9%) is purposefully much higher than the actual percentage (4.4%) in the country. Additionally, role modeling of friends along with membership in groups were the most common reasons for cigarette smoking among Iranian females [39]. The results of another qualitative study in Iran showed that from the perspective of teachers, parents, and students, the most important factor in smoking in adolescents smoking was the feeling of looking good and getting attention from others [41]. The results of a qualitative study by Rezaei et al. revealed that the easy access and low price of cigarettes are effective factors in adolescents’ tendency to smoke [42].

Tehrani et al. study results showed that ignoring the side effects of cigarette smoking is one of the main factors of cigarette smoking among Iranian female adolescents. They concluded that the participants did not take these risks seriously and continued to smoke due to reasons: the first reason is that they may not have had enough information about smoking and its side effects. The second reason for their inattention can be due to the immediate enjoyment of smoking, which has led them to deny the side effects and consequences of smoking [43]. The sociocultural changes in smoking among Iranians have made cigarettes smoking more normal behavior which leads to the low perceived risk of smoking in general.

The findings of this study indicate that the perceived risk of cardiovascular diseases (such as heart attack, stroke, and high blood pressure) among the participants is lower than anticipated. Similar results have been replicated in other studies. For instance, the findings of Strecher et al.‘s study, which investigated the perceived risk of cardiovascular diseases among both smokers and non-smokers, revealed that while smokers are more inclined to perceive themselves at risk of heart attack and stroke, their perception remains lower compared to non-smokers while non-smokers exhibit an optimistic bias [44]. The findings of the study by Desgraz et al., focusing on smokers aged 40 to 70 years, revealed that 39–50% of participants underestimated their risk of developing cardiovascular diseases in the next ten years based on the Framingham Ten-Year Risk Perception Scale and assessed Prospective Cardiovascular Münster (PROCAM) more than anticipated, a lower percentage, 9–12%, underestimated their risk of cardiovascular disease over the same period. Notably, among men, the odds ratio (OR) was 8.16, indicating a higher likelihood of underestimation, and among the elderly, the odds ratio was 1.06, surpassing that of other age groups [45].

The findings of Ayanian et al.‘s study revealed that only 29% of smokers were identified as being at high risk of heart attack due to smoking, while this figure rose to 40% for the risk of lung cancer. Furthermore, older individuals, those with lower educational attainment, and light smokers (defined as those consuming fewer than 20 cigarettes per day) exhibited a diminished perceived risk of heart attack and lung cancer compared to heavier smokers [46].

The findings of Kaddumukasa et al.‘s study, conducted in a rural area in Uganda, revealed that none of the subjects regarded smoking as a risk factor for stroke [47]. The findings of Dawood et al.‘s study, which involved 386 smokers in Iraq, demonstrated that 66.3% of participants lacked awareness regarding the perceived risk of smoking causing stroke [48].

Overall, smokers appear to have a diminished perceived risk compared to non-smokers which might justify their continuation of smoking. In Campbell et al.‘s study, individuals who smoked reported a lower perceived risk compared to non-smokers [49]. This trend has been observed in other studies as well [50, 51].

The results of this study indicate a relatively low perceived risk of participants. Study findings have implications for informing public education messaging on cigarette smoking risks, especially related to CVD. Therefore, it is important to develop interventions to educate the public about the harms of smoking in general and its role in causing cardiovascular disease, especially in the long term. Our findings could help health policymakers identify strategies to enhance public health knowledge to increase the perceived risk of cigarette smoking and reduce its consumption. Additionally, our findings highlight new targets for future educational efforts and health warnings that are specific to the perceived risk of CVD among cigarette smokers. To reach a more comprehensive conclusion, longitudinal studies with larger sample sizes can be undertaken in other parts of Iran. Public health professionals and policymakers should put more emphasis on preventive programs on the health harms of smoking, especially among adolescents and youth.