Department of Forensic Medicine and Toxicology, University of Benghazi-Libya, Benghazi, Libya
*Corresponding author: Samir Elmrghni, Faculty of Medicine, Department of Forensic Medicine and Toxicology, University of Benghazi-Libya, Benghazi, Libya, Tel: 002-189-1653-1753; E-mail: Samir3272@yahoo.ie
Smoking is a major cause of cardiovascular disease (CVD) and causes one of every three deaths from CVD, according to the 2014 Surgeon General’s Report on smoking and health. Even people who smoke fewer than five cigarettes a day may show signs of early CVD. The risk of CVD increases with the number of cigarettes smoked per day, and when smoking continues for many years. Smoking cigarettes with lower levels of tar or nicotine does not reduce the risk for cardiovascular disease. Exposure to second hand smoke causes heart disease in non smokers. More than 33,000 non smokers die every year with coronary heart disease caused by exposure to second hand smoke. Exposure to second hand smoke can also cause heart attacks and strokes in non smokers. Smoking Index is a parameter used to express cumulative smoking exposure quantitatively. This is especially useful in defining risk ratio of a smoking related disease. The parameter is similar to Pack Year.
In order to observe the effect of cigarette smoking on cardiovascular system active and passive Libyan smokers; 100 volunteers were divided into 50 males and 50 females and then further sub classified according to smoking index into mild , moderate and heavy. Furthermore our study also indicated that the effect of passive smoking as a risk for cardiovascular diseases is more in female than that in male, and female non smokers have higher risk than that in males.
The pathophysiological mechanisms by which smoking results in the development of atherothrombosis are unknown. However, suggested mechanisms include endothelial disturbance, changes in fibrin formation and turnover, changes in lipids and lipoproteins and reduced availability of antioxidants. It has been postulated that cigarette smoking is associated with abnormal lipid profile in the form of raised plasma triglycerides and cholesterol . The impact of smoking on blood hemostatic mechanisms was revealed by increased levels of fibrinogen and alterations of fibrin turnover . These changes were smoke exposure correlated with the degree of elevated tissue plasminogen activator (t-PA) and Von Will brand factor antigen levels were shown in the coronary artery of smokers and indicate impaired fibrinolytic activity . Moreover, smoking related alterations in blood clotting factors have been proved [3,4]. Both active and passive smoking are associated with deterioration in the elastic properties of the aorta and big arteries . Recent studies have suggested the involvement of impaired endothelial cell dependent vasodilatation in the genesis of smoking induced hypertension . This impaired relaxation of the arteries may be, at least in part, mediated through the degradation of released nitric oxide (NO) by superoxide anions derived from cigarette smoke [5,6]. Increased vascular tone in smokers has been claimed to be primarily due to sympathetic over stimulation as a direct effect of nicotine on sympathetic ganglia with release of catecholamines . A role of endothelin-l, a potent vasoconstrictor, in the initiation of smoking associated vascular changes have been also postulated [7,8], have also proposed a role for smoking induced activation of renin-angiotensin system in the patho-genesis of vasomotor changes associated with smoking. Smokers have also been shown to have reversible increases in blood viscosity compared to non smokers due to increased haematocrit value and plasma viscosity . Increases in plasma viscosity are largely due to elevated fibrinogen levels together with acute phase reactant proteins such as alpha-2 macroglobulin [9,10].
Types of smokers
Types of active smokers include: Psychological smokers, indulgent smokers, tranquilization smokers, stimulation smokers and addictive smokers. In the addictive smokers the withdrawal symptoms are felt when the subject has been about 30 minutes without smoking and he has to smoke to relieve this tension [11,12].
Passive smokers: Passive smoking is the involuntary inhalation of tobacco combustion products by non-smokers. The situation is characterized more precisely by the term forced smoking which should be used in preference to passive smoking . Passive smoking is estimated to account for approximately 3000 new cases of lung cancer per year in the USA . In passive smoking, environmental tobacco smoke (ETS) is inhaled by someone in the presence of active smoking . The (ETS) emerges from either mainstream smoke which is emitted from the mouth piece during puffing and then exhaled by the smoker or side stream smoke which is emitted between puffs at the burning cone and from the mouth piece [13,14].
Exhaled main stream smoke: Main stream smoke (MS) contributes from 15 to 43% of the particulate matter in ETS [13,14].
Side stream smoke: Side stream smoke usually contains relatively high concentrations of many noxious substances including heavy metals. As particle sizes are smaller inside stream smoke than in main stream smoke, their deposition in the lung tissues of passive smokers reaches deeper into the alveolar spaces, Some of the components of the inhaled side stream smoke occur in relatively higher concentration than in main stream smoke, such as, nicotine, benzene, and nitrosodimethylamine [13,14].
Smoking Index: Smoking index (SI)  is the product of multiplying the number of cigarettes smoked per day by the number of years of smoking. The smokers categorized into:
Having less than 200 SI
Havig 200-600 SI
Having more than 600 SI
Both active and passive smoking expose an individual to the same substances but the relative concentrations differ. Thus, being exposed to passive smoking 2 hours/day for 25 years was found to be equivalent to having actively smoked an average of 20 cigarettes/day for 20 years .
Subjects and Methods
Subjects: 100 healthy volunteers consist of 50 adult males and 50 adult females from different age groups (20–70 years). Included 20 active and 20 passive male smokers which divided to (mild, moderate and severe) according to smoking index (the number of cigarettes smoked per day multiply by the duration of smoking by years). And 40 passive female smokers can measure the toxic effect of smoking here by multiply the hours of exposure per day in the number of the smoking by years, and 20 cases of non smokers of both sexes were chosen for this cross-sectional study.
Those volunteers selected when they presented with their relative patients in hospital after complete informed consent. All chosen subjects were medically examined in seven October hospital with negative past medical history (no diseases detected before especially heart diseases). Questioner form was designed to be filled with each volunteer to record all necessary personal data (these data includes personal information and medical history).
Data were analyzed by statistical package of social science (SPSS) Program.
Data were presented in percentage for comprising the variables, tables and pie charts were used to summarize and presenting the data.
Table 1 and figure 1 show the Distribution of active smokers according to smoking index
Smoking index = number of cigarettes per day multiply in duration by a year
Mild smoking index <200 = 20% 4 cases
Moderate smoking index = 200-600 = 55% 11 cases
Heavy smoking index > 600 = 25% 5 cases
Table1: Distribution of active smokers according to smoking index
Figure 1: Distribution of Smokers according to smoking index.
Smoking causes more than 230,000 deaths from heart and blood vessel disease each year in the United States, smoking is a major risk factor for getting heart and blood vessel disease. The more you smoke, the greater your risk [17–25].
We show that from our cross sectional study that the results in those volunteers increase slightly with males than in females. This if compared with passive male smokers the female passive smokers may have the higher level due to the method of exposure in passive females more closely and contact to smoking inside houses that in males, this will go with studies that prove the risk of exposing to exhale of cigarette smoking. As female passive smokers exposed to smoking per year and per hours per day increased the risk of cardiovascular diseases, any passive smoker expose to smoking more than 25 years and 2 hours per day will be excepted as active smoker for 20 years . According to control groups of females and males (nonsmokers) we observe from our study that the female non smokers have higher risk than that in males, this as we discussed above because the method of exposure in females more close to smoking inside houses than in males, and this will open a door for more studies about this result and to take the non smokers females as a profile for Libyan population to be compared with others.
Our cross-sectional study suggested that smoking habits according to smoking index considered as a risk factor for cardiovascular system both in active males as well as in passive females.
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