3.2 Cardiovascular diseases

Show / hide chapter menu

3.0 Background

3.1 Tobacco—a leading preventable cause of death and disease

3.2 Cardiovascular diseases

3.3 Lung cancer

3.4 Respiratory diseases

3.5 Other cancers caused by or associated with smoking

3.6 Reproductive health and smoking

3.7 Pregnancy and smoking

3.8 Infant health and smoking

3.9 Increased susceptibility to infection in smokers

3.10 Eye diseases

3.11 Dental diseases

3.12 Gastrointestinal diseases

3.13 Bone density and risk of fractures

3.14 Effects of smoking on the skin

3.15 Smoking and complications in medical treatment

3.16 Smoking and diabetes

3.17 Poorer levels of general health

3.18 Smoking, motor vehicle crashes and other injuries

3.19 Burns and fires caused by tobacco use

3.20 Tobacco poisoning

3.21 Health effects for younger smokers

3.22 Genetic influences on tobacco-caused disease

3.23 Smoking, dementia and cognitive decline

3.24 Lung disease, smoking and occupational exposures

3.25 Air pollution, cigarette smoking and ill health

3.26 Health effects of smoking brands that claim to deliver lower levels of tar, nicotine and carbon monoxide

3.27 Health effects of smoking tobacco in other forms

3.28 Health 'benefits' of smoking?

3.29 Morbidity (ill health) attributable to tobacco-caused disease

3.30 Deaths attributable to tobacco by disease category

3.31 Morbidity and mortality due to tobacco-caused disease and socioeconomic disadvantage

3.32 Health effects of smoking other substances

3.33 Health effects of chewing tobacco, and of other smokeless tobacco products

3.34 Public perceptions of tobacco as a drug, and knowledge and beliefs about the health consequences of smoking

3.35 Health benefits of cessation

3.36 The global tobacco pandemic

Acknowledgments

References

Cardiovascular disease (CVD) is the umbrella term for a variety of disease processes related to the functioning of the heart and the circulatory system. CVD is the leading cause of death in Australia, causing about 38% of all deaths in 2002, and long-term disability for 1.1 million people.10

There are a number of modifiable or avoidable risk factors for developing CVD. These are smoking, having elevated blood fat levels (cholesterol and triglycerides), having high blood pressure, being overweight, being physically inactive, poor nutrition, and drinking at harmful levels. Individuals with diabetes mellitus are also at higher risk of developing cardiovascular disease. There is also recognition that socioeconomic factors and psychosocial factors, such as depression and social isolation, influence the development of CVD. To a large extent, therefore, CVD is preventable. Disease trends in Australia show that CVD impacts most heavily on population groups which suffer socioeconomic disadvantage, including Australia's Aboriginal people and Torres Strait Islanders.10, 11

Cigarette smoking contributes to cardiovascular disease in a number of ways. Toxic products from cigarette smoke circulate in the bloodstream, interfering with the efficient working of the endothelium (the inner cellular layer of the arterial wall), and causing the development of atherosclerotic lesions (collections of cholesterol, fat and other matter) in the arterial walls. These collections narrow the arteries, gradually impairing blood flow, and making the arteries harder, less elastic, and more liable to rupture. The first signs of atherosclerosis, plaque (fatty streaks) deposited within the inner layers of the arteries, may start developing as early as in teenage years and the 20s. Smoking also has a direct effect on platelets (blood cells involved in the clotting process), leading to increased activation and stickiness. This in turn causes an increased risk of thrombosis, or development of blood clots.5

Smoking a cigarette also temporarily increases heart rate and blood pressure, which raises the body's demand for oxygen, but at the same time deprives the body of oxygen through the effects of carbon monoxide, one of the main components of cigarette smoke. The resulting imbalance in oxygen supply and demand promotes the complications of atherosclerosis. These include ischaemia (lack of oxygen due to poor blood supply), with resultant angina pectoris (chest pain or tightness) or myocardial dysfunction (poor heart muscle function).5, 12

Nicotine and carbon monoxide in tobacco smoke are most strongly implicated in the processes leading to development of cardiovascular disease but other chemicals may also be involved.5 There is now strong evidence that exposure to secondhand cigarette smoke is also a cause of heart disease in non-smokers (see Chapter 4, Section 4.4).

3.2.1 Coronary heart disease

Coronary heart disease (CHD), also known as ischaemic heart disease, is the most common form of cardiovascular disease, and the most common cause of sudden death in Australia.10 It occurs when the arteries around the heart become narrowed due to atherosclerosis. This reduces the blood flow, forcing the heart to work harder to compensate, and can lead to angina. If the damaged artery splits, a blood clot may form, blocking the artery completely. This in turn can lead to acute myocardial infarction (heart attack), which is the death of vital heart muscle due to oxygen starvation. More than 80% of heart attacks occur outside the hospital environment, and in about half of all cases, a heart attack is fatal.10

Smoking is a cause of coronary heart disease,5 increasing the risk of disease incidence by between two- and four-fold, the risk increasing with heaviness of smoking.13 Even light smoking significantly increases the risk of dying from coronary heart disease, the steepest increase in risk occurring in smokers of up to four cigarettes a day.14

Smokers who have CHD are more likely to die of the disease than non-smokers with the disease. The mortality rate for CHD among heavy smokers is up to three times higher than that of non-smokers.13 The heaviest burden of excess death due to tobacco-caused CHD is felt in early middle age. In Australia in 2004–05, 40% of all deaths due to CHD occurring in males between the ages of 35 and 39 were due to smoking. Among women aged 40–44, smoking caused about 34% of all deaths due to CHD.7 In women who smoke and use the contraceptive pill there is a synergistic interaction, resulting in a particularly elevated risk of coronary heart disease15 (see also Section 3.6.1.2).

Lower tar and nicotine cigarettes have not been shown to reduce the incidence of CHD, and they do not provide a lower risk alternative for smokers who cannot or do not wish to quit.5

3.2.2 Cerebrovascular disease (stroke)

A stroke occurs when blood flow to the brain is interrupted, leading to injury or death of brain tissue. This occurs most commonly because of arterial blockage caused by atherosclerosis or a blood clot, an event known as an ischaemic stroke. Happening less often, but more likely to be fatal when it does arise, is a haemorrhagic stroke, in which bleeding occurs from a leaking or ruptured arterial wall at a point weakened by atherosclerosis. Sometimes the artery stretches at the site of weakness, causing it to balloon out, forming an aneurysm. The bigger the aneurysm, the more likely it is to rupture, causing haemorrhage and a resultant stroke.

One in five people experiencing their first stroke episode will die within four weeks, and one in six stroke patients who survive the first two days following a stroke will experience a second stroke over the next five years. Stroke is a major cause of disability in Australia. By the end of the first year following a stroke, about half of stroke survivors still require assistance with daily activities.10

Smoking is an important cause of stroke, the risk of having a stroke rising with amount of tobacco smoked and possibly with duration of smoking as well.2, 5 Smokers are two to four times more likely to have a stroke than non-smokers.5

Smokers who also have high blood pressure are at greater risk of experiencing a haemorrhagic smoke than smokers who do not have high blood pressure. The interaction between the two risk factors appears to be synergistic,16 meaning that when the risk factors are combined, the risk of disease is multiplicative rather than additive.

As with cardiovascular disease, the impact of stroke caused by tobacco is greatest among the middle aged. In Australia in 2004–05, 40% of all deaths due to stroke in men aged between 35–39 were caused by smoking. The greatest impact occurred in women aged 40–44, among whom 35% of all stroke deaths were due to tobacco.7 Research has shown that the risk of having a stroke decreases steadily after quitting smoking, ex-smokers having the same risk as never-smokers after 5–15 years, depending on the study.5

3.2.3 Atherosclerotic peripheral vascular disease

Atherosclerotic peripheral vascular disease (PVD), also known as peripheral artery disease, occurs when blockages within the blood vessels prevent proper blood circulation. PVD most commonly occurs in the legs and feet, but it can also develop in the arms and hands. This may result in severe pain (claudication), especially when exercising. PVD can lead to death of part of the limb. Amputation may be necessary for relief of pain, and to prevent the development of gangrene. Given that the disease process is the same, it is not uncommon for individuals with PVD to die from stroke or heart attack.10

Smoking is a cause of peripheral vascular disease. The likelihood of developing PVD increases with amount smoked and duration of exposure to tobacco smoke.5 In Australia in 2004–05, about 37% of all deaths due to PVD in males aged over 35 were attributable to smoking, and 30% of all PVD deaths in women aged over 35.7

3.2.4 Abdominal aortic aneurysm

Abdominal aortic aneurysm is a weakening of the wall of the aorta (the major artery carrying oxygenated blood from the heart to the body) in the region below the diaphragm. The weakening occurs as a result of atherosclerotic lesions developing in the aortic wall. The wall may eventually stretch and then leak or burst. Abdominal aortic aneurysm is frequently fatal.5

Smoking is a cause of abdominal aortic aneurysm, the risk rising with increased exposure to tobacco smoke. Smoking is one of the few currently modifiable risk factors for this disease. Stopping smoking approximately halves the risk of abdominal aortic aneurysm compared to continuing smokers, but even after quitting, former smokers still retain around twice the risk of developing abdominal aortic aneurysm than never smokers.5

3.2.5 Sudden cardiac death

Sudden cardiac death describes death occurring due to sudden, unexpected loss of heart function in an individual who may have no previous history of heart trouble. Cardiac dysrhythmias (irregular muscular contractions of the heart, also referred to as cardiac arrhythmias) are the usual cause of sudden cardiac death. Smokers have a two to threefold greater risk of suffering sudden cardiac death than non-smokers, the risk increasing with increased exposure to cigarette smoke.5, 13

In Australia it is estimated that smoking causes between 30–40% of all deaths due to cardiac dysrhythmias in men aged between 35–59, and about one third of all deaths due to cardiac dysrhythmias in women aged between 35–44.7

3.2.6 Congestive heart failure

Congestive heart failure (CHF) occurs when the heart becomes less able to pump blood through the body effectively. The heart may become enlarged or thicken, and fluid may collect in the lungs (causing shortness of breath) or in other parts of the body (causing swelling or weight gain). CHF usually occurs in individuals with a history of heart problems such as high blood pressure or coronary heart disease.17 As well as contributing to the disease processes that primarily lead to CHF, smoking is also an independent risk factor for CHF.5

CHF sufferers experience high levels of disability and have a reduced life expectancy.5 In Australia, it is estimated that smoking causes between 30–40% of all deaths due to CHF in men aged between 35–59, and about one third of all deaths due to CHF in women aged between 35–44.7