Smoking: The Major Preventable Cause of Disease

Ronald O’quin, MD
Critical Care Medicine, Internal Medicine, and Pulmonary
MD2, Bellevue WA
The single most important thing you can do to improve your health is to quit smoking. If you do not smoke, don’t start! Smoking is the single most preventable cause of disease in the United States. It is estimated that 400,000 deaths annually are directly related to smoking. In addition, 40,000 deaths annually from heart disease are attributed to passive smoking.

Smoking cessation has both immediate and long-term benefits. If you stop smoking before age 50, you have one- half the risk of dying over the next 15 years compared with individuals who continue to smoke. Smoking is the main cause or a major causative factor for many diseases:

The most commonly recognized disease attributable to smoking is lung cancer. Smoking alone is responsible for 90% of all lung cancers. Smoking cessation will result in a significant reduction in cancer risk but it takes approximately 15 years for the risk to approach non-smokers risk. Thus, cancers start at early age and by the time of diagnosis, most have spread and have little chance for cure. Smoking is also implicated as a cause of numerous other cancers including head and neck, esophagus, pancreas and bladder.

In addition to lung cancer, smoking is the major cause of chronic obstructive pulmonary disease including chronic bronchitis and emphysema. It also exacerbates asthma when present. Chronic bronchitis results from the inflammation of the airways caused by exposure to inhaled smoke. Fortunately, it is, to a significant degree, reversible with cessation of smoking. Emphysema on the other hand is the loss of lung tissue related to smoking. This damage is permanent. Smoking causes the loss of lung tissue at two and one-half times the normal rate of non-smokers. Smoking cessation will immediately result in tissue loss returning to the normal rate thus reducing the risk of developing debilitating lung disease overtime.

Smoking is a major risk factor in the development of cardiovascular disease. Cigarette smokers have double the risk of developing coronary heart disease (CHD) and a 2-4 fold increase in sudden death compared with non-smokers. One year after smoking cessation, this increased risk of CHD is reduced by one-half and at two years, the risk approaches that of a non-smoker. The incidence of a heart attack is increased 3-fold in men smoking 20 cigarettes daily. The average smoker dies three years earlier than a non-smoker and among those individuals at risk for development of CHO, smokers die 10- 15 years earlier.

Smoking also accelerates the develop­ment of atherosclerosis in other major arteries of the body, including the aorta and extremity blood vessels, known as peripheral vascular disease (PVD). PVD can cause pain in the extremities when walking (claudication), leg ulcers and sexual dysfunction. Smokers also have a 2-fold increase in the incidence of stroke

In addition to the above health problems, smoking is associated with increased risk for peptic ulcer disease, gastroesophageal reflux disease, osteoporosis and sexual dysfunction.

Smoking cessation is not easy but can be successful if one is committed to quitting. The hazards of smoking cessation are far outweighed by the benefits. There are several adverse consequences of smoking cessation. Withdrawal symptoms are common and include insomnia, irritability, anxiety, restlessness, frustration and difficulty with concentration. These symptoms typically peak in the first three days and decrease over the next three to four weeks. Mild depression and weight gain can also occur. All are temporary and can be treated with the help of your physician.

Many treatment modalities are available to assist you with stopping smoking including group counseling, social support from family and friends, hypnosis, acupuncture and pharmacology.

Pharmacology can be particularly helpful in reducing the severity of the withdrawal symptoms mentioned above. Nicotine replacement therapy is now available in many forms including patches, spray, gum and via an inhaler. None seems to be superior to another but individuals may find one form particularly suited to their needs. Nicotine replacement therapy is safe even in individuals with known cardiovascular disease. Smoking and the concomitant use of nicotine are not recommended. Recently, Bupropion has been found to significant help individuals quit smoking, especially if used in conjunction with Nicotine. Bupropion has been available as an antidepressant medication since 1989. Sustained release forms (Zyban and Wellbutrin SR) are available. Bupropion is a prescription medication and should be used under the advice and direction of your physician. Typi­cally, it is used for 8-12 weeks with Nicotine replacement therapy. It is usually well tolerated but can cause dry mouth and insomnia. It is not recom­mended in individuals with seizure disorder, heavy alcohol use, anorexia or bulimia. Bupropion when used in combination with Nicotine replacement therapy has the best short and long-term success rates when compare with other modalities and medications used in aiding smokers to quit.

Picking a “quit day” is preferable to gradual reduction of smoking. Use of the above treatment modalities can help with this approach.

Relapse is common but do not get discouraged. The first few days and weeks when withdrawal symptoms are greatest account for most relapses. Medication, the support of family and friends and continued follow up with your physician can help you through these difficult times.

Your doctor is the best source of information. He/she can help individualize what therapy would work best for you. Some web sites that with self-help materials for smoking cessation include:

American Lung Association

National Heart, Lung, and Blood Institute

American Heart Association


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