COPD or chronic obstructive pulmonary disease is a diagnosis usually associated with smoking but even non-smokers can develop COPD. Approximately 80% of patients with COPD in the United States are current or previous smokers so it is easy to see why people think only smokers get COPD. However, contrary to popular opinion, some people do develop the same progressive and debilitating chronic lung disease even though they never smoked a day in their lives. In fact, approximately twenty to twenty five percent of patients battling with COPD never smoked. In certain parts of the world this percentage is even higher.
According to data from the Third National Health and Nutrition Examination Survey, between 1988 and 1994, of those Americans who had COPD, 24.9 percent never smoked. The United Kingdom and Spain reported similar findings of 22.9 percent and 23.4 percent, respectively.
How does a person develop COPD and emphysema from smoking anyway? The cartoon to the left shows a normal set of lungs on the upper left side and appearance of normal alveoli; the small thin air sacks at the ends of the distal airways where gas exchange occurs. Harmful particles get trapped in these air sacks causing an inflammatory cascade reaction which leads to breakdown of the thin lining of multiple sacks forming a larger coalescence of sacks into one emphysematous bulla. Carbon gets deposited in these sacs further breaking down the alveoli until full blown emphysema is formed. It is harder for air to get out of these larger coalescent sacks and creates poor gas exchange.
We are realizing that genetics plays a major role in development of COPD. Approximately seventy five percent of patients with a history of smoking do not develop symptoms of COPD and it is believed that these people have the genetic predisposition to be able to fight off the harmful effects of tobacco smoke. On the other hand, genetics can play a role in development of COPD and emphysema in people with Alpha-1 antitrypsin deficiency. Alpha-1 antitrypsin deficiency is the only currently known genetic abnormality that directly causes COPD. Alpha-1 antitrypsin is an enzyme produced in the liver that helps maintain elasticity of the lung. People with a genetic abnormality in this enzyme can develop COPD and emphysema regardless of tobacco exposure. Smokers who are Alpha-1 deficient lose lung function at a faster rate than other smokers. But not all patients with COPD and emphysema have this deficiency, even if the severity of their COPD is quite significant. It is not clear why one person may smoke two packs per day for 30 years and never develop COPD symptoms and another person may smoke only half a pack per day for 10 years and still develop significant COPD symptoms. For this reason, it stands to reason that there are other genetic factors and causes for a person to have a higher propensity to develop COPD. With genetic research booming it is likely that we will eventually find other genetic causes for COPD other than just Alpha-1.
Of course, despite not necessarily developing significant COPD symptoms smokers are still at risk for many other diseases such as heart disease, peripheral vascular disease and cancer. The National Institutes of Health is currently working on research to try to identify genes responsible for development of COPD and the protection against developing the progressive disease.
The incidence of COPD in non-smokers is higher in some parts of the world compared to the United States. This is likely related to exposure to smog and toxic fumes in countries with lesser environmental protection and working safety regulations.
Poorly or under-treated asthma, which is another type of obstructive lung disease, can progress to COPD. Asthma is an obstructive lung disease that is reversibly with bronchodilator therapy. Under-treated asthma can progress to a fixed defect as is seen in COPD.
Second-hand smoke has long been known to be associated with COPD, but we are realizing that second-hand exposure to tobacco smoke may be even more harmful than previously thought. Women especially appear to be at risk of developing COPD due to second-hand smoke exposure and it has been hypothesized that this is due to having smaller airways and a greater reactivity in their airways compared to men.
We all lose lung function over time and smokers lose it faster than non-smokers. If they can quit smoking they can go back to the same rate of decline of function as non-smokers, but they never go back to normal. As depicted in graph below showing smoker quitting age 45 and further rate of decline in lung function matches the never smoked curve rate but the person never goes back up to the never smoked curve. I continue to hear from patients that they heard that “Once you quit smoking your lungs will go back to normal in ten years.” I do not know who first made this claim but, unfortunately, it is bogus.
The prognosis for non-smokers who have developed COPD symptoms is like that of smokers and treatment is essentially the same with the exception that the non-smoker is ahead of the curve because they do not need to fight the battle of needing to quit smoking. Quitting smoking is the only known conclusive way to slow disease progression in smokers.
If you’re a non-smoker with COPD symptoms, do not panic, there are steps you can take to keep symptoms under control and even slow its progression:
Take your medications as prescribed by your lung doctor. Keeping symptoms under control and reducing flairs of the disease will help keep the rate of lung decline at a minimum.
Get your Flu shot annually with the beginning of Flu season and keep up to date on pneumonia vaccines.
Maintain activity. Deconditioning is a major contributor to COPD symptom progression. If needed, pulmonary rehabilitation programs can make a big difference.
Healthy diet and weight control. Often losing even just a little bit of that extra belly fat can make a big difference in symptoms of shortness of breath.
Avoid second-hand smoke exposure and other toxins. Non-smokers who develop COPD may be particularly susceptible to airborne pollutants. Watch for poor air quality days in your area and stay inside during these times.
The American Journal of Medicine reports that there are 4.6 million never-smokers in the United States alone who have evidence on spirometry testing of obstructive airway disease.
Smokers can find educational material for help with quitting smoking on my website www.dresterle.com
If you are interested in getting a free test kit to check to see if you or a loved one could have Alpha-1 antitrypsin deficiency, copy link as listed below or call Dr Esterle for appointment.
Gross pathology picture of lung with emphysema