It was somewhat difficult for me to think of a good title for this article. There is nothing “normal” about smoking. As an organism we are designed to breath air and anything else is not normal. However, we do know that there are a group of patients who have a significant smoking history but at the time of their first presentation had normal pulmonary function test results. A recent study looked at a large number of patients (approx. 3,000) between the ages of 45 and 80 with a smoking history greater or equal to 10 pack years. (This means the patient was smoking one pack of cigarettes a day for at least 10 years).
Here are some important reference facts. Normally it is expected that a non-smoking patient will have a decline in lung function due to aging by about 30 cc’s a year. Patients with a smoking history but normal lung function will have exacerbations just like patients with COPD. These exacerbations along with the continued smoking causes a decline in lung function for more than twice the expected aging decline.
What does this all mean? It means that those patients that had normal lung functions at their first meeting will have a more rapid decline in function and their normal pulmonary functions will not be normal for long. It also means that the flair-ups we call exacerbations will have a much more devastating effect on their lung function.
Finally, it continues to support the fact that smoking is not a good idea.
