Source: J Urol  |  Posted 10 years ago

By Cameron Johnston
Special to DG News
BERLIN, GERMANY -- September 25, 2001 -- Smokers who quit for a while and then resume the habit might be doing more damage to their lungs than those who continue smoking.
The subjects underwent full lung function examinations in 1986 and then again in 1996.

Swedish investigators reported these findings yesterday (September 24) at the annual meeting of the European Respiratory Society, in Berlin, Germany.
As part of the Obstructive Lung Disease in Northern Sweden (OLIN) study, investigators looked at a cohort of more than 1,100 smokers and ex-smokers. Subjects were divided into five groups: 1) never smokers; 2) they had quit smoking before the 10-year study began; 3) they quit smoking after the study began; 4) they had never stopped smoking, and still smoked; 5) they quit smoking at some point during the 10-year study, then restarted.
In terms of forced expiratory volume over one second (FEV[_]1[]), it was observed that those who had quit but restarted had a 4.77 percent decrease of lung function over 10 years, while those who continued smoking lost only 3.3 percent of lung function.
Those who quit smoking and then restarted also lost a mean of 44 mL per year in FEV[_]1[], while those who continued smoking and had never quit lost almost 39 mL per year.
Those who had never smoked actually showed a mean FEV[_]1[] increase of 0.5 percent , while those who stopped more than 10 years ago had a loss in FEV[_]1[] of just 0.10 mL, and those who stopped within the past 10 years had a loss of 1.2 percent.
According to Dr. Bo Lundback, an associate professor of medicine at the National Institute of Working Life, in Stockholm, Sweden, an average man of around 40-50 years of age would be expected to lose approximately 25 mL per year of lung function merely as a product of the lungs aging. Therefore, for a man to lose an additional four per cent or thereabouts over 10 years should be considered significant, he said.
Dr. Lundback speculated that part of the reason for this phenomenon is that long-term smokers develop a natural defense mechanism, which keeps working as long as they are smoking. However, when a person stops and the re-starts, this in effect kick-starts the defense mechanism each time a person starts smoking again, and this puts extra strain on the body