TORONTO - Patients with COPD - a lung disease usually caused by smoking - can't be cured, but a study released Friday suggests that drug therapy may reduce the loss of lung function.
Chronic obstructive pulmonary disease, which includes emphysema and chronic bronchitis, has been diagnosed in an estimated 1.5 million Canadians, and another 1.6 million may have COPD but haven't yet been diagnosed, according to the Lung Association.
"Pulmonary physicians are looking desperately for anything to improve the clinical course of patients with COPD," Dr. John Heffner, past president of the American Thoracic Society, said from Portland, Ore.
Heffner, who wasn't involved in the research, said specialists have been waiting for this particular study for a couple of years.
The research, published in the American Journal of Respiratory and Critical Care Medicine, involved an analysis of approximately 5,300 patients in about 40 countries, including Canada, who were followed for three years.
The study, led by Dr. Bartoleme Celli of Tufts University School of Medicine, looks at the effects of two different drug therapies, as well as a combination of the two drugs, on the volume of air that a person can exhale in the first second of trying to exhale with as much strength as possible. In more technical terminology, it's called forced expiratory volume in one second, or FEV1.
"The main finding is that all three arms of pharmacotherapy - and this included inhaled corticosteroids, a long-acting beta-agonist called salmeterol and a combination of both - were effective in altering the rate of decline," Celli said from Boston.
"So the decline was not as quick and as steep as those patients who were receiving placebo."
Samy Suissa of McGill University, director of clinical epidemiology at Jewish General Hospital in Montreal, wrote an accompanying editorial in the journal.
Many studies had looked at the same question previously but there were contradictory findings, possibly because of missing data, he said.
"This study is a much larger study, and it does have some of the same flaws as the other studies, mainly that some patients are not contributing any data on lung function, in fact a large number," Suissa said in an interview from Fort Lauderdale, Fla.
"And because of that, you can't really know. That's why my editorial says there's some hopeful signs here, but we can't really be conclusive."
But he said that if these data are accepted, and because all three medication groups have about the same slope of decline compared to placebo, then practitioners should say "well, why should we want to use all of these medications, and especially the combination one?"
Suissa said inhaled steroids come with side-effects, which include increased risk of pneumonia, cataracts, glaucoma and osteoporosis.
"If the three (drug therapies) are giving exactly the same slope of decline, the same improvement in slope of decline, which one of the three should we choose?" he said.
"They should choose the safest one, and that's the salmeterol by itself."
The study was funded by GlaxoSmithKline, which makes both salmeterol and fluticasone propionate, the inhaled corticosteroid.
Heffner, who said he doesn't do any consulting work for drug companies, was impressed with Suissa's conclusion.
He too gleaned from the study that it makes sense to treat patients with moderate COPD with long-term bronchodilators like salmeterol, but to hold off on steroids.
"It will alter my practice, probably as of this afternoon when I go for a clinic to see a new COPD patient," he said.
Celli noted that the combination of both drugs, which are sold in a single inhaler, was slightly better in reducing lung function loss, "although not statistically better than either component alone."
A healthy person's rate of decline in FEV1 as they age is 30 millilitres a year. The study found that among COPD patients, from week 24 of the research onward, the adjusted rate of decline in FEV1 was 39 ml per year for the combined drug therapy, 42 ml per year for the salmeterol and the corticosteroids and 55 ml per year for those on placebo.
"There is a slightly higher chance of pneumonia, of getting an infection of the lung when you use the combination - at least when you use either the inhaled corticosteroids, or inhaled corticosteroids with the salmeterol," he said.
"So yes, there is a slight risk but it is relatively small and it does not affect mortality."
"The main finding is that for the first time, it's been shown that administering pharmacotherapy to patients with COPD can change and modify the clinical course of their disease."
But Suissa, who has received funding for research grants from two drug companies in the past, including GlaxoSmithKline, said that the new combination therapy is not the answer.
"In fact, it may be harming more than it's benefiting," he said.
