Smokers, patients with emphysema or bronchodilator reversibility show higher decline rates
MONDAY, Sept. 26 (HealthDay News) -- The rate of change of forced expiratory volume in 1-second (FEV1) is highly variable among patients with chronic obstructive pulmonary disease (COPD), according to a study published online Sept. 26 in the New England Journal of Medicine to coincide with late-breaking presentations at the European Respiratory Society Congress, held from Sept 24 to 28 in Amsterdam, Netherlands.
Jørgen Vestbo, Dr.Med.Sc., from the Hvidovre Hospital in Copenhagen, and colleagues investigated the variability and determinants of changes in FEV1 in patients with COPD. A bronchodilator was administered to 2,163 patients, and changes in FEV1 were analyzed over a three-year period. Possible predictors of FEV1 levels, and their changes over time were evaluated using a random-coefficient model.
The investigators found that the mean rate of change in FEV1 declined by 33±2 ml/year, with significant variation among the patients. The standard deviation for between-patient rate of decline was 59 ml/year. The FEV1 decreased by 20 to 40 ml/year and by more than 40 ml/year in 31 and 38 percent of patients, respectively. A change in FEV1 ranging from a decrease of 20 to an increase of 20 ml/year or an increase of more than 20 ml/year was seen in 23 and 8 percent of patients, respectively. The mean per-year rate of decline was greater by 21±4 ml in current smokers versus nonsmokers, by 13±4 ml in patients with emphysema versus without, and 17±4 ml in patients with bronchodilator reversibility versus those without.
"The rate of change in FEV1 among patients with COPD is highly variable," the authors write.
The authors disclosed financial relationships with pharmaceutical companies, including GlaxoSmithKline, which funded the study.