Research IDs Frequent-Exacerbation COPD Phenotype
Best predictor of exacerbations is history of them; these are more common with severe COPD
WEDNESDAY, Sept. 15 (HealthDay News) -- Some patients with chronic obstructive pulmonary disease (COPD), irrespective of disease severity, appear to fall within a susceptibility phenotype, according to research published in the Sept. 16 issue of the New England Journal of Medicine.
John R. Hurst, Ph.D., of the University College London Medical School, and colleagues analyzed data from 2,138 adults with COPD, aged 40 to 75 years. Subjects were followed for exacerbations over three years.
The researchers found that patients had more frequent and more severe exacerbations as the COPD increased in severity. Forty-seven percent of patients with stage 4 disease had frequent exacerbations -- defined as at least two in the first year of follow-up -- compared to 22 percent of patients with stage 2 disease. However, the best predictor of exacerbations across all stages was history of exacerbations.
"In conclusion, our study confirms the observation that exacerbations become more frequent and more severe as the severity of underlying COPD increases and shows that the most important determinant of frequent exacerbations is a history of exacerbations. This finding supports the hypothesis that patients who are more subject to frequent exacerbations, some of whom have milder disease, have a distinct susceptibility phenotype that is relatively stable over time and can be identified on the basis of the patient's recall of previously treated events," the authors write.
The study was supported by grants from GlaxoSmithKline, which employs several co-authors. A number of co-authors disclosed financial relationships with various pharmaceutical companies, including GlaxoSmithKline.