A history of asthma in patients with chronic obstructive pulmonary disease heightened the risk for disease-related hospitalizations, according to a population study published in Journal of Allergy and Clinical Immunology.
“Little is known about the natural history of chronic obstructive pulmonary disease (COPD) that has developed from airway remodeling due to asthma, as compared with other COPD phenotypes,” Tetyana Kendzerska, MD, PhD, from the Institute for Clinical Evaluative Sciences in Toronto, Canada, and colleagues wrote.
The researchers enrolled 9,053 patients aged 40 to 55 years diagnosed with COPD between 2009 and 2011 who did and did not have a history of asthma.
A total of 2,717 (30%) had a documented history of asthma; these patients showed symptoms of asthma at least two years prior to being diagnosed with COPD. Participants were followed until March 2013.
Kendzerska and colleagues assessed the long-term health outcomes of patients with a history of asthma compared with those without. They used a Cox regression model to assess the risks of COPD-, respiratory-, and cardiovascular-related hospitalizations and all-cause mortality. The model controlled for demographic characteristics, comorbidities and level of health care.
Over a median of 2.9 years, patients reported to the hospital for the first time for COPD- (n = 712; 8%), respiratory- (n = 964; 11%) and cardiovascular-related (n = 342; 4%) events. In addition, 556 patients died (6%).
Data showed that COPD and respiratory-related hospitalizations were significantly associated with a history of asthma (HR, 1.53 [95% CI, 1.29-1.82] and HR, 1.63 [95% CI, 1.14-1.88], respectively). Conversely, cardiovascular-related hospitalizations and all-cause mortality were not associated with history of asthma.
The investigators note that these results were not influenced by unmeasured confounding or misclassification.
“Middle-aged individuals with physician-diagnosed COPD and a history of asthma had a higher hazard of hospitalizations due to COPD and other respiratory diseases than did those without,” Kendzerska and colleagues concluded. – by Alaina Tedesco
Disclosure: The researchers report funding by the Canadian Respiratory Research Network.