Background: Hypoxemia is a major complication of COPD and is a strong predictor of mortality. We previously\nidentified independent risk factors for the presence of resting hypoxemia in the COPDGene cohort. However, little\nis known about characteristics that predict onset of resting hypoxemia in patients who are normoxic at baseline.\nWe hypothesized that a combination of clinical, physiologic, and radiographic characteristics would predict\ndevelopment of resting hypoxemia after 5-years of follow-up in participants with moderate to severe COPD\nMethods: We analyzed 678 participants with moderate-to-severe COPD recruited into the COPDGene cohort who\ncompleted baseline and 5-year follow-up visits and who were normoxic by pulse oximetry at baseline.\nDevelopment of resting hypoxemia was defined as an oxygen saturation ââ?°Â¤88% on ambient air at rest during\nfollow-up. Demographic and clinical characteristics, lung function, and radiographic indices were analyzed with\nlogistic regression models to identify predictors of the development of hypoxemia.\nResults: Forty-six participants (7%) developed resting hypoxemia at follow-up. Enrollment at Denver (OR 8.30,\n95%CI 3.05ââ?¬â??22.6), lower baseline oxygen saturation (OR 0.70, 95%CI 0.58ââ?¬â??0.85), self-reported heart failure (OR 6.92,\n95%CI 1.56ââ?¬â??30.6), pulmonary artery (PA) enlargement on computed tomography (OR 2.81, 95%CI 1.17ââ?¬â??6.74), and\nprior severe COPD exacerbation (OR 3.31, 95%CI 1.38ââ?¬â??7.90) were independently associated with development of\nresting hypoxemia. Participants who developed hypoxemia had greater decline in 6-min walk distance and greater\n5-year decline in quality of life compared to those who remained normoxic at follow-up.\nConclusions: Development of clinically significant hypoxemia over a 5-year span is associated with comorbid heart\nfailure, PA enlargement and severe COPD exacerbation. Further studies are needed to determine if treatments\ntargeting these factors can prevent new onset hypoxemia.
Loading....