Emphysema augments the risk of exercise induced desaturation (EID), both of which are linked to more severe chronic obstructive pulmonary disease (COPD), according to a study published in Respiratory Medicine.

In this study, 283 patients with COPD were prompted to complete a 6 minute walk test (6MWT) at baseline and after one year. Emphysema severity was assessed as percent of low attenuation areas (%LAA) under -950 Hounsfield units using high-resolution computed tomography at baseline.

According to the results, even a 1% increase in %LAA augments the relative risk (RR) of new desaturation by 10% (RR 1.1; 95% confidence interval [CI] 1.1-1.2) and for repeated desaturation by 20% (RR 1.2; 95%CI 1.1-1.3). Compared with other important desaturation risk factors, %LAA ranked as number one in the dominance analysis and accounted for 50% and 37% of the predicted variance for new and repeated de-saturators, respectively, according to the researchers.

“Emphysema increases the risk of developing and repeatedly experiencing EID. Emphysema seems to be a more important risk factor for desaturation than FEV1% predicted and resting saturation,” the researchers concluded.

Keywords: 6MWT, COPD, Emphysema, Exercise induced desaturation, FEV(1)/lung function

Link: https://pubmed.ncbi.nlm.nih.gov/34340175/