Overlap syndrome linked to pulmonary embolism
Overlap syndrome (OS), the coexistence of both obstructive sleep apnoea (OSA) and chronic obstructive pulmonary disease (COPD), is associated with pulmonary embolism (PE), a recent study has found.
Researchers retrospectively reviewed 1,939 sleep study participants, of whom 62 had isolated COPD, 735 had isolated OSA and 49 had OS. The remaining 1,093 participants were designated as controls. Those with both COPD and OSA tended to have higher body mass index (BMI) values and were more likely to have chronic hypertension, diabetes and heart failure.
Relative to controls, OS patients were significantly more likely to develop PE (odds ratio [OR], 9.61; 95 percent CI, 4.02–21.31; p<0.001). This relationship remained significant even after adjustments for BMI, sex, age and comorbidities (OR, 5.66; 1.80–16.18; p=0.004).
Similarly, OS patients were significantly more likely to develop PE than their isolated OSA counterparts in both univariate (OR, 4.79; 2.04–10.33; p=0.0007) and multivariate (OR, 3.89; 1.27–10.68; p=0.019) analyses. No such effect was observed when OS was compared with isolated COPD (OR, 2.61; 0.65–11.53; p=0.177).
Moreover, subgroup analysis showed that the risk of PE was significantly higher in male (OR, 8.12; 1.86–31.87; p=0.007) OS patients and those at least 58 years of age (OR, 5.50; 1.51–18.14; p=0.012).
“Longitudinal studies are needed to investigate the relationship between OS and PE incidence, and whether [positive airway pressure] treatment may reduce hypoxaemia and even hypercoagulation in patients with OS and thus the risk of thrombotic events is also to be determined,” said researchers.