PT - JOURNAL ARTICLE AU - Gleeson, Margaret AU - McNicholas, Walter T. TI - Bidirectional relationships of comorbidity with obstructive sleep apnoea AID - 10.1183/16000617.0256-2021 DP - 2022 Jun 30 TA - European Respiratory Review PG - 210256 VI - 31 IP - 164 4099 - http://err.ersjournals.com/content/31/164/210256.short 4100 - http://err.ersjournals.com/content/31/164/210256.full SO - EUROPEAN RESPIRATORY REVIEW2022 Jun 30; 31 AB - Obstructive sleep apnoea (OSA) is frequently associated with comorbidities that include metabolic, cardiovascular, renal, pulmonary and neuropsychiatric. There is considerable evidence that OSA is an independent risk factor for many of these comorbidities but, more recently, there is evidence that some of these comorbidities may predispose to the development of OSA. Thus, there is growing evidence of a bidirectional relationship between OSA and comorbidity, especially for heart failure, metabolic syndrome and stroke. Potential mechanisms of bidirectional relationships differ in individual comorbidities with fluid retention and redistribution being especially important in heart failure and end-stage renal disease, whereas neural mechanisms may be more important in diabetes mellitus and stroke. The evidence for other comorbidities, such as hypertension and atrial fibrillation, support these being more a consequence of OSA with limited evidence to support a bidirectional relationship. The present review explores the evidence for such bidirectional relationships with a particular perspective on comorbidities that may predispose to OSA. The impact of therapy in bidirectional relationships is also reviewed, which highlights the clinical importance of accurate diagnosis. This aspect is especially true of COPD, where the identification of co-existing OSA has important implications for optimum therapy.Obstructive sleep apnoea (OSA) is an independent risk factor for comorbidity, especially cardiometabolic. However, some comorbidities may be risk factors for OSA, supporting a bidirectional relationship that may have important implications for treatment. https://bit.ly/3BbJy6V