Is sleep apnoea an independent risk factor for severe COVID-19 infection finds BMJ study

Obstructive sleep apnoea (OSA) is associated with higher body mass index (BMI), diabetes, older age and male gender, which are all risk factors for severe COVID-19. Strausz et al from University of Helsinki demonstrated the higher risk for COVID-19 hospitalisation in patients with OSA, independently of BMI and other known risk factors for OSA.

From previous evidence, risk factors for severe COVID-19 have been identified as older age, male sex, obesity, diabetes, cardiovascular disease ,poor lung function and other respiratory diseases. OSA is a common disease affecting at least 8% of the population with higher prevalence in older age groups reaching to over 20% in individuals over 60 years of age, hence researchers aimed at evaluating if OSA associates with the risk for severe COVID-19 infection independently of other potential risk factors including age, sex, body mass index (BMI), hypertension, diabetes (including type 1 and type 2 diabetes), coronary heart disease (CHD) asthma and chronic obstructive pulmonary disease (COPD), and also whether the risk for contracting COVID-19 is elevated among patients with OSA

Key findings of the study are:

1. Of all patients with COVID-19 diagnosis (n=445, 37.3% male, mean age 52.7 years) ;38 patients also had OSA diagnosis(8.5%).

2. Among Severe COVID-19(total of 91 patients hospitalized), OSA occurred in 19 patients(20.9%).

3. Prevalence of OSA , hypertension , diabetes ,obesity and CHD were statistically significantly higher in the hospitalised group.

4. Patients with OSA had the same risk of contracting COVID-19 than non-OSA individuals, but patients with OSA had a considerably elevated risk for being hospitalised due to severe COVID-19.

There are at least two potential pathological mechanisms how OSA may relate to severe COVID-19. First, individuals with OSA often have one or more comorbidities that are known risk factors for severe COVID-19. For example, high BMI increases the risk for severe COVID-19. Furthermore, OSA exacerbates the effects of many underlying risk factors increasing blood pressure. Second, OSA may worsen the core symptoms of severe COVID-19, especially during the night, when decreased oxygen saturation levels occur in OSA. The findings of current study together with earlier reports suggest that OSA should be taken into account when assessing who will develop life-threatening complications of COVID-19 infection.

Authors conclude: "Patients with OSA had 2.93 times higher risk to be hospitalised when affected by COVID-19 than non-OSA individuals."

Source:Strausz S, Kiiskinen T, Broberg M, Ruotsalainen S, Koskela J, Bachour A; FinnGen, Palotie A, Palotie T, Ripatti S, Ollila HM. Sleep apnoea is a risk factor for severe COVID-19. BMJ Open Respir Res. 2021 Jan;8(1):e000845. doi: 10.1136/bmjresp-2020-000845.