Post-Covid effects: disturbed sleep is the cause of shortness of breath

More than three years after the start of the Covid epidemic which affected the whole world, research continues its work of understanding the virus and the disease. On the occasion of the European Congress of Clinical Microbiology and Infectious Diseases currently being held in Copenhagen, new studies are gradually making it possible to see more clearly the consequences of this infection.

Sleep disrupted during Covid linked to shortness of breath

An early UK study notably found that disrupted sleep patterns in patients hospitalized with COVID-19 were likely to be a factor in shortness of breath.

Conducted at 38 institutions across the UK, the University of Manchester and Leicester study first found that 62% of participants who had been admitted to hospital with COVID-19 suffered from impaired sleep. Sleep quality was assessed using self-reported measures by 638 patients, but also measured objectively in another 729 patients, via devices measuring nighttime activity levels.

Both measures consistently revealed a higher prevalence of sleep disturbance among people hospitalized with COVID-19 compared to matched UK Biobank controls who had been hospitalized for any cause.

Study researchers also found that participants with sleep disturbances were more likely to suffer from anxiety and muscle weakness, common symptoms of the post-COVID-19 state. However, according to their statistical analysis, sleep disturbances were likely to directly cause shortness of breath. But reduced muscle function and increased anxiety, two known causes of shortness of breath, may partially mitigate the association between sleep disturbance and shortness of breath.

One of the authors, Dr John Blaikley, pulmonologist, said: “This study showed that sleep disturbance could be a significant contributor to post-COVID-19 shortness of breath – or dyspnea – due to its association with reduced muscle function and anxiety. For these cases, interventions targeting poor sleep quality could be used to better manage symptoms and recovery from hospitalization.”

The consequences of long COVID are no worse than post-flu

According to another Australian study, the incidence and severity of post-Covid syndrome would not be greater than the incidence of seasonal flu, especially in a vaccinated population like that of Queensland where the research was carried out. Furthermore, the impact on health systems would not come from the severity of the disease, but rather from the number of people infected.

To better understand the potential impacts of long covid and their severity, Australian researchers interviewed adults with PCR-confirmed infection for COVID-19 and influenza in Queensland between June 12 and June 25, 2022.

At the time, over 90% of Queensland’s population had been vaccinated against COVID-19. During the simultaneous waves of Omicron and influenza that occurred in mid-2022, 2,195 adults diagnosed with COVID-19 and 951 adults diagnosed with influenza were followed for 12 weeks and interviewed about ongoing symptoms and functional disorders using a questionnaire.

• Of those diagnosed with Omicron, one-fifth (21%, 469) reported persistent symptoms at 12 weeks and 4% (90) reported having moderate to severe functional limitations in daily living;
• Similarly, about one-fifth (23%, 214) of adults diagnosed with influenza reported persistent symptoms and 4% (42) reported moderate to severe functional limitations.

After controlling for influencing factors including age, gender, ethnicity, vaccination status and socioeconomic profile (based on postcode), the analysis found no evidence to suggest that adults Omicron patients were more likely to have persistent or moderate to severe symptoms.

Interestingly, analyzes suggest that younger age groups and non-Indigenous populations were more likely to report moderate to severe functional limitations after influenza than after Omicron.