Long COVID mostly affects sleep

Fatigue and insomnia are among the most common symptoms of long-term COVID, according to a new international study. A researcher from Laval University took part.

Mathieu Perreault

The Press

Insomnia

First fatigue, then weakness and third insomnia. These are the three symptoms most frequently reported by patients who have a long COVID, lasting more than three months. “What strikes us is above all insomnia, it is very specifically a sleep disorder,” explains psychologist Charles Morin, sleep specialist at Laval University and co-author of the study published this week in the Journal of Sleep Research. “There is also daytime sleepiness, further down the list of the most common symptoms of long COVID. We think there is potentially less attention being paid to long COVID sleep issues. It certainly has clinical significance. The most common symptoms after the first three months are “mind fog”, shortness of breath, memory problems, muscle aches, daytime sleepiness, sweating and tachycardia.

Gravity

Researchers looked at symptoms of long COVID in five groups: those who did not have COVID-19 and those who had asymptomatic, mild, moderate, or hospitalized COVID-19. “It allows us to better see the frequency of symptoms associated with long COVID,” says Morin. There was almost no difference in symptom prevalence between those who did not have COVID-19 and those who had asymptomatic COVID-19. But for fatigue, rates jumped from 17% to 61% depending on whether the participant had asymptomatic or hospitalized COVID-19; the difference for these two groups in weakness, a symptom category that includes nausea, was 9% versus 49%.

Men and women

A sign that long COVID is causing sleep problems, insomnia is more common in men than in women after COVID-19. “Usually, women have more insomnia,” says Mr. Morin. But since more men than women have severe COVID-19, more of them have problems with insomnia. Among the 16,000 participants, men were 50% more likely to be hospitalized with COVID-19.

Screening

The presence of insomnia after COVID-19 could be a way to screen and diagnose long-lasting COVID. “And it could be that treating insomnia improves the prognosis of long COVID,” adds Morin.

Six countries

The ICOSS project – International Study of Sleep during COVID-19 – was born in March 2020 and brings together sleep specialists from 16 countries. “At the start, it was a question of seeing the effect of the modification of habits due to confinement, says Mr. Morin. But we quickly realized that COVID-19 has an impact on sleep. For example, last spring the group identified a higher incidence of sleep movement disorder with COVID-19. As this movement disorder is associated with an increased risk of Parkinson’s disease, this indicates possible neurological impairment from COVID-19.