How Has Long COVID-19 Affected Sleep Patterns?

Hypersomnia, insomnia, and circadian rhythms were among the sleep disorders discussed in a panel at SLEEP 2023 as having an association with postacute sequelae of COVID-19 (PASC), which is defined as “the condition that occurs in individuals with a history of probable or confirmed [COVID-19] infection, usually 3 months from the onset of COVID-19, with symptoms that last at least 2 months and cannot be explained by an alternative diagnosis,” according to the World Health Organization. The effect of long COVID-19 on neurological disorders, including sleep, is being studied, and current data were presented during this panel.

An estimated 6% (95% CI, 5.3-5.9) of adults in the United States are currently experiencing symptoms of long COVID-19, according to data presented by Sairam Parthasarathy, MD, professor of medicine at University of Arizona, Tucson. Changes in sleep patterns were reported during the COVID-19 pandemic, which has prompted researchers to investigate the effects long term.

Hypersomnia in Long COVID-19

According to Parthasarathy, sleep disturbances and sleep apnea were strongly associated with PASC, with greater risk of PASC seen for people who had multiple infections and more virulent strains of the virus.

This was made evident through evidence of PASC’s association with hypersomnia, presented by Matthew B. Maas, MD, MS, chief of hospital neurology in the Department of Neurology at Northwestern.

“If any of you ever had a severe acute illness and found yourself wallowing in your bed languishing, not moving around, not sleeping…you’re not alone, worms have this problem too,” Maas joked to start his presentation, calling attention to how sick animals of all kinds go into hypersomnic states when injured or ill. This was especially true in patients who contracted COVID-19, said Maas.

Activity was found to be low and less rhythmic in “normal” alertness patients who were sick compared with healthy patients, according to Maas. “And then as people emerge from these illnesses and come out the other side into recovery…the outcomes that come out of that are this mixed set of changes to their functional abilities and quality of life,” he said. “And one of the classic outcomes of this is that persistent sleep disturbance, fatigue, daytime hypersomnia.”

Illnesses rarely stay in a single organ system, and treating just the initial illness rarely restores the patient to baseline, according to Maas. Hypersomnia has proven to be one of the more persistent features of long COVID-19. Studies have found that individuals who report hypersomnia after COVID-19 often have other neurological disorders, with the median number of discrete neurologic symptoms attributed to PASC found to be 6, with 87% reporting 4 or more symptoms, according to data from a study presented by Maas. Fatigue (94.9%), brain fog (89.7%), and insomnia (74.4%) were often reported.

However, Maas said that there is still a lot that scientists don’t know about this link. “One of the realities is we need to conclude by being very upfront about how much we don’t know, how much the biology is very uncertain to us, and approach this that way,” he said.

Insomnia’s Correlation With Long COVID-19

Daniel J. Buysse, MD, UPMC Endowed Chair in Sleep Medicine at the University of Pittsburgh, presented information on the link between insomnia and PASC. A nationwide uptick in searches for insomnia during the pandemic clued researchers into looking at the potential link between the 2 disorders.

Prevalence estimates of insomnia during the COVID-19 pandemic were presented by Buysse, who compiled the data from various meta-analyses and studies. “And you can see that it pretty rough[ly] averages about 25% or 30% of the population describe insomnia during the COVID-19 pandemic, which is not so far off from what population estimates for insomnia usually are,” he said.

However, prevalence of insomnia in health care workers was significantly higher in the studies presented, averaging about 35% to 40%. All of these studies had high heterogeneity.

Clinical insomnia symptoms were also found in 36.7% (95% CI, 36.0-37.4) of individuals surveyed during the pandemic in 14 different countries, whereas probable insomnia disorder was found in 17.4% (95% CI, 16.9-17.9). A separate study found that there was a 26.7% increase in insomnia during the pandemic.

“But generally people who are good sleepers, the majority of them stayed good sleepers,” said Buysse. “There was some transition to mild insomnia. People who had severe insomnia for the most part retain their severe insomnia, and people with subsyndromal insomnia could go either way. But two-thirds of these people overall had subsyndromal or severe symptoms during the pandemic.”

Buysse also presented data from a study conducted in 16 countries that found that PASC symptoms were more prevalent in people who had more severe COVID-19, with sleep symptoms at the core of PASC including fatigue (61.3%), insomnia symptoms (49.6%), and excessive daytime sleepiness (35.8%). A group with the best sleep health had a 30% lower risk of post–COVID-19 condition compared with the worst sleep health group in a different study.

Buysse concluded by saying that there is a high prevalence of insomnia during and following infection of COVID-19 and insomnia is a prevalent symptom of PASC. Insomnia and poor sleep health may also predict PASC in individuals. However, he highlighted that treatment for insomnia in relation to PASC is still unknown.

“Treatment in the future, I think, needs to focus on [incorporating] patient perspectives. We need to recognize that we don’t have all the answers, that presentations that our patients have are more complex than we are used to, and we need to be adaptive and keep our ears and our minds open as we do our best to try and help these patients,” he said.

Although disorders as a consequence of contracting COVID-19 or having symptoms of PASC have few treatment options, acknowledging the association between PASC and neurological disorders such as sleep disturbances is an important first step to the future of treating the disorder. Hypersomnia and insomnia are just 2 of the ways that PASC has affected those previously infected with COVID-19 and serve as a prominent reminder of the continued research needed into PASC and long COVID-19 in general.