Researchers following nearly 1,000 people with long COVID found few changes to their symptoms in the second year of illness.
Two-thirds of people with long COVID (post-COVID-19 syndrome) have persistent, objective symptoms—including reduced physical exercise capacity and reduced cognitive test performances—for a year or more, with no major changes in symptom clusters during the second year of their illness, according to a study published in PLOS Medicine.
Self-reported health problems following SARS-CoV-2 infection have commonly been described and may persist for months. However, the long-term prognosis of long COVID is unknown.
In the new study, researchers studied 982 people aged 18 to 65 who had previously been identified as having long COVID, as well as 576 controls. All participants visited one of several university health centers in southwestern Germany for comprehensive assessments, including neurocognitive, cardiopulmonary exercise, and laboratory testing.
The predominant symptom clusters among people with long COVID were fatigue/exhaustion, neurocognitive disturbances, chest symptoms/breathlessness, and anxiety/depression/sleep problems. Nearly 68% of people who originally reported PCS still struggled with symptoms in the second year. Exercise intolerance with post-exertional malaise was reported by 35.6% of people with persistent long COVID, and these people had worse outcomes and more severe symptoms. People with lower educational attainment, obesity, or more severe illness during the initial COVID-19 infection were also at higher risk of prolonged symptoms.
When they looked at objective measures of health and cognition, the team found that people with persistent long COVID had significant reductions in handgrip strength, maximal oxygen consumption, and ventilatory efficiency. Patients with persistent long COVID and post-exertional malaise scored lower than control patients on cognitive tests measuring memory, attention, and processing speed; however, the researchers point out that they had no data on cognition before acute COVID-19 infection. The team was not able to identify differences in cardiac function or laboratory values, including tests of viral persistence.
“The results call for the inclusion of cognitive and exercise testing in the clinical evaluation and monitoring of patients with suspected [long COVID],” the authors say. “Observational studies with longer follow-up are urgently needed to evaluate factors for improvement and non-recovery from [long COVID].”
The authors add, “Grave symptoms with mental and physical exercise dysfunction, but no laboratory markers in Long Covid/post-Covid syndrome.”
