Summary: A study of nearly 1,000 people with post-COVID-19 syndrome (PCS) revealed that two-thirds still experienced significant symptoms, including reduced exercise capacity and cognitive performance, two years after infection. Persistent symptom clusters included fatigue, neurocognitive disturbances, and post-exertional malaise, with worse outcomes in individuals with obesity, lower education, or severe initial infections.
Patients with PCS showed reduced oxygen consumption and cognitive test scores, highlighting the need for exercise and cognitive evaluations in clinical care. The findings underscore the long-term impact of PCS and the urgent need for research into recovery factors.
Key Facts:
- Long-Term Symptoms: Two-thirds of PCS patients report persistent symptoms two years post-infection.
- Key Impairments: PCS is associated with reduced exercise capacity, memory, and attention.
- Clinical Care Needs: Cognitive and exercise testing should be prioritized for PCS evaluations.
Source: PLOS
Two-thirds of people with 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 new study published January 23rd in the open-access journal PLOS Medicine by Winfried Kern of Freiburg University, Germany, and colleagues.
Self-reported health problems following SARS-CoV-2 infection have commonly been described and may persist for months. However, the long-term prognosis of post-COVID-19 syndrome (PCS) is unknown.
In the new study, researchers studied 982 people aged 18 to 65 who had previously been identified as having PCS, 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 PCS 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 PCS, 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 PCS had significant reductions in handgrip strength, maximal oxygen consumption, and ventilatory efficiency.
Patients with persistent PCS 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 PCS,” the authors say.
“Observational studies with longer follow-up are urgently needed to evaluate factors for improvement and non-recovery from PCS.”
The authors add, “Grave symptoms with mental and physical exercise dysfunction, but no laboratory markers in Long Covid/post-Covid syndrome.”
Funding: This work was funded by a Baden-Württemberg Federal State Ministry of Science and Art grant (number MR/S028188/1) to WVK, HGK, UM, DR, SG and JS. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
About this Long COVID and cognition research news
Author: Claire Turner
Source: PLOS
Contact: Claire Turner – PLOS
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Persistent symptoms and clinical findings in adults with post-acute sequelae of COVID-19/post-COVID-19 syndrome in the second year after acute infection: A population-based, nested case-control study” by Winfried Kern et al. PLOS Medicine
Abstract
Persistent symptoms and clinical findings in adults with post-acute sequelae of COVID-19/post-COVID-19 syndrome in the second year after acute infection: A population-based, nested case-control study
Background
Self-reported health problems following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are common and often include relatively non-specific complaints such as fatigue, exertional dyspnoea, concentration or memory disturbance and sleep problems.
The long-term prognosis of such post-acute sequelae of COVID-19/post-COVID-19 syndrome (PCS) is unknown, and data finding and correlating organ dysfunction and pathology with self-reported symptoms in patients with non-recovery from PCS is scarce.
We wanted to describe clinical characteristics and diagnostic findings among patients with PCS persisting for >1 year and assessed risk factors for PCS persistence versus improvement.
Methods and findings
This nested population-based case-control study included subjects with PCS aged 18–65 years with (n = 982) and age- and sex-matched control subjects without PCS (n = 576) according to an earlier population-based questionnaire study (6–12 months after acute infection, phase 1) consenting to provide follow-up information and to undergo comprehensive outpatient assessment, including neurocognitive, cardiopulmonary exercise, and laboratory testing in four university health centres in southwestern Germany (phase 2, another 8.5 months [median, range 3–14 months] after phase 1).
The mean age of the participants was 48 years, and 65% were female. At phase 2, 67.6% of the patients with PCS at phase 1 developed persistent PCS, whereas 78.5% of the recovered participants remained free of health problems related to PCS.
Improvement among patients with earlier PCS was associated with mild acute index infection, previous full-time employment, educational status, and no specialist consultation and not attending a rehabilitation programme.
The development of new symptoms related to PCS among participants initially recovered was associated with an intercurrent secondary SARS-CoV-2 infection and educational status.
Patients with persistent PCS were less frequently never smokers (61.2% versus 75.7%), more often obese (30.2% versus 12.4%) with higher mean values for body mass index (BMI) and body fat, and had lower educational status (university entrance qualification 38.7% versus 61.5%) than participants with continued recovery.
Fatigue/exhaustion, neurocognitive disturbance, chest symptoms/breathlessness and anxiety/depression/sleep problems remained the predominant symptom clusters. Exercise intolerance with post-exertional malaise (PEM) for >14 h and symptoms compatible with myalgic encephalomyelitis/chronic fatigue syndrome were reported by 35.6% and 11.6% of participants with persistent PCS patients, respectively.
In analyses adjusted for sex-age class combinations, study centre and university entrance qualification, significant differences between participants with persistent PCS versus those with continued recovery were observed for performance in three different neurocognitive tests, scores for perceived stress, subjective cognitive disturbances, dysautonomia, depression and anxiety, sleep quality, fatigue and quality of life.
In persistent PCS, handgrip strength (40.2 [95% confidence interval (CI) [39.4, 41.1]] versus 42.5 [95% CI [41.5, 43.6]] kg), maximal oxygen consumption (27.9 [95% CI [27.3, 28.4]] versus 31.0 [95% CI [30.3, 31.6]] ml/min/kg body weight) and ventilatory efficiency (minute ventilation/carbon dioxide production slope, 28.8 [95% CI [28.3, 29.2]] versus 27.1 [95% CI [26.6, 27.7]]) were significantly reduced relative to the control group of participants with continued recovery after adjustment for sex-age class combinations, study centre, education, BMI, smoking status and use of beta blocking agents.
There were no differences in measures of systolic and diastolic cardiac function at rest, in the level of N-terminal brain natriuretic peptide blood levels or other laboratory measurements (including complement activity, markers of Epstein–Barr virus [EBV] reactivation, inflammatory and coagulation markers, serum levels of cortisol, adrenocorticotropic hormone and dehydroepiandrosterone sulfate).
Screening for viral persistence (PCR in stool samples and SARS-CoV-2 spike antigen levels in plasma) in a subgroup of the patients with persistent PCS was negative. Sensitivity analyses (pre-existing illness/comorbidity, obesity, medical care of the index acute infection) revealed similar findings.
Patients with persistent PCS and PEM reported more pain symptoms and had worse results in almost all tests. A limitation was that we had no objective information on exercise capacity and cognition before acute infection.
In addition, we did not include patients unable to attend the outpatient clinic for whatever reason including severe illness, immobility or social deprivation or exclusion.
Conclusions
In this study, we observed that the majority of working age patients with PCS did not recover in the second year of their illness. Patterns of reported symptoms remained essentially similar, non-specific and dominated by fatigue, exercise intolerance and cognitive complaints.
Despite objective signs of cognitive deficits and reduced exercise capacity, there was no major pathology in laboratory investigations, and our findings do not support viral persistence, EBV reactivation, adrenal insufficiency or increased complement turnover as pathophysiologically relevant for persistent PCS.
A history of PEM was associated with more severe symptoms and more objective signs of disease and might help stratify cases for disease severity.
