Co-occurrence of memory impairment & fatigue distinguishes post COVID from pandemic-related health effects...CON-VINCE cohort, 2025, Martins Conde

Dolphin

Dolphin

Senior Member (Voting Rights)
www.nature.com

Co-occurrence of memory impairment and fatigue distinguishes post COVID from pandemic-related health effects in the 4-year CON-VINCE cohort study - Scientific Reports

A major challenge in diagnosing post COVID lies in differentiating symptoms following a confirmed SARS-CoV-2 infection from those that may also occur in uninfected individuals (post COVID mimics) and be associated with a broader impact of the pandemic. The WHO post COVID definition was applied...
www.nature.com www.nature.com

Co-occurrence of memory impairment and fatigue distinguishes post COVID from pandemic-related health effects in the 4-year CON-VINCE cohort study​

Scientific Reports volume 15, Article number: 37381 (2025) Cite this article

Abstract​

A major challenge in diagnosing post COVID lies in differentiating symptoms following a confirmed SARS-CoV-2 infection from those that may also occur in uninfected individuals (post COVID mimics) and be associated with a broader impact of the pandemic.

The WHO post COVID definition was applied to the Luxembourgish longitudinal CON-VINCE cohort, where SARS-CoV-2 infection was confirmed via either a positive RT-qPCR or a serology test.

Risk factor analysis was conducted on 1,865 individuals.

Female gender, lower resilience, greater loneliness, and a higher number of comorbidities were associated with symptoms persistence.

The symptomatology and comorbidity profiles of 559 participants (including 50 post COVID and 66 post COVID mimics) were investigated.

Two distinct clusters of persistent symptoms were identified: (1) depression with anxiety, present in both infected and non-infected groups, and (2) memory impairment with fatigue, unique to the post COVID group.

Therefore, presence of both memory impairment and fatigue may help differentiate post COVID patients from post COVID mimics.

Yet, verification that memory impairment was newly developed was not possible, as this symptom was not recorded at baseline.

Our findings suggest that future studies should consider factors affecting development of persistent post COVID-like symptoms observed in individuals that were never infected.
 
A study from Luxembourg.

From the abstract, the argument looks rather circular.
Two distinct clusters of persistent symptoms were identified: (1) depression with anxiety, present in both infected and non-infected groups, and (2) memory impairment with fatigue, unique to the post COVID group.

Therefore, presence of both memory impairment and fatigue may help differentiate post COVID patients from post COVID mimics.
Click to expand...
As in, 'we've defined post Covid as involving memory impairment with fatigue. Therefore, looking for memory impairment and fatigue may help separate post Covid from post Covid mimics.'

It's great that the authors seem to be focussed on a group with symptoms similar to ME/CFS. They even mention PEM. But what about people who lost their sense of taste or smell but don't have memory impairment or fatigue? Are their health conditions 'post-covid mimics'largely defined by depression and anxiety? What about the people with breathing difficulties as a result of lung damage as a result of a significant acute infection?


The clinical presentation of post COVID might be similar to the chronic fatigue syndrome often triggered by a viral infection as seen in post-Ebola syndrome, chikungunya and in myalgia encephalomyelitis, and has been previously referred as "post-viral fatigue". Persisting symptoms months after viral infection have been also described for other respiratory pathogens, such as Influenza (H1N1) and Middle East respiratory syndrome coronavirus (MERS-CoV). Individuals suffering from post COVID can present a combination of symptoms that may vary over time, whereas almost any system of a human body can be impacted.
Click to expand...

Extensive research has been conducted to understand the characteristics, frequency and nature of persisting symptoms after the recovery from an acute infection. The most common reported symptoms at 6 months after infection are fatigue, post-exertional malaise and neurocognitive impairment. Furthermore, several risk factors of post COVID have been identified, such as being of female gender or older age, suffering from obesity, depression, anxiety or from a post-traumatic stress disorder. However, the estimated prevalence of post COVID varies widely and depends on the definition and the selection of the timeframe between the infection and the assessment.
Click to expand...
If you muddle up the various long term consequences of a SARS-CoV2 infection, then the risk factors for the consequences also get muddled up. They seem to acknowledge this, while contributing to the muddling.
 
Last edited:
Hutan said:
From the abstract, the argument looks rather circular.
As in, 'we've defined post Covid as involving memory impairment with fatigue. Therefore, looking for memory impairment and fatigue may help separate post Covid from post Covid mimics.'
Click to expand...
I’m not sure that’s what they did.

I think they looked a longitudinal symptom data for infected and uninfected with persistent symptoms, and then looked at the symptoma clustering and found that the uninfected didn’t have a cluster with the combination of memory impairment and fatigue, but the infected group did.

Symptom clusters, stratified by infection status​

Pairwise associations of symptoms were calculated in the infected and non-infected subgroups to identify potential co-occurring symptoms in each subgroup (Fig. 4).

Two combinations of persistent symptoms occurring in SARS-CoV-2 infected individuals (n = 50) were identified: (1) fatigue and memory impairment, (2) depression and anxiety, while in non-infected (n = 66) individuals depression and anxiety was the only pair of significantly associated symptoms (see Supplementary Table 3 for an exploratory cluster analysis of the co-occurrence of comorbidities with symptoms).

Interestingly, the combination of anxiety and depression was the most frequently reported in both groups, suggesting an infection-unrelated occurrence of these. Moreover, there was no difference in the dynamics of presence of depression or anxiety between infected and non-infected participants (n = 566). These conditions persisted or resolved in similar patterns, independently of infection status (Supplementary Fig. 4).

We further investigated whether infected individuals with depression (n = 12) or anxiety (n = 10) experience these symptoms with higher severity when compared to non-infected individuals with depression (n = 17) or anxiety (n = 20), and found no significant differences in the severity scores of depression (CES-D) and anxiety (GAD-7) between infected and non-infected individuals (p-value = 0.98 and 0.91, respectively). The median score of depression (CES-D) was 23 [Q1, Q3: 18, 30] in infected depressed individuals, and 22 [Q1, Q3: 19, 25] in non-infected depressed individuals at visit 8. While the median anxiety score (GAD-7) was 8 [Q1, Q3: 6, 11] in infected individuals with anxiety, and 8 [Q1, Q3: 6, 9] in the non-infected group with anxiety at visit 8.
Click to expand...
 
The CON-VINCE study (COvid-19 National survey for assessing VIral spread by Non-affected CarriErs) is a longitudinal observational study, where participants (18–84 years) completed online questionnaires, and donated blood and other biosamples, over seven visits between April 2020 and June 2021, n = 1,865 at baseline visit. Serological analyses of blood samples and RT-qPCR (quantitative reverse transcription polymerase chain reaction) from naso/oropharyngeal swabs were performed.

A subset of individuals from the CON-VINCE cohort (n = 1,220) was further followed-up between December 2021 and March 2024 within the framework of ORCHESTRA Europe, where additional online questionnaire data and dried blood samples were collected for four additional visits (CON-VINCE visits 7 to 10).

In total, this manuscript considers the data from 10 study visits, covering the pandemic and lockdown conditions, as well as post-pandemic timepoints.
Click to expand...
It was a good plan. Unfortunately, it suffers from the problem of difficulty defining exactly who had Covid-19, because we know that not everyone who has had Covid-19 tests positive to it at various times. It also suffers from the problem of a large proportion of the sample being lost to followup. For example at visit 9, only 591 individuals were assessed.

SARS-CoV-2 infection status was considered positive, if an individual met one or more of the following criteria:
  • Positive RT-qPCR result, and/or,
  • Positive IgG-S titres to SARS-CoV-2 prior to vaccination, and/or,
  • Presence of IgG-N titres to SARS-CoV-2.
Click to expand...

They chose to use data fro visit 8. The problem with this is that people were infected at different times, so there is no consistency in the number of months post-Covid. Also, only 550 people were assessed, creating significant participant bias.

Figure 2 gives the 5 persisting symptoms that had the 5 lowest p values, in terms of differences between the infected group and the uninfected group. The five persisting symptoms, the number of infected with the symptom, the number of 'uninfected' with the symptom and the p values adjusted for fdr were

loss taste/smell - infected 4/214 - uninfected 0/335 - p 0.64
hair loss - infected 2/216 - uninfected 0/337 - p 1.00
runny nose - infected 2/216 - uninfected 0/335 - p 1.00
memory impairment - infected 23/197 - uninfected 24/315- p 1.00
muscle pain - infected 6/212 - uninfected 4/332 - p 1.00

This is hopeless. None of the p values for persisting symptoms are significant after adjustment. The p value for memory impairment isn't even significant before adjustment (0.16). And fatigue doesn't even make it to the list of top five differentiating symptoms. I don't know how they can make the conclusions they made. I'll stop here.
 
Utsikt said:
I think they looked a longitudinal symptom data for infected and uninfected with persistent symptoms, and then looked at the symptoma clustering and found that the uninfected didn’t have a cluster with the combination of memory impairment and fatigue, but the infected group did.
Click to expand...
I think they did that after not finding individual persisting symptoms that were significantly different between the two groups. The data is way too thin for them to be drawing conclusions in the way that they did in the abstract.
 
You must log in or register to reply here.
Back
Top Bottom