COVID-19 shortens leukocyte telomere length but this is not associated with cognitive impairment issues

Medical News: In a recent study led by Mexican researchers from the Universidad Anáhuac Querétaro, Instituto Nacional de Medicina Genómica, and the Universidad Juarez Autónoma de Tabasco, new insights have emerged regarding the effects of COVID-19 on telomere length and its potential impact on cognitive function. Telomeres, which are protective caps at the ends of chromosomes, play a critical role in cellular aging and are often linked to age-related diseases. The study reveals that while COVID-19 causes a significant reduction in leukocyte telomere length (LTL), this shortening is not associated with cognitive impairment in individuals who have recovered from the infection. This Medical News report will delve into the key findings of this study and its implications for understanding the long-term effects of COVID-19 on health.


COVID-19 shortens leukocyte telomere length but this is not associated with
cognitive impairment issues

Telomeres and Their Role in Cellular Health
Telomeres protect the ends of chromosomes, preventing them from deteriorating or fusing with other chromosomes. As cells divide, telomeres shorten, eventually leading to cellular aging and death. Shorter telomeres have been linked to various health conditions, including cardiovascular diseases, diabetes, and even cognitive decline.
 
COVID-19 has been shown to accelerate telomere shortening in some patients. This shortening is thought to be a result of the intense immune response to the virus, which puts a significant strain on the body’s cellular repair mechanisms. Previous studies have linked shorter telomeres to more severe outcomes in COVID-19 patients, such as prolonged hospitalization or even death. However, the association between telomere length and cognitive impairment in post-COVID-19 individuals has remained unclear.
 
The Study’s Design and Methodology
The study involved 256 participants aged between 18 and 68, divided into four groups based on their COVID-19 infection status and psychiatric history:
-Group I: Individuals without COVID-19 but with a psychiatric diagnosis.
-Group II: Individuals with COVID-19 and a psychiatric diagnosis.
-Group III: Healthy individuals with no psychiatric conditions and no history of COVID-19.
-Group IV: Individuals with a history of COVID-19 but no psychiatric diagnosis.
 
Blood samples were collected from all participants to measure their LTL using Polymerase Chain Reaction (PCR) technology. Cognitive function was assessed using two widely recognized tools: the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). These tests were designed to evaluate various cognitive domains, including memory, attention, and visuospatial abilities.
 
The study findings showed that while COVID-19 causes a reduction in LTL, it does not correlate with cognitive decline in recovered patients. The researchers conducted this study between 2020 and 2023, examining both psych iatric and non-psychiatric individuals with and without a history of COVID-19 infection.
 
Key Findings: Telomere Shortening But No Cognitive Decline
One of the study’s main findings was that individuals who had been infected with COVID-19 showed significantly shorter telomeres than those who had never contracted the virus. This was especially evident in participants from Group IV (individuals with a history of COVID-19 but no psychiatric diagnosis), who had the shortest telomere lengths compared to the other groups.
 
However, despite this significant reduction in telomere length, no link was found between telomere shortening and cognitive impairment. Participants who showed telomere shortening did not exhibit poorer cognitive performance on the MMSE and MoCA tests when compared to those with longer telomeres. This finding challenges earlier research that suggested a strong association between telomere length and cognitive decline.
 
Interestingly, participants in Group II (COVID-19 patients with psychiatric diagnoses) showed a slight increase in LTL compared to the other groups. This increase may be attributed to the use of psychiatric medications such as antidepressants and antipsychotics, which have been linked to the activation of telomerase, the enzyme responsible for maintaining telomere length.
 
Potential Explanations for the Lack of Cognitive Decline
The absence of a correlation between telomere shortening and cognitive impairment in post-COVID-19 patients is surprising, given the body of evidence that suggests a link between telomere length and cognitive health. One potential explanation is that the impact of COVID-19 on telomere length may be temporary, with the body’s natural repair mechanisms able to restore telomere length after recovery from the virus. Alternatively, cognitive impairment in post-COVID-19 patients may be driven by other factors, such as inflammation or damage to specific areas of the brain, rather than telomere shortening alone.
 
Sex Differences in Telomere Length
Another intriguing finding of the study was the difference in telomere length between male and female participants. On average, men had longer telomeres than women, a result that contrasts with previous research, which has consistently shown that women tend to have longer telomeres than men. The researchers suggest that this finding may be due to the small sample size of the study or other confounding factors, such as lifestyle differences between the male and female participants.
 
Implications for Long-Term Health Monitoring
The results of this study have important implications for the long-term health monitoring of individuals who have recovered from COVID-19. While telomere shortening is a cause for concern, especially in the context of aging and age-related diseases, the fact that it does not appear to be linked to cognitive impairment is reassuring. However, the researchers caution that more studies are needed to determine the long-term effects of telomere shortening in COVID-19 survivors.
 
In particular, they recommend that individuals who have recovered from COVID-19 should undergo regular cognitive assessments to monitor for any signs of decline over time. This is especially important for individuals with pre-existing psychiatric conditions, who may be at higher risk for cognitive impairment.
 
Conclusions and Future Research
In conclusion, the study reveals that while COVID-19 infection leads to shorter leukocyte telomere length, this shortening does not appear to be associated with cognitive impairment in recovered individuals. This finding is significant because it suggests that telomere length alone may not be a reliable biomarker for predicting cognitive decline in post-COVID-19 patients.
 
The researchers suggest that future studies should focus on identifying other factors that may contribute to cognitive impairment in COVID-19 survivors, such as inflammation, oxidative stress, or changes in brain structure. In addition, further research is needed to understand the long-term effects of telomere shortening in these individuals and whether interventions such as lifestyle changes or medications can help restore telomere length and improve overall health outcomes.
 
The study findings were published on a preprint server and are currently being peer reviewed.
https://www.preprints.org/manuscript/202409.0276/v1
 
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https://www.thailandmedical.news/news/breaking-university-of-vermont-scientists-confirms-that-sars-cov-2-has-ability-to-damage-human-dna-and-telomeres-causing-long-covid-issues