We are out of lockdown and into the UK national tiered system. After some relaxation of the rules over Christmas, it is unlikely that much will improve until early spring-time, it feels like a long winter ahead. There is also mention of “Long COVID” with increased exposure to the virus, so what does this mean and what are the implications?
Post infectious morbidity?
Mortality rates have dominated discussions, so far, the global death toll of COVID-19 is estimated at 1.4m. Deaths are now running at a little under 10,000 a day or about 3.5m a year. If this were maintained, cumulative deaths over the first two years might reach close to 5m, or just over 0.06 per cent of the global population. To put this in context, the Spanish flu, which emerged in 1918, lasted 26 months and cost somewhere between 17m and 100m lives, or between 1 and 6 per cent of the then global population.
However, as data from infected people who survive begins to surface, there is a growing appreciation for the impact of post-infectious morbidity, duration and intensity. Substantial long-term morbidity is at least possible, as the Sars Cov-2 virus enters pulmonary and brain tissue and causes cardiac dysfunction.
Kings College has recently pre published work in the Lancet’s eBioMedicine along with the University of Trieste and the International Centre for Genetic Engineering and Biology in Italy on the effects on the lungs of people post infection. Their findings indicate that COVID-19 is not simply a disease caused by the death of virus-infected cells but is likely the consequence of these abnormal cells persisting for long periods inside the lungs.
Currently, there is no consensus definition of post-acute COVID-19 (Long COVID). Based on the COVID Symptom Study, in which more than 4 million people in the US, UK and Sweden have entered their symptoms after a COVID-19 diagnosis, post-acute COVID-19 is defined as the presence of symptoms extending beyond 3 weeks from the initial onset of symptoms and chronic COVID-19 as extending beyond 12 weeks.
Data from a recent study by Kings College of 4 million individuals and overseen by Prof Tim Spector indicates that:
- Symptoms can be varied: Symptoms of long COVID include excessive fatigue/exhaustion, breathlessness, headache, insomnia, muscle fatigue/pains, chest pain, persistent cough, a loss of taste and smell, intermittent fevers, skin rashes and worsening of symptoms post-exercise.
- It’s relatively common: 1 in 10 COVID patients had symptoms that were still present one month later and between 1.5-2 percent still had symptoms after three months.
- Early disease patterns predict long COVID: Having a persistent cough, hoarse voice, headache, diarrhoea, loss of appetite and shortness of breath in the first week of acute COVID meant someone was two to three times more likely to get longer-term symptoms.
- There are health-related risk factors for long COVID: The most common risk factors associated with persistent COVID symptoms include high blood pressure, obesity, and mental health conditions.
- It affects working-age individuals, women more than men: Long COVID appears to be twice as common in women compared to men, and the median age of those experiencing long-term symptoms is 45.
Cell Membranes and Fatigue
It is early days for the purpose of identifying mechanisms of certainty and consistency, but as with many post-viral insults, there are likely to be common findings. The most common one being fatigue. There are enormous numbers of patients recovering from SARS-CoV-2 infection worldwide. A lengthy post-infection fatigue burden will impair quality of life and will have a significant impact on individuals, employers and healthcare systems. Seeking safe effective interventions for people with fatigue related to their viral insult will be a core part of reducing their challenges.
Over several years there have been various publications exploring the role of lipids in the restoration of cell membranes, altered by numerous insults, and related mitochondrial damage. Early proposals suggest that mitochondrial dysfunction is associated with defective immune responses in ageing and different age-related diseases, and with many of the comorbidities associated with poor prognosis in the progression of COVID-19. The chronic inflammation caused by mitochondrial dysfunction may be one factor responsible for the explosive release of inflammatory cytokines causing severe pneumonia, multi-organ failure and finally death in COVID-19 patients as well as Long Covid symptoms.
In the case of metabolic syndrome, a key factor in COVID-19 severity, mitochondrial dysfunction is key in the increase of insulin resistance associated with type 2 diabetes and connected with the increase of mutations in mtDNA, changes in ATP levels, generation of ROS and unbalanced mitochondrial turnover. This suggests that the maintenance of mitochondrial health through healthy life habits, specialised dietary supplements able to improve mitochondrial activity, dynamics and turnover such as phospholipids and CoQ10 would reduce the levels of inflammatory cytokines and the severity of COVID-19 and other respiratory diseases such as seasonal flu.
The symptoms of Long COVID are a characteristic of an already well-documented, potentially devastating, and largely unexplained post-viral illness, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This disease is already known to be associated with other viral infections such as Epstein Barr or glandular fever. A review paper in Chronic Diseases and Translational Medicine out on the 21st Nov 2020, looks at oxidative stress and mitochondrial dysfunction and explores the potential role of CoQ10, MitoQ and antioxidants in the potential nutritional recovery strategy for Long COVID patients. Previous work by Nicolson and Ash has also examined the role of glycophospholipids in the recovery of fatigue plagued people, the results of which strongly suggest a role for mitochondrial lipid damage being a factor in the inflammatory cascade that precipitates fatigue, brain fog, pain and other symptoms.
Looking ahead, as we migrate from the various protection strategies to recovery interventions, keep in mind that nutritional supplements have a direct role to play in the repair of cellular damage caused by viral insult and the related immune activation.