Women aged 50–60 most at risk of ‘long COVID’: Research

While most patients who develop COVID-19 recover from their illness in a relatively short period, some report ongoing issues.
 
These patients often refer to themselves as ‘long haulers’, or are said to have ‘long COVID’.
 
In August, newsGP reported on a paper that found approximately 10% of people diagnosed with COVID-19 remain unwell beyond three weeks after diagnosis.
 
But the percentage of people who develop long COVID may be even higher.
 
According to the World Health Organization (WHO), a telephone survey of symptomatic adults who had a positive outpatient test result for SARS-CoV-2 indicated 35% had not returned to their usual state of health when interviewed 2–3 weeks after testing.
 
So why do some patients recover, while others go on to develop long COVID?
 
The WHO lists high blood pressure, obesity and mental health conditions as risk factors for persistence of symptoms.
 
New research sheds further light on the risk factors for developing long COVID. The pre-print non-peer-reviewed study analysed data from 4182 incident cases of COVID-19. People logged their symptoms prospectively in the COVID Symptom Study app.
 
The authors of this research defined long COVID as occurring in people reporting symptoms lasting more than 28 days – 558 people (13.3%) had symptoms lasting for more than 28 days, 189 (4.5%) for more than eight weeks and 95 (2.3%) for more than 12 weeks.
 
The study found that long COVID was more likely with increasing age, higher body mass index (BMI), female sex and in those who experienced more than five symptoms during the first week of illness. Long COVID affected all socioeconomic groups, and asthma was the only pre-existing condition with significant association.
 
Age was significantly associated with long COVID, rising from almost 10% in 18–49-year-olds to almost 22% in those 70 and older.
 
Long COVID was more likely to affect women (14.8%) compared to men (9.5%), although the sex effect was not significant in the older age group.
 
Perhaps most significantly, women aged 50–60 were eight times more likely to experience lasting symptoms of long COVID than those aged 18–30.
 
‘This is a similar pattern to what you see in autoimmune diseases,’ co-author Professor Tim Spector said.
 
‘Things like rheumatoid arthritis, thyroid disease and lupus are two to three times more common in women until just before menopause, and then it becomes more similar.’
 
The Guardian reported that Professor Spector’s ‘guess’ is that gender differences in the way the immune system responds to coronavirus may account for this discrepancy.
 
Associate Professor Hassan Vally, an epidemiologist with a special interest in infectious diseases at La Trobe University, told newsGP this research adds to growing understanding of long COVID.
 
‘We’ve been living with the virus for such a relatively short time, so it’s a useful study and a really important and rigorous way to describe people’s illnesses,’ he said.
 
Associate Professor Vally was not surprised by the findings that older people and those with a number of symptoms early in the illness were most likely to develop the condition.
 
‘If you were going to predict people who were going to have poorer long-term outcomes [following a viral illness], you’d say people who have the most severe disease would have the most long-term outcomes,’ he said.
 
Associate Professor Vally says the relationship between symptom severity and development of long COVID may relate to viral load.
 
He also notes the way COVID-19 affects men versus women is interesting.
 
In July, newsGP reported that twice as many men were dying from COVID-19 than women, yet this new study found women are more likely to develop long COVID.
 
Study co-author Dr Claire Steves from Kings College London discussed this issue with BBC News.
 
‘We’ve seen from the early data coming out that men were at much more risk of very severe disease and, sadly, of dying from COVID,’ she said.


Associate Professor Hassan Vally says this research is a ‘really useful contribution’ to growing understanding about long COVID.

‘It appears that women are more at risk of long COVID.’
 
Associate Professor Vally says men and women generally respond differently to COVID. He believes the reason women are more likely to develop long COVID relates to ‘differences in immune systems and immune responses’.
 
‘[The researchers are] clearly equating this longer COVID with immune system dysfunction and some sort of imbalance in, or ongoing response of, the immune system,’ he said.
 
‘Women are more likely to have their immune system unregulated and attack the body.’
 
The study also outlined the most reported symptoms in those with long COVID.
 
Fatigue was reported in 97.7% of participants and headache in 91.2%, followed by anosmia and lower respiratory symptoms.
 
Associate Professor Vally says that both of those main symptoms can occur in post-viral fatigue syndrome.
 
‘We know that people who have post-viral syndromes, which may also be due to immune system dysregulation, they definitely have the classic two – fatigue and headache,’ he said.
 
The researchers also examined whether there were different types of symptomatology in those with long COVID.
 
‘We found two main patterns: those reporting exclusively fatigue, headache and upper-respiratory complaints (shortness of breath, sore throat, persistent cough and loss of smell) and those with multi-system complaints including ongoing fever and gastroenterological symptoms,’ the authors wrote.
 
Associate Professor Vally believes further understanding of long COVID is needed.
 
‘If there’s one thing that we learnt fairly early on, it’s that COVID-19 is not just a cold and it’s not even just like an average respiratory virus,’ he said.
 
‘It clearly has the capacity to affect other parts of the body and other organs and other systems.
 
‘So it’s not surprising that as we travel through time with this virus we’re starting to see its effects and they’re quite different to the course of an infection with some of the other viruses that we know.
 
‘Long COVID seems to be a very significant issue that we wouldn’t have predicted.’
 
Associate Professor Vally says further research would help explore those most likely to develop long COVID, the effects of the condition and how it should be managed.
 
‘This is what we have to do: we have to keep collecting as much information as we can to understand this disease,’ he said.
 
‘This study is a really useful contribution. I think there’s going to be a lot more done in this area.
 
‘And the longer we live with COVID in the world, the longer we’ll have to observe people and see how long [long COVID] actually lasts, and what the longer-term consequences are.’
 
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