top cx logo
cx logo
Explorearrow down
search icon

Covid-19: French experts respond to new studies on long-term effects

New studies show ‘increased’ and ‘surprising’ risk of severe long-term conditions post-infection, which ‘do not go away over time’, say French doctors. It should be noted though that the likelihood of their occurring is still very low.

A woman looking exhausted

Studies show that long-term complications of Covid can include ‘brain fog’ and exhaustion, as well as more severe cardiovascular and neurological problems Pic: Agenturfotografin / Shutterstock

French doctors have warned of “surprising” new studies that highlight the possible long-term effects and complications of Covid, including serious cardiovascular issues, and even increased risk of dementia.

The comments come following a series of peer-reviewed research studies into the long-term effects of Covid, including one by the University of Saint-Louis in the US, published in the journal Nature, which showed that people who had contracted the virus had a greater risk of a range of conditions afterwards.

In the worst cases, these included: “nervous system and neurocognitive disorders, mental health disorders, metabolic disorders, cardiovascular disorders, gastrointestinal disorders, malaise, fatigue, musculoskeletal pain and anaemia.”

Although the risk of these health issues increases in people who have had Covid, it should be noted that the likelihood of their occurring is still very low.

The study said its “results will help to inform health system planning and the development of multidisciplinary care strategies to reduce chronic health loss among individuals with Covid-19.”

Cardiovascular risk

Another study, also published in Nature, showed a heightened risk of cardiac issues.

Professor Ariel Cohen, cardiology expert and former president of the Société française de cardiologie, told FranceInfo: “The results of these American researchers are a surprise.”

He said that previously, doctors had thought that these conditions were only more represented among Covid patients because people who were predisposed to these problems would declare them when they became infected.

However, the new study shows “a risk multiplied by 1.5 or 2 for all events [medical conditions]” not only the cardiac inflammations well known in Covid-19 patients [but also] the risk of stroke (multiplied by 1.52 in the year following infection), the risk of pulmonary embolism (2.93) and that of acute coronary syndrome (1.72).

"This study shows that there is an increased risk related to the infection itself and that it does not go away with time as we thought,” said Professor Cohen.

Dr Olivier Robineau, an infectious diseases specialist at Tourcoing hospital (Nord), said that the results corroborate his own observations, which is “that the virus attacks the blood vessel walls”.

Neurological and kidney problems

Another study, published in the Journal of the American Society of Nephrology showed that people who have recovered from Covid are three times more at risk of developing kidney problems. This is largely because the virus causes vascular issues, which can affect the whole body.

Prof Cohen said: “All these organs are connected. As soon as the function of the artery is impaired, there is a risk that they will be affected.”

Covid has also been found to affect the brain and nervous system, causing not only a loss of taste and smell, but also longer-term effects such as “brain fog” and difficulty concentrating.

One study published in Nature Communications showed damage "that could lead to [these] long-term neurological symptoms of long Covid", even when the patient did not develop a severe form of the virus.

Dr Robineau said: “[Covid] can lead to these neurological symptoms in the long-term..and researchers are now alert to a risk of dementia.”

Another study in the journal Science “raised the possibility that the infection may accelerate or trigger the future development of neurodegenerative diseases such as Alzheimer's or Parkinson's”.

Dr Robineau highlighted that this is less certain than the risk of cardiovascular issues, and said that these conditions can take years to appear. 

Yet, another study, published in the British Medical Journal found that there was a 1.8 higher risk of cognitive decline and a 1.39 higher risk of depression in the year after Covid infection.

Diabetes ‘discovery’

Recent studies also suggest that the pandemic could cause “a legacy of chronic illnesses” including Type 2 diabetes, another study, published in Nature, has suggested.

The study found that “even mild SARS-CoV-2 infections can amplify a person’s chance of developing diabetes, especially for those already susceptible to the disease”. 

This corroborated findings in another similar study, published in The Lancet, which suggested that people who have had Covid have 40% more chance of developing Type 2 diabetes in the year afterwards.

Eric Renard, vice-president of the Société francophone du diabète, told FranceInfo that this is because “Covid-19 stresses the body, which can reveal latent diabetes”.

He said that he does not believe that Covid itself causes diabetes, but simply enables it to become apparent in already-susceptible people.

“These patients will simply have discovered their diabetes in an unusual way,” he said.

‘Still-rare’ diseases

Despite the proliferation of studies, Dr Robineau has been careful to warn that “we must remain calm”. He said that while the studies show "an indisputable excess risk", they are “still rare events”. 

“We are not going to have an epidemic of pulmonary embolisms,” he said, and added that smoking and a poor diet still carry far more risk when it comes to the development of cardiovascular issues.

Dr Jérôme Larché, regional head of monitoring Long Covid in the Occitanie region, said: “There is no reason to scare people for whom the infection has gone, and they feel perfectly well. All we need to do is encourage them to see a GP if they have an issue.”

He said that identifying people who have contracted long-term issues is already a “major challenge”.

Prof Cohen added that another priority is simply to “make up for the delay in treating many patients” whose medical interventions were delayed “because of the pandemic”.

Further work is needed on the after-effects of Covid, as these studies are still new and only focused on certain population types (men, veterans, older people).

Similarly, while the studies suggest that long-term effects did affect some people who contracted a mild form, the more severe effects are still found among those who had a severe form of the virus. This is good news for those who had a less-severe form of the virus since the onset of Omicron.

Yet, Dr Larché said that the studies highlight the ongoing importance of not getting infected if possible, and continuing to “use all possible levers to avoid being contaminated, from vaccination to wearing a mask". 

He said: "Covid-19 is anything but a small, transient infection with no consequences."

Current Covid situation in France

It comes as recent figures suggest that France could be past the peak of the latest wave of the virus, and some doctors claim that the virus is largely “over” in the country (although others disagree).

Read more: Coronavirus: Daily updates on the situation in France 

The latest situation on April 11, 2022, the latest official statistics available recorded at 14:00:

  • Recorded new cases in France in previous 24 hours: 25,492
  • New deaths: 178 (total number of deaths in France now 143,466)
  • Rate of positive tests: 32.1%
  • Number of people having received at least one Covid-19 vaccine dose: 54,284,456 (+240 in the 24 hours to April 10 the date of the latest update)
  • Number of people having received three doses: 36,144,950 (+1,636 in the 24 hours to April 10, the date of the latest update)

Related articles

Is France past the peak of Covid cases? Latest figures

Is Covid ‘over’ in France? Doctors disagree and debate

France Covid: fourth vaccine dose now being offered to over-60s

Resident or second-home owner in France?
Benefit from our daily digest of headlines and how-to's to help you make the most of life in France
By joining the newsletter, you agree to our Terms & Conditions and Privacy Policy
See more popular articles
The Connexion Help Guides
featured helpguide
Healthcare in France*
Featured Help Guide
- Understand the French healthcare system, how you access it and how you are reimbursed - Useful if you are new to the French healthcare system or want a more in-depth understanding - Reader question and answer section Aimed at non-French nationals living here, the guide gives an overview of what you are (and are not) covered for. There is also information for second-home owners and regular visitors.
Get news, views and information from France