There is both good and bad news in the findings from a massive new UK study tracking half a million subjects for up to a year following COVID-19. The study found COVID patients were at significantly greater risk of cardiovascular problems and new diabetes diagnoses for many weeks after an infection, however, that risk did return to baseline after several months.
Alongside the acute challenges of COVID-19 and the distinct persistent condition of long COVID, researchers are increasingly seeing that recovered patients suffer higher rates of stroke, diabetes and heart disease in the months following an infection. But the long-term outcomes from COVID-19 are still unclear.
One of the largest longitudinal studies on the subject was published earlier this year. From Washington University, around 150,000 COVID cases were followed for up to 12 months. Those subjects were 55 percent more likely to experience a serious cardiovascular event in the year after recovering.
This new research, led by a team from King’s College London, looked at health records from 428,650 COVID-19 patients in the United Kingdom. Each patient was demographically matched against a control patient and two specific health outcomes were tracked in the 12 months following COVID infection: new diagnoses of cardiovascular disease and diabetes.
To paint a more accurate picture of the temporal risks of COVID in the months after infection, the follow-up period was split into three categories: acute COVID (the first four weeks after infection), post-acute-COVID (five to 12 weeks after infection), and long COVID (13 to 52 weeks after infection).
In terms of new diabetes diagnoses, the study found a patient’s risk spiked 81 percent in the first four weeks after COVID-19. Across the first three months post-COVID that diabetes risk remained at around 27 percent above average before returning to baseline about five to six months after the initial infection.
Risk of cardiovascular events tracked along a similar timeline, with a six-fold increase in heart conditions diagnosed across the first month after an infection. This increased risk declined slowly over the following weeks and returned to baseline levels by three months.
“Use of a large, national database of electronic health records from primary care has enabled us to characterize the risk of cardiovascular disease and diabetes mellitus during the acute and longer-term phases following COVID-19 infection,” explained lead author Emma Rezel-Potts. “Whilst it is in the first four weeks that COVID-19 patients are most at risk of these outcomes, the risk of diabetes mellitus remains increased for at least 12 weeks.”
While the cardiovascular complications associated with COVID-19 are well-characterized, it is still unclear exactly how the disease could be influencing the onset of diabetes. It has been hypothesized that contact with the health system due to COVID has led to doctors catching more cases of undiagnosed diabetes but there also is a suggestion SARS-CoV-2 could be directly, or indirectly, damaging pancreatic cells and hastening the onset of diabetes in those already predisposed to the disease.
Ultimately it will take time and further research to understand exactly what the longer term impacts are from one, or more, bouts of COVID-19. Co-author on the study Ajay Shah said these findings should help doctors and patients stay on the lookout for these conditions as one recovers from an acute case of COVID.
“The information provided by this very large population-based study on the longer-term effects of COVID-19 on development of cardiovascular conditions and diabetes will be extremely valuable to doctors managing the millions of people who have had COVID-19 by now,” said Shah. “It is clear that particular vigilance is required for at least the first three months after COVID-19.”
The new study was published in PLOS Medicine.