COVID-19 infection associated with greater likelihood of Type 2 diabetes, according to patient records review

People who had a COVID-19 infection were at greater risk of developing Type 2 diabetes within a year than those who managed to avoid the coronavirus, according to a large review of patient records released Monday.

The finding is true even for people who had mild or asymptomatic forms of COVID-19, though the chances of developing new-onset diabetes were greater as the severity of COVID-19 symptoms increased, according to researchers who reviewed the records of more than 181,000 Department of Veterans Affairs patients diagnosed with COVID-19 between March 1, 2020, and Sept. 30, 2021.

Their data was compared to the medical records of more than 4.1 million VA patients who were not infected during the same period and another 4.28 million who received medical care from VA in 2018 and 2019. This kind of study cannot prove cause and effect, but it showed a strong association between the two diseases.

Overall, the researchers calculated that people diagnosed with COVID-19, the disease caused by SARS-CoV-2, were 46% more likely to develop Type 2 diabetes for the first time or be prescribed medication to control their blood sugar. The research was released Monday in the Lancet Diabetes & Endocrinology, a medical journal.

Put another way, 2 in 100 COVID-19 patients were more likely to develop Type 2 diabetes, a condition in which the pancreas makes insufficient amounts of the hormone insulin, leaving blood sugar levels poorly controlled. Type 2 diabetes can damage kidneys, nerves, blood vessels and the heart, among its other effects.

The results have implications for the more than 471 million people known to have been infected during the pandemic, nearly 80 million of them in the U.S. and especially for people suffering from long-haul COVID-19.

“For the broader public, if you’ve had COVID-19, you need to pay attention to your blood sugar,” said Ziyad Al-Aly, chief of research and development at VA St. Louis Health Care System, who led the review.

Previous smaller studies and physicians who have treated COVID-19 patients have noted an apparent increase in new diabetes diagnoses associated with coronavirus infection. But Al-Aly said his review was the largest consideration of the issue and looked at the greatest length of time after the acute phase of an infection – from 31 days after infection to a median of nearly one year per patient.

VA patients tend to be older than the general population, with more white people and males. But Al-Aly said the large numbers of people involved made him confident that his findings were applicable to the public.

“The risk was evident in all subgroups,” including women, racial minorities, younger people and people with different body mass indexes, he said.

More than 99% of the infected VA patients developed Type 2 diabetes, as opposed to Type 1, a condition in which insulin-producing cells in the pancreas stop producing the hormone entirely. Al-Aly speculated that the cells’ reduced efficiency may be caused by inflammation, produced either by the virus itself or the body’s response to it.

“Taken together,” the researchers wrote, “current evidence suggests that diabetes is a facet of the multifaceted long COVID-19 syndrome, and that post-acute care strategies of people with COVID-19 should include identification and management of diabetes.”