The following is a summary of some recent studies on COVID-19. They include research that warrants further study to corroborate the findings and that has yet to be certified by peer review.

Type 2 diabetes risk rises after COVID-19

People may be at increased risk for developing diabetes for up to a year after a diagnosis of COVID-19, according to two studies.

One study used data from the U.S. Department of Veterans Affairs to track more than 181,000 adults with COVID-19 for a year after recovery. Comparing these patients to more than 8 million people not infected with the coronavirus, researchers found that among every 1,000 people, there were 13 more new cases of diabetes among the COVID-19 patients after 12 months than among the uninfected individuals.

The COVID-19 group also had an extra 12 people per thousand who started taking medication for diabetes. Overall, two of every 100 people with COVID-19 developed diabetes in the year afterward, Ziyad Al-Aly of the VA St. Louis Health Care System said on Twitter. After accounting for other risk factors, including how often subjects in both groups saw their doctors, that translated to a 40% higher risk after COVID-19, his team reported on Monday in The Lancet Diabetes & Endocrinology. The higher risk for diabetes was evident even in people who had mild or asymptomatic COVID-19 and even in people who did not have any other risk factors for diabetes, Al-Aly told Reuters.

In a separate study of 35,865 people with COVID-19 published last week in Diabetologia, researchers found a 28% higher risk of developing diabetes compared to a group with non-COVID upper respiratory infections. Nearly all new cases in both studies were type 2 diabetes, which can sometimes be controlled by weight loss and diet changes. The authors all recommend that COVID-19 survivors with symptoms of diabetes, such as excessive thirst or frequent urination should seek medical attention.

Organ transplants from donors who had COVID likely safe

Organ donation from dying donors with current or previous COVID-19 infection is likely safe, transplant teams from the United States and Italy will report next month at the European Congress of Clinical Microbiology & Infectious Diseases.

Both teams are expected to outline their experimental protocols for use of such organs. Dr. Cameron Wolfe and Dr. Emily Eichenberger, from Duke University Medical Center in North Carolina, will advise that lungs or intestines should only be used if the donor last tested positive for the virus more than 20 days prior, while other organs can be transplanted safely if the donor was not dying of COVID-19 or having excessive blood clotting, the conference organizers said in a statement.

Professor Paolo Grossi of the University of Insubria in Italy and colleagues have transplanted livers, hearts, and kidneys from SARS-CoV-2-positive donors. "As we move deeper into 2022, the transplant community will undoubtedly learn more about using various organs from donors with recent or active COVID-19," Grossi wrote in an advance copy of his presentation seen by Reuters. "Although the published data are encouraging, the safety of deceased donors in these scenarios is (unproven) given the small sample size of the published studies," he said.

Neuropsychiatric after-effects not unique to severe COVID-19

Neurological, psychiatric and cognitive problems are often reported by patients who were hospitalized for severe SARS-CoV-2 infections, but those problems are not unique to COVID-19 survivors, a new study suggests.

Researchers in Denmark compared 85 survivors of severe COVID-19 to 61 closely matched patients who were similarly ill during the pandemic with other diseases. Six months after patients first became sick, "the overall burden of neuropsychiatric and neurologic diagnoses and symptoms appeared similar" in the two groups, according to a report published on Wednesday in JAMA Psychiatry. Cognitive impairment was worse in the COVID-19 survivors, but the absolute difference was small, the researchers said. They point out that persistent neuropsychiatric and cognitive symptoms are known to follow hospitalizations involving heart attacks, over-activated immune responses, and stays in intensive care units. They said this study's findings highlight the importance of including well-matched control groups when investigating the after-effects of COVID-19.