Scientists are investigating a possible increase in diabetes cases since the beginning of the coronavirus pandemic.

Diabetes is a condition in which the body cannot control sugars in the blood.

The scientists want to find out if COVID-19 has a connection with the increase or if it is a coincidence.

Increase in diabetes

A report from the Centers for Disease Control and Prevention recently examined two large U.S. insurance databases. The databases included information about new diabetes cases from March 2020 through June 2021.

The study found that diabetes was more common in children who had had COVID-19. The report did not look at the difference between Type 1 diabetes, which usually starts in childhood, and Type 2, the kind tied to being overweight.

Rates of both kinds of diabetes have risen in U.S. children in recent years. But reports from Europe and some U.S. hospitals suggest the rates may have increased more during the pandemic.

Dr. Inas Thomas of the University of Michigan's C.S. Mott Children's Hospital said, "I think we're all a little worried."

Her hospital has seen a 30 percent increase in Type 1 diabetes, compared with the years before the pandemic, Thomas said. It is not known how many of the cases had COVID-19 at some point, but the timing raises concerns that there could be a connection, she said.

What causes diabetes?

Type 1 diabetes develops when the pancreas, an organ near the kidneys, produces little or no insulin, a hormone that controls blood sugar. It is thought to involve an autoimmune reaction. That means the body's defense system attacks insulin-making cells in the pancreas. Patients must use manufactured insulin to deal with the condition.

Experts have believed for a long time that some earlier infection may set off that autoimmune reaction.

With COVID-19, "We don't know if it's a direct effect or some other factor that's not fully understood yet, but we are hoping that this trend may help us figure out the trigger for what causes Type 1 diabetes," Thomas said.

At Rady Children's Hospital in San Diego, Type 1 diabetes cases jumped almost 60 percent during the first year of the pandemic, compared with the previous 12 months. Researchers recently reported the finding in the medical publication JAMA Pediatrics.

Just two percent of those children had had active COVID-19. The report did not have information on any previous infections. But the sharp increase was striking and "clearly there's a lot more work to be done to try to answer why is this happening,″ said Dr. Jane Kim. She co-wrote the report.

Type 2 diabetes mostly affects adults. It changes how the body uses insulin, leading to poorly controlled blood sugar. Causes are uncertain but genetics, too much weight, inactivity and unhealthy eating habits play a part. It can sometimes be treated or cured with lifestyle changes.

Around the world, more than 540 million people have diabetes, including about 37 million in the United States. Most have Type 2 diabetes. Many more have higher than normal blood sugar levels, or prediabetes.

Rising diabetes cases might reflect conditions involving pandemic restrictions. These could include delayed medical care for early signs of diabetes or unhealthy eating habits and inactivity in people already at risk for Type 2 diabetes.

A diabetes center at Chicago's La Rabida Children's Hospital has seen an increase in prediabetes during the pandemic. Center co-director Rosemary Briars suspects long hours of online learning without physical activity played a part.

Dr. Rasa Kazlauskaite is a diabetes specialist at Chicago's Rush University Medical Center. She said steroid drugs that are sometimes used to reduce inflammation in hospitalized patients with infections including COVID-19 can cause blood sugar increases leading to diabetes. Sometimes the condition goes away after steroids are stopped, but not always, she said.

The physical stress of severe COVID-19 and other illnesses can also cause high blood sugar and temporary diabetes, she added.

Does the virus have an effect on insulin production?

Developing evidence suggests that the coronavirus — like some other viruses — can attack insulin-producing cells in the pancreas. That process might cause at least temporary diabetes in some people.

To learn more, scientists in Denmark are getting adults recently diagnosed with Type 1 diabetes to take part in a study. The study group includes some people who had COVID-19.

Over time, the researchers try to find out whether the condition progresses faster in those who had COVID-19. Such a study could help show how or if the infection might affect the development of diabetes, said researcher Dr. Morten Bjerregaard-Andersen. He is a diabetes specialist at the Hospital of South West Jutland.

"The theory is if you had COVID-19, then your own insulin production will be more compromised than if you weren't infected," Bjerregaard-Andersen said.

I'm John Russell.

Lindsey Tanner reported on this story for the Associated Press. John Russell adapted it for VOA Learning English.

__________________________________________________________________

coincidence – n. the occurrence of events that happen at the same time by accident but seem to have some connection

autoimmune –adj. of or related to the system that protects the body against infection and disease

factor –n. something that helps produce or influence a result; one of the things that cause something to happen

trend – n. a general direction of change

reflect – v. to show (something) : to make (something) known

theory – n. an idea that is suggested or presented as possibly true but that is not known or proven to be true