Elderly people with diabetes who contract COVID-19 are at a much higher risk of dying from the disease – and the virus may actually trigger the onset of diabetes in normally healthy people, an international review has found.

Published in Lancet Diabetes and Endocrinology, the review co-authored by Professor Paul Zimmet of Monash University finds that 20-50% of patients diagnosed with COVID-19 during the pandemic had diabetes.

The study authors says the data show that people with diabetes have an increased risk of severe complications including Acute Respiratory Distress Syndrome and multiple organ failure, including lung, heart and kidney failure.

“Evidence from epidemiological observations in regions heavily affected by COVID-19and reports from the Centres for Disease Control (CDC) and other national health centres and hospitals showed the risk of a fatal outcome from COVID-19 is up to 50% higher in patients with diabetes than in those who do not have diabetes,” they note.

However Professor Zimmet says the risk from COVID-19 in young people with type 1 diabetes appears to be much lower than in older people. Providing they have access to satisfactory health care and good control of their diabetes, he says that parents of children and adolescents with type 1 diabetes should be reassured on this issue.

The report also draws attention to the damage to pancreatic β cells seen in COVID-19 disease leading to insulin deficiency, suggesting the that infection could result in causing new onset diabetes. This is supported by the observation of Italian clinicians who have reported frequent cases of severe diabetic ketoacidosis (DKA) at the time of hospital admission.

It proposes implementation of testing for diabetes in people with the COVID-19 infection to identify if previously healthy individuals have developed diabetes as a result of contracting the virus.

“We should consider everyone who gets sick with COVID-19 is also tested for diabetes. They should be tested at the time they become ill as it clearly will influence their medical management and health outcome,” says Professor Zimmet.

The report includes suggestions on the potential metabolically interfering effects of drugs in suspected or COVID-19 positive patients with type 2 diabetes:

• Metformin

Dehydration and lactic acidosis will probably occur if patients are dehydrated, so patients should stop taking the drug and follow sick day rules;

During illness, renal function should be carefully monitored because of the high risk of chronic kidney disease or acute kidney injury;

• SGLT2 inhibitors

Risk of dehydration and diabetic ketoacidosis during illness, so patients should stop taking the drugs and follow sick day rules;

Patients should avoid initiating therapy during respiratory illness;

Renal function should be carefully monitored for acute kidney injury;

• GLP-1 receptor agonists

Dehydration is likely to lead to a serious illness so patients should be closely monitored;

Adequate fluid intake and regular meals should be encouraged;

• DPP-4 inhibitors

These drugs are generally well tolerated and can be continued;

• Insulin

Insulin therapy should not be stopped;

Regular self-monitoring of blood-glucose every 2–4 hours should be encouraged, or continuous glucose monitoring;

Carefully adjust regular therapy if appropriate to reach therapeutic goals according to diabetes type, comorbidities, and health status.