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Diabetes Qualified

COVID-19 and Diabetes

COVID-19 and Diabetes

Article by Carolien Koreneff, CDE-RN, FADEA

It has been nearly three years since the first case of the novel coronavirus SARS-CoV-2 was detected. Initially, there were fears that people with diabetes may be at greater risk of acquiring COVID-19. However, this does not appear to be the case.

What is clear is that both diabetes and uncontrolled hyperglycaemia are risk factors for infection including severe COVID-19. Studies on in-patients suggest a four-fold increase in mortality in these groups.

A few different mechanisms that have been linked to the increased risk of severe COVID-19 in people with diabetes include:

  • The counter-regulatory stress response is often increased in infections, including COVID-19 infections, which can cause hyperglycaemia.
  • Angiotensin-converting-enzyme 2 (ACE2) has been found to be the receptor for the coronavirus spike protein.
  • Acute hyperglycaemia seems to upregulate ACE2 expression on cells which may allow the coronavirus to enter. And the coronavirus itself may damage islet cells in the pancreas directly.1

Many people with diabetes who acquired COVID-19 developed ketoacidosis and hyperosmolarity, and needed high doses of insulin to combat the excessive hyperglycaemia.

Dexamethasone is often used to treat people with severe COVID-19 who need oxygen treatment, this can lead to insulin resistance, hyperglycaemia and increased insulin requirements.

The good news is, that effective management of blood glucose levels in people with diabetes and COVID-19 leads to better outcomes and lower mortality.2

COVID-19 and developing new onset diabetes

SARS-CoV-2 has been associated with new onset diabetes. However, research conducted so far has differed significantly in criteria, and hence it is difficult to compare the findings and draw conclusions. For example, some only looked at children, others only at adults.

A study in the UK found that the net incidence for the development of diabetes increased in the first 4 weeks after COVID-19. They also found that it remained elevated from 5 to 12 weeks before declining. The authors additionally suggest that people who did not have diabetes before COVID-19 do not appear to have a long-term increase in the incidence of diabetes.3

An American group found that persons under the age of 18 who had COVID-19 were more likely to receive a new diagnosis of diabetes 30 days or more after the infection than the control group of people who did not have a COVID infection and those with pre-pandemic respiratory infections. Non-SARS-CoV-2 respiratory infections were not associated with an increased risk for diabetes.4

It should be noted that a large group of people who have COVID-19 and hyperglycaemia may have previously undiagnosed diabetes, as indicated by a significantly elevated HbA1c.

Another thing to consider is that we do not yet fully understand if, or when, blood glucose levels will return to normal after the person has recovered from COVID-19. One study found that, in nearly 50% of people, blood glucose levels returned to normal within a month after hospitalisation for COVID-19 and hyperglycaemia.5

Registry of COVID-related Diabetes NSW

An international group of leading diabetes researchers, including researchers from Monash University, are establishing a global registry of COVID-19 related diabetes.

This registry is specifically designed to establish the extent and characteristics of new-onset, COVID-19-related diabetes and to investigate its pathogenesis, management and outcomes. The registry also collects data about presentations with severe metabolic disturbance in pre-existing diabetes (DKA, hyperosmolarity, severe insulin resistance).6

To ensure the timely acquisition of a sufficiently large set of observations, the registry will draw data from across the world. If you, or your organisation, would like to contribute to the registry you can register here.


  1. https://tangello.com.au/diabetes-management-journal/dmj-feb-2022 page 18
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7266597/
  3. https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1004052
  4. https://www.cdc.gov/mmwr/volumes/71/wr/mm7102e2.htm?_ga=2.138781360.242886239.1642019673-45613661.1642019673
  5. https://www.sciencedirect.com/science/article/pii/S1056872722000253?dgcid=rss_sd_all
  6. http://covidiab.e-dendrite.com/