Causes & What We Know/October 23, 2026/2 min read

COVID-19 and Type 2 Diabetes: What a Large Study Found

A new analysis of millions of people shows SARS-CoV-2 infection was linked to a higher risk of developing type 2 diabetes, though the connection varied by COVID variant. The findings add to our understanding of how COVID-19 may affect metabolism.

PubMed indexed literature

Evidence label explains the kind of source behind this article (for example peer-reviewed literature vs community video). It is not medical advice.

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Key takeaways

People who had SARS-CoV-2 infection showed a 25% increased risk of later developing type 2 diabetes in pooled data from 15 studies covering nearly 49 million participants.
The increased risk appeared strongest in studies that included multiple COVID variants, but was not found in studies looking only at Delta or Omicron variants alone.
The connection between COVID-19 and type 1 diabetes did not reach statistical significance, meaning researchers cannot yet confirm a link.
Globally, the researchers estimated COVID-19 infection may have contributed to millions of new type 2 diabetes cases in 2023.

The Question Behind the Research

Since the start of the COVID-19 pandemic, doctors and researchers have noticed that some people developed diabetes or worsening blood sugar control after having SARS-CoV-2 infection. But whether COVID-19 actually increases the risk of developing diabetes for the first time—and by how much—has remained unclear. A large international review published in Frontiers in Immunology set out to answer this question by analyzing years of patient data.

What the Researchers Found

The team reviewed 15 studies that tracked nearly 49 million people. When they combined the results, they found that people who had been infected with SARS-CoV-2 had a 25% higher risk of developing type 2 diabetes later compared to those who had not been infected. However, the strength of this link varied depending on which COVID variant people were exposed to.

When researchers looked only at studies tracking single variants—either Delta or Omicron—they found no excess risk of type 2 diabetes. But studies that included multiple variants showed a stronger association. This suggests that the variant circulating at the time may matter for understanding COVID-19's relationship to diabetes risk.

What About Type 1 Diabetes?

The researchers also looked for a link between COVID-19 infection and type 1 diabetes. They analyzed 10 studies on this question and found a possible increase in risk, but the evidence was not strong enough to reach conventional statistical significance. In other words, based on current data, researchers cannot yet confirm that SARS-CoV-2 infection increases the risk of developing type 1 diabetes.

What This Means

This large review suggests that COVID-19 infection may have real effects on metabolism and blood sugar control, particularly regarding type 2 diabetes risk. The variation in results across different variants underscores that our understanding is still evolving. More research is needed to explain why this connection exists and whether certain people are at higher risk than others.

For the type 1 diabetes community, the current evidence does not support a strong link between SARS-CoV-2 and new-onset type 1 diabetes, though ongoing research continues to monitor this question.

Evidence label

Source: Frontiers in immunology. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.

Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.

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