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The Connections Between COVID and Diabetes


Community Health Workers connect with workers in the field

People who had COVID are 40% More Likely to Develop Diabetes, According to New Study, And People with Diabetes Are Also More Likely to Develop Severe COVID and Long COVID

Over the last two and a half years, as thousands of COVID patients cycled through the rural hospital where I work in Pennsylvania, I have noticed a concerning trend. When I see young, seemingly healthy patients with no comorbidities, who are very ill with COVID, I check their A1C – and I have often found it to be very high. These patients had uncontrolled diabetes but were undiagnosed. Over a dozen patients fit this description; most of those patients were Latinx. Such anecdotes tell us nothing concrete about the connection between diabetes and severity of COVID.  New research, however, is beginning to show the complex and bidirectional relationship between diabetes and COVID.  While more studies need to be conducted to better understand the mechanisms driving these connections, data confirm that those with diabetes have a greater risk of severe acute COVID as well as long COVID. Additionally, and startlingly, those who had acute COVID have a higher likelihood of a new type 2 diabetes diagnosis in the months following infection.

From COVID to Diabetes:

One study in The Lancet Diabetes & Endocrinology found that of the 180,000 people seen through the Veterans Administration’s health care system, people who had COVID were about 40% more likely to develop diabetes, up to a year later, than those who didn’t have COVID.1 Even a mild case of acute COVID increases a person’s chance of developing diabetes, but the diabetes risk grew with increasing COVID severity. The authors used the same database review process earlier in the year to uncover the increased risk of heart disease after COVID.2 Diabetes could be defined as an aspect of long COVID, but without a uniform definition of long COVID, it’s hard to make that distinction concretely. Some people who develop diabetes after acute COVID have no other long COVID symptoms, but that doesn’t mean they do not have long COVID. The inflammatory processes that go on in the aftermath of an acute infection might be precipitating diabetes in some patients – we are just not sure yet. In one article, the authors found that COVID may be causing damage to the pancreas, which could worsen hyperglycemia and perhaps be responsible for the increased number of diabetes cases after COVID.3 Those inflammatory processes and organ damage could be the instigators of the wide range of symptoms we are calling long COVID. Those with pre-diabetes or diabetes who have severe COVID and are hospitalized are commonly administered dexamethasone (also known as its brand name, Decadron). However, dexamethasone temporarily increases glucose levels. Due to limited data, it is unclear what the effect dexamethasone may have on glucose levels in the longer term. More research is needed to determine whether the temporary increase in glucose levels may trigger some people who have pre-diabetes to develop diabetes. Despite the lack of understanding of the mechanisms, it is clear that after a case of COVID, a person is at greater risk of diabetes.

From Diabetes to COVID:

Diabetes is one of the most frequent comorbidities in people with COVID-19, with a prevalence somewhere around seven to 30%.4 People with diabetes who contract COVID are more likely to be hospitalized for COVID, more likely to have severe pneumonia, and are more likely to die of COVID. For patients with diabetes, it is more important than ever that they maintain control over their diabetes, to reduce the risk of a severe or deadly case of COVID.

From Diabetes to Long COVID:

A new study that was presented at the American Diabetes Association’s conference in June 2022 found that individuals with diabetes are up to four times more likely to develop long COVID.5 The study found that 43% of peer-reviewed studies that reported on long COVID and diabetes identified diabetes as a risk factor of long COVID. The limitations of the study were significant in the face of a lack of a uniform definition of long COVID, and more studies need to be completed with consistent definitions to confirm the findings. Nonetheless, these initial findings are concerning, particularly for an agricultural worker population.

The agricultural worker community may already have a higher burden of diabetes than the general population, although firm data are lacking.6,7 Numerous compounding factors like migration, rural locations and food deserts, lack of transportation, poverty, lack of health insurance, poor access to health care, and more reduce agricultural workers’ ability to get a diagnosis and maintain a care plan for diabetes, including an insulin regimen, regular exercise, and a balanced diabetes-appropriate diet. Consequently, it’s even more critical that this community is informed about the risks related to diabetes and COVID. Health care providers, Community Health Workers, outreach workers, and others working directly with the agricultural worker communities should inform people who have gotten COVID about their increased risk, as well as the signs and symptoms of diabetes. “Careful monitoring of glucose levels in at-risk individuals may help to mitigate excess risk and reduce the burden of lingering symptoms that inhibit their overall wellbeing,” said Jessica Harding, PhD, the lead author on the study linking diabetes and long COVID. Those already diagnosed with diabetes should be informed of their increased risk of severe COVID and long COVID.

The best way to avoid a COVID infection precipitating diabetes, or a diabetes comorbidity increasing severity of a COVID infection, is to not get COVID in the first place. There are certain aspects of the pandemic which are out of our control. Among agricultural workers, many must go to work and cannot work from home or change careers. With many obstacles in their way, they may struggle to keep their diabetes under control as they move for work, cannot get care, and live with very little. However, there is something concrete that everyone can do to reduce their risk of severe COVID: get vaccinated and stay up to date on boosters. If an agricultural worker, or anyone else, gets vaccinated and then gets COVID, that person is less likely to have a severe bout of COVID, compared to if the person is unvaccinated. There is also a correlation between severity of symptoms during acute COVID and severity of long COVID. Additionally, research is now indicating that getting vaccinated after a COVID infection may reduce the severity of long COVID.8 Some of this is still in our power. Make sure patients know that their best option is to get vaccinated.

1 Xie Y, Al-Aly Z. Risks and burdens of incident diabetes in long COVID: a cohort study. Lancet Diabetes Endocrinol. 2022;10(5):311-321. doi:10.1016/S2213-8587(22)00044-4

2 Xie Y, Xu E, Bowe B, Al-Aly Z. Long-term cardiovascular outcomes of COVID-19. Nat Med. 2022;28(3):583-590. doi:10.1038/s41591-022-01689-3

3 Lima-Martínez MM, Carrera Boada C, Madera-Silva MD, Marín W, Contreras M. COVID-19 and diabetes: A bidirectional relationship. COVID-19 y diabetes mellitus: una relación bidireccional. Clin Investig Arterioscler. 2021;33(3):151-157. doi:10.1016/j.arteri.2020.10.001

4 Lima-Martínez MM, Carrera Boada C, Madera-Silva MD, Marín W, Contreras M. COVID-19 and diabetes: A bidirectional relationship. COVID-19 y diabetes mellitus: una relación bidireccional. Clin Investig Arterioscler. 2021;33(3):151-157. doi:10.1016/j.arteri.2020.10.001

5 American Diabetes Association. Press Release: Individuals with Diabetes are Up to Four Times More Likely to Develop Long COVID-19. 04 June 2022. Available at:

6 National Center for Farmworker Health, Inc. Diabetes and US Agricultural Workers. 2014. Available at:

7 Moyce S, Hernandez K, Schenker M. Diagnosed and Undiagnosed Diabetes among Agricultural Workers in California. J Health Care Poor Underserved. 2019;30(4):1289-1301. doi:10.1353/hpu.2019.0102

8 Tran VT, Perrodeau E, Saldanha J, Pane I, Ravaud P. Efficacy of COVID-19 Vaccination on the Symptoms of Patients with Long COVID. 29 September 2021. Preprint. Available at:


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Migrant Clinicians Network
Chief Medical Officer