Association between COVID-19 and new-onset Diabetes

Summary:

This study demonstrates a greater risk of getting diabetes after catching COVID-19, especially for older men.

Lacy, M.E. et al., (2025) summarised by Nikky Yusifova

Introduction

Studies conducted during the COVID-19 pandemic have demonstrated an association between this infection and the development of long-term conditions, including new-onset diabetes. According to the latest analysis, there is an average 66% increase in the risk of new-onset diabetes among individuals with documented COVID-19, compared to those without the infection. However, the wide disparity of reported risk prompted the authors to adopt a consistent study design and analytical approach to reach statistically robust conclusions.

Summary

This study analysed three U.S. based populations to investigate the risk of new-onset diabetes following COVID-19 infection, while accounting for risk factors such as pre-existing conditions, hospitalisation, and severity of illness. The first dataset comprised electronic health records of nearly 900,000 patients from University of Kentucky HealthCare, covering the period from January 2017 to October 2022. The second population, sourced from the MarketScan database, included approximately 9 million individuals from January 2009 to December 2021. The third dataset was a custom extract from MarketScan, enhanced with linked laboratory data, encompassing 1.4 million individuals from January 2018 to December 2020.

All datasets included records of inpatient, outpatient, and emergency encounters, laboratory results and medications. Individuals were categorised into COVID-positive and COVID-negative cohorts, across both pre-pandemic and pandemic periods. Where possible, the study distinguished between type 1 diabetes and type 2 diabetes. Across all three datasets, individuals in the COVID-positive cohort were more likely to be female and to present with metabolic risk factors such as hypertension, prediabetes, overweight/obesity, and depression.

In every dataset, the incidence of new-onset diabetes was significantly higher among COVID-positive individuals than in the COVID-negative cohort. Shared risk factors for new-onset diabetes included male sex, age over 65 (compared to under 25), and hospitalisation due to COVID-19. While type 2 diabetes was more common, type 1 diabetes was also frequently observed after COVID-19, particularly among children. The incidence of type 1 diabetes in children was notably higher in the COVID-positive group than in the COVID-negative group. Patients diagnosed with COVID-19 in an inpatient setting had a greater risk of developing diabetes compared to those treated in outpatient settings. The presence of comorbidities such as obesity further increased the likelihood of developing diabetes after COVID-19.

Conclusion

This study examined three large-scale datasets to assess the association between COVID-19 infection and new-onset diabetes. In all datasets, the incidence of diabetes was significantly higher in the COVID-positive cohorts compared to both pre-pandemic and COVID-negative cohorts. Despite a higher proportion of females having COVID-19 in the datasets, males presented a greater risk of developing new-onset diabetes. Individuals aged 65 and older also had an elevated risk. Overall, the findings suggest that the risk of new-onset diabetes following COVID-19 may be higher than previously reported in many earlier studies.

Read the study here