Type 1 and Type 2 Diabetes Increases Risk for Severe or Fatal COVID-19 Infection

At home during Lockdown. Real people in their real environment. A nurse helping a senior woman perform a diabetes test
In addition to a diabetes diagnosis, people with a history of smoking and who have specific comorbidities, such as heart disease, liver disease, and chronic lower respiratory disease, are at increased risk of poorer COVID-19 outcomes.

Patients with type 1 and type 2 diabetes face substantially higher risks of fatal or critical events with a COVID-19 diagnosis, shows a study published in The Lancet Diabetes and Endocrinology.

To date, more than one-quarter of people admitted to the hospital in Scotland for COVID-19 treatment have also had diabetes, which is a known risk factor for poorer outcomes following a COVID-19 diagnosis. However, not all patients respond with the same degree of severity. In this study, researchers led by Helen M. Colhoun, MD, FRCP, of the University of Edinburgh, United Kingdom, evaluated data from the first wave of the pandemic in Scotland focusing on COVID-19 patients with diabetes.

The study is based on an assessment of data collected between March 1 to July 31 that showed of 5,463,300 Scottish residents, 319,349  had diabetes and of these, 1,082 developed fatal or critical care level COVID-19 and 963 died. Of all diabetes patients, 2,724 had evidence of COVID-19.

Compared with the general population, risk for severe or fatal COVID-19 was associated with diabetes (odds ratio [OR], 1.395; 95% CI, 1.304-1.494; P <.0001). Stratified by type, those with type 1 had a more elevated risk (OR, 2.396; 95% CI, 1.815-3.163; P <.0001) than persons with type 2 (OR, 1.369; 95% CI, 1.276-1.468; P <.0001).

Among patients with diabetes, 2.8% of the patients who were 50 years old or younger and 89.9% people who were at least  60 years developed severe or fatal infections (OR, 1.044; 95% CI, 1.036-1.051; P <.0001); as did 0.4% of men and 0.3% of women (OR, 0.535; 95% CI, 0.470-0.608; P <.0001).

Increased risk for severe or fatal infection among patients with diabetes was associated with living in a care home (OR, 10.828; 95% CI, 9.251-12.675; P <.0001), hospital admittance during previous year (OR, 1.595; 95% CI, 1.481-1.717; P <.0001), neurologic or dementia comorbidities (OR, 1.273; 95% CI, 1.081-1.499; P =.0038), body mass index (OR, 1.091; 95% CI, 1.047-1.136; P <.0001), number of diabetic drugs prescribed (OR, 1.065; 95% CI, 1.004-1.129; P =.036), number of anatomical therapeutic drugs prescribed (OR, 1.027; 95% CI, 1.013-1.041; P =.0002), and glycated hemoglobin (OR, 1.005; 95% CI, 1.001-1.009; 95% CI, P =.0084).

These findings were likely limited by the underlying diversity of the Scottish population and may not be generalizable to more diverse areas.

The study authors concluded individuals with type 1 or type 2 diabetes had substantially increased risk for developing severe or fatal COVID-19, especially among older individuals.

“For the first time, to our knowledge, we have shown that people with recent admissions history for hypoglycaemia and diabetic ketoacidosis have an increased risk of severe or fatal disease. People with a history of smoking had increased risks.

Prior specific comorbidities, including heart disease, liver disease, and chronic lower respiratory disease, also increased risk. We showed for the first time, to our knowledge, that being exposed to more drug classes and having more previous hospital admissions are markers of risk,” the authors wrote.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.


McGurnaghan S J, Weir A, Bishop J, et al. Risks of and risk factors for COVID-19 disease in people with diabetes: a cohort study of the total population of Scotland. Lancet Diabetes Endocrinol. 2021;9(2):82-93. doi: 10.1016/S2213-8587(20)30405-8.