Severity of SARS-CoV-2 Illness in Patients With Type 1 and Type 2 Diabetes Mellitus

Diabetes is a well-known risk factor for the severity of illness in patients with SARS-CoV-2 infection (COVID-19). However, there is less published data on illness severity differences between patients with type 1 (T1D) and type 2 (T2D) diabetes mellitus.

We performed a retrospective review of records of patients with COVID-19 (March 2020 - November 2020) extracted from a large, private hospital system database. Of the 76 467 patients with COVID-19, 54 007 (70.6%) did not have a diabetes diagnosis (NON), 22 084 (28.9%) had T2D, and 376 (0.49%) had T1D. We further subgrouped diabetic patients into groups with A1C above 7% (T2D7 and T1D7) or above 8% (T2D8 and T1D8). Logistic regression analysis was used to determine the association between selected predictor variables and our primary outcome variables of ventilator, intensive care unit (ICU) admission, mortality, and length of stay.

Patients with T2D were substantially older (62.9 years) than NON (48.8) or T1D (43.2). The proportion of Black, White, and other race patients was similar, with a somewhat higher proportion of Black patients having T1D. Patients with T1D and T2D had significantly higher odds of requiring a ventilator, being admitted to ICU, and had a higher mortality rate than NON. As an example, T1D had 5.68 higher odds and T2D 1.82 higher odds of ICU admission compared to NON. T2D patients with A1C above 7% or 8% were roughly 2 times more likely to require a ventilator, were less likely to be admitted to the ICU, and had a roughly 3-day longer length of stay than T1D patients with A1C above 7% or 8%.

Both T1D and T2D were independent predictors of illness severity for SARS-CoV-2 patients, leading to higher odds of requiring ventilation, ICU admission, mortality, and hospital stay duration. Our older patient group with T2D had somewhat worse outcomes and longer hospital stays than T1D.