Association of metformin, dipeptidyl dipeptidase-4 inhibitors, and insulin with COVID-19-related hospital outcomes in patients with type 2 diabetes

OBJECTIVE: The effects of diabetes medications on COVID-19 hospitalization outcomes have not been consistent. We sought to determine the effect of metformin, DPP-4 inhibitors (DPP-4i), and insulin on admission to the intensive care unit (ICU), need for assisted ventilation, development of renal insufficiency, and mortality, in patients admitted with COVID-19 infection after controlling for clinical variables and other relevant diabetes-related medications in patients with type 2 DM. METHODS: This was a retrospective study of patients hospitalized with COVID-19 from a single hospital system. Univariate and multivariate analyses were performed that included demographic data, HbA1c, kidney function, smoking status, insurance, Charlson comorbidity index, number of diabetes medications, use of angiotensin-converting enzyme inhibitors (ACEi) and statin prior to admission, and glucocorticoids during admission. RESULTS: A total of 529 patients with type 2 DM were included in our final analysis. Neither metformin nor DPP4i prescription was associated with ICU admission, need for assisted ventilation, nor mortality. . Insulin prescription was associated with increased ICU admission. Insulin prescription was not associated with need for assisted ventilation nor mortality. There was no association with any of these medications with development of renal insufficiency. CONCLUSIONS: In this population limited to type 2 diabetes, and controlling for multiple variables that have not been consistently studied (such as a measure of general health, HbA1c, insurance status), insulin prescription was associated with increased ICU admission. Metformin and DPP4i prescription did not have an association on the outcomes.