Insulin Use, Diabetes Control, and Outcomes in Patients with COVID-19.

Background: The novel coronavirus (SARS CoV-2) has caused significant morbidity and mortality in patients with diabetes. However, the effects of diabetes control including insulin use remain uncertain in terms of clinical outcomes of patients with COVID-19.
Methods: In this single-center, retrospective observational study, all adult patients admitted to Einstein Medical Center, Philadelphia, from March 1 through April 24, 2020 with a diagnosis of COVID-19 and diabetes were included. Demographic, clinical and laboratory data, insulin dose at home and at the hospital, other anti-hyperglycemic agents use, and outcomes were obtained. Multivariate logistic regression was used to evaluate the factors associated with diabetes control and mortality.
Results: Patients who used insulin at home had higher mortality compared to those who did not (35% vs 18% p = .015), this was true even after adjustment for demographics, comorbidities and a1c OR 2.65 95% CI (1.23-5.71) p = .013. However, the mean a1c and the median home requirements of insulin did not significantly differ among patients who died compared to the ones that survived. Patients who died had significantly higher inpatient insulin requirements (highest day insulin requirement recorded in units during hospitalization) 36 (11-86) vs 21 (8-52) p = .043 despite similar baseline a1c and steroid doses received. After adjusting for demographics, comorbidities and a1c, peak insulin requirements remained significantly associated with inpatient mortality OR 1.022 95% CI (1.00-1.04) p = .044.
Conclusion: Among diabetic patients infected with COVID-19, insulin therapy at home was significantly independently associated with increased mortality. Peak daily inpatient insulin requirements was also independently associated with increased inpatient mortality.