Impact of Basal Bolus Insulin Therapy on Glucose Control and Mortality in Patients with Type 2 Diabetes Hospitalized With COVID-19: A Retrospective Study

Introduction:
Insulin is the mainstay of diabetes therapy in the inpatient setting. However, the treatment of diabetes in patients with COVID-19 remains unclear. In this study we investigate the influence of different insulin regimens and other antidiabetic medications on glucose control in COVID-19 patients with type 2 diabetes.

Methods:
We conducted a retrospective electronic medical record analysis of 359 type 2 diabetes patients hospitalized with COVID-19 in the Emek Medical Center. We divided the patients into two groups based on their diabetes treatment during hospitalization. The first group included patients treated only with insulin, and the second group of patients were treated with insulin and other classes of antidiabetic drugs

Results:
Of 359 patients, 82 were mechanically ventilated and 110 patients suffered a severe course of COVID-19. During hospitalization, most of the patients in the combination therapy group received metformin on top of insulin (131 out of 162, 80%), 28 patients (17%) received SGLT-2 inhibitors, 12 (7%) were treated with DPP-IV or GLP-1 agonists. Average blood glucose was higher in patients treated only with insulin 192±69 mg/dl versus 169± 59 in the second group ( p=0.003). HbA1C levels improved after hospitalization in both groups of treatment, and overall: A1C levels before admission were 7.9±1.9 mg% and after 7.5±1.7 mg% (P=0.002).

Conclusion:
Our study shows that new antidiabetic medications, such as incretin-based therapy and SGLT-2i, as well as metformin in combination with insulin may be safe, and effectively control glucose levels in hospitalized COVID-19 patients with type 2 diabetes.