Background and aims: Few studies have reported on the use of continuous glucose monitoring (CGM) during the Covid-19 pandemic . We aimed to examine glycemic control metrics using flash glucose monitoring during insulin treatment and the clinical outcome in hospitalized patients with COVID-19.

Methods: Prospective, single-center cohort of adult patients diagnosed with type 2 diabetes or hyperglycemia and COVID-19 infection treated with basal bolus insulin regimen . Glycemic control was assessed with the use of intermittent Freestyle Libre flash glucose monitoring during the hospital stay . Outcome of interest were time in range [TIR], time above [TAR] and below [TBR] range, glycemic variability [coefficient of variation [% CV] ), and differences in a composite of complications including ICU admission, acute respiratory distress syndrome (ARDS) and acute kidney injury .

Results: A total of 60 patients were included (44 known diabetes and 16 new onset hyperglycemia). In total 190,080 data points of CGM were available, of which 72.5% of values were within the target area [TIR (70–180 mg/dL) ], 22% TAR (> 180 mg/dL), and 3% were TBR (< 70 mg/dL). During treatment, the coefficient of variation (% CV) was 30% . There were no association with TIR, but patients with TAR> 180 mg/dl had higher rates of a composite of complications (22.5% vs 16%, p = 0.04).

Conclusions: Basal bolus insulin regimen was safe and effective in achieving inpatient glycemic control in most patients with COVID-19. The association between TAR and complications indicates the need for improved inpatient glycemic control in hospitalized patients with COVID-19.