Regardless of Diabetes Status, Tight Glucose Control Reduces Risk for Severe Disease in COVID-19

blood glucose test and covid
person doing fingertip test for blood glucose, with vacuum tube for blood testing of test blood with covid-19 label
Hyperglycemic patients treated with insulin infusion to maintain tight glucose control were at lower risk for severe disease in COVID-19.

Improved glycemic control may improve outcomes in patients with novel coronavirus disease 2019 (COVID-19) and hyperglycemia, according to study results published in Diabetes Care.

Patients with COVID-19 may present with stress hyperglycemia, which can cause overproduction of inflammatory cytokines and exacerbate disease progression. To determine whether tight glycemic control is warranted in patients with COVID-19 with moderate disease, investigators evaluated the effects of hyperglycemia on disease markers and outcomes in patients with COVID-19.

Patients with COVID-19 with moderate pneumonia were grouped based on diabetes status and normoglycemic or hyperglycemic status, which was defined as an admission plasma glucose level >7.7 mmol/L. Clinical markers, including blood interleukin 6 (IL-6) and D-dimer levels and chest radiographs/computed tomography scans were assessed at admission and weekly intervals during hospitalization.

The composite outcome of interest was admission to an intensive care unit, the use of mechanical ventilation, or death.

Of the 59 patients (81.4% men) included in the analysis, 25 (42.4%) were hyperglycemic, of whom 18 (72.0%) were diagnosed with diabetes prior to admission. In the normoglycemic group, 8 patients (23.5%) had diabetes. At admission, IL-6 and D-dimer levels were higher in patients with hyperglycemia than in patients with normoglycemia (P <.001). Elevated IL-6 and D-dimer levels persisted at 1 and 2 weeks after admission in patients with hyperglycemia.

At 7 days after admission, imaging revealed that pneumonia had progressed in 40% of patients with hyperglycemia compared with 8.8% of patients with normoglycemia (P <.01). The composite endpoint occurred in 52% of patients with hyperglycemia and 14.7% of patients with normoglycemia (P <.01). Patients with and without diabetes who had hyperglycemia were both at higher risk for severe disease than patients with normoglycemia (P <.05 for both).

Patients with hyperglycemia with blood glucose levels >9.9 mmol/L (n=15) received continuous insulin infusion (50 U in 50 mL NaCl), which was halted when blood glucose levels fell to <7.7 mmol/L for ≥24 hours (mean duration of infusion, 32.7 hours). All patients with hyperglycemia received subcutaneous insulin injections starting at admission or after insulin infusion was stopped.

Plasma glucose reduction was greater in patients who received insulin infusion (4.57±1.09 mmol/L) than in those who did not (1.96±1.06 mmol/L; P <.001). During hospitalization, IL-6 and D-dimer levels were higher in the group that did not receive insulin infusion than in the group that did received intravenous insulin (P <.001).

Radiographic assessment of the lungs showed that pneumonia progressed in 70% of hyperglycemic patients without insulin infusion compared with 20% in hyperglycemic patients who received infusion (P <.01). The composite endpoint occurred in 33% and 80% of the infusion and noninfusion groups, respectively (P <.01). Hyperglycemic patients treated with insulin infusion were at lower risk for severe disease than those who did not receive insulin infusion (P <.01).

The researchers noted that the small cohort size and the lack of random assignment of patients to insulin infusion represented limitations of the current study.

“Our key message is that optimal glycemic control during hospitalization has been associated with [reduced] risk of severe disease and death in patients with [COVID-19],” the study authors concluded. “Thus, in the critical care setting, insulin infusion may be an effective method for achieving glycemic targets and reducing mortality in patients with [COVID-19].”

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Sardu C, D’Onofrio N, Balestrieri ML, et al. Outcomes in patients with hyperglycemia affected by Covid-19: can we do more on glycemic control? [published online May 19, 2020]. Diabetes Care. doi:10.2337/dc20-0723