Blood Sugar Fluctuations Lead to Poor Outcomes for Diabetes Patients with Coronavirus

Blood sugar levels of 70 to 160 mg/dL are considered normal, and anything outside these levels could negatively affect patients with diabetes and COVID-19.

According to a study in China, wide variations in glucose levels give patients diagnosed with coronavirus and diabetes an increased risk of developing adverse effects. This research was developed by monitoring patients’ blood sugars with diabetes and coronavirus during their hospitalization in Wuhan, China (where the pandemic originated). Therefore, it is advisable to initiate medication therapy in COVID-19 and diabetes patients with blood glucose levels less than 70 or greater than 160. The goal for initiating therapy is to get the patient’s glucose within a normal range, thereby improving their chances and decreasing their risks of developing adverse effects.

When looking at patients’ A1c levels, researchers determined that these levels may not be a good reference for coronavirus outcomes. A1c can show up normal in test results, even if it is not, in patients who regularly experience hypoglycemia and hyperglycemia. Because of the potential for a false normal result, A1c is not a good measure of glycemic fluctuation. When monitoring patients for glucose variability, only blood sugar levels should be measured and used.

The study was small and made up of 35 patients with diabetes. These patients were hospitalized after being diagnosed with coronavirus. Patients were observed with intermittently scanned continuous glucose monitoring (also known as isCGM). Of the 35 patients who participated in the study, 15 of them were either very ill, admitted to the intensive care unit, or put on ventilators. There was no mortality in any of the patients. The patients meeting the composite outcome criteria spent more time above blood sugar levels from 140 to 200 mg/dL than other patients. Patients meeting the composite outcome criteria spent 52.1 percent of their stay with their blood glucose levels above 160 mg/dL, whereas those who didn’t spent 29.8 percent of their hospital stay over 160 mg/Dl. The patient group that met the composite outcome criteria also spent more of their time with blood sugar levels below 70 than those who did not meet the criteria.

Adjustments had to be made for a lot of patient factors. The factors that required adjustments were glucocorticoid use, age, body mass index, sex, symptoms when admitted, and blood pressure. Once researchers adjusted the study, time spent above thresholds of 160 to 200 mg/dL and below 70 mg/dL were directly related to increased risk for adverse composite results of coronavirus and extended hospital stay. The average hospital stays for patients reaching the previously stated thresholds were over a month. Patients meeting the composite outcome also experienced a higher average glucose level, as seen on their isCGM. With all the data presented, there was no statistical significance between glucose levels and adverse composite outcomes in patients with diabetes and COVID-19.

It is believed that the increased risk of poor outcomes in patients with diabetes and coronavirus is due to abnormal humoral immunity, decreased T-cell function, and dysfunctional neutrophils. Because patients with diabetes are at an increased risk of adverse outcomes associated with COVID-19, they must do everything to prevent themselves from catching it. Aside from taking regular COVID-19 precautions such as always wearing a mask, social distancing, and handwashing, patients should also manage their disease state to mitigate risks. Patients should continue to check their blood sugar regularly, comply with their medication regimens, exercise regularly, and maintain a healthy weight and dietary habits.

Practice Pearls:

• Patients with diabetes whose blood sugar levels are below 70 mg/dL and above 160 mg/dL are at an increased risk of having adverse outcomes due to COVID-19.
• Researchers believe that the increased risk of poor outcomes in patients with diabetes and coronavirus is due to abnormal humoral immunity, decreased T-cell function, and dysfunctional neutrophils.
• Patients with diabetes must continue to manage their condition well to decrease the risks associated with COVID-19.

Miriam E. Tucker. Wide Glucose Swings Equal Poor COVID-19 Outcomes in Hospitalized Patients with Diabetes. Medscape, 25 February 2021.

Yun Shen, Xiaohong Fan, Thresholds of Glycemia and the Outcomes of COVID-19 Complicated with Diabetes: A Retrospective Exploratory Study Using Continuous Glucose Monitoring. American Diabetes Association, February 2021.

Oluwatayo Ishola, PharmD. Candidate, South College, School of Pharmacy

See more about diabetes and COVID-19.