Routine HbA1c measurement may help detect diabetes in COVID-19 patients

Testing for glycated haemoglobin (HbA1c) levels in admitted COVID-19 patients may facilitate the timely detection of diabetes, a recent study has found.

Researchers conducted a retrospective analysis of 462 COVID-19 inpatients (mean age 56.8 years, 53.8 percent men), of whom 76 had diabetes before admission. During hospitalization, 40 patients were eventually diagnosed with diabetes according to fasting blood or random blood glucose levels. Patients with diabetes were significantly older, heavier, more likely to be male, and had worse kidney function.

Of the 116 cases of diabetes, 34.4 percent were detected only after routine HbA1c measurement upon admission. Those who had overlooked diabetes showed significantly lower Hb1Ac levels than those with prediagnoses (7.1 percent vs 7.5 percent; p<0.05). Casual blood glucose (157 vs 179 mg/dL; p<0.05) and daily insulin usage during hospitalization (16.0 vs 34.5 units; p<0.05) were likewise lower among those with overlooked diabetes.

Logistic regression analysis found that patients with overlooked diabetes were more than 50 percent more likely to develop more severe COVID-19 than those who had been prediagnosed, but this effect fell short of statistical significance (odds ratio, 1.57, 95 percent confidence interval, 0.93–2.69; p=0.072). Diabetes overall was a significant indicator of COVID-19 aggravation, increasing such likelihood by more than twofold.

“In our study, 8.7 percent of patients with COVID-19 were diagnosed with diabetes only after the HbA1c levels were measured on admission,” the researchers said. “In patients with both COVID-19 and diabetes, a high HbA1c level is a risk factor for severe disease. Therefore, it is important to measure HbA1c levels in patients with COVID-19.”