Impact of prediabetes with a high risk of diabetes stratified by glycated hemoglobin level on the severity of coronavirus disease 2019 during admission.

Objective: Prediabetes with a glycated hemoglobin (HbA1c) level of 5.7 - 6.4% is associated with a poor prognosis of coronavirus disease 2019 (COVID-19), but whether the degree of glycemic control is associated with COVID-19 severity is unknown. The aim of this study was to evaluate the association between the degree of glycemic control and COVID-19 severity in patients with prediabetes.

Materials and methods: We reviewed 254 patients with COVID-19 admitted to our hospital between April 2020 and September 2021. Based on their HbA1c level, patients were classified into low (HbA1c level < 5.7%), moderate (HbA1c level, 5.7 - 5.9%), and high risk of diabetes (HbA1c level, 6.0 - 6.4%). The association between risk of diabetes and the worst COVID-19 symptom in terms of severity during admission was evaluated using binary logistic regression analysis.

Results: Seventy-one and 88 patients had moderate and high risks of diabetes, respectively. Sixty-three and seven patients presented severe (requiring non-invasive oxygen therapy) or critical (intensive care unit admission or artificial respiratory management) COVID-19. The multivariate logistic regression analysis showed that a high risk of diabetes was correlated with severe COVID-19 (P = 0.01) after adjusting for baseline characteristics, whereas a moderate risk of diabetes was not (P = 0.17).

Conclusion: Prediabetes with a high risk of diabetes is associated with the worst COVID-19 symptom in terms of severity during admission. Our findings could aid in more efficient allocation of healthcare resources to a narrower population of prediabetic patients.

Supplementary information: The online version contains supplementary material available at 10.1007/s13340-023-00643-z.