Admission HbA1c value as a prognostic marker in patients admitted with COVID-19


  • Vaibhav Jain Department of General Medicine, SIMS and RC, Mangalore, Karnataka, India
  • Suraj S. Hegde Department of General Medicine, SIMS and RC, Mangalore, Karnataka, India



COVID-19, Diabetes mellitus, Glycated hemoglobin, HbA1c, Hypertension, Inflammation, Endothelial glycocalyx


Background: Diabetes mellitus has been firmly established as a risk factor for the prognosis of COVID-19. However, the impact of pre-COVID-19 glycemic control on prognosis is yet to be fully understood. Our study aimed to establish the effect of HbA1c at admission on the outcome of patients admitted with COVID-19.

Methods: It was a prospective observational study of admitted adult patients with confirmed SARS-CoV-2 infection in a tertiary care centre based on data collected from the medical record section using the patient data registry between April 2021 to June 2021. Information regarding demographic and clinical features, laboratory values, and hospital outcomes was collected and analysed.

Results: 182 patients admitted to the hospital with COVID-19 during the study period were included, their mean age was 48.75 years, the mean HbA1c was 6.1. Males accounted for 69.8% (127) of the sample population. 41.2% (75) were known diabetics. 44.8% (81) were known hypertensives. The mortality rate overall was 25.3% (46). 63.7% (116) had HbA1c values >6.5. High HbA1c values was associated with longer duration of hospital stay (p=0.032), higher levels of inflammatory markers, increased need for mechanical ventilation (p=0.001), higher mortality rate (p=0.001).

Conclusions: Patients with COVID-19 with poor glycemic control as evidenced by admission HbA1c levels were found to have more severe disease course with increased level of inflammatory markers, longer duration of hospital stay and higher risk of mortality. 

Author Biographies

Vaibhav Jain, Department of General Medicine, SIMS and RC, Mangalore, Karnataka, India

PG resident

Dept. of Internal Medicine

Suraj S. Hegde, Department of General Medicine, SIMS and RC, Mangalore, Karnataka, India

Senior Resident

Dept. of General Medicine


WHO. COVID-19 Dashboard, 2020. Available at: Accessed on 02 October 2022.

Gao YD, Ding M, Dong X, Zhang J, Azkur AK, Azkur D, et al. Risk factors for severe and critically ill COVID-19 patients: A review. Allergy. 2021;76(2):428-55.

Daniel J Drucker. Coronavirus infections and type 2 diabetes-shared pathways with therapeutic implications. Endocr Rev. 2020;41(3):011.

Nassar M, Daoud A, Nso N, Medina L, Ghernautan V, Bhangoo H, et al. Diabetes Mellitus and COVID-19: review article. Diabetes Metab Syndr. 2021;15(6):102268.

Holman N, Knighton P, Kar P, O'Keefe J, Curley M, Weaver A, et al. Risk factors for COVID-19-related mortality in people with type 1 and type 2 diabetes in England: a population-based COHORT study. Lancet Diabetes Endocrinol. 2020;8(10):823-33.

Lim S, Bae JH, Kwon H, Nauck MA. COVID-19 and diabetes mellitus: from pathophysiology to clinical management. Nat Rev Endocrinol. 2021;17(1):11-30.

Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, Zhang L, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395(10223):497-506.

Teuwen L, Geldhof V, Pasut A, Carmeliet P. COVID-19: the vasculature unleashed. Nat Rev Immunol. 2020;20(7):389-91.

Bhandari S, Rankawat G, Singh A, Gupta V, Kakkar S. Impact of glycemic control in diabetes mellitus on management of COVID-19 infection. Int J Diabetes Dev Ctries. 2020;40(3):340-5.

Codo AC, Davanzo GG, Monteiro LDB, Souza GFD, Muraro SP, Virgilio-da-Silva JV, et al. Elevated glucose levels favor SARS-CoV-2 infection and monocyte response through a HIF-1α/glycolysis-dependent axis. Cell Metab. 2020;32(3):437-46.

Ceriello A, Nigris VD, Prattichizzo F. Why is hyperglycaemia worsening COVID-19 and its prognosis? Diabetes Obes Metab. 2020;22(10):1951-2.

Chen J, Wu C, Wang X, Yu J, Sun Z. the impact of covid-19 on blood glucose: a systematic review and meta-analysis. Front Endocrinol (Lausanne). 2020;11:574541.

Apicella M, Campopiano MC, Mantuano M, Mazoni L, Coppelli A, DelPrato S. COVID-19 in people with diabetes: understanding the reasons for worse outcomes, Lancet Diabetes Endocrinol. 2020;8(9):782-92.

Zhu L, She Z, Cheng X, Qin J, Zhang X, Cai J, et al. Association of blood glucose control and outcomes in patients with COVID-19 and pre-existing type 2 diabetes. Cell Metab. 2020;31(6):1068-77.

Manna S, Baindara P, Manda SMl. Molecular pathogenesis of secondary bacterial infection associated to viral infections including SARS-CoV-2. J Infect Public Health. 2020;13(10):1397-404.

Azkur AK, Akdis M, Azkur D, Sokolowska M, Veen WVD, Brüggen M, et al. Immune response to SARS-CoV-2 and mechanisms of immunopathological changes in COVID-19. Allergy. 2020;75(7):1564-81.

Giacco F, Brownlee M. Oxidative stress and diabetic complications 2010. Circ Res. 2010;107(9):1058-70.






Original Research Articles