Abstract: Comparison of clinical and laboratory parameters of COVID-19 in diabetic patients using different glucose-lowering drugs: a retrospective study Soraya Khafri1, Seyedeh Farzaneh Jalali2, Faezeh Mohsenipoor3, Hadi Parsian4, Masoumeh Bayani 5, Sahar Rostami-Mansoor2,4* 1.Social Determinants of Health Research Center, Health resrearch institute, Babol University of Medical Sciences, Babol, Iran. 2.Department of Laboratory Sciences, Faculty of Paramedical Sciences, Babol University of Medical Sciences, Babol, Iran 3.Student Research Committee, Babol University of Medical Sciences, Babol, Iran 4.Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran 5.Infectious Diseases and Tropical Medicine Research, Center, Health Research Institute, Babol University of Medical Sciences, [ Babol, Iran Article Info ABSTRACT Article type: Research Article Background and Objective: Diabetes is a common metabolic disease that Received: 2 December 2022 Revised: 16 December 2022 Accepted: 17 December 2022 increases the risk of mortality of COVID-19. This study was done to compare the clinical characteristics and laboratory parameters of COVID-19 in diabetic patients using different glucose-lowering drugs to find out the proper predictors of disease severity. Methods: 157 diabetic patients with confirmed COVID-19 were enrolled in three groups according to the antidiabetic medications used before admission (metformin, insulin and sulfonylurea). Findings: In 157 diabetic patients, the hospitalization length in the metformin group was lower than the no metformin group while duration of hospitalization and critical form of the disease in the insulin group were higher than the no insulin group. Furthermore, the levels of blood sugar, BUN, ALT and WBC were lower in the metformin group while ALP, ALT, BUN and creatinine levels were significantly higher in insulin group. In sulfonylurea group the levels of BUN and ALT were lower compared to the no sulfonylurea group. We also found that BUN and total bilirubin were the proper parameters to predict COVID-19 severity and mortality in metformin and insulin group respectively. Conclusion: It seems that the outcomes of renal function test, bilirubin and O2 saturation are important parameters to predict COVID-19 severity in diabetic patients using different antidiabetic medications. Keywords: COVID-19, diabetes, glucose- lowering drugs, laboratory parameters. Cite this article: khafri S, et al. Comparison of clinical and laboratory parameters of COVID-19 in diabetic patients using different glucose-lowering drugs: a retrospective study. Current Research in Medical Sciences. 2022; 6(2): 32-49 © The Author(s). [ DOI: 10.22088/crms.6.2.32 ] Publisher: Babol University of Medical Sciences  Corresponding Author: Dr. Sahar Rostami-Mansoor; Address: Assistant Professor of Clinical Biochemistry, Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran Tel: +98 1132 238 284 E-mail: srostami.m@gmail.com, ORCID:0000-0003-4999-5806 COVID-19 and different glucose-lowering drugs / Khafri S, et al 33 [ DOI: 10.22088/crms.6.2.32 ] [