ABSTRACT
Background The coronavirus disease of 2019 (COVID-19) was spread all over the world, while diabetes mellitus (DM) remains the most prevalent chronic disease worldwide. Aims This study aims to investigate the effect of COVID-19 on glycemic control, insulin resistance (IR), and pH in elderly patients with type 2 diabetes. Methods A retrospective study was conducted on patients with type 2 DM who were diagnosed with COVID-19 infection in the central hospitals of the Tabuk region. Patient data were collected from September 2021 to August 2022. Four non-insulin-based insulin resistance indexes were calculated for patients: the triglyceride-glucose (TyG) index, the triglyceride glucose-body mass index (TyG-BMI) index, the triglyceride to high-density lipoprotein cholesterol (TG/HDL) ratio, and the metabolic score for insulin resistance (METS-IR). Results Patients showed increased serum fasting glucose and blood HbA1c associated with a high TyG index, TyG-BMI index, TG/HDL ratio, and METS-IR as compared with results before COVID-19. Moreover, during COVID-19, patients revealed a reduction in pH, associated with a reduction in cBase and bicarbonate, and an elevation in PaCO2 as compared with their results before COVID-19. After complete remission, all patients' results turn back to their level before COVID-19. Conclusions Patients with type 2 DM who catch the COVID-19 infection suffer from dysregulation of glycemic control and elevated insulin resistance associated with a significant reduction in their pH.