The Role of Diabetes on the mortality rate of Patients with COVID-19: A systematic review

Background: Type 2 Diabetes Mellitus (T2DM) as a burgeoning health concern in the context of COVID-19 emphasizes the need for solicitous attention and tailored preventive strategies to reduce morbidity and mortality risk. Consistent with this attitude, this systematic review aimed to highlight a wide range of predictive factors that could be related to worse outcomes in COVID-19_DM patients. Methods: : The search was done in Pub Med, Web of Sciences, and Science Direct databases using keywords Diabetes, COVID-19, and mortality rates from September 2020 until April 2022 to identify and evaluate the numerous possible prognostic factors that are associated with significant mortality rates in COVID-19_DM patients. Results: : Among more than 1200 Studies, 10 articles were considered eligible for more evaluation and were taken forward to the full-text review. Additionally, among more than 25000 COVID-19 patients and more than 6000 COVID-19_DM patients, older age and male gender were the most important mortality-related predictors in COVID-19_DM patients which were pointed out in 5 and 4 studies respectively. It should be noted, that high D-dimer and blood glucose levels could potentiate the risk of death in COVID-19_DM patients. Conclusion: In conclusion and in addition to older age, male gender, high D-dimer, and blood glucose levels, there were several determinant factors like high ferritin, Procalcitonin, A1C (HBA1C), White Blood Cell (WBC), C-Reactive Protein (CRP) level, and also lower Oxygen (O2) saturation and lymphocyte count that are related with the mortality risk in patients. Likewise, pulmonary involvement and some medications like exogenous insulin could result in a debilitating condition in COVID-19_DM patients.