The Impact of Diabetes Mellitus and Hyperglycemia on the Severity and Outcome of Patients with COVID-19 Disease: A Single-Center Experience

PURPOSE: Diabetes mellitus (DM) has been reported to be associated with a worse outcome of COVID-19 infection. The evidence is scarce in the Middle East and Saudi Arabia. We aimed to evaluate the impact of diabetes mellitus and hyperglycemia in non-diabetic individuals on the severity and outcome of COVID-19 infection. METHODS: This is a retrospective observational study, which included patients with confirmed COVID-19 infection [RT-PCR positive for SARS-CoV2] who were admitted to King Fahd Hospital of the University-Khobar-Eastern Province-Saudi Arabia from March to September 2020. Baseline demographic data, laboratory investigations, and markers of the severity of COVID-19 were analyzed. The collected data were categorized according to the Saudi Arabian Ministry of Health COVID-19 infection severity criteria. Patients were divided into three groups as follows: patients in Group 1 had pre-existing DM, patients in Group 2 did not have DM but were documented to have hyperglycemia at presentation, and patients in Group 3 were neither diabetics nor hyperglycemics at presentation and served as the control group. The severity and outcome of the control group were compared with the other two groups. The effect of risk factors on the severity and outcome of COVID-19 infection was studied in the DM group. RESULTS: A total of 414 patients were included (70.5% males and 29.5% females). The mean age (SD) of patients was 52.3 (±15.5) years. Compared to the control group, pre-existing DM was found to be significantly associated with severe (OR 3.61), critical disease (OR 4.32), intensive care unit (ICU) admission (OR 2.0), and death (OR 2.0) from COVID-19 infection. Hyperglycemia without known DM was also found to be associated with critical COVID-19 pneumonia (P 0.001), and had longer duration of hospitalization (P 0.014), higher ICU admission, mechanical ventilation, and death from COVID-19 infection (P < 0.0001). CONCLUSION: Diabetes mellitus and hyperglycemia at presentation, even in the absence of pre-existing DM, are independent risk factors for disease severity and worse outcome of COVID-19 infection. These patients should be identified and managed accordingly. The COVID-19 vaccination program should also target those populations to improve their outcomes.