A More Important Role of Diabetes Mellitus in Mortality in Elderly Critical COVID-19 Patients: a Single-center Retrospective Study

Background: COVID-19 has been circulating worldwide since December 2019. However, its independent risk factors of mortality need further insights in elderly critical COVID-19 patients. Methods: Totally 48 elderly and critically ill COVID-19 patients with clear end point were enrolled when the data were collected, with 16 discharged and 32 died. Kaplan-Meier analysis and Cox regression were performed to identify the risk factors of mortality in elderly critical COVID-19 patients. Survival curve was conducted to present the impact of Diabetes Mellitus on mortality. Mann-Whitney U and t tests were used to 39 clinical variates between the survivor and non-survivor groups. Results: As Kaplan-Meier analysis confirmed, only three variates Diabetes Mellitus, chronic obstructive pulmonary disease and family aggregation showed significant difference between the survivor and non-survivor groups. However, only variate Diabetes Mellitus presented significance in Cox regression. Higher C-reaction protein, interleukin-2 (IL-2), IL-8 and creatinine were detected in survivor group than non-survivor group, which was reverse to estimated glomerular filtration rate. The other laboratory finding showed no significant difference between survivor and non-survivor groups. Conclusions: Diabetes Mellitus, chronic obstructive pulmonary disease and family aggregation can contribute to mortality by COVID-19 while Diabetes Mellitus also reduces the survival time of elderly and critically ill COVID-19 patients, highlighting the more important role of Diabetes Mellitus. Laboratory findings could not serve as good predictors of death for elderly and critically ill COVID-19 patients.