Erratum to “Clinical Characteristics of Diabetic Patients with COVID-19”

[This corrects the article DOI: 10.1155/2020/1652403.].

Diabetes mellitus (DM) is often identified as an independent risk factor for developing respiratory tract infections [8]. Studies have reported the relationship between blood glucose levels and the clinical course of severe acute respiratory syn-drome (SARS) [9]. Up to now, information regarding the clinical characteristics of patients with diabetes with 2019 novel SARS-COV-2 pneumonia was scarce. In this study, the aim was to determine clinical symptoms, laboratory findings, and mortality of patients with diabetes and patients without diabetes in COVID-19, and to report on any difference.

2.2.
Definitions. COVID-19 was confirmed by detecting SARS-CoV-2 RNA in throat swab samples using a virus nucleic acid detection kit according to the manufacturer's protocol (Shanghai BioGerm Medical Biotechnology Co., Ltd). All of patients were admitted to the general fever ward excluding the intensive care unit. The cases were divided into diabetic and nondiabetic groups according to the history of taking antidiabetic drugs or by plasma fasting blood glucose level at admission.

Data Collection.
The case report form of COVID-19 was designed to document primary clinical data regarding previous medical history, clinical symptoms, laboratory findings, and clinical outcomes from electronic medical records. The following information was extracted for each patient: gender, age, medical history, clinical outcomes, and signs, symptoms, oxygen saturation, and laboratory findings at admission.

Data
Analysis. Categorical data were described as percentages, and continuous data as median with interquartile range (IQR). χ 2 test for categorical data and Mann-Whitney U test for continuous data were used to compare variables between groups. All statistical analyses were performed using SPSS Statistics version 16.0 software. P < 0:05 was considered statistically significant.

Regression Analysis.
We included 199 patients with complete data for all variables (181 survivors and 18 nonsurvivors) in the multivariable logistic regression model. We found that diabetes, higher level of D-dimer at admission, and lymphocyte count less than 0:6 × 10 9 /L at admission were associated with increasing odds of death. Antidiabetic drugs were associated with decreasing odds of death. Treatment with low molecular weight heparin was not related to odds of death (Table 3).

Discussion
Coronavirus has received more attention compared to other causes of pneumonia, especially after the emergence of SARS and MERS. In certain risk factors, clinical manifestations, and clinical outcomes, COVID-19 was similar to SARS and MERS. It had been reported that a known history of diabetes was independent predictors for morbidity and death in patients with SARS [9]. In our study, 11 (14.5%) patients with COVID-19 pneumonia with diabetes died, while 7 (5.7%) patients with COVID-19 pneumonia without diabetes died (P = 0:036). Diabetes was associated with increasing odds of death. Antidiabetic drugs were associated with decreasing odds of death. Until now, large-scale analyses of clinical characteristics and outcome of patients with COVID-19 pneumonia with diabetes had been scarce. In this study, 199 COVID-19 patients were divided into diabetic and nondiabetic groups. We compared the clinical features, laboratory findings, and clinical outcome between the two groups. The study found similar proportions of male and female patients in COVID-19 with and without diabetes.

Journal of Diabetes Research
The median age of patients with diabetes with COVID-19 was significantly older than that of patients without diabetes. According to previous reports, older age was an important independent predictor of mortality in MERS and SARS [10,11]. Recent studies had confirmed that death in patients with COVID-19 was associated with increased age [12]. Nearly 85% of COVID-19-related death in Italy have been individuals in the 70+ year-old age group. It is common sense that in a patient with a fatality, in the presence of severe renal or pulmonary or cardiac disease, the mere presence of COVID-19 positivity does not confirm the role of coronavirus in causing death [13]. In our study, patients with diabetes with COVID-19 were older than patients without diabetes. Therefore, they were at increased risk for death also for their age.
In our cohort, compared with nondiabetic patients, patients with diabetes had a lower level of lymphocyte. Lymphocyte count less than 0:6 × 10 9 /L at admission was associated with increasing odds of death. In previous studies, lymphocytopenia is also common in the critically ill patients with MERS infection, which is the result of apoptosis of lymphocytes [14,15]. Yang et al. reported that lymphocytopenia occurred in more than 80% of critically ill patients with COVID-19 [16]. Lymphocytopenia is a prominent feature of critically ill patients with COVID-19 because targeted invasion by SARS-CoV viral particles damages the cytoplasmic component of the lymphocyte and causes its destruction [17]. Hence, we speculate that necrosis or apoptosis of lymphocytes also induces lymphocytopenia in critically ill patients with COVID-19. In our study, patients with diabetes with COVID-19 at admission had only mild lymphocytopenia. The severity of lymphocytopenia may reflect the aggravation of the disease.
Higher level of D-dimer at admission was associated with increased odds of death in our study. D-dimer levels were quite different between the diabetic and nondiabetic groups (P ≤ 0:001). For patients with diabetes with COVID-19, D-dimer levels increased dramatically. Ddimer is an activation marker of fibrinolysis. Some studies have shown that D-dimer is a significant prognostic factor in patients with pneumonia and sepsis [18,19]. D-dimer is a marker of mortality in patients admitted to the emergency department with suspected infection and sepsis [19]. In recent studies, the level of D-dimer was higher in the death group than in the survival group, and elevated levels of D-dimer at admission were risk factors for death of adult patients with COVID-19 [7,12,20]. We found that patients with COVID-19 with higher level of D-dimer at admission, especially those with diabetes, are significantly associated with the risk of death. Treatment with low molecular weight heparin was not related to odds of death. Magro et al. reported that severe COVID-19 infection was associated with microvascular injury and thrombosis [21]. There is a need for further clinical trials using anticoagulants to determine whether the application of anticoagulants is effective.
Currently, few public studies have shown the specific cause of high mortality in patients with COVID-19 with diabetes. Diabetes mellitus (DM) has been identified as an independent risk factor for developing respiratory infections. Many changes occurred in the immune system of DM patients. There were significant changes in humoral and cell-mediated immune function, especially related to abnormal pulmonary function.
In patients with diabetes with signs of microangiopathy, the lung's diffusion capacity was significantly reduced [22]. In this cohort, compared with patients without diabetes, patients with diabetes with COVID-19 had significantly higher age and D-dimer. These factors might be involved in changing immune function and pulmonary function in patients with diabetes with COVID-19, which further promoted the patient's death. The mechanism needed further study.
However, with the small sample size of this retrospective study, selection bias might occur. This study was based on a single center, and a large-scale study was needed.
In conclusion, the mortality rate for diabetic patients with COVID-19 was 14.5%, which was significantly higher than that of patients without diabetes. Diabetes, higher level of D-dimer, and lymphocyte count less than 0:6 × 10 9 /L at admission were the risk factors associated with in-hospital death. So, patients with COVID-19 with diabetes require extra attention.

Data Availability
The Excel data used to support the findings of this study are available from the corresponding author upon request.

Conflicts of Interest
The authors declare that they have no conflicts of interest.