The Correlation Between Triglyceride-Glucose Index and SARS-CoV-2 RNA Re-Positive in Discharged COVID-19 Patients

Abstract

Objective: Facing the challenge to manage the SARS-CoV-2 RNA re-positive in discharged COVID-19 patients, it is necessary to explore the limited early risk factors for identifying SARS-CoV-2 RNA re-positive. The triglyceride and glucose index (TyG) has been developed as a surrogate marker of insulin resistance. This study aims to evaluate the correlation of the TyG index with the re-positive of COVID-19.

Methods: A total of 144 COVID-19 patients from Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University (China) were enrolled in this study. All of them were discharged after recovery according to the guidelines. We compared the clinical characteristics and laboratory indexes of re-positive and non-re-positive COVID-19 patients, and analyzed the early risk factors for identifying SARS-CoV-2 RNA re-positive.

Results: During the follow-up, a total of 18 patients were tested re-positive for SARS-CoV-2 RNA. Re-positive COVID-19 patients had higher proportion of abidol (P=0.018), antibiotic use (P=0.024) and hepatitis-based diseases (P=0.042), and higher heart rate (P=0.011) at admission (P=0.026), while lower TyG index (P=0.036), eGFR (P=0.034), TG (P=0.015) and C1q (P=0.023). Multivariate logistic regression analysis showed that TyG index was an independent risk factor for the re-positive of SARS-CoV-2 RNA (P=0.005). TyG index was significantly correlated with Glu (P<0.001), TG (P<0.001) and HDL-C (P<0.001). In addition, it was found that TyG index decreased at SARS-CoV-2 RNA positive stage and increased at negative stage (P<0.05).

Conclusion: TyG index may be a valuable marker for identifying the re-positive of COVID-19 patients and may play a role in determining the stage of the patient's disease. We hope to provide a reliable theoretical basis for clinical prediction and effective control of re-positive episodes, and to provide a breakthrough for further research on the causes of re-positive episodes and the immune mechanism of the virus.

Keywords: COVID-19; TyG index; correlation; re-positive.

Graphical abstract

Figure 1

Baseline information of 18 re-positive COVID-19 patients.

Figure 2

Boxplots of inflammatory indexes, renal function, lipoprotein and immune indexes between non-re-positive and re-positive COVID-19 patients.

Figure 3

Risk factors for re-positive COVID-19 patients. Multivariate logistic regression was applied to compute p-values.

Figure 4

Correlation of TyG index with lipoprotein, renal function, inflammatory indexes and immune indexes in non-re-positive and re-positive COVID-19 patients. (A) Heatmap of correlation between TyG index and lipoprotein, renal function, inflammatory indexes and immune indexes. (B) Correlation between 12 selected clinical indicators and TyG index.

Figure 5

TyG index, Urea, and IL-2 in re-positive patients of COVID-19 at different stages. (A) TyG index, Urea, and IL-2 at different stages of the COVID-19 patients. The TyG index of the re-positive patients at positive and re-positive stage was lower than that of the negative stage, and the difference was statistically significant. The X-axis represents the stage of the patient’s course, which is segmented based on RT-PCR results, and the Y-axis is the value of the index. (B) Thirty-weeks temporal expressions of TyG index, Urea, and IL-2. The X-axis represents the time from onset to nucleic acid testing and the Y-axis is the value of the index. (C) Dynamic changes of TyG index, Urea, and IL-2 in re-positive patients of COVID-19 at different stages. The X-axis represents the stage of the patient’s course, which is segmented based on RT-PCR results, and the Y-axis is the value of the index.