Diabetes and COVID-19: Role of insulin resistance as a risk factor for COVID-19 severity

Maximum insulin dose in patients admitted to the intensive care units with severe COVID-19 in the "Cross ICU Searchable Information System" study: A multicenter retrospective cohort study

AIMS

This study aimed to determine the maximum daily insulin dose (MDI) and associated factors in critically ill patients with coronavirus disease 2019 (COVID-19) receiving insulin therapy, under ventilator and/or extracorporeal membrane oxygenation (ECMO) management.

MATERIALS AND METHODS

This cross-sectional analysis used the Cross ICU Searchable Information System data from a Japanese multicenter retrospective observational cohort study of critically ill patients with COVID-19 receiving ventilation and/or ECMO, from February 2020 to March 2022. Maximum daily insulin dose was determined, and factors associated with it and maximum daily insulin dose per body weight were assessed using linear regression analysis.

RESULTS

The analysis included 788 patients. Their mean age, glycated hemoglobin level, maximum daily insulin dose, and time from admission to the maximum daily insulin dose were 65.2 ± 13.0 years, 7.0 ± 1.5% (53.0 ± 7.1 mmol/mol), 46.0 ± 43.6 U/day, and 7.3 ± 7.0 days, respectively. Male sex (β = 6.902, P = 0.034), body mass index (β = 1.020, P = 0.001), glycated hemoglobin (β = 12.272, P < 0.001), and having renal failure (β = 20.637, P = 0.003) were independent determinants of maximum daily insulin dose. Age (β = 0.004, P = 0.035), glycated hemoglobin (β = 0.154, P < 0.001), and having renal failure (β = 0.282, P = 0.004) were independent determinants of maximum daily insulin dose per body weight.

CONCLUSIONS

In patients with COVID-19 on ventilator and/or ECMO management, the maximum daily insulin dose reached after about 1 week of hospitalization was approximately 46.0 U/day. Glycated hemoglobin and renal failure were both associated with the maximum daily insulin dose and maximum daily insulin dose per body weight.

Increased Insulin Requirements in Severe Cases of Covid-19 are Higher Than in Moderate Cases

Purpose

Despite the low overall death rate of coronavirus disease 2019 (COVID-19), no study has examined the association between COVID-19 severity and the total daily insulin dose required for glycemic control. The aim of this study was to determine the maximum total daily insulin dose required according to COVID-19 severity, and the number of days required to reach the maximum insulin dose in patients with COVID-19 who used insulin during hospitalization.

Patients and Methods

This retrospective cohort study included participants aged 20-90 years with a confirmed diagnosis of COVID-19 who used insulin during hospitalization at Kyoto Prefectural University of Medicine Hospital between March 4, 2020, and May 31, 2021. Factors associated with maximum insulin dose during hospitalization were evaluated using linear regression analyses.

Results

The maximum insulin doses were 31.8, 76.8, and 230.7 U/day, and the numbers of days between COVID-19 diagnosis and the need for maximum insulin were 15.6, 17.1, and 13.7 days in patients without ventilator management, with ventilator management, and with ventilator and extracorporeal membrane oxygenation management, respectively. Multivariate linear regression analyses revealed that hemoglobin A1c level (β = 15.87, P = 0.001), use of a ventilator (β = 50.53, P < 0.001), and use of extracorporeal membrane oxygenation (β = 150.36, P < 0.001) were independent determinants of maximum insulin dose.

Conclusion

Patients with severe COVID-19 required a significantly higher maximum insulin dose than did those with moderate COVID-19. The maximum insulin dose was reached approximately 2 weeks after onset. Furthermore, the hemoglobin A1c level on admission and the use of a ventilator or extracorporeal membrane oxygenation during hospitalization were associated with the need for maximum insulin dose.

The prognostic significance of insulin resistance in COVID-19: a review

Objectives

Emerging publications indicate that diabetes predisposes patients with COVID-19 to more severe complications, which is partly attributed to inflammatory condition. In the current review, we reviewed recent published literature to provide evidence on the role of insulin resistance (IR) in diabetes, the association between diabetes and COVID-19 severity and mortality, the impact of COVID-19 infection on incident new-onset diabetes, mechanisms responsible for IR in COVID-19 patients, and the predictive value of different surrogates of IR in COVID-19.

Method

The literature search performs to find out studies that have assessed the association between IR surrogates and morbidity and mortality in patients with COVID-19.

Results

We showed that there is a bulk of evidence in support of the fact that diabetes is a potent risk factor for enhanced morbidity and mortality in COVID-19 patients. COVID-19 patients with diabetes are more prone to remarkable dysglycemia compared to those without diabetes, which is associated with an unfavourable prognosis. Furthermore, SARS-COV2 can make patients predispose to IR and diabetes via activating ISR, affecting RAAS signaling pathway, provoking inflammation, and changing the expression of PPARɣ and SREBP-1. Additionally, higher IR is associated with increased morbidity and mortality in COVID-19 patients and different surrogates of IR can be utilized as a prognostic biomarker for COVID-19 patients.

Conclusion

Different surrogates of IR can be utilized as predictors of COVID-19 complications and death.

Impaired retinal oxygen metabolism and perfusion are accompanied by plasma protein and lipid alterations in recovered COVID-19 patients

The aim of the present study was to investigate retinal microcirculatory and functional metabolic changes in patients after they had recovered from a moderate to severe acute COVID-19 infection. Retinal perfusion was quantified using laser speckle flowgraphy. Oxygen saturation and retinal calibers were assessed with a dynamic vessel analyzer. Arterio-venous ratio (AVR) was calculated based on retinal vessel diameter data. Blood plasma samples underwent mass spectrometry-based multi-omics profiling, including proteomics, metabolomics and eicosadomics. A total of 40 subjects were included in the present study, of which 29 had recovered from moderate to severe COVID-19 within 2 to 23 weeks before inclusion and 11 had never had COVID-19, as confirmed by antibody testing. Perfusion in retinal vessels was significantly lower in patients (60.6 ± 16.0 a.u.) than in control subjects (76.2 ± 12.1 a.u., p = 0.006). Arterio-venous (AV) difference in oxygen saturation and AVR was significantly lower in patients compared to healthy controls (p = 0.021 for AVR and p = 0.023 for AV difference in oxygen saturation). Molecular profiles demonstrated down-regulation of cell adhesion molecules, NOTCH3 and fatty acids, and suggested a bisphasic dysregulation of nitric oxide synthesis after COVID-19 infection. The results of this study imply that retinal perfusion and oxygen metabolism is still significantly altered in patients well beyond the acute phase of COVID-19. This is also reflected in the molecular profiling analysis of blood plasma, indicating a down-regulation of nitric oxide-related endothelial and immunological cell functions.Trial Registration: ClinicalTrials.gov ( https://clinicaltrials.gov ) NCT05650905.

COVID-19-Induced Diabetes Mellitus: Comprehensive Cellular and Molecular Mechanistic Insights

Despite evidence demonstrating the risks of developing diabetes mellitus because of SARS-CoV-2, there is, however, insufficient scientific data available to elucidate the relationship between diabetes mellitus and COVID-19. Research indicates that SARS-CoV-2 infection is associated with persistent damage to organ systems due to the systemic inflammatory response. Since COVID-19 is known to induce these conditions, further investigation is necessary to fully understand its long-term effects on human health. Consequently, it is essential to consider the effect of the COVID-19 pandemic when predicting the prevalence of diabetes mellitus in the future, especially since the incidence of diabetes mellitus was already on the rise before the pandemic. Additional research is required to fully comprehend the impact of SARS-CoV-2 infection on glucose tolerance and insulin sensitivity. Therefore, this article delves deeper into the current literature and links the perceived relationship between SARS-CoV-2 and diabetes. In addition, the article highlights the necessity for further research to fully grasp the mechanisms that SARS-CoV-2 utilises to induce new-onset diabetes. Where understanding and consensus are reached, therapeutic interventions to prevent the onset of diabetes could be proposed. Lastly, we propose advocating for the regular screening of diabetes and pre-diabetes, particularly for the high-risk population with a history of COVID-19 infection.

Utility of the triglyceride-glucose index for predicting restenosis following revascularization surgery for extracranial carotid artery stenosis: A retrospective cohort study

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are effective interventions for treating extracranial carotid artery stenosis (ECAS), but long-term prognosis is limited by postoperative restenosis. Carotid restenosis is defined as carotid stenosis >50% by various examination methods in patients after carotid revascularization. This retrospective cohort study examined the value of the triglyceride-glucose (TyG) index for predicting vascular restenosis after carotid revascularization.

METHODS

A total of 830 patients receiving CEA (408 cases, 49.2%) or CAS (422 cases, 50.8%) were included in this study. Patients were stratified into three subgroups according to TyG index tertile (high, intermediate, and low), and predictive value for restenosis was evaluated by constructing multivariate Cox proportional hazard regression models.

RESULTS

Incidence of postoperative restenosis was significantly greater among patients with a high TyG index according to univariate analysis. Kaplan-Meier survival curve analysis revealed a progressive increase in restenosis prevalence with rising TyG index. Multivariate Cox regression models also identified TyG index as an independent predictor of restenosis, while receiver operating characteristic (ROC) curve analysis showed that TyG index predicted restenosis with moderate sensitivity (57.24%) and specificity (67.99%) (AUC: 0.619, 95% CI 0.585-0.652, z-statistic=4.745, p<0.001). Addition of the TyG index to an established risk factor model incrementally improved restenosis prediction (AUC: 0.684 (0.651-0.715) vs 0.661 (0.628-0.694), z-statistic =2.027, p = 0.043) with statistical differences.

CONCLUSION

The TyG index is positively correlated with vascular restenosis risk after revascularization, which can be used for incremental prediction and has certain predictive value.

The severity and outcome of Covid-19 depend on the various activities of the renin-angiotensin-aldosterone system, level of the opioid growth factor, [met5]-enkephalin and pre-existing comorbidities

OBJECTIVE

Aim: The aim of the study was evaluation of the methionine-enkephalin in patients with severe COVID-19 with various activities of the renin-aldosterone system in comparison with COVID-19 patients with pre-existing comorbidities (renal cell cancer, critical limb ischemia) and adverse pregnancy outcomes..

PATIENTS AND METHODS

Materials and Methods: To test our hypothesis, this case-control study consisted of 20 healthy donors (control group); 49 patients with a positive diagnosis of COVID-19 according to PCR analysis; 15 patients with a positive diagnosis of COVID-19 in combination with renal cell cancer; 29 patients with a positive diagnosis of COVID-19 in combination with critical limb ischemia, 10 pregnant womens with COVID-19. Methionine-enkephalin, plasma renin activity, plasma aldosterone was measured by radioimmunoassay. Statistical and graphical analyses were done using Statistica 7.0 StatSoft software and using MedCalc.

RESULTS

Results: As our results have shown, hyperreninemia against the background of hypoaldosteronism and inhibition of enkephalinergic activity is fatal for COVID-19 patients. In COVID-19 patients with renal cell carcinoma, met-enkephalin, aldsterone, and plasma renin activity also showed a high predictive value for mortality. Whereas in patients with critical limb ischemia the strongest predictor biomarkers of mortality were only renin plasma activity. In conditions of physiological hyperreninemia during pregnancy, met-enkephalin acts as a biomarker for preterm birth, and in pregnant patients with COVID-19, plasma renin activity acts as such a biomarker.

CONCLUSION

Conclusions: We found that in different categories of patients with COVID-19, the severity and outcome depend on the different activity of the renin-angiotensinaldosterone and enkephalinergic systems.

Association of triglyceride-glucose index with vascular risk factors and clinical outcomes among COVID-19 patients: a retrospective cross-sectional study in Mengo Hospital, Kampala, Uganda

Introduction

triglyceride-glucose (TyG) index is a reliable surrogate marker of insulin resistance. We assessed the association between triglyceride-glucose (TyG) index and vascular risk factors and clinical outcomes of critically ill adult COVID-19 patients.

Methods

data from the charts of all patients with a confirmed diagnosis of COVID-19 who were hospitalized at Mengo Hospital Uganda from December 2020 to August 2021 was used for this study. Data on demographics, past medical history, clinical presentation, laboratory findings and clinical outcomes within the first 10 days of admission was extracted. TyG index was calculated as Inverse (triglyceride (mg/dl) x fasting glucose level (mg/dl)/2 and defined vascular risk factors using standard methods. Bivariate and multivariate logistic regression was conducted to establish a significant association. Statistical significance was set at p< 0.05.

Results

out of 314 patients, 176 (56%) were females. The mean age ± SD was 58.2 years ± 16.82. The median TyG index was 9.76 (9.29-10.33). A high TyG index was found among 85.4% (n= 268, 95% CI: 0.809-0.889) of patients. Elevated total cholesterol was in 55.4% (n=174), triglycerides 70.7% (n=222), LDL 64.7% (n=203), blood glucose 80.6% (n=253), systolic blood pressure 43% (n=135) and 24.8% (n=78) diastolic blood pressure. The majority 49.7% ( n=156) were discharged, 22.0% (n=69) needed admission to the intensive care unit (ICU), 15.3% (n=48) died in the unit and 13.0% (n=41) had a composite outcome. The TyG index was significantly associated with glycated hemoglobin (AOR=1.029, 95%CI 0.561-1.496, p<0.001), low-density lipoprotein cholesterol (AOR=0.121,95%CI 0.023-0.219, p=0.016), high-density cholesterol (AOR=1.956, 95%CI 1.299-2.945, p=0.001), total cholesterol (AOR=2.177, 95%CI 1.5222-3.144, p<0.001, hospital death (AOR=0.778, 95%CI 0.623-0.972, p=0.028) and composite outcome (AOR=1.823, 95% CI 1.221-2.559, p=0.023). There was no association between hypertension and TyG index.

Conclusion

a high TyG index was associated with vascular risk factors and clinical outcomes.

Antidiabetic Drug Efficacy in Reduction of Mortality during the COVID-19 Pandemic

Background and Objectives: The COVID-19 pandemic caused by the Coronavirus SARS-CoV-2 is a complex challenge for the existing scientific and medical landscape. It is an ongoing public health crisis, with over 245,373,039 confirmed cases globally, including 4,979,421 deaths as of 29 October 2021. Exploring molecular mechanisms correlated with the disease's severity has demonstrated significant factors of immune compromise, noted in diabetic patients with SARS-CoV-2 infections. Among diabetics, the altered function of the immune system allows for better penetration of the virus into epithelial cells, increased viral binding affinity due to hyperglycemia, reduced T cell function, decreased viral clearance, high risks of cytokine storm, and hyper-inflammatory responses, altogether increasing the susceptibility of these patients to an extreme COVID-19 disease course. Materials and Methods: This research involved a systematic literature search among various databases comprising PubMed and Google Scholar in determining credible studies about the effects of antidiabetic drugs on the high mortality rates among diabetic patients infected with COVID-19. The primary search found 103 results. Duplicated results, non-pertinent articles, and the unavailability of full text were excluded. Finally, we included 74 articles in our review. The inclusion criteria included articles published during 2020-2023, studies that reported a low risk of bias, and articles published in English. Exclusion criteria included studies published in non-peer-reviewed sources, such as conference abstracts, thesis papers, or non-academic publications. Results: Among the studied anti-diabetic drugs, Metformin, the Glucagon-like peptide 1 receptor agonist (GLP-1RA), and Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) have demonstrated decreased mortality rates among diabetic patients infected with COVID-19. Insulin and Dipeptidyl peptidase 4 inhibitors (DPP-4i) have demonstrated increased mortality rates, while Sulfonylureas, Thiazolidinedione (TZD), and Alpha-glucosidase inhibitors (AGI) have demonstrated mortality-neutral results.

Assessment of the Immune Response in Patients with Insulin Resistance, Obesity, and Diabetes to COVID-19 Vaccination

The SARS-CoV-19 pandemic overwhelmed multiple healthcare systems across the world. Patients with underlying medical conditions such as obesity or diabetes were particularly vulnerable, had more severe symptoms, and were more frequently hospitalized. To date, there have been many studies on the severity of SARS-CoV-2 in patients with metabolic disorders, but data on the efficiency of vaccines against COVID-19 are still limited. This paper aims to provide a comprehensive overview of the effectiveness of COVID-19 vaccines in individuals with diabetes, insulin resistance, and obesity. A comparison is made between the immune response after vaccination in patients with and without metabolic comorbidities. Additionally, an attempt is made to highlight the mechanisms of immune stimulation affected by SARS-CoV-2 vaccines and how metabolic comorbidities modulate these mechanisms. The focus is on the most common COVID-19 vaccines, which include mRNA vaccines such as Pfizer-BioNTech and Moderna, as well as viral vector vaccines such as AstraZeneca and Johnson & Johnson. Furthermore, an effort is made to clarify how the functional differences between these vaccines may impact the response in individuals with metabolic disorders, drawing from available experimental data. This review summarizes the current knowledge regarding the post-vaccination response to COVID-19 in the context of metabolic comorbidities such as diabetes, insulin resistance, and obesity.

Biomarkers Associated With Severe COVID-19 Among Populations With High Cardiometabolic Risk: A 2-Sample Mendelian Randomization Study

Importance

Cardiometabolic parameters are established risk factors for COVID-19 severity. The identification of causal or protective biomarkers for COVID-19 severity may facilitate the development of novel therapies.

Objective

To identify protein biomarkers that promote or reduce COVID-19 severity and that mediate the association of cardiometabolic risk factors with COVID-19 severity.

Design, Setting, and Participants

This genetic association study using 2-sample mendelian randomization (MR) was conducted in 2022 to investigate associations among cardiometabolic risk factors, circulating biomarkers, and COVID-19 hospitalization. Inputs for MR included genetic and proteomic data from 4147 participants with dysglycemia and cardiovascular risk factors collected through the Outcome Reduction With Initial Glargine Intervention (ORIGIN) trial. Genome-wide association study summary statistics were obtained from (1) 3 additional independent plasma proteome studies, (2) genetic consortia for selected cardiometabolic risk factors (including body mass index [BMI], type 2 diabetes, type 1 diabetes, and systolic blood pressure; all n >10 000), and (3) the COVID-19 Host Genetics Initiative (n = 5773 hospitalized and 15 497 nonhospitalized case participants with COVID-19). Data analysis was performed in July 2022.

Exposures

Genetically determined concentrations of 235 circulating proteins assayed with a multiplex biomarker panel from the ORIGIN trial for the initial analysis.

Main Outcomes and Measures

Hospitalization status of individuals from the COVID-19 Host Genetics Initiative with a positive COVID-19 test result.

Results

Among 235 biomarkers tested in samples totaling 22 101 individuals, MR analysis showed that higher kidney injury molecule-1 (KIM-1) levels reduced the likelihood of COVID-19 hospitalization (odds ratio [OR] per SD increase in KIM-1 levels, 0.86 [95% CI, 0.79-0.93]). A meta-analysis validated the protective association with no observed directional pleiotropy (OR per SD increase in KIM-1 levels, 0.91 [95% CI, 0.88-0.95]). Of the cardiometabolic risk factors studied, only BMI was associated with KIM-1 levels (0.17 SD increase in biomarker level per 1 kg/m2 [95% CI, 0.08-0.26]) and COVID-19 hospitalization (OR per 1-SD biomarker level, 1.33 [95% CI, 1.18-1.50]). Multivariable MR analysis also revealed that KIM-1 partially mitigated the association of BMI with COVID-19 hospitalization, reducing it by 10 percentage points (OR adjusted for KIM-1 level per 1 kg/m2, 1.23 [95% CI, 1.06-1.43]).

Conclusions and Relevance

In this genetic association study, KIM-1 was identified as a potential mitigator of COVID-19 severity, possibly attenuating the increased risk of COVID-19 hospitalization among individuals with high BMI. Further studies are required to better understand the underlying biological mechanisms.

Association between the triglyceride-glucose index and carotid plaque incidence: a longitudinal study

BACKGROUND

Carotid plaque and triglyceride-glucose (TyG) index are associated with insulin resistance. However, a highly debated question is whether there is an association between the TyG index and carotid plaque incidence. Thus we performed an in-depth longitudinal study to investigate the relationship between carotid plaque occurrence and the TyG index among Chinese individuals.

METHODS

Two thousand and three hundred seventy subjects (1381 males and 989 females) were enrolled and followed up for three years. The subjects were stratified into four groups based on the quartile of the TyG index at baseline. Univariate and multivariate Cox proportional hazard models were conducted to examine the role of TyG played in the carotid plaque. The strength of association was expressed as hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

After three years of follow-up, 444 subjects were detected with newly formed carotid plaque. The overall 3-year cumulative carotid plaque incidence was 18.7%, and the risk of carotid plaque increased with elevated TyG index (p < 0.001). The Cox regression analysis showed that males (HR: 1.33, 95% CI: 1.10-1.61), and people with higher systolic blood pressure (HR:1.01, 95% CI: 1.01-1.02), lower high-density lipoprotein cholesterol (HR: 0.68, 95% CI: 0.50-0.93), diabetes (HR: 2.21, 95% CI: 1.64-2.97), and hypertension (HR:1.49, 95% CI: 1.23-1.81) had a significantly increased risk for the carotid plaque formation. Similar results remained in the sensitivity analysis.

CONCLUSIONS

The TyG index can be used as a dose-responsive indicator of carotid plaque in the Chinese population. Elderly males with dyslipidemia, diabetes, or hypertension should be more vigilant about their TyG index since they are susceptible to developing carotid plaque. Physicians are encouraged to monitor the TyG index to help identify and treat patients with carotid plaque at an early stage.

Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

Importance of Insulin Resistance in the COVID-19 Era: A Retrospective Analysis of a Single Center in Mexico

Introduction and objectives Type 2 diabetes mellitus (T2DM) has been one of the main risk factors associated with mortality from the coronavirus disease 2019 (COVID-19). Insulin resistance (IR) is a preceding and underlying condition of T2DM, which has been thought that it could increase mortality from COVID-19 since it favors the entry of severe acute respiratory syndrome coronavirus type 2 in the host cell. This article reports a biochemical study that estimated the prevalence of IR in COVID-19 patients and non-diabetic patients without COVID-19 history. It also assesses the prognostic role of IR in the evolution of patients with COVID-19. Materials and methods In this single-center, retrospective and cross-sectional design, we included patients with severe and critical COVID-19 and non-diabetic patients without COVID-19 history. We calculated the Homeostatic Model Assessment Insulin Resistance (HOMA-IR) and defined IR with a HOMA-IR >2.6. We estimated the prevalence of IR in both groups and used x 2 to assess the association between IR and mortality from severe and critical COVID-19. Results One hundred and twenty-three COVID-19 patients were included with a mean age of 53±15 years: 77 (62.6%) were men and 46 (37.4%) were women. Eighty (65%) patients were critical while the rest were severe. Forty-three (35%) patients died. Seventy-one (57.7%) patients had IR; there was no evidence of an association between IR and mortality from severe or critical COVID-19. Fifty-five non-diabetic patients without COVID-19 history were included with a median age of 40 (26-60) years; 35 (63.6%) were men and 20 (36.4%) were women. Nineteen (34.5%) people had IR. Conclusion IR was more prevalent in patients with severe and critical COVID-19 than in non-diabetic patients without COVID-19 history. Our results showed no evidence of the association between IR and mortality from severe and critical COVID-19.

Long-term effects of COVID-19 in diabetic and non-diabetic patients

The literature presents several reports of the impact of glycemic control and diabetes in the inflammatory and coagulatory response during coronavirus disease 2019 (COVID-19). Nevertheless, the long-term impact of the COVID-19 in diabetic patients is still to be explored. Therefore, we recruited 128 patients and performed a longitudinal analysis on COVID-19-associated biomarkers of patients with COVID-19, tree and 6 months after COVID-19 recovery and put into perspective the possible long-term complication generated after COVID-19. In our investigation, we failed to verify any long-term modification on inflammatory biomarkers, but detected an increase in the glycemia and glycated hemoglobin in patients without any pre-existing history or diagnosis of diabetes (non-diabetic patients). Although diabetic and non-diabetic patients presented elevated levels of glycated hemoglobin, the c-peptide test indicated a normal beta cell function in all patients.

Implicazioni cliniche extraglicemiche dell’insulino-resistenza

L’insulino-resistenza si definisce come un’alterazione del processo di trasduzione del segnale dell’insulina, per cui concentrazioni di insulina normali o aumentate producono un effetto biologico attenuato. Ciò spesso determina un’iperinsulinemia compensatoria. Considerati i suoi effetti biologici, l’insulino-resistenza si manifesta con un quadro clinico variabile, noto come Sindrome da insulino-resistenza, che include alterazioni metaboliche, obesità viscerale, danno d’organo e associazione con altre patologie: sindrome dell’ovaio policistico (PCOS), sindrome delle apnee ostruttive del sonno (OSAS), malattie neurodegenerative, patologie neoplastiche.

Association of triglyceride-glucose index with prognosis of COVID-19: A population-based study

Background

Triglyceride-glucose (TyG) index is a simple and reliable surrogate marker for insulin resistance. Epidemiology studies have shown that insulin resistance is a risk factor for various infectious diseases. We evaluated the prognostic value of TyG index measured before the COVID-19 infection in COVID-19 infected patients.

Methods

From a nationwide COVID-19 cohort dataset in Korea, we included COVID-19 patients diagnosed between Jan and Jun 2020. Based on the nationwide health screening data between 2015 and 2018, TyG index was calculated as ln [triglyceride (mg/dL) × fasting glucose level (mg/dL)/2]. Primary outcome is development of severe complications of COVID-19 defined as composite of mechanical ventilation, intensive care unit care, high-flow oxygen therapy, and mortality within two months after the diagnosis of COVID-19.

Results

This study included 3887 patients with COVID-19 confirmed by reverse transcription polymerase chain reaction. Mean ± standard deviation of TyG index was 8.54 ± 0.61. Severe complications of COVID-19 were noted in 289 (7.44%) patients. In the multivariate logistic regression, TyG index was positively associated with severe complications of COVID-19 (adjusted odds ratio: 1.42, 95% confidence interval [1.12–1.79]).

Conclusions

In COVID-19 infected patients, high TyG index was associated with increased risk for severe complications. TyG index might be useful predictor for the severity of COVID-19 infection.

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

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.

Severe Glutathione Deficiency, Oxidative Stress and Oxidant Damage in Adults Hospitalized with COVID-19: Implications for GlyNAC (Glycine and N-Acetylcysteine) Supplementation

Humanity is battling a respiratory pandemic pneumonia named COVID-19 which has resulted in millions of hospitalizations and deaths. COVID-19 exacerbations occur in waves that continually challenge healthcare systems globally. Therefore, there is an urgent need to understand all mechanisms by which COVID-19 results in health deterioration to facilitate the development of protective strategies. Oxidative stress (OxS) is a harmful condition caused by excess reactive-oxygen species (ROS) and is normally neutralized by antioxidants among which Glutathione (GSH) is the most abundant. GSH deficiency results in amplified OxS due to compromised antioxidant defenses. Because little is known about GSH or OxS in COVID-19 infection, we measured GSH, TBARS (a marker of OxS) and F2-isoprostane (marker of oxidant damage) concentrations in 60 adult patients hospitalized with COVID-19. Compared to uninfected controls, COVID-19 patients of all age groups had severe GSH deficiency, increased OxS and elevated oxidant damage which worsened with advancing age. These defects were also present in younger age groups, where they do not normally occur. Because GlyNAC (combination of glycine and N-acetylcysteine) supplementation has been shown in clinical trials to rapidly improve GSH deficiency, OxS and oxidant damage, GlyNAC supplementation has implications for combating these defects in COVID-19 infected patients and warrants urgent investigation.