Endothelial dysfunction, oxidative stress and low-grade endotoxemia in COVID-19 patients hospitalised in medical wards

BACKGROUND

Endothelial dysfunction, assessed by flow-mediated dilation (FMD), is related to poor prognosis in patients with COVID-19 pneumonia (CP). In this study, we explored the interplay among FMD, NADPH oxidase type 2 (NOX-2) and lipopolysaccharides (LPS) in hospitalised patients with CP, community acquired pneumonia (CAP) and controls (CT).

METHODS

We enrolled 20 consecutive patients with CP, 20 hospitalised patients with CAP and 20 CT matched for sex, age, and main cardiovascular risk factors. In all subjects we performed FMD and collected blood samples to analyse markers of oxidative stress (soluble Nox2-derived peptide (sNOX2-dp), hydrogen peroxide breakdown activity (HBA), nitric oxide (NO), hydrogen peroxide (H2O2)), inflammation (TNF-α and IL-6), LPS and zonulin levels.

RESULTS

Compared with controls, CP had significant higher values of LPS, sNOX-2-dp, H2O2,TNF-α, IL-6 and zonulin; conversely FMD, HBA and NO bioavailability were significantly lower in CP. Compared to CAP patients, CP had significantly higher levels of sNOX2-dp, H2O2, TNF-α, IL-6, LPS, zonulin and lower HBA. Simple linear regression analysis showed that FMD inversely correlated with sNOX2-dp, H2O2, TNF-α, IL-6, LPS and zonulin; conversely FMD was directly correlated with NO bioavailability and HBA. Multiple linear regression analysis highlighted LPS as the only predictor of FMD.

CONCLUSION

This study shows that patients with COVID-19 have low-grade endotoxemia that could activate NOX-2, generating increased oxidative stress and endothelial dysfunction.

Asymptomatic and symptomatic deep venous thrombosis in hospitalized acutely ill medical patients: risk factors and therapeutic implications

BACKGROUND

Acutely ill medical patients experience deep venous thrombosis (DVT) during the hospitalization, however the time course of DVT is still unclear.

OBJECTIVES

To evaluate risk factors in acutely ill hospitalized medical patients for proximal asymptomatic DVT (ADVT) and symptomatic DVT (SDVT) at admission and discharge.

PATIENTS/METHODS

In this prospective observational study, consecutive acutely ill medical patients (hospitalized mainly for acute medical disease as infections, neoplasm, anemia, heart failure) underwent compression ultrasonography (CUS) of proximal lower limb veins within 48 h from admission and at discharge to diagnose ADVT and SDVT. Covid-19 patients, anticoagulant therapy, surgical procedures, acute SDVT, and acute pulmonary embolism, were exclusion criteria. Biographical characteristics at hospitalization, D-Dimer (assessed by ELISA)) and DD-improve score.

RESULTS

Of 2,100 patients (1002 females, 998 males, age 71 ± 16 years) 58 (2.7%) had proximal ADVT at admission. Logistic regression analysis showed that age, and active cancer were independently associated with ADVT at admission. The median length of hospitalization was 10 days [interquartile range: 6-15]. During the hospital stay, 6 patients (0.3%) with a negative CUS at admission experienced DVT (2 SDVT and 4 ADVT). In the subgroup of patients (n = 1118), in whom D-dimer was measured at admission, D-Dimer and IMPROVE-DD score were associated with ADVT at admission (n = 37) and with all DVT (n = 42) at discharge. ROC curve defined an IMPROVE-DD score of 2.5 as the optimal cut-off for discriminating patients with and without thrombotic events.

CONCLUSIONS

We provide evidence of early development of ADVT in unselected acutely ill medical patients suggesting the need of investigating patients by CUS immediately after hospital admission (within 48 h). Advanced age, active cancer, known thrombophilia and increased IMPROVE-DD score may identify patients at risk. The benefit of anticoagulation needs to be investigated in patients with these specific risk factors and negative CUS at admission.

TRIAL REGISTRATION

NCT03157843.

Chocolate enriched by extra virgin olive oil improves endothelial function and oxidative stress in patients with diabetes

OBJECTIVE

Endothelial dysfunction and oxidative stress are among the most relevant mechanisms underlying the atherosclerotic process in patients with type 2 diabetes mellitus (T2 DM). Extra virgin olive oil (EVOO) reduces postprandial glycemia with a mechanism counteracting oxidative stress-mediated incretin down-regulation in healthy subjects and in patients with impaired fasting glucose. The aim of this study was to evaluate if the intake of chocolate enriched by EVOO had positive effects on endothelial function and oxidative stress in patients with T2 DM.

METHODS

In this study we enrolled and randomly assigned 25 consecutive patients with T2 DM to receive 40 g of EVOO-enriched chocolate or 40 g of control chocolate spread. Participants were assessed at baseline and 2 h after chocolate intake. Endothelial function was assessed by arterial brachial flow-mediated dilation (FMD); oxidative stress was evaluated by the measurement of serum nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-2 (Nox2) levels, nitric oxide availability, and serum hydrogen peroxide breakdown activity (HBA).

RESULTS

We observed a significant increase of FMD, nitric oxide (NO) availability, and HBA in the EVOO-enriched chocolate group (P < 0.001). Conversely, soluble Nox2-derived peptide (sNox2-dp) levels significantly decreased (P < 0.001). No significant change was observed in the control chocolate group. To assess the relation of EVOO-enriched chocolate to endothelial function and oxidative stress, a general linear model (GLM) analysis was performed; a significant difference for treatments was found with respect to FMD, NO availability, HBA, and sNox-dp.

CONCLUSIONS

Administration of 40 g of EVOO-enriched chocolate is associated with increased endothelial function and reduction of oxidative stress in patients with T2 DM. Future studies are needed to analyze the effect of chronic assumption of EVOO-enriched chocolate on vascular function, oxidative stress, and cardiovascular complications in patients with T2 DM.