Association of epicardial adipose tissues with obstructive sleep apnea and its severity: A meta-analysis study

A comprehensive analysis of microRNA alteration in an ApoE(-/-) mice model of white adipose tissue injury induced by chronic intermittent hypoxia

Background

MicroRNAs (miRNAs) represent a class of noncoding small RNAs and are implicated in many diseases. However, the role of miRNA in obstructive sleep apnea (OSA)-induced white adipose tissue (WAT) dysfunction remains to be fully elucidated. Using miRNA sequencing (miRNA-seq), we uncovered the miRNA expression profiles in chronic intermittent hypoxia (CIH)-induced WAT dysfunction mice.

Methods

We established an apolipoprotein-deficient (ApoE-/-) CIH mouse model and identified differentially expressed miRNAs (DEmiRs) using miRNA-seq technology. With the help of Gene Ontology (GO) functional enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, we determined the biological functions of these DEmiRs. In addition, RT-qPCR was performed for further evaluation of the sequencing data. Finally, we constructed a conserved negative correlation (CNC) network to expound the relationship between miRNA and target genes.

Results

Overall, 13 miRNAs were found to be upregulated and 18 miRNAs downregulated in the CIH-induced mouse model of WAT dysfunction. KEGG pathway analysis results indicated that the lysosome pathway participated in CIH-induced WAT dysfunction. Then, eight miRNAs were shortlisted for RT-qPCR validation. Based on the data, we chose these DEmiRs to construct a miRNA-mRNA regulatory network.

Conclusion

Overall, we identified 31 DEmiRs in the ApoE-/- CIH mouse model. Our findings may play a major role in explaining the pathophysiological mechanisms of WAT dysfunction induced by obstructive sleep apnea.

Cardio-Lipotoxicity of Epicardial Adipose Tissue

Epicardial adipose tissue is a unique visceral adipose tissue depot that plays a crucial role in myocardial metabolism. Epicardial adipose tissue is a major source of energy and free fatty acids for the adjacent myocardium. However, under pathological conditions, epicardial fat can affect the heart through the excessive and abnormal influx of lipids. The cardio-lipotoxicity of the epicardial adipose tissue is complex and involves different pathways, such as increased inflammation, the infiltration of lipid intermediates such as diacylglycerol and ceramides, mitochondrial dysfunction, and oxidative stress, ultimately leading to cardiomyocyte dysfunction and coronary artery ischemia. These changes can contribute to the pathogenesis of various cardio-metabolic diseases including atrial fibrillation, coronary artery disease, heart failure, and obstructive sleep apnea. Hence, the role of the cardio-lipotoxicity of epicardial fat and its clinical implications are discussed in this review.

New Mechanisms to Prevent Heart Failure with Preserved Ejection Fraction Using Glucagon-like Peptide-1 Receptor Agonism (GLP-1 RA) in Metabolic Syndrome and in Type 2 Diabetes: A Review

This review examines the impact of obesity on the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and focuses on novel mechanisms for HFpEF prevention using a glucagon-like peptide-1 receptor agonism (GLP-1 RA). Obesity can lead to HFpEF through various mechanisms, including low-grade systemic inflammation, adipocyte dysfunction, accumulation of visceral adipose tissue, and increased pericardial/epicardial adipose tissue (contributing to an increase in myocardial fat content and interstitial fibrosis). Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the enteroendocrine L-cells in the gut. GLP-1 reduces blood glucose levels by stimulating insulin synthesis, suppressing islet α-cell function, and promoting the proliferation and differentiation of β-cells. GLP-1 regulates gastric emptying and appetite, and GLP-1 RA is currently indicated for treating type 2 diabetes (T2D), obesity, and metabolic syndrome (MS). Recent evidence indicates that GLP-1 RA may play a significant role in preventing HFpEF in patients with obesity, MS, or obese T2D. This effect may be due to activating cardioprotective mechanisms (the endogenous counter-regulatory renin angiotensin system and the AMPK/mTOR pathway) and by inhibiting deleterious remodeling mechanisms (the PKA/RhoA/ROCK pathway, aldosterone levels, and microinflammation). However, there is still a need for further research to validate the impact of these mechanisms on humans.

Increased Levels of VCAM-1 in Patients with High Cardiovascular Risk and Obstructive Sleep Apnea Syndrome

(1) Background: Although obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity, the link between OSA and cardiovascular disease (CVD) is not completely elucidated. Thus, we aim to assess cardiovascular risk (CVR) using SCORE 2 and SCORE 2 for older persons (SCORE 2OP), and to evaluate the association between the endothelial biomarkers VCAM-1, ICAM-1, epicardial fat, and sleep study parameters in order to improve current clinical practices and better understand the short-and long-term CVRs in OSA patients. (2) Methods: 80 OSA patients and 37 healthy volunteers were enrolled in the study. SCORE2 and SCORE 2 OP regional risk charts (validated algorithms to predict the 10-year risk of first-onset CVD) were used for the analysis of CVR. Two-dimensional echocardiography was performed on all patients and epicardial fat thickness was measured. VCAM-1 and ICAM-1 serum levels were assessed in all patients. (3) Results: OSA patients were classified as being at high CVR, regardless of the type of score achieved. Increased EFT was observed in the OSA group. VCAM-1 was associated with a high CVR in OSA patients, but no significant correlation was observed between adhesion molecules and epicardial fat thickness. (4) Conclusions: OSA patients have a high CVR according to the SCORE 2 and SCORE 2OP risk scores. VCAM-1 may be associated with a high CVR in OSA patients. Extending conventional risk stratification scores by adding other potential biomarkers improves the risk stratification and guide treatment eligibility for CVD prevention in the OSA population.

Weight reduction added to CPAP decreases blood pressure and triglyceride level in OSA: Systematic review and meta-analysis

Obstructive sleep apnea (OSA) is associated with treatment-resistant hypertension and high cardiovascular risk. Continuous positive airway pressure (CPAP) fails to reduce cardiovascular risks consistently. Obesity and OSA show reciprocal association and they synergistically increase hypertension via different pathways. Our meta-analysis aimed to assess the cardiovascular benefits of combining weight loss (WL) with CPAP (vs. WL or CPAP alone) in OSA. Outcomes included systolic and diastolic blood pressure (BP) and blood lipid parameters. We explored Medline, Embase, Cochrane, and Scopus. Eight randomized controlled studies (2627 patients) were included. The combined therapy decreased systolic BP more than CPAP alone. Weighted mean difference (WMD) for CPAP + WL versus CPAP was -8.89 mmHg, 95% confidence interval (95% CI; -13.67 to -4.10, p < 0.001) for systolic BP. For diastolic BP, this decrease was not significant. In case of blood lipids, the combined treatment decreased triglyceride levels more than CPAP alone (WMD = -0.31, 95% CI -0.58 to -0.04, p = 0.027). On the other hand, addition of CPAP to WL failed to suppress BP further. The certainty of evidence according to GRADE was very low to moderate. In conclusion, our results showed that the addition of WL to CPAP significantly improved BP and blood lipid values in OSA. On the other hand, the addition of CPAP to WL could not significantly improve BP or blood lipid values. Review protocol: PROSPERO CRD42019138998.

Association of epicardial adipose tissue with the severity and adverse clinical outcomes of COVID-19: A meta-analysis

Objectives

Epicardial adipose tissue (EAT) has been proposed to be an independent predictor of visceral adiposity. EAT measures are associated with coronary artery disease, diabetes, and chronic obstructive pulmonary disease, which are risk factors for COVID-19 poor prognosis. Whether EAT measures are related to COVID-19 severity and prognosis is controversial.

Methods

We searched 6 databases for studies until January 7, 2022. The pooled effects are presented as the standard mean difference (SMD) or weighted mean difference with 95% confidence intervals (CIs). The primary end point was COVID-19 severity. Adverse clinical outcomes were also assessed.

Results

A total of 13 studies with 2482 patients with COVID-19 were identified. All patients had positive reverse transcriptase-polymerase chain reaction results. All quantitative EAT measures were based on computed tomography. Patients in the severe group had higher EAT measures compared with the nonsevere group (SMD = 0.74, 95% CI: 0.29–1.18, P = 0.001). Patients with hospitalization requirement, requiring invasive mechanical ventilation, admitted to intensive care unit, or with combined adverse outcomes had higher EAT measures compared to their controls (all P < 0.001).

Conclusions

EAT measures were associated with the severity and adverse clinical outcomes of COVID-19. EAT measures might help in prognostic risk stratification of patients with COVID-19.

An umbrella review of systematic reviews and meta-analyses of observational investigations of obstructive sleep apnea and health outcomes

PURPOSE

The previous analysis of systematic reviews and meta-analyses have illustrated that obstructive sleep apnea (OSA) is correlated with multiple health outcomes. In the present research, our main aim was to execute an umbrella review to assess the available evidence for the associations between OSA and health outcomes.

METHODS

Herein, a meta-analysis of previous observational investigations that have reported associations between OSA and health outcomes in all human populations and settings was performed. We used these studies to execute an umbrella review of available meta-analyses and systematic reviews.

RESULTS

Sixty-six articles comprising 136 unique outcomes were enrolled in this analysis. Of the 136 unique outcomes, 111 unique outcomes had significant associations (p < 0.05). Only 7 outcomes (coronary revascularization after PCI, postoperative respiratory failure, steatosis, alaninetrans aminase (ALT) elevation, metabolic syndrome (MS), psoriasis, and Parkinson's disease) had a high quality of evidence. Twenty-four outcomes had a moderate quality of evidence, and the remaining 80 outcomes had a weak quality of evidence. Sixty-nine outcomes exhibited significant heterogeneity. Twenty-five outcomes exhibited publication bias. Sixty-three (95%) studies showed critically low methodological quality.

CONCLUSION

Among the 66 meta-analyses exploring 136 unique outcomes, only 7 statistically significant outcomes were rated as high quality of evidence. OSA may correlate with an increased risk of coronary revascularization after PCI, postoperative respiratory failure, steatosis, ALT elevation, MS, psoriasis, and Parkinson's disease.

A Meta-Analysis of Different Types of Cardiac Adipose Tissue in HIV Patients

Background

Antiretroviral therapy transformed HIV infection into a chronic disease but accelerated cardiovascular disease (CVD). Both of epicardial adipose tissue (EAT) and pericardial fat (PCF) have close relationships with CVD. The associations between these two cardiac adipose tissue and HIV are unclear.

Methods

Eligible studies were searched in PubMed, Embase, Web of Science, and Scopus from database inception to March 24, 2020. The summarized standard mean difference (SMD) or weighted mean difference (WMD) with 95% confidence intervals (CIs) was used to assess the association between EAT/PCF and HIV. Subgroup analysis was performed based on EAT types. Trial sequential analysis was conducted to estimate whether the evidence of the results is sufficient.

Results

In total, 2561 HIV patients and 1767 non-HIV participants were included. Compared to the control group, EAT was significantly higher in the HIV overall group and subgroup with EAT thickness (SMD = 0.59, 95% CI: 0.24-0.95, P = 0.001; SMD = 1.10, 95% CI: 0.41-1.79, P = 0.002); however, the EAT volume and PCF volume were unchanged in the HIV group (SMD = 0.16, 95% CI: -0.07-0.39, P = 0.169; WMD = 10.78, 95% CI: -14.11-35.67, P = 0.396). Trial sequential analysis indicated that the available samples were sufficient in the HIV overall group and subgroup with EAT thickness, and more studies are needed for EAT volume and PCF volume.

Conclusions

EAT thickness was significantly higher in patients with HIV. The association between EAT/PCF volume and HIV needs more studies to confirm.

Effectiveness and safety of direct-acting oral anticoagulants compared to vitamin K antagonists in patients with left ventricular thrombus: A meta-analysis

BACKGROUND

Left ventricular thrombus (LVT) is a complication of multiple cardiovascular diseases. There has been an increasing trend of off-label using direct-acting oral anticoagulants (DOACs) for the treatment of patients with LVT. The effectiveness and safety of DOACs remain to be determined.

METHOD

We searched for publications (PubMed, MEDLINE, Web of Science, EMBASE, Scopus, and ClinicalTrials.gov) comparing DOACs with Vitamin K antagonists (VKAs) in patients with LVT. We estimated odds ratio (OR) and 95% confidence intervals (CIs) for stroke, systemic embolism, major bleeding events, and thrombus resolution as the effectiveness and safety outcomes. The subgroup analysis and meta-regression were also performed.

RESULTS

Nine retrospective observational studies with a total of 2028 participants were included. DOACs demonstrated a similar risk of stroke, systemic embolism, major bleeding events, and thrombus resolution (OR = 0.79, 95% CI: 0.50-1.23; OR = 1.22, 95% CI: 0.65-2.26; OR = 0.82, 95% CI: 0.47-1.42; OR = 1.34, 95% CI: 0.62-2.90, respectively).

CONCLUSIONS

There is no difference between DOACs and VKAs in patients with LVT from the perspectives of stroke, systemic embolism, major bleeding events, and thrombus resolution. Prospective randomized controlled trials with adequate sample sizes are urgently needed to confirm findings.