ACE2 expression in adipose tissue is associated with COVID-19 cardio-metabolic risk factors and cell type composition

Effects of Body Mass Index on Presentation and Outcomes of COVID-19 among Heart Transplant and Left Ventricular Assist Device Patients: A Multi-Institutional Study

The coronavirus disease 2019 (COVID-19) pandemic continues to pose a significant threat to patients receiving advanced heart failure therapies. The current study was undertaken to better understand the relationship between obesity and outcomes of SARS-CoV-2 infection in patients with a left ventricular assist device (LVAD) or heart transplant. We performed a retrospective review of patients with a heart transplant or LVAD who presented to one of the participating 11 institutions between April 1 and November 30, 2020. Patients were grouped by body mass index (BMI) into obese (BMI ≥ 30 k/m2) and nonobese cohorts (BMI < 30 kg/m2). Multivariable logistic regression models were used to estimate effects of obesity on outcomes of interest. Across all centers, 162 heart transplant and 81 LVAD patients were identified; 54 (33%) and 38 (47%) were obese, respectively. Obese patients tended to have more symptoms at presentation. No differences in rates of hospitalization or ICU admission were noted. Obese patients with LVADs were more likely to require mechanical ventilation (39% vs. 8%, p < 0.05). No differences in renal failure or secondary infection were noted. Mortality was similar among heart transplant patients (11% [obese] vs. 16% [nonobese], p = 0.628) and LVAD patients (12% vs. 15%, p = 1.0). BMI was not associated with increased adjusted odds of mortality, ICU admission, or mechanical ventilation (all p > 0.10). In summary, acute presentations of SARS-CoV-2 among heart transplant and LVAD recipients carry a significantly higher mortality than the general population, although BMI does not appear to impact this. Further studies on the longer-term effects of COVID-19 on this population are warranted.

Obesity Impact on SARS-CoV-2 Infection: Pros and Cons “Obesity Paradox”—A Systematic Review

Background: During the last years, the COVID-19 pandemic meets the pandemic generated by obesity, raising many questions regarding the outcomes of those with severe forms of infection. Methods: The present systematic review summarises and analyses the data providing evidence for or against the “obesity-paradox” in COVID-19 patients. After applying the inclusion and exclusion criteria, 23 studies were included. We also analysed the presumably underlying basic mechanisms. Results: The patients with a body mass index (BMI) of 30–40 kg/m² presented severe symptoms that led to intensive care unit (ICU) admission but not increased death rate. Those with a higher degree of obesity, with a BMI higher than 40 kg/m², led to a rise in the death rate, particularly in young patients. Obesity was associated with a higher rate of ICU admission but was not determined as an independent predictor of increased mortality. In contrast, some studies suggest a strong association between obesity or morbid obesity and the risk of death. Conclusions: The existence of “obesity-paradox” cannot be stated; our study presents obesity as a critical risk factor in the evolution of COVID-19.

Detection of SARS-CoV-2 in subcutaneous fat but not visceral fat, and the disruption of fat lymphocyte homeostasis in both fat tissues in the macaque

The well documented association between obesity and the severity of SARS-CoV-2 infection raises the question of whether adipose tissue (AT) is impacted during this infection. Using a model of SARS-CoV-2 infection in cynomolgus macaques, we detected the virus within subcutaneous AT (SCAT) but not in visceral AT (VAT) or epicardial AT on day 7 post-infection. We sought to determine the mechanisms responsible for this selective detection and observed higher levels of angiotensin-converting-enzyme-2 mRNA expression in SCAT than in VAT. Lastly, we evaluated the immunological consequences of SARS-CoV-2 infection on AT: both SCAT and VAT T cells showed a drastic reduction in CD69 expression, a standard marker of resident memory T cell in tissue, that is also involved in the migratory and metabolic properties of T cells. Our results demonstrate that in a model of mild infection, SCAT is selectively infected by SARS-CoV-2 although changes in the immune properties of AT are observed in both SCAT and VAT.

Subcutaneous fat tissue expresses higher angiotensin-converting-enzyme 2 mRNA than visceral fat tissue and is selectively infected by SARS-Cov-2, while both fat tissues show drastic reduction in CD69 expression in T cells.

Socio-demographic, lifestyle and health characteristics as predictors of self-reported Covid-19 history among older adults: 2006-2020 Health and Retirement Study

Background

To identify key socio-demographic, lifestyle, and health predictors of self-reported coronavirus disease 2019 (Covid-19) history, examine cardiometabolic health characteristics as predictors of self-reported Covid-19 history and compare groups with and without a history of Covid-19 on trajectories in cardiometabolic health and blood pressure measurements over time, among United States (U.S.) older adults.

Methods

Nationally representative longitudinal data on U.S. older adults from the 2006-2020 Health and Retirement Study were analyzed using logistic and mixed-effects logistic regression models.

Results

Based on logistic regression, number of household members (OR=1.26, 95% CI: 1.05, 1.52), depressive symptoms score (OR = 1.21, 95% CI: 1.04, 1.42) and number of cardiometabolic risk factors or chronic conditions (“1-2” vs “0”) (OR = 0.27, 95% CI: 0.11, 0.67) were significant predictors of self-reported Covid-19 history. Based on mixed-effects logistic regression, several statistically significant predictors of Covid-19 history were identified, including female sex (OR = 3.06, 95% CI: 1.57, 5.96), other race (OR = 5.85, 95% CI: 2.37, 14.43), Hispanic ethnicity (OR = 2.66, 95% CI: 1.15, 6.17), number of household members (OR = 1.25, 95% CI: 1.10, 1.42), moderate-to-vigorous physical activity (1-4 times per month vs never) (OR = 0.38, 95% CI: 0.18, 0.78) and number of cardiometabolic risk factors or chronic conditions (“1-2” vs “0”) (OR = 0.34, 95% CI: 0.19, 0.60).

Conclusions

Number of household members, depressive symptoms and number of cardiometabolic risk factors or chronic conditions may be key predictors for self-reported Covid-19 history among U.S. older adults. In-depth analyses are needed to confirm preliminary findings.

Predictors of Covid-19 level of concern among older adults from the health and retirement study

The purpose of this longitudinal study is to construct a prediction model for Covid-19 level of concern using established Covid-19 socio-demographic, lifestyle and health risk characteristics and to examine specific contributions of obesity-related cardiometabolic health characteristics as predictors of Covid-19 level of concern among a representative sample of U.S. older adults. We performed secondary analyses of existing data on 2872 2006–2020 Health and Retirement Study participants and examined 19 characteristics in relation to the outcome of interest using logistic regression and machine learning algorithms. In mixed-effects ordinal logistic regression models, a history of diabetes, stroke as well as 1–2 cardiometabolic risk factors and/or chronic conditions were associated with greater Covid-19 level of concern, after controlling for confounders. Female sex, birth cohort, minority race, Hispanic ethnicity and total wealth as well as depressive symptoms were associated with higher level of Covid-19 concern, and education was associated with lower level of Covid-19 concern in fully adjusted mixed-effects ordinal logistic regression models. The selected socio-demographic, lifestyle and health characteristics accounted for < 70% of the variability in Covid-19 level of concern based on machine learning algorithms. Independent risk factors for Covid-19 level of concern among U.S. older adults include socio-demographic characteristics and depressive symptoms. Advanced research is needed to identify relevant predictors and elucidate underlying mechanisms of observed relationships.

Novel biomarkers of childhood and adolescent obesity

Regulation of the Renin-Angiotensin System (RAS) and the kallikrein-kinin system (KKS) by obesity in adolescents.

An Overview of Adipose Tissue ACE2 Modulation by Diet and Obesity. Potential Implications in COVID-19 Infection and Severity

The present review is aimed at analysing the current evidence concerning the potential modulation of obesity and/or diet in adipose tissue ACE2. Additionally, the potential implications of these effects on COVID-19 are also addressed. The results published show that diet and obesity are two factors that effectively influence the expression of Ace2 gene in adipose tissue. However, the shifts in this gene do not always occur in the same direction, nor with the same intensity. Additionally, there is no consensus regarding the implications of increased adipose tissue ACE2 expression in health. Thus, while in some studies a protective role is attributed to ACE2 overexpression, other studies suggest otherwise. Similarly, there is much debate regarding the role played by ACE2 in COVID-19 in terms of degree of infection and disease outcomes. The greater risk of infection that may hypothetically derive from enhanced ACE2 expression is not clear since the functionality of the enzyme seems to be as important as the abundance. Thus, the greater abundance of ACE2 in adipose tissue of obese subjects may be counterbalanced by its lower activation. In addition, a protective role of ACE2 overexpression has also been suggested, associated with the increase in anti-inflammatory factors that it may produce.

The Impact of Angiotensin-Converting Enzyme 2 (ACE2) Expression on the Incidence and Severity of COVID-19 Infection

The novel coronavirus disease 2019 (COVID-19) pandemic has led to an unprecedented threat to the international community and raised major concerns in terms of public health safety. Although our current understanding of the complexity of COVID-19 pathogenesis remains limited, the infection is largely mediated by the interaction of viral spike protein and angiotensin-converting enzyme 2 (ACE2). The functional importance of ACE2 in different demographic and comorbid conditions may explain the significant variation in incidence and mortality of COVID-19 in vulnerable groups, and highlights its candidacy as a potential therapeutic target. We provide evidence supporting the idea that differences in incidence and severity of COVID-19 infection may be related to ACE2. Emerging data based on the prevalence and severity of COVID-19 among those with established high levels of ACE2 expression strongly support our hypothesis. Considering the burden of COVID-19 infection in these vulnerable groups and the impact of the potential therapeutic and preventive measures that would result from adopting ACE2-driven anti-viral strategies, our hypothesis may expedite global efforts to control the current COVID-19 pandemic.

Public Database-Driven Insights Into Aging Stress-Associated Defective Gut Barrier With Low SARS-CoV-2 Receptors

The novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a global pandemic, and resulted in high case-fatality rate in the elderly. In addition to typical respiratory responses, ~50% of clinical cases include gastrointestinal symptoms such as diarrhea, vomiting, abdominal pain, and persistent fecal shedding of the virus even after its clearance from the pulmonary system. In the present study, we assessed aging-associated gut transcriptomic responses considering the gastrointestinal symptoms contributing to COVID-19 severity. Intestinal expression of SARS-CoV-2 receptors and defense biomarkers decreased with increasing age. Moreover, aging-associated integrated stress responses (ISR) and mTOR-linked cell metabolic stress signals counteracted gut defense biomarkers. However, SARS-CoV-2 receptor expression was positively associated with gut barrier integrity potently via downregulation of the two stress-responsive signals. Gut transcriptome-based mechanistic prediction implicates that high susceptibility to COVID-19 in the elderly with low SARS-CoV-2 receptors is due to aging stress-associated defective gut defense, providing a new avenue for viral entry receptor-independent interventions.