Immunity to influenza: Impact of obesity

Reduced risk of pneumonia and influenza infection after bariatric surgery: a retrospective cohort study among patients with nondiabetic obesity in Taiwan

BACKGROUND

Bariatric surgery is associated with significant improvements in immunity in individuals with obesity, but the exact efficacy in reducing pneumonia and influenza infections is unclear.

OBJECTIVE

To investigate the association between bariatric surgery and the risk of pneumonia and influenza infection.

SETTING

Nondiabetic patients who underwent bariatric surgery and matched controls were identified from the National Health Insurance Research Database of Taiwan.

METHODS

We identified 1648 nondiabetic patients who underwent bariatric surgery from the National Health Insurance Research Database of Taiwan in 2001-2009. These patients were matched by propensity score with 4881 nondiabetic patients with obesity who did not undergo bariatric surgery. We followed the surgical and control cohorts until death, any diagnosis of pneumonia or influenza, or December 31, 2012. The Cox proportional hazards regression model was used to calculate the relative risk of pneumonia and influenza infection in those who underwent bariatric surgery compared with those who did not.

RESULTS

Overall, there was a .87-fold (95% CI, .78-.98) reduced risk of pneumonia and influenza infection in the surgical group versus the control group. Four years after bariatric surgery, a sustainable effect of the surgery was observed, and the risk of pneumonia and influenza infection was .83-fold reduced in the surgical group (95% CI, .73-.95). Individuals with obesity who underwent bariatric surgery had a reduced risk of pneumonia and influenza infection compared with matched control individuals.

CONCLUSION

Individuals with obesity who underwent bariatric surgery had a reduced risk of pneumonia and influenza infection compared with matched control individuals.

Implications of obesity and adiposopathy on respiratory infections; focus on emerging challenges

Obesity is characterized by excessive adipose tissue accumulation, which impacts physiological, metabolic, and immune functions. Several respiratory infections, including bacterial pneumonia, influenza, and coronavirus disease 2019, appear to be linked to unfavorable results in individuals with obesity. These may be attributed to the direct mechanical/physiological effects of excess body fat on the lungs’ function. Notably, adipose tissue dysfunction is associated with a low-grade chronic inflammatory status and hyperleptinemia, among other characteristics. These have all been linked to immune system dysfunction and weakened immune responses to these infections. A better understanding and clinical awareness of these risk factors are necessary for better disease outcomes.

Immune response to arbovirus infection in obesity

Obesity is a global health problem that affects 650 million people worldwide and leads to diverse changes in host immunity. Individuals with obesity experience an increase in the size and the number of adipocytes, which function as an endocrine organ and release various adipocytokines such as leptin and adiponectin that exert wide ranging effects on other cells. In individuals with obesity, macrophages account for up to 40% of adipose tissue (AT) cells, three times more than in adipose tissue (10%) of healthy weight individuals and secrete several cytokines and chemokines such as interleukin (IL)-1β, chemokine C-C ligand (CCL)-2, IL-6, CCL5, and tumor necrosis factor (TNF)-α, leading to the development of inflammation. Overall, obesity-derived cytokines strongly affect immune responses and make patients with obesity more prone to severe symptoms than patients with a healthy weight. Several epidemiological studies reported a strong association between obesity and severe arthropod-borne virus (arbovirus) infections such as dengue virus (DENV), chikungunya virus (CHIKV), West Nile virus (WNV), and Sindbis virus (SINV). Recently, experimental investigations found that DENV, WNV, CHIKV and Mayaro virus (MAYV) infections cause worsened disease outcomes in infected diet induced obese (DIO) mice groups compared to infected healthy-weight animals. The mechanisms leading to higher susceptibility to severe infections in individuals with obesity remain unknown, though a better understanding of the causes will help scientists and clinicians develop host directed therapies to treat severe disease. In this review article, we summarize the effects of obesity on the host immune response in the context of arboviral infections. We have outlined that obesity makes the host more susceptible to infectious agents, likely by disrupting the functions of innate and adaptive immune cells. We have also discussed the immune response of DIO mouse models against some important arboviruses such as CHIKV, MAYV, DENV, and WNV. We can speculate that obesity-induced disruption of innate and adaptive immune cell function in arboviral infections ultimately affects the course of arboviral disease. Therefore, further studies are needed to explore the cellular and molecular aspects of immunity that are compromised in obesity during arboviral infections or vaccination, which will be helpful in developing specific therapeutic/prophylactic interventions to prevent immunopathology and disease progression in individuals with obesity.

Effects of Different Corticosteroid Doses in Elderly Unvaccinated Patients with Severe to Critical COVID-19

SARS-CoV-2 infection can induce a broad range of clinical symptoms, and the most severe cases are characterized by an uncontrolled inflammatory response with the overproduction of proinflammatory cytokines. Elevated levels of C-reactive protein, interleukin-1B, and interleukin-6 have become key signatures of severe COVID-19. For this reason, the use of 6 mg of dexamethasone has become a standard of care, although this regime may not be optimal. Even though various glucocorticoid doses have been proposed, it is still unclear which dose should be used to prevent adverse effects while at the same time reducing the inflammatory response. Here, we compared two different doses of corticosteroids in 52 elderly hospitalized patients with severe to critical COVID-19 to assess efficacy and safety. We showed that in patients receiving a higher dose of prednisone, the time to negative swab was significantly longer. Furthermore, although neither dose was correlated with the risk of death, patients receiving the high dose were more likely to have adverse events such as hyperglycemia, leukocytosis, an increase in systemic blood pressure, and others. Finally, the BMI, WBC number, and NLR value were directly related to death. In conclusion, although the optimal glucocorticoid dose is still undefined, our retrospective study supports the absence of beneficial effects in the utilization of higher doses of corticosteroids in elderly patients with severe to critical COVID-19.

COVID-19 cases, hospitalizations and deaths after vaccination: a cohort event monitoring study, Islamic Republic of Iran

Objective

To investigate the incidence of coronavirus disease 2019 (COVID-19) cases, hospitalizations and deaths in Iranians vaccinated with either AZD1222 Vaxzevria, CovIran® vaccine, SARS-CoV-2 Vaccine (Vero Cell), Inactivated (lnCoV) or Sputnik V.

Methods

We enrolled individuals 18 years or older receiving their first COVID-19 vaccine dose between April 2021 and January 2022 in seven Iranian cities. Participants completed weekly follow-up surveys for 17 weeks (25 weeks for AZD1222) to report their COVID-19 status and hospitalization. We used Cox regression models to assess risk factors for contracting COVID-19, hospitalization and death.

Findings

Of 89 783 participants enrolled, incidence rates per 1 000 000 person-days were: 528.2 (95% confidence interval, CI: 514.0-542.7) for contracting COVID-19; 55.8 (95% CI: 51.4-60.5) for hospitalization; and 4.1 (95% CI: 3.0-5.5) for death. Compared with SARS-CoV-2 Vaccine (Vero Cell), hazard ratios (HR) for contracting COVID-19 were: 0.70 (95% CI: 0.61-0.80) with AZD1222; 0.73 (95% CI: 0.62-0.86) with Sputnik V; and 0.73 (95% CI: 0.63-0.86) with CovIran®. For hospitalization and death, all vaccines provided similar protection 14 days after the second dose. History of COVID-19 protected against contracting COVID-19 again (HR: 0.76; 95% CI: 0.69-0.84). Diabetes and respiratory, cardiac and renal disease were associated with higher risks of contracting COVID-19 after vaccination.

Conclusion

The rates of contracting COVID-19 after vaccination were relatively high. SARS-CoV-2 Vaccine (Vero Cell) provided lower protection against COVID-19 than other vaccines. People with comorbidities had higher risks of contracting COVID-19 and hospitalization and should be prioritized for preventive interventions.

Association between visceral fat and influenza infection in Japanese adults: A population-based cross-sectional study

Background

Several studies have reported that obesity is associated with influenza infection; however, the role of visceral fat remains unclear. The aim of this study was to investigate the association between visceral fat and influenza infection in community-dwelling Japanese adults.

Methods

A cross-sectional study was performed using data from an annual community-based health check-up conducted from May to June in 2019. In total, 1,040 Japanese adults aged 20–89 years were enrolled in this study. Influenza infection status was determined by participants’ responses to a self-administered questionnaire. The visceral fat area (VFA) was measured using a bioimpedance-type visceral fat meter. Participants were classified into four groups using the following cut-off points: VFA < 100 cm² was set as the reference category according to the Japanese criteria, 100 ≤ VFA < 150 cm², 150 ≤ VFA < 200 cm², and 200 cm² ≤ VFA. Logistic regression models were used to assess the association between VFA and influenza infection.

Results

In total, 119 participants had influenza infections in the past year. In the multivariate adjusted model, a higher VFA was significantly associated with increased influenza infection; the adjusted odds ratio for 200 cm² ≤ VFA was 5.03 [95% confidence interval (CI): 1.07–23.6], that for 150 ≤ VFA < 200 cm² was 1.97 (95% CI: 0.71–5.45), and that for 100 ≤ VFA < 150 cm² was 1.62 (95% CI: 0.84–3.12), compared with that for VFA < 100 cm² (p for trend = 0.049). These findings were confirmed in the same cohort the following year.

Conclusions

Our results suggest that visceral fat accumulation is associated with influenza infection. Large-scale prospective studies using diagnostic information for influenza infection are required to confirm this association.

Survival analysis based on body mass index in patients with Covid-19 admitted to the intensive care unit of Amir Al-Momenin Hospital in Arak - 2021

INTRODUCTION

The potential risk of obesity on the severity of COVID-19 has been proposed. The main purpose of this study was to investigate the effect of BMI on the survival rate of COVID-19 patients admitted to the ICU.

METHODS & MATERIALS

Patients with COVID-19 admitted to ICU were included. Gender, height, weight, BMI, age, underlying disease status, prescribed drugs and nutritional supplements, and clinical and laboratory parameters at the beginning of admission were recorded. Death or discharge from the ICU and the days elapsed to these events were also reviewed and recorded. Data analysis was performed using the Cox regression model.

RESULTS

assessing 193 patients showed that BMI was not related to the survival rate even after adjusting for other potential confounding variables. It was shown that arterial oxygen saturation and taking Famotidine were the significant factors determining the time to event in these patients.

CONCLUSION

The BMI at the time of ICU admission has no effect on survival rate and time to event in COVID-19 infected patients admitted to ICU.

Diet Impact on Obesity beyond Calories and Trefoil Factor Family 2 (TFF2) as an Illustration: Metabolic Implications and Potential Applications

Obesity is a health problem with increasing impacts on public health, economy and even social life. In order to reestablish the energy balance, obesity management focuses mainly on two pillars; exercise and diet. Beyond the contribution to the caloric intake, the diet nutrients and composition govern a variety of properties. This includes the energy balance-independent properties and the indirect metabolic effects. Whereas the energy balance-independent properties are close to "pharmacological" effects and include effects such as antioxidant and anti-inflammatory, the indirect metabolic effects represent the contribution a diet can have on energy metabolism beyond the caloric contribution itself, which include the food intake control and metabolic changes. As an illustration, we also described the metabolic implication and hypothetical pathways of the high-fat diet-induced gene Trefoil Factor Family 2. The properties the diet has can have a variety of applications mainly in pharmacology and nutrition and further explore the "pharmacologically" active food towards potential therapeutic applications.

Clinical Characteristics and Outcome of SARS-CoV-2 Patients. An Experience from Anbar province - West of Iraq

The SARS-CoV2 infection emerged in Iraq in February 2020. In this study, we describe the clinical characteristics and outcomes of the initial SARS-CoV2 patients. A total of 529 patients were included in this study from April to August 2020 in Anbar province. Patients were confirmed to be infected in nasal swabs by real-time RT-PCR or chest CT scan findings. The gathered data included the demographic variables (age, sex, residency), presence of comorbidity (hypertension, diabetes mellitus, respiratory illness, coronary heart disease, chronic kidney disease, obesity), and history of contact with a known case of SARS-CoV2. The results showed that 64% of the patients were males and 36% were female, 48% of the patients lied in the age category 40-59 years, 74% had exposure history, 95% did not have a history of smoking, 46% were overweight, 60% had no comorbidity, 78% presented with mild/moderate disease, 70% had typical chest CT scan finding (CO-RAD 5), and 76% of patients showed positive PCR. The fatality rate is 16%. Most of the patients had a history of exposure to a confirmed case of SARS-CoV2 before the illness. The severity and outcome were correlated with risk factors and comorbidity. Combining chest computed tomography images with the qPCR analysis of nasal swab samples can improve the accuracy of SARS-CoV2 diagnosis.

Liver involvement in children with SARS-COV-2 infection: Two distinct clinical phenotypes caused by the same virus

BACKGROUND AND AIMS

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) associated acute liver injury (ALI) has been linked to poor outcomes in adults. Here we compare characteristics in children with elevated ALT (E-ALT) in two distinct manifestations of the infection, multisystem inflammatory syndrome-children (MIS-C) and coronavirus disease 2019 (COVID-19).

METHODS

This is a retrospective study of patients ≤21 years of age with positive for SARS-CoV-2 PCR. E-ALT was defined as alanine aminotransferase (ALT) > 40 U/L. Bivariate analysis and multivariable logistic regression were obtained to describe differences in children with and without E-ALT in COVID-19 and MIS-C.

RESULTS

E-ALT was detected in 36% of the 291 patients; 31% with COVID-19, and 51% with MIS-C. E-ALT in COVID-19 was associated with obesity (P < .001), immunocompromised status (P = .04), and chronic liver disease (P = .01). In the regression models, E-ALT in COVID-19 was associated with higher c-reactive protein (OR 1.08, P = .01) after adjusting for common independent predictors. Children with E-ALT and MIS-C were more often boys (P = .001), Hispanic (P = .04), or Black (P < .001). In MIS-C, male gender (OR 5.3, P = .02) and Black race (OR 4.4, P = .04) were associated with increased odds of E-ALT. Children with E-ALT in both cohorts had significantly higher multiorgan dysfunction, longer hospitalization, and ICU stay. Children with MIS-C had 2.3-fold increased risk of E-ALT compared to COVID-19. No association was found between E-ALT and mortality.

CONCLUSION

E-ALT with SARS-CoV-2 presents as elevated transaminases without hepatic synthetic dysfunction. Patients with either manifestation of SARS-CoV-2 infection and E-ALT experienced more severe disease.

Mortality-related risk factors of COVID-19: a systematic review and meta-analysis of 42 studies and 423,117 patients

Background

Mortality rates of coronavirus disease-2019 (COVID-19) continue to rise across the world. The impact of several risk factors on coronavirus mortality has been previously reported in several meta‐analyses limited by small sample sizes. In this systematic review, we aimed to summarize available findings on the association between comorbidities, complications, smoking status, obesity, gender, age and D-dimer, and risk of mortality from COVID-19 using a large dataset from a number of studies.

Method

Electronic databases including Google Scholar, Cochrane Library, Web of Sciences (WOS), EMBASE, Medline/PubMed, COVID-19 Research Database, and Scopus, were systematically searched till 31 August 2020. We included all human studies regardless of language, publication date or region. Forty-two studies with a total of 423,117 patients met the inclusion criteria. To pool the estimate, a mixed-effect model was used. Moreover, publication bias and sensitivity analysis were evaluated.

Results

The findings of the included studies were consistent in stating the contribution of comorbidities, gender, age, smoking status, obesity, acute kidney injury, and D-dimer as a risk factor to increase the requirement for advanced medical care. The analysis results showed that the pooled prevalence of mortality among hospitalized patients with COVID-19 was 17.62% (95% CI 14.26–21.57%, 42 studies and 423,117 patients). Older age has shown increased risk of mortality due to coronavirus and the pooled odds ratio (pOR) and hazard ratio (pHR) were 2.61 (95% CI 1.75–3.47) and 1.31 (95% CI 1.11–1.51), respectively. A significant association were found between COVID-19 mortality and male (pOR = 1.45; 95% CI 1.41–1.51; pHR = 1.24; 95% CI 1.07–1.41), and current smoker (pOR = 1.42; 95% CI 1.01–1.83). Furthermore, risk of mortality among hospitalized COVID-19 patients is highly influenced by patients with Chronic Obstructive Pulmonary Disease (COPD), Cardiovascular Disease (CVD), diabetes, hypertension, obese, cancer, acute kidney injury and increase D-dimer.

Conclusion

Chronic comorbidities, complications, and demographic variables including acute kidney injury, COPD, diabetes, hypertension, CVD, cancer, increased D-dimer, male gender, older age, current smoker, and obesity are clinical risk factors for a fatal outcome associated with coronavirus. The findings could be used for disease’s future research, control and prevention.

The Mechanism behind Influenza Virus Cytokine Storm

Influenza viruses are still a serious threat to human health. Cytokines are essential for cell-to-cell communication and viral clearance in the immune system, but excessive cytokines can cause serious immune pathology. Deaths caused by severe influenza are usually related to cytokine storms. The recent literature has described the mechanism behind the cytokine–storm network and how it can exacerbate host pathological damage. Biological factors such as sex, age, and obesity may cause biological differences between different individuals, which affects cytokine storms induced by the influenza virus. In this review, we summarize the mechanism behind influenza virus cytokine storms and the differences in cytokine storms of different ages and sexes, and in obesity.

Obesity and severe coronavirus disease 2019: molecular mechanisms, paths forward, and therapeutic opportunities

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appears to have higher pathogenicity among patients with obesity. Obesity, termed as body mass index greater than 30 kg/m2, has now been demonstrated to be important comorbidity for disease severity during coronavirus disease 2019 (COVID-19) pandemic and associated with adverse events. Unraveling mechanisms behind this phenomenon can assist scientists, clinicians, and policymakers in responding appropriately to the COVID-19 pandemic. In this review, we systemically delineated the potential mechanistic links between obesity and worsening COVID-19 from altered physiology, underlying diseases, metabolism, immunity, cytokine storm, and thrombosis. Problematic ventilation caused by obesity and preexisting medical disorders exacerbate organ dysfunction for patients with obesity. Chronic metabolic disorders, including dyslipidemia, hyperglycemia, vitamin D deficiency, and polymorphisms of metabolism-related genes in obesity, probably aid SARS-CoV-2 intrusion and impair antiviral responses. Obesity-induced inadequate antiviral immunity (interferon, natural killer cells, invariant natural killer T cell, dendritic cell, T cells, B cell) at the early stage of SARS-CoV-2 infection leads to delayed viral elimination, increased viral load, and expedited viral mutation. Cytokine storm, with the defective antiviral immunity, probably contributes to tissue damage and pathological progression, resulting in severe symptoms and poor prognosis. The prothrombotic state, driven in large part by endothelial dysfunction, platelet hyperactivation, hypercoagulability, and impaired fibrinolysis in obesity, also increases the risk of severe COVID-19. These mechanisms in the susceptibility to severe condition also open the possibility for host-directed therapies in population with obesity. By bridging work done in these fields, researchers can gain a holistic view of the paths forward and therapeutic opportunities to break the vicious cycle of obesity and its devastating complications in the next emerging pandemic.

Anthropometric analysis of body habitus and outcomes in critically ill COVID-19 patients

Aims

This study aimed to determine whether anthropometric markers of thoracic skeletal muscle and abdominal visceral fat tissue correlate with outcome parameters in critically ill COVID-19 patients.

Methods

We retrospectively analysed thoracic CT-scans of 67 patients in four ICUs at a university hospital. Thoracic skeletal muscle (total cross-sectional area (CSA); pectoralis muscle area (PMA)) and abdominal visceral fat tissue (VAT) were quantified using a semi-automated method. Point-biserial-correlation-coefficient, Spearman-correlation-coefficient, Wilcoxon rank-sum test and logistic regression were used to assess the correlation and test for differences between anthropometric parameters and death, ventilator- and ICU-free days and initial inflammatory laboratory values.

Results

Deceased patients had lower CSA and PMA values, but higher VAT values (p < 0.001). Male patients with higher CSA values had more ventilator-free days (p = 0.047) and ICU-free days (p = 0.017). Higher VAT/CSA and VAT/PMA values were associated with higher mortality (p < 0.001), but were negatively correlated with ICU length of stay in female patients only (p < 0.016). There was no association between anthropometric parameters and initial inflammatory biomarker levels. Logistic regression revealed no significant independent predictor for death.

Conclusion

Our study suggests that pathologic body composition assessed by planimetric measurements using thoracic CT-scans is associated with worse outcome in critically ill COVID-19 patients.

The central role of mitochondrial fitness on antiviral defenses: An advocacy for physical activity during the COVID-19 pandemic

Mitochondria are central regulators of cellular metabolism, most known for their role in energy production. They can be "enhanced" by physical activity (including exercise), which increases their integrity, efficiency and dynamic adaptation to stressors, in short "mitochondrial fitness". Mitochondrial fitness is closely associated with cardiorespiratory fitness and physical activity. Given the importance of mitochondria in immune functions, it is thus not surprising that cardiorespiratory fitness is also an integral determinant of the antiviral host defense and vulnerability to infection. Here, we first briefly review the role of physical activity in viral infections. We then summarize mitochondrial functions that are relevant for the antiviral immune response with a particular focus on the current Coronavirus Disease (COVID-19) pandemic and on innate immune function. Finally, the modulation of mitochondrial and cardiorespiratory fitness by physical activity, aging and the chronic diseases that represent the most common comorbidities of COVID-19 is discussed. We conclude that a high mitochondrial - and related cardiorespiratory - fitness should be considered as protective factors for viral infections, including COVID-19. This assumption is corroborated by reduced mitochondrial fitness in many established risk factors of COVID-19, like age, various chronic diseases or obesity. We argue for regular analysis of the cardiorespiratory fitness of COVID-19 patients and the promotion of physical activity - with all its associated health benefits - as preventive measures against viral infection.

The Nature of Immune Responses to Influenza Vaccination in High-Risk Populations

The current pandemic has brought a renewed appreciation for the critical importance of vaccines for the promotion of both individual and public health. Influenza vaccines have been our primary tool for infection control to prevent seasonal epidemics and pandemics such as the 2009 H1N1 influenza A virus pandemic. Certain high-risk populations, including the elderly, people with obesity, and individuals with comorbidities such as type 2 diabetes mellitus, are more susceptible to increased disease severity and decreased vaccine efficacy. High-risk populations have unique microenvironments and immune responses that contribute to increased vulnerability for influenza infections. This review focuses on these differences as we investigate the variations in immune responses to influenza vaccination. In order to develop better influenza vaccines, it is critical to understand how to improve responses in our ever-growing high-risk populations.

The impact of obesity on immune response to infection: Plausible mechanisms and outcomes

Emerging data suggest an association between obesity and infectious diseases. Although the mechanisms underlying this link are not well established, a number of potential factors may be involved. Indeed, the obesity-related vulnerability to infectious diseases could be due to chronic low-grade inflammation, hyperglycemia, hyperinsulinemia, and hyperleptinemia, which lead to a weakening of both the innate and adaptive immune responses. In addition, obesity results in anatomical-functional changes by the mechanical obstacle of excessive adipose tissue that blunt the respiratory mechanisms and predisposing to respiratory infections. Subjects with obesity are also at risk of skin folds and sweat more profusely due to the thick layers of subcutaneous fat, favoring the proliferation of microorganisms and slowing the repair of wounds down. All these factors make subjects with obesity more prone to develop nosocomial infections, surgical site, skin and soft tissue infections, bacteremia, urinary tract infections, and mycosis. Furthermore, infections in subjects with obesity have a worse prognosis, frequently prolonging hospitalization time as demonstrated for several flu viruses and recently for COVID-19. Thus, the aim of this manuscript is to provide an overview of the current clinical evidence on the associations between obesity and infectious diseases highlighting physio pathological insights involved in this link.

Bioinformatic HLA Studies in the Context of SARS-CoV-2 Pandemic and Review on Association of HLA Alleles with Preexisting Medical Conditions

After the announcement of a new coronavirus in China in December 2019, which was then called SARS-CoV-2, this virus changed to a global concern and it was then declared as a pandemic by WHO. Human leukocyte antigen (HLA) alleles, which are one of the most polymorphic genes, play a pivotal role in both resistance and vulnerability of the body against viruses and other infections as well as chronic diseases. The association between HLA alleles and preexisting medical conditions such as cardiovascular diseases and diabetes mellitus is reported in various studies. In this review, we focused on the bioinformatic HLA studies to summarize the HLA alleles which responded to SARS-CoV-2 peptides and have been used to design vaccines. We also reviewed HLA alleles that are associated with comorbidities and might be related to the high mortality rate among COVID-19 patients. Since both genes and patients' medical conditions play a key role in both severity of the disease and the mortality rate in COVID-19 patients, a better understanding of the connection between HLA alleles and SARS-CoV-2 can provide a wider perspective on the behavior of the virus. Such understanding can help scientists, especially in terms of protecting healthcare workers and designing effective vaccines.

Regular aerobic exercise activates PDGF-BB/PDGFR-β signaling and modulates the inflammatory-anti-inflammatory balance in diet-induced obese mice

OBJECTIVE

Regular aerobic exercise induces cardioprotection by counteracting the obesity-associated inflammatory response, dyslipidemia. PDGF-BB/PDGFR-β signaling is established as a crucial mechanism of endothelial cell-cardiomyocyte communication and cardioprotection, but its physiological roles in response to obesity and regular aerobic exercise are unknown.

METHODS

Thirty C57BL/6 mice were divided into three groups: a normal diet group, a high-fat diet group, and a high-fat diet plus aerobic exercise group. Glucose metabolic parameters, inflammation-related indicators, and blood lipids indicators were detected. In addition, gene expression levels of the inflammatory factors, PDGF-BB, PDGFR-β, PI3K, Akt, eNOS, and P53 in cardiac tissue were quantified. Morphological analysis was also used to quantify the magnitude of inflammation.

RESULTS

High-fat diet (HFD) feeding resulted in adiposity, dyslipidemia, and low levels of cardioprotective factors such as APN and eNOS (P < 0.05), which were improved significantly by 8 weeks of aerobic exercise (P < 0.05). HFD feeding increased the gene expression levels of proinflammatory cytokines and decreased the gene expression levels of anti-inflammatory cytokines in cardiac tissue (P < 0.05), which was reversed by regular aerobic exercise (P < 0.05). In addition, HFD feeding suppressed the levels of the cardioprotective factors PDGF-BB and eNOS through PDGF-BB/PDGFR-β/PI3K/Akt/eNOS signaling in cardiac tissue, while regular aerobic exercise activated PDGF-BB/PDGFR-β/PI3K/Akt/eNOS signaling.

CONCLUSION

Regular aerobic exercise improved adiposity, dyslipidemia induced by HFD feeding. Regular aerobic exercise exerted a prominent role in modulating the inflammatory-anti-inflammatory balance and activating the levels of the cardioprotective factors eNOS and PDGF-BB through PDGF-BB/PDGFR-β signaling.

Obesity is a strong risk factor for short-term mortality and adverse outcomes in Mexican patients with COVID-19: a national observational study

Conflicting results have been obtained through meta-analyses for the role of obesity as a risk factor for adverse outcomes in patients with coronavirus disease-2019 (COVID-19), possibly due to the inclusion of predominantly multimorbid patients with severe COVID-19. Here, we aimed to study obesity alone or in combination with other comorbidities as a risk factor for short-term all-cause mortality and other adverse outcomes in Mexican patients evaluated for suspected COVID-19 in ambulatory units and hospitals in Mexico. We performed a retrospective observational analysis in a national cohort of 71 103 patients from all 32 states of Mexico from the National COVID-19 Epidemiological Surveillance Study. Two statistical models were applied through Cox regression to create survival models and logistic regression models to determine risk of death, hospitalisation, invasive mechanical ventilation, pneumonia and admission to an intensive care unit, conferred by obesity and other comorbidities (diabetes mellitus (DM), chronic obstructive pulmonary disease, asthma, immunosuppression, hypertension, cardiovascular disease and chronic kidney disease). Models were adjusted for other risk factors. From 24 February to 26 April 2020, 71 103 patients were evaluated for suspected COVID-19; 15 529 (21.8%) had a positive test for SARS-CoV-2; 46 960 (66.1%), negative and 8614 (12.1%), pending results. Obesity alone increased adjusted mortality risk in positive patients (hazard ratio (HR) = 2.7, 95% confidence interval (CI) 2.04-2.98), but not in negative and pending-result patients. Obesity combined with other comorbidities further increased risk of death (DM: HR = 2.79, 95% CI 2.04-3.80; immunosuppression: HR = 5.06, 95% CI 2.26-11.41; hypertension: HR = 2.30, 95% CI 1.77-3.01) and other adverse outcomes. In conclusion, obesity is a strong risk factor for short-term mortality and critical illness in Mexican patients with COVID-19; risk increases when obesity is present with other comorbidities.

Polyunsaturated fatty acids, specialized pro-resolving mediators, and targeting inflammation resolution in the age of precision nutrition

Chronic inflammation contributes toward the pathogenesis of numerous diseases including, but not limited to, obesity, autoimmunity, cardiovascular diseases, and cancers. The discovery of specialized pro-resolving mediators (SPMs), which are critical for resolving inflammation, has commenced investigation into targeting pathways of inflammation resolution to improve physiological outcomes. SPMs are predominately synthesized from the n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Therefore, one viable strategy to promote inflammation resolution would be to increase dietary intake of EPA/DHA, which are deficient in select populations. However, there are inconsistencies between the use of EPA/DHA as dietary or pharmacological supplements and improved inflammatory status. Herein, we review the literature on the relationship between the high n-6/n-3 PUFA ratio, downstream SPM biosynthesis, and inflammatory endpoints. We highlight key studies that have investigated how dietary intake of EPA/DHA increase tissue SPMs and their effects on inflammation. We also discuss the biochemical pathways by which EPA/DHA drive SPM biosynthesis and underscore mechanistic gaps in knowledge about these pathways which include a neglect for host genetics/ethnic differences in SPM metabolism, sexual dimorphism in SPM levels, and potential competition from select dietary n-6 PUFAs for enzymes of SPM synthesis. Altogether, establishing how dietary PUFAs control SPM biosynthesis in a genetic- and sex-dependent manner will drive new precision nutrition studies with EPA/DHA to prevent chronic inflammation in select populations.

Immune Response to SARS-CoV-2 Infection in Obesity and T2D: Literature Review

In December 2019, a novel coronavirus known as SARS-CoV-2 was first detected in Wuhan, China, causing outbreaks of the coronavirus disease COVID-19 that has now spread globally. For this reason, The World Health Organization (WHO) declared COVID-19 a public health emergency in March 2020. People living with pre-existing conditions such as obesity, cardiovascular diseases, type 2 diabetes (T2D), and chronic kidney and lung diseases, are prone to develop severe forms of disease with fatal outcomes. Metabolic diseases such as obesity and T2D alter the balance of innate and adaptive responses. Both diseases share common features characterized by augmented adiposity associated with a chronic systemic low-grade inflammation, senescence, immunoglobulin glycation, and abnormalities in the number and function of adaptive immune cells. In obese and T2D patients infected by SARS-CoV-2, where immune cells are already hampered, this response appears to be stronger. In this review, we describe the abnormalities of the immune system, and summarize clinical findings of COVID-19 patients with pre-existing conditions such as obesity and T2D as this group is at greater risk of suffering severe and fatal clinical outcomes.

Obesity and COVID-19: what makes obese host so vulnerable?

The disease (COVID-19) novel coronavirus pandemic has so far infected millions resulting in the death of over a million people as of Oct 2020. More than 90% of those infected with COVID-19 show mild or no symptoms but the rest of the infected cases show severe symptoms resulting in significant mortality. Age has emerged as a major factor to predict the severity of the disease and mortality rates are significantly higher in elderly patients. Besides, patients with underlying conditions like Type 2 diabetes, cardiovascular diseases, hypertension, and cancer have an increased risk of severe disease and death due to COVID-19 infection. Obesity has emerged as a novel risk factor for hospitalization and death due to COVID-19. Several independent studies have observed that people with obesity are at a greater risk of severe disease and death due to COVID-19. Here we review the published data related to obesity and overweight to assess the possible risk and outcome in Covid-19 patients based on their body weight. Besides, we explore how the obese host provides a unique microenvironment for disease pathogenesis, resulting in increased severity of the disease and poor outcome.

The Role of Obesity in Predicting the Clinical Outcomes of COVID-19

INTRODUCTION

The aim of this was to describe the predictors of mortality related to COVID-19 infection and to evaluate the association between overweight, obesity, and clinical outcomes of COVID-19.

METHODS

We included the patients >18 years of age, with at least one positive SARS-CoV-2 reverse transcriptase-polymerase chain reaction. Patients were grouped according to body mass index values as normal weight <25 kg/m2 (Group A), overweight from 25 to <30 kg/m2 (Group B), Class I obesity 30 to <35 kg/m2 (Group C), and ≥35 kg/m2 (Group D). Mortality, clinical outcomes, laboratory parameters, and comorbidities were compared among 4 groups.

RESULTS

There was no significant difference among study groups in terms of mortality. Noninvasive mechanical ventilation requirement was higher in group B and D than group A, while it was higher in Group D than Group C (Group B vs. Group A [p = 0.017], Group D vs. Group A [p = 0.001], and Group D vs. Group C [p = 0.016]). Lung involvement was less common in Group A, and presence of hypoxia was more common in Group D (Group B vs. Group A [p = 0.025], Group D vs. Group A [p < 0.001], Group D vs. Group B [p = 0.006], and Group D vs. Group C [p = 0.014]). The hospitalization rate was lower in Group A than in the other groups; in addition, patients in Group D have the highest rate of hospitalization (Group B vs. Group A [p < 0.001], Group C vs. Group A [p < 0.001], Group D vs. Group A [p < 0.001], Group D vs. Group B [p < 0.001], and Group D vs. Group C [p = 0.010]).

CONCLUSION

COVID-19 patients with overweight and obesity presented with more severe clinical findings. Health-care providers should take into account that people living with overweight and obesity are at higher risk for COVID-19 and its complications.

Clinical Impact Potential of Supplemental Nutrients as Adjuncts of Therapy in High-Risk COVID-19 for Obese Patients

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) in China at the end of 2019 caused a major global pandemic and continues to be an unresolved global health crisis. The supportive care interventions for reducing the severity of symptoms along with participation in clinical trials of investigational treatments are the mainstay of COVID-19 management because there is no effective standard therapy for COVID-19. The comorbidity of COVID-19 rises in obese patients. Micronutrients may boost the host immunity against viral infections, including COVID-19. In this review, we discuss the clinical impact potential of supplemental nutrients as adjuncts of therapy in high-risk COVID-19 for obese patients.

Obesity and mortality of COVID-19. Meta-analysis

Background

Obesity is a global disease with at least 2.8 million people dying each year as a result of being overweight or obese according to the world health organization figures. This paper aims to explore the links between obesity and mortality in COVID-19.

Methods

Electronic search was made for the papers studying obesity as a risk factor for mortality following COVID-19 infection. Three authors independently selected the papers and agreed for final inclusion. The outcomes were the age, gender, body mass index, severe comorbidities, respiratory support and the critical illness related mortality in COVID-19. 572 publications were identified and 42 studies were selected including one unpublished study data. Only 14 studies were selected for quantitative analysis.

Results

All the primary points but the gender are significantly associated with COVID-19 mortality. The age >70, [odd ratio (OR): 0.17, CI; 95%, P-value: <0.00001], gender [OR: 0.89; CI: 95%, P-value: 0.32], BMI > 25 kg/m² [OR: 3.68, CI: 95%, P-value: <0.003], severe comorbidities [OR: 1.84, CI:95%, P-value: <0.00001], advanced respiratory support [OR: 6.98, CI: 95%, P-value: <0.00001], and critical illness [OR: 2.03, CI: 95%, P-value: <0.00001].

Conclusions

Patients with obesity are at high risk of mortality from COVID-19 infection.

Obesity, Cardiovascular Disease, and Influenza: How Are They Connected?

Purpose of Review

To better understand the impact of obesity and cardiovascular diseases on influenza A infection.

Recent Findings

This infection could have detrimental outcomes in obese patients with cardiovascular diseases, such as an increased risk, length of hospitalization, disease severity, morbidity, and mortality. Nevertheless, there also might be some cardioprotective benefits associated with influenza vaccination, such as a reduced mortality, hospitalization, and acute coronary syndromes, in patients with coronary heart disease and/or heart failure.

Summary

Obesity negatively impacts immune function and host defense. Recent studies report obesity to be an independent risk factor for increased morbidity and mortality following infection. Obese patients might need special considerations in the treatment; however, there is not enough evidence to fully comprehend the mechanisms behind the reduced immunocompetence when influenza A infection occurs. Future studies should focus on special consideration treatments when the patients have not been vaccinated and have cardiovascular diseases.