The Role of Adipose Tissue and Adipokines in Sepsis: Inflammatory and Metabolic Considerations, and the Obesity Paradox

Calorie restriction increases the sensitivity of progeroid Ercc1Δ/- mice to acute (neuro)inflammation

Hospitalized elderly patients frequently suffer from delirium, especially in the context of sepsis-associated encephalopathy. Current treatments of delirium are merely symptomatic. Calorie restriction (CR) is both a promising strategy to protect against sepsis and has beneficial effects on aging-induced neurodegeneration. In this study, we investigated whether six weeks of 30% CR had protective effects on lipopolysaccharide (LPS) induced (neuro)inflammation in wild-type (WT) and progeroid mice deficient in the DNA excision-repair gene Ercc1 (Ercc1Δ/-). While CR did not affect the LPS-induced inflammatory response in WT mice, CR exaggerated the peripheral inflammatory response in Ercc1Δ/- mice, as evidenced by an increase of pro-inflammatory serum cytokines (TNF-α, IL-1β, and IFN-γ) and kidney injury marker Ngal. Neuroinflammatory effects were assessed by RNA-sequencing of isolated microglia. Similarly, CR did not affect microglia gene expression in WT mice, but increased neuroinflammation-associated gene expression in Ercc1Δ/- mice. In conclusion, CR increases the peripheral and brain inflammatory response of Ercc1Δ/- mice to a systemic inflammatory stimulus.

The obesity paradox in younger adult patients with sepsis: analysis of the MIMIC-IV database

BACKGROUND

The obesity paradox suggests that individuals with obesity may have a survival advantage against specific critical illnesses, including sepsis. However, whether this paradox occurs at younger ages remains unclear. Therefore, we aimed to investigate whether obesity could improve survival in younger adult patients with sepsis.

METHODS

We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with Sequential Organ Failure Assessment score ≥2 and suspected infection at the time of ICU admission were identified as having sepsis, following the Sepsis-3 definition. Individuals were classified into the obesity (BMI ≥30 kg/m²) and non-obesity (BMI <30 kg/m²) groups. Patients aged <50 and ≥50 years were categorized as younger adult patients and older patients, respectively.

RESULTS

Of 73,181 patients in the MIMIC-IV ICU database, 18,120 satisfied the inclusion criteria: 2642 aged <50 years and 15,478 aged ≥50 years. The Kaplan-Meier curve showed that obesity was not associated with an improved mortality rate among younger adult patients with sepsis (log-rank test: P = 0.197), while obesity exhibited a survival benefit in older patients with sepsis (log-rank test: P < 0.001). After propensity score matching, in-hospital mortality did not differ significantly between the obesity and non-obesity groups (13.3% vs. 12.2%; P = 0.457) in the younger adult patients with sepsis. Multivariate logistic regression analysis revealed that BMI was not an independent risk factor for in-hospital mortality in younger adult patients with sepsis (underweight: adjusted odds ratio [aOR] 1.72, P = 0.076; overweight: aOR 0.88, P = 0.437; obesity: aOR 0.93, P = 0.677; and severe obesity: aOR 1.22, P = 0.580, with normal weight as the reference).

CONCLUSION

Contrary to findings regarding older patients with sepsis, our findings suggest that the obesity paradox does not apply to younger adult patients with sepsis.

The Kidney in Obesity: Current Evidence, Perspectives and Controversies

PURPOSE OF REVIEW

As obesity and chronic kidney disease (CKD) remain a public health issue, we aim to elaborate on their complex relationship regarding pathogenetic mechanisms and therapeutic potential as well. The purpose of this review is to enhance our understanding of the interplay between obesity and CKD in order to timely diagnose and treat obesity-related CKD.

RECENT FINDINGS

Obesity and CKD pose significant intertwined challenges to global health, affecting a substantial portion of the population worldwide. Obesity is recognized as an independent risk factor, intricately contributing to CKD pathogenesis through mechanisms such as lipotoxicity, chronic inflammation, and insulin resistance. Recent evidence highlights additional factors including hemodynamic changes and intestinal dysbiosis that exacerbate kidney dysfunction in obese individuals, leading to histologic alterations known as obesity-related glomerulopathy (ORG). This narrative review synthesizes current knowledge on the prevalence, pathophysiology, clinical manifestations, and diagnostic strategies of obesity-related kidney disease. Furthermore, it explores mechanistic insights to delineate current therapeutic approaches, future directions for managing this condition and controversies. By elucidating the multifaceted interactions between obesity and kidney health, this review aims to inform clinical practice and stimulate further research to address this global health epidemic effectively.

Protocol to examine murine visceral adipose tissue immune cells using fluorescence-based flow cytometry

Adipose tissue immune cells are heterogeneous and dynamic, alter metabolism, and drive immune responses. Here, we present a protocol for assessment and characterization of murine adipose tissue immune cells using fluorescence-based flow cytometry and sorting into pure populations. We describe steps for isolation of the stromovascular fraction, antibody staining, and data collection by flow cytometry. We also discuss common issues and troubleshooting steps. For complete details on the use and execution of this protocol, please refer to Carey et al.1.

Proprotein Convertase Subtilisin/Kexin Type 9 Induction in COVID-19 Is Poorly Associated with Disease Severity and Cholesterol Levels

SARS-CoV-2 infection was shown to induce proprotein convertase subtilisin/kexin type 9 (PCSK9) plasma levels in sepsis. Here, we investigate the association between serum PCSK9 levels and disease severity. PCSK9 was measured in serum of 55 controls, 40 patients with moderate and 60 patients with severe COVID-19 disease. Serum PCSK9 was elevated in moderate COVID-19 compared to controls and further increased in severe cases. PCSK9 levels were not associated with C-reactive protein, bacterial superinfections, interventions, or survival in patients with severe COVID-19. PCSK9 regulates circulating cholesterol levels, and 15 cholesteryl ester (CE) species and free cholesterol (FC) were quantified by direct flow injection analysis using a high-resolution hybrid quadrupole-Orbitrap mass spectrometer. Most CE species with shorter fatty acid chains were decreased in severe compared to moderate COVID-19, and none of the CE species were correlated with PCSK9 in patients with severe COVID-19. Levels of all CE species negatively correlated with C-reactive protein in severe COVID-19 patients. Notably, FC was induced in severe compared to moderate COVID-19. The FC/CE ratio correlated positively with inflammatory markers and was associated with non-survival. The current study suggests that the imbalance between CE and FC levels is associated with disease severity and mortality in patients with COVID-19.

Neutrophil Migration Is Mediated by VLA-6 in the Inflamed Adipose Tissue

Adipose tissue, well known for its endocrine function, plays an immunological role in the body. The inflamed adipose tissue under LPS-induced systemic inflammation is characterized by the dominance of pro-inflammatory immune cells, particularly neutrophils. Although migration of macrophages toward damaged or dead adipocytes to form a crown-like structure in inflamed adipose tissue has been revealed, the neutrophilic interaction with adipocytes or the extracellular matrix remains unknown. Here, we demonstrated the involvement of adhesion molecules, particularly integrin α6β1, of neutrophils in adipocytes or the extracellular matrix of inflamed adipose tissue interaction. These results suggest that disrupting the adhesion between adipose tissue components and neutrophils may govern the accumulation of excessive neutrophils in inflamed tissues, a prerequisite in developing anti-inflammatory therapeutics by inhibiting inflammatory immune cells.

Clinical metabolomics: Useful insights, perspectives and challenges

Metabolomics, a cutting-edge omics technique, is a rapidly advancing field in biomedical research, concentrating on the elucidation of pathogenetic mechanisms and the discovery of novel metabolite signatures predictive of disease risk, aiding in earlier disease detection, prognosis and prediction of treatment response. The capacity of this omics approach to simultaneously quantify thousands of metabolites, i.e. small molecules less than 1500 Da in samples, positions it as a promising tool for research and clinical applications in personalized medicine. Clinical metabolomics studies have proven valuable in understanding cardiometabolic disorders, potentially uncovering diagnostic biomarkers predictive of disease risk. Liquid chromatography-mass spectrometry is the predominant analytical method used in metabolomics, particularly untargeted. Metabolomics combined with extensive genomic data, proteomics, clinical chemistry data, imaging, health records, and other pertinent health-related data may yield significant advances beneficial for both public health initiatives, clinical applications and precision medicine, particularly in rare disorders and multimorbidity. This special issue has gathered original research articles in topics related to clinical metabolomics as well as research articles, reviews, perspectives and highlights in the broader field of translational and clinical metabolic research. Additional research is necessary to identify which metabolites consistently enhance clinical risk prediction across various populations and are causally linked to disease progression.

Assessment of antimicrobial, antidiabetic, and anti-inflammatory properties of acetone extract of Aerva lanata (L.) by in-vitro approach and bioactive compounds characterization

The antimicrobial, antidiabetic, and anti-inflammatory activities efficiency of Aerva lanata plant extracts (aqueous (Aqu-E), acetone (Ace-E), and ethanol (Eth-E)) were investigated in this study. Furthermore, the active molecules exist in the crude extract were characterized by UV-Visible spectrophotometer, Fourier transform infrared (FTIR), High-performance liquid chromatography (HPLC), and Gas Chromatography-Mass Spectrometry (GC-MS) analyses. The preliminary phytochemical study revealed that the Ace-E restrain more phytochemicals like alkaloids, saponins, anthraquinone, tannins, phenolics, flavonoids, glycosides, terpenoids, amino acid, steroids, protein, coumarin, as well as quinine than Aqu-E and Eth-E. Accordingly to this Ace-E showed considerable antimicrobial activity as the follows: for bacteria S. aureus > E. coli > K. pneumoniae > P. aeruginosa > B. subtilis and for fungi T. viride > A.flavus > C. albicans > A.niger at 30 mg ml concentration. Similarly, Ace-E showed considerable antidiabetic (α-amylase: 71.7 % and α-glucosidase: 70.1 %) and moderate anti-inflammatory (59 % and 49.8 %) activities. The spectral and chromatogram studies confirmed that the Ace-E have pharmaceutically valuable bioactive molecules such as (Nbutyl)-octadecane, propynoic acid, neophytadiene, and 5,14-di (N-butyl)-octadecane. These findings suggest that Ace-E from A. lanata can be used to purify additional bioactive substances and conduct individual compound-based biomedical application research.

Integrated Analysis Identified TGFBI as a Biomarker of Disease Severity and Prognosis Correlated with Immune Infiltrates in Patients with Sepsis

Background

Sepsis is a major contributor to morbidity and mortality among hospitalized patients. This study aims to identify markers associated with the severity and prognosis of sepsis, providing new approaches for its management and treatment.

Methods

Data were mined from the Gene Expression Omnibus (GEO) databases and were analyzed by multiple statistical methods like the Spearman correlation coefficient, Kaplan-Meier analysis, Cox regression analysis, and functional enrichment analysis. Candidate indicator' associations with immune infiltration and roles in sepsis development were evaluated. Additionally, we employed techniques such as flow cytometry and neutral red staining to evaluate its impact on macrophage functions like polarization and phagocytosis.

Results

Twenty-eight genes were identified as being closely linked to the severity of sepsis, among which transforming growth factor beta induced (TGFBI) emerged as a distinct marker for predicting clinical outcomes. Notably, reductions in TGFBI expression during sepsis correlate with poor prognosis and rapid disease progression. Elevated expression of TGFBI has been observed to mitigate abnormalities in sepsis-related immune cell infiltration that are critical to the pathogenesis and prognosis of the disease, including but not limited to type 17 T helper cells and activated CD8 T cells. Moreover, the protein-protein interaction network revealed the top ten genes that interact with TGFBI, showing significant involvement in the regulation of the actin cytoskeleton, extracellular matrix-receptor interactions, and phagosomes. These are pivotal elements in the formation of phagocytic cups by macrophages, squaring the findings of the Human Protein Atlas. Additionally, we discovered that TGFBI expression was significantly higher in M2-like macrophages, and its upregulation was found to inhibit lipopolysaccharide-induced polarization and phagocytosis in M1-like macrophages, thereby playing a role in preventing the onset of inflammation.

Conclusion

TGFBI warrants additional exploration as a promising biomarker for assessing illness severity and prognosis in patients with sepsis, considering its significant association with immunological and inflammatory responses in this condition.

Obesity and Leukemia: Biological Mechanisms, Perspectives, and Challenges

PURPOSE OF REVIEW

To examine the epidemiological data on obesity and leukemia; evaluate the effect of obesity on leukemia outcomes in childhood acute lymphoblastic leukemia (ALL) survivors; assess the potential mechanisms through which obesity may increase the risk of leukemia; and provide the effects of obesity management on leukemia. Preventive (diet, physical exercise, obesity pharmacotherapy, bariatric surgery) measures, repurposing drugs, candidate therapeutic agents targeting oncogenic pathways of obesity and insulin resistance in leukemia as well as challenges of the COVID-19 pandemic are also discussed.

RECENT FINDINGS

Obesity has been implicated in the development of 13 cancers, such as breast, endometrial, colon, renal, esophageal cancers, and multiple myeloma. Leukemia is estimated to account for approximately 2.5% and 3.1% of all new cancer incidence and mortality, respectively, while it represents the most frequent cancer in children younger than 5 years. Current evidence indicates that obesity may have an impact on the risk of leukemia. Increased birthweight may be associated with the development of childhood leukemia. Obesity is also associated with worse outcomes and increased mortality in leukemic patients. However, there are several limitations and challenges in meta-analyses and epidemiological studies. In addition, weight gain may occur in a substantial number of childhood ALL survivors while the majority of studies have documented an increased risk of relapse and mortality among patients with childhood ALL and obesity. The main pathophysiological pathways linking obesity to leukemia include bone marrow adipose tissue; hormones such as insulin and the insulin-like growth factor system as well as sex hormones; pro-inflammatory cytokines, such as IL-6 and TNF-α; adipocytokines, such as adiponectin, leptin, resistin, and visfatin; dyslipidemia and lipid signaling; chronic low-grade inflammation and oxidative stress; and other emerging mechanisms. Obesity represents a risk factor for leukemia, being among the only known risk factors that could be prevented or modified through weight loss, healthy diet, and physical exercise. Pharmacological interventions, repurposing drugs used for cardiometabolic comorbidities, and bariatric surgery may be recommended for leukemia and obesity-related cancer prevention.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Patients with systemic lupus erythematosus who are underweight have distinct disease characteristics

OBJECTIVE

This study aimed to detail the disease characteristics of systemic lupus erythematosus (SLE) in individuals who are underweight and assess whether underweight status is associated with SLE disease activity.

METHODS

This was a retrospective cohort study involving 218 patients newly diagnosed with SLE. Patients were categorized as underweight (body mass index [BMI] <18.5 kg/m2) or not underweight (BMI ≥18.5 kg/m2). We reviewed disease characteristics including the SLE Disease Activity Index 2000 (SLEDAI-2K) at diagnosis. High disease activity was defined as SLEDAI-2K ≥10. Disease characteristics were compared between those who were underweight and not underweight. We used multivariable logistic regression analysis to determine whether underweight status is associated with high disease activity.

RESULTS

Out of the 218 patients, 35 (16.1%) were underweight and 183 (83.9%) were not. Underweight patients had less renal involvement (5.7% vs 20.2%, p = .040), lower C-reactive protein levels (1.0 [0.3-2.3] mg/L vs 1.2 [0.8-5.0] mg/L, p = .028), and lower SLEDAI-2K scores (6.7 ± 4.6 vs 9.1 ± 5.7, p = .009), and were less likely to be at high disease activity status (22.9% vs 42.6%, p = .028), compared with those who were not underweight. Following adjustment for multiple covariates, being underweight was inversely associated with high disease activity status (adjusted odds ratio = 0.38, 95% confidence interval = 0.16 to 0.92, p = .031).

CONCLUSION

Patients with SLE who were underweight showed less renal involvement and lower SLEDAI-2K scores compared with those who were not underweight. Moreover, those with SLE who were underweight had a 60% lower risk of exhibiting high disease activity.

Periodontitis is associated with the increased levels of visfatin: a meta-analysis

OBJECTIVE

Periodontitis is a common inflammatory disease associated with systemic factors. Visfatin is a pleiotropic adipokine that exerts metabolic and immune functions. Studies have shown visfatin played roles in the development of periodontitis. The present study aims to compare the levels of visfatin in body fluids including serum, saliva, and gingival crevicular fluid (GCF) between periodontitis patients and healthy individuals, and to elucidate the alteration of visfatin levels after periodontal treatments.

MATERIALS AND METHODS

The database searched included Pubmed, Embase, Web of Science, and Cochrane Library. According to the Eligibility criteria, the records were screened and the eligible studies were included. The methodological qualities of the included case-controlled studies were assessed according to the Newcastle-Ottawa scale (NOS). The Methodological Index for Nonrandomized Studies (MINORS) was applied for assessing the qualities of the included clinical trials. The statistical analyses were processed using STATA 15.0.

RESULTS

Twenty-three studies were included in the statistical analyses. The meta-analysis showed significantly elevated visfatin levels of GCF, serum, and saliva in the periodontitis population compared with the controls (GCF: SMD = 5.201, 95% CI: 3.886-6.516, Z = 7.75, P < 0.05; Serum: SMD = 7.417, 95% CI: 3.068-11.767, Z = 3.34, P = P < 0.05; Saliva: SMD = 2.683, 95% CI: 1.202-4.163, Z = 3.34, P < 0.05). Visfatin levels of saliva serum and GCF were significantly decreased after periodontal treatment. (Saliva: SMD = -1.338, 95% CI: -2.289-0.487, Z = 39.77, P < 0.05; Serum: SMD = -2.890, 95% CI: -5.300-0.480, Z = 2.35, P < 0.05; GCF: SMD = -6.075, 95% CI: -11.032-1.117, Z = 2.40, P = 0.016; I 2 = 95.9%, P < 0.05).

CONCLUSIONS

Periodontitis elevated the visfatin levels in GCF, serum, and saliva. Additionally, GCF, serum, and saliva visfatin levels could be reduced after periodontal treatment.

Obesity and Peripheral Artery Disease: Current Evidence and Controversies

PURPOSE OF REVIEW

Obesity is a significant public health problem and a major risk factor for the development and progression of atherosclerosis and its cardiovascular manifestations. Lower extremity peripheral artery disease (PAD) affects 3%-10% of the Western population and, if left untreated, can lead to devastating outcomes with both an increased risk of morbidity and mortality. Interestingly, the association between obesity and PAD remains debatable. Whereas it is well known that PAD and obesity frequently overlap in the same patients, many studies have demonstrated a negative association between obesity and PAD and a protective effect of obesity on disease development and progression, a phenomenon described as the "obesity paradox." Possible mechanisms for this paradox may include genetic background, as assessed by mendelian randomization studies, adipose tissue dysfunction, and body fat distribution rather than adiposity, while other factors, such as sex, ethnicity, sarcopenia in the elderly population, or aggressive treatment of co-existing metabolic conditions in individuals with obesity compared to those with normal weight, could have some impact as well.

RECENT RINDINGS

Few reviews and meta-analyses examining systematically the relationship between obesity and PAD exist. The impact of PAD development due to the presence of obesity remains largely controversial. However, the most current evidence, backed by a recent meta-analysis, suggests a potential protective role of a higher body mass index on PAD-related complications and mortality. In this review, we discuss the association between obesity and PAD development, progression, and management, and the potential pathophysiologic mechanisms linking the two diseases.

Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges

Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; a chronic, low-grade inflammatory response; immune dysregulation and a defective immune response; the reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal and metabolic dysregulation; mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response, although this effort may be hampered by challenges pertaining to the non-specific nature of the majority of clinical manifestations in the LC spectrum, small sample sizes of relevant studies and other methodological issues. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation, including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, the reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; and cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers, their link to etiopathogenetic mechanisms or the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on pathogenetic mechanisms and the main LC symptomatology in the frame of the epidemiological and clinical aspects of the syndrome and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions.

Propofol inhibits neuroinflammation and metabolic reprogramming in microglia in vitro and in vivo

Microglial activation-induced neuroinflammation is closely related to the development of sepsis-associated encephalopathy. Accumulating evidence suggests that changes in the metabolic profile of microglia is crucial for their response to inflammation. Propofol is widely used for sedation in mechanically ventilated patients with sepsis. Here, we investigate the effect of propofol on lipopolysaccharide-induced neuroinflammation, neuronal injuries, microglia metabolic reprogramming as well as the underlying molecular mechanisms. The neuroprotective effects of propofol (80 mg/kg) in vivo were measured in the lipopolysaccharide (2 mg/kg)-induced sepsis in mice through behavioral tests, Western blot analysis and immunofluorescent staining. The anti-inflammatory effects of propofol (50 μM) in microglial cell cultures under lipopolysaccharide (10 ng/ml) challenge were examined with Seahorse XF Glycolysis Stress test, ROS assay, Western blot, and immunofluorescent staining. We showed that propofol treatment reduced microglia activation and neuroinflammation, inhibited neuronal apoptosis and improved lipopolysaccharide-induced cognitive dysfunction. Propofol also attenuated lipopolysaccharide-stimulated increases of inducible nitric oxide synthase, nitric oxide, tumor necrosis factor-α, interlukin-1β and COX-2 in cultured BV-2 cells. Propofol-treated microglia showed a remarkable suppression of lipopolysaccharide-induced HIF-1α, PFKFB3, HK2 expression and along with downregulation of the ROS/PI3K/Akt/mTOR signaling pathway. Moreover, propofol attenuated the enhancement of mitochondrial respiration and glycolysis induced by lipopolysaccharide. Together, our data suggest that propofol attenuated inflammatory response by inhibiting metabolic reprogramming, at least in part, through downregulation of the ROS/PI3K/Akt/mTOR/HIF-1α signaling pathway.

Diagnostic and Prognostic Value of Serum Omentin-1 in Sepsis: A Prospective Study in Critically Ill Patients

Background and Objectives: Omentin-1, also known as intelectin-1, is a novel adipokine with anti-inflammatory activities implicated in inflammatory diseases and sepsis. We aimed to explore serum omentin-1 and its kinetics in critically ill patients early in sepsis and its association with severity and prognosis. Materials and Methods: Serum omentin-1 was determined in 102 critically ill patients with sepsis during the first 48 h from sepsis onset and 1 week later, and in 102 age- and gender-matched healthy controls. The outcome of sepsis at 28 days after enrollment was recorded. Results: Serum omentin-1 at enrollment was significantly higher in patients compared to controls (763.3 ± 249.3 vs. 451.7 ± 122.3 μg/L, p < 0.001) and it further increased 1 week after (950.6 ± 215.5 vs. 763.3 ± 249.3 μg/L, p < 0.001). Patients with septic shock (n = 42) had higher omentin-1 compared to those with sepsis (n = 60) at enrollment (877.9 ± 241.2 vs. 683.1 ± 223.7 μg/L, p < 0.001) and 1 week after (1020.4 ± 224.7 vs. 901.7 ± 196.3 μg/L, p = 0.007). Furthermore, nonsurvivors (n = 30) had higher omentin-1 at sepsis onset (952.1 ± 248.2 vs. 684.6 ± 204.7 μg/L, p < 0.001) and 1 week after (1051.8 ± 242 vs. 908.4 ± 189.8 μg/L, p < 0.01). Patients with sepsis and survivors presented higher kinetics than those with septic shock and nonsurvivors (Δ(omentin-1)% 39.8 ± 35.9% vs. 20.2 ± 23.3%, p = 0.01, and 39.4 ± 34.3% vs. 13.3 ± 18.1%, p < 0.001, respectively). Higher omentin-1 at sepsis onset and 1 week after was an independent predictor of 28-day mortality (HR 2.26, 95% C.I. 1.21-4.19, p = 0.01 and HR: 2.15, 95% C.I. 1.43-3.22, p < 0.001, respectively). Finally, omentin-1 was significantly correlated with the severity scores, the white blood cells, coagulation biomarkers, and CRP, but not procalcitonin and other inflammatory biomarkers. Conclusions: Serum omentin-1 is increased in sepsis, while higher levels and lower kinetics during the first week of sepsis are associated with the severity and 28-day mortality of sepsis. Omentin-1 may be a promising biomarker of sepsis. However, more studies are needed to explore its role in sepsis.

High-fat diet increases mortality and intensifies immunometabolic changes in septic mice

Immunometabolic changes in the liver and white adipose tissue (WAT) caused by high-fat (HF) diet intake may worse metabolic adaptation and protection against pathogens in sepsis. We investigate the effect of chronic HF diet (15 weeks) on mortality and immunometabolic responses in female mice after sepsis induced by cecum ligation and perforation (CLP). At week 14, animals were divided into four groups: sham C diet (C-Sh), sepsis C diet (C-Sp), sham HF diet (HF-Sh) and sepsis HF diet (HF-Sp). The surviving animals were euthanised on the 7th day. The HF diet decreased survival rate (58.3% vs 76.2% C-Sp group), increased serum cytokine storm (IL-6 (1.41 ×; vs HF-Sh), IL-1β (1.37 ×; vs C-Sp), TNF (1.34 ×; vs C-Sp and 1.72 ×; vs HF-Sh), IL-17 (1.44 ×; vs HF-Sh), IL-10 (1.55 ×; vs C-Sp and 1.41 ×; HF-Sh), WAT inflammation (IL-6 (8.7 ×; vs C-Sp and 2.4 ×; vs HF-Sh), TNF (5 ×; vs C-Sp and 1.7 ×;vs HF-Sh), IL-17 (1.7 ×; vs C-Sp), IL-10 (7.4 ×; vs C-Sp and 1.3 ×; vs HF-Sh), and modulated lipid metabolism in septic mice. In the HF-Sp group liver's, we observed hepatomegaly, hydropic degeneration, necrosis, an increase in oxidative stress (reduction of CAT activity (-81.7%; vs HF-Sh); increase MDA levels (82.8%; vs HF-Sh), and hepatic IL-6 (1.9 ×; vs HF-Sh), and TNF (1.3 × %;vs HF-Sh) production. Furthermore, we found a decrease in the total number of inflammatory, mononuclear cells, and in the regenerative processes, and binucleated hepatocytes in a HF-Sp group liver's. Our results suggested that the organism under metabolic stress of a HF diet during sepsis may worsen the inflammatory landscape and hepatocellular injury and may harm the liver regenerative process.

Obesity and main urologic cancers: Current systematic evidence, novel biological mechanisms, perspectives and challenges

Urologic cancers (UC) account for 13.1% of all new cancer cases and 7.9% of all cancer-related deaths. A growing body of evidence has indicated a potential causal link between obesity and UC. The aim of the present review is to appraise in a critical and integrative manner evidence from meta-analyses and mechanistic studies on the role of obesity in four prevalent UC (kidney-KC, prostate-PC, urinary bladder-UBC, and testicular cancer-TC). Special emphasis is given on Mendelian Randomization Studies (MRS) corroborating a genetic causal association between obesity and UC, as well as on the role of classical and novel adipocytokines. Furthermore, the molecular pathways that link obesity to the development and progression of these cancers are reviewed. Available evidence indicates that obesity confers increased risk for KC, UBC, and advanced PC (20-82%, 10-19%, and 6-14%, respectively), whereas for TC adult height (5-cm increase) may increase the risk by 13%. Obese females tend to be more susceptible to UBC and KC than obese males. MRS have shown that a higher genetic-predicted BMI may be causally linked to KC and UBC but not PC and TC. Biological mechanisms that are involved in the association between excess body weight and UC include the Insulin-like Growth Factor axis, altered availability of sex hormones, chronic inflammation and oxidative stress, abnormal secretion of adipocytokines, ectopic fat deposition, dysbiosis of the gastrointestinal and urinary tract microbiomes and circadian rhythm dysregulation. Anti-hyperglycemic and non-steroidal anti-inflammatory drugs, statins, and adipokine receptor agonists/antagonists show potential as adjuvant cancer therapies. Identifying obesity as a modifiable risk factor for UC may have significant public health implications, allowing clinicians to tailor individualized prevention strategies for patients with excess body weight.

Obesity Paradox: Fact or Fiction?

PURPOSE OF REVIEW

Obesity is related to several comorbidities such as type 2 diabetes mellitus, cardiovascular disease, heart failure, and various types of cancers. While the detrimental effect of obesity in both mortality and morbidity has been well established, the concept of the obesity paradox in specific chronic diseases remains a topic of continuous interest. In the present review, we examine the controversial issues around the obesity paradox in certain conditions such as cardiovascular disease, several types of cancer and chronic obstructive pulmonary disease, and the factors that may confound the relation between obesity and mortality.

RECENT FINDINGS

We refer to the obesity paradox when particular chronic diseases exhibit an interesting "paradoxical" protective association between the body mass index (BMI) and clinical outcomes. This association, however, may be driven by multiple factors among which the limitations of the BMI itself; the unintended weight loss precipitated by chronic illness; the various phenotypes of obesity, i.e., sarcopenic obesity or the athlete's obesity phenotype; and the cardiorespiratory fitness levels of the included patients. Recent evidence highlighted that previous cardioprotective medications, obesity duration, and smoking status seem to play a role in the obesity paradox. The obesity paradox has been described in a plethora of chronic diseases. It cannot be emphasized enough that the incomplete information received from a single BMI measurement may interfere with outcomes of studies arguing in favor of the obesity paradox. Thus, the development of carefully designed studies, unhampered by confounding factors, is of great importance.

Could exercise hormone irisin be a therapeutic agent against Parkinson's and other neurodegenerative diseases?

Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease (AD). The pathologic hallmarks of the disease are the loss of dopaminergic neurons of substantia nigra pars compacta and the presence of intraneuronal alpha synuclein (a-syn) aggregates. Clinical features of PD include motor symptoms such as bradykinesia, rigidity, tremors, postural instability, and gait impairment, and non-motor symptoms such as constipation, orthostatic hypotension, REM sleep disorder, depression and dementia. Currently, there is no disease-modifying therapy for PD. Several human studies have shown that exercise reduces progression of motor symptoms, improves performance on cognitive tasks, and slows functional deterioration. However, regular exercise may not always be feasible in PD patients. Irisin is an exercise-induced myokine involved in metabolism modulation and body fat reduction, but it also crosses the blood-brain barrier and may mediate some of the benefits of exercise in brain function. Recent evidence has shown that irisin could be therapeutically promising in PD as an "exercise-mimicking" intervention. Exogenous irisin administration decreases brain a-syn pathology and loss of dopaminergic neurons, while it improves motor outcomes in preclinical models. Several other neurodegenerative disorders such as AD share common underlying pathogenetic mechanisms with PD such as protein misfolding and aggregation, neuroinflammation, brain metabolic abnormalities, and neuronal loss. Therefore, investigation of irisin as a disease-modifying therapy could be promising for PD and other neurodegenerative disorders including AD.

Electroacupuncture pre-treatment alleviates sepsis-induced cardiac inflammation and dysfunction by inhibiting the calpain-2/STAT3 pathway

Electroacupuncture (EA) has both anti-inflammatory and cardio-protective effects. Activation of calpain pathway is involved in several myocardiopathy. In sepsis, the role of calpain-2-regulated STAT3 in cardio-protective mechanism of electroacupuncture remains unclear. In this study, we aimed to elucidate the mechanism by which electroacupuncture reduces cardiac inflammation and apoptosis and improves cardiac function during sepsis. Electroacupuncture pretreatment for 7 days was applied in septic cardiomyopathy model induced by lipopolysaccharide (LPS). lipopolysaccharide-induced sepsis was associated with a dramatically systemic inflammation and cardiac dysfunction, which was alleviated by electroacupuncture pre-treatment. Lipopolysaccharide resulted in increases of pro-inflammatory factors (TNF-α,IL1βand IL-6) and apoptosis (TUNEL staining and BAX/Bcl2) via activation of calpain-2/STAT3 pathway.Electroacupuncture pre-treatment inhibited LPS-induced activation of cardiac calpain-2/STAT3 signalling and ameliorated inflammatory and apoptosis. Additionally, inhibition of calpain-2 expression using the corresponding siRNA decreased the Phosphorylation of STAT3,pro-inflammatory factors and apoptosis in lipopolysaccharide- treated cardiomyocytes, confirming that calpain-2 activated p-STAT3 participate in septic cardiomyopathy. Furthermore, suppression of STAT3 by stattic enhanced anti-inflammatory and anti-apoptosis effects of electroacupuncture. These findings reveal mechanisms of electroacupuncture preconditioning protection against cardiac inflammation and apoptosis in sepsis mouse via calpain-2/STAT3 pathway and may provide novel targets for clinical treatments of the sepsis-induced cardiac dysfunction.

Obesity, Hypovitaminosis D, and COVID-19: the Bermuda Triangle in Public Health

PURPOSE OF REVIEW

The COVID-19 pandemic has challenged public health to a significant extent by markedly increasing morbidity and mortality. Evidence suggests that obesity and hypovitaminosis D constitute important risk factors for SARS-CoV-2 infection, severity of disease, and poor outcomes. Due to their high prevalence globally, obesity and hypovitaminosis D are considered pandemics. This review presents current epidemiologic and genetic data linking obesity, hypovitaminosis D, and COVID-19, highlighting the importance of the convergence of three pandemics and their impact on public health. We also briefly summarize potential mechanisms that could explain these links.

RECENT FINDINGS

Epidemiologic data have shown that obesity is an independent risk factor for COVID-19, severe disease and death, and genetic evidence has suggested a causal association between obesity-related traits and COVID-19 susceptibility and severity. Additionally, obesity is independently associated with hypovitaminosis D, which is highly prevalent in subjects with obesity. Hypovitaminosis D is independently associated with a higher risk for COVID-19, severity, hospitalization, infectious complications, acute respiratory distress syndrome, and poor outcomes. However, genome-wide association studies have not revealed any causal association between vitamin D levels and the risk for COVID-19, while there is no robust evidence for a beneficial role of vitamin D supplementation in the prevention and treatment of COVID-19. In the context of the ongoing COVID-19 pandemic, the epidemiologic impact of obesity and hypovitaminosis D is emphasized. Efforts to increase public awareness and reinforce preventive and therapeutic measures against obesity and hypovitaminosis D are strongly required.

Highlighting the Role of Obesity and Insulin Resistance in Type 1 Diabetes and Its Associated Cardiometabolic Complications

PURPOSE OF REVIEW

This narrative review appraises research data on the potentially harmful effect of obesity and insulin resistance (IR) co-existence with type 1 diabetes mellitus (T1DM)-related cardiovascular (CVD) complications and evaluates possible therapeutic options.

RECENT FINDINGS

Obesity and IR have increasingly been emerging in patients with T1DM. Genetic, epigenetic factors, and subcutaneous insulin administration are implicated in the pathogenesis of this coexistence. Accumulating evidence implies that the concomitant presence of obesity and IR is an independent predictor of worse CVD outcomes. The prevalence of obesity and IR has increased in patients with T1DM. This increase can be partly attributed to general population trends but, additionally, to iatrogenic weight gain caused by insulin treatment. This association might be the missing link explaining the excess CVD burden observed in patients with T1DM despite optimal glycemic control. Data on newer agents for type 2 diabetes mellitus (T2DM) treatment are unraveling novel ways to challenge this aggravating coexistence.

Inhibition of visfatin alleviates sepsis-induced intestinal damage by inhibiting Hippo signaling pathway

Background

The aim of this study is to investigate role of Visfatin, one of the pro-inflammatory adipokines, in sepsis-induced intestinal injury and to clarify the potential mechanism.

Methods

C57BL/6 mice underwent cecal ligation and puncture (CLP) surgery to establish sepsis model in vivo. Intestinal epithelial cells were stimulated with LPS to mimic sepsis-induced intestinal injury in vitro. FK866 (the inhibitor of Visfatin) with or without XMU-MP-1 (the inhibitor of Hippo signaling) was applied for treatment. The expression levels of Visfatin, NF-κB and Hippo signaling pathways-related proteins were detected by western blot or immunohistochemistry. The intestinal cell apoptosis and intestinal injury were investigated by TUNEL staining and H&E staining, respectively. ELISA was used to determine the production of inflammatory cytokines.

Results

The expression of Visfatin increased in CLP mice. FK866 reduced intestinal pathological injury, inflammatory cytokines production, and intestinal cell apoptosis in sepsis mice. Meanwhile, FK866 affected NF-κB and Hippo signaling pathways. Additionally, the effects of FK866 on inflammatory response, apoptosis, Hippo signaling and NF-κB signaling were partly abolished by XMU-MP-1, the inhibitor of Hippo signaling. In vitro experiments also revealed that FK866 exhibited a protective role against LPS-induced inflammatory response and apoptosis in intestinal cells, as well as regulating NF-κB and Hippo signaling, whereas addition of XMU-MP-1 weakened the protective effects of FK866.

Conclusion

In short, this study demonstrated that inhibition of Visfatin might alleviate sepsis-induced intestinal injury through Hippo signaling pathway, supporting a further research on Visfatin as a therapeutic target.

Circulating eNAMPT as a biomarker in the critically ill: acute pancreatitis, sepsis, trauma, and acute respiratory distress syndrome

Background

Nicotinamide phosphoribosyltransferase (NAMPT) exhibits dual functionality – as an intracellular enzyme regulating nicotinamide adenine dinucleotide metabolism and as an extracellular secreted protein (eNAMPT) to function as a cytokine regulator of innate immunity via binding to Toll-Like receptor 4 and NF-κB activation. In limited preclinical and clinical studies, eNAMPT was implicated in the pathobiology of acute respiratory distress syndrome (ARDS) suggesting that eNAMPT could potentially serve as a diagnostic and prognostic biomarker. We investigated the feasibility of circulating eNAMPT levels to serve as a biomarker in an expanded cohort of patients with ARDS and ARDS-predisposing conditions that included acute pancreatitis, sepsis, and trauma with comparisons to controls.

Methods

A total of 671 patients and 179 healthy controls were included in two independent cohorts. Plasma and serum eNAMPT levels were quantified using one of two complementary Enzyme-linked Immunosorbent Assays. After log base 2 variance stabilizing transformation of plasma/serum eNAMPT measurements, differences between healthy controls and each disease cohort were compared using linear regression or a generalized estimating equation (GEE) model where applicable. Complementary analyses included sensitivity, specificity, positive predictive values, negative predictive values, and the area under the receiver operating curve.

Results

Compared to controls, circulating eNAMPT levels were significantly elevated in subjects with acute pancreatitis, sepsis, trauma, and ARDS (all p < 0.01). In the acute pancreatitis cohort, circulating eNAMPT levels positively correlated with disease severity (p < 0.01).

Conclusions

Circulating eNAMPT levels are novel biomarker in the critically ill with acute pancreatitis, sepsis, trauma, and/or ARDS with the potential to reflect disease severity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01718-1.

Prognostic Role of Liver Biopsy in Patients With Severe Indeterminate Acute Hepatitis

BACKGROUND AND AIMS

Severe indeterminate acute hepatitis (sIAH) is a poorly understood rare disease with no specific therapy. This study aims to define the clinicopathological characteristics of sIAH and the role of liver biopsy in determining prognosis.

METHODS

Patients with sIAH admitted to a single center between 2010 and 2019 were included. Histopathological patterns of liver biopsies were reviewed by 2 histopathologists, and key findings further were specified by multiplex immunofluorescence. Patients that died or underwent liver transplantation were analyzed as nonsurvivors.

RESULTS

Of 294 patients with acute hepatitis, 43 with sIAH were included. Seventeen (39.5%) underwent liver transplantation and 7 (16.2%) died within 3 months. Multilobular necrosis was the predominant histopathological feature, being significantly more frequent in nonsurvivors (62.5% vs 21.1%; P = .016). Necrotic areas showed low HNF4α and Ki67 expression but high expression of CK19 and cell death markers identifying areas of severe tissue injury and inadequate regenerative response. Patients with multilobular necrosis had higher international normalized ratio, Model for End-Stage Liver Disease, and Model for End-Stage Liver Disease-Sodium scores compared with those without (P values for all markers <.05). Multivariate Cox analysis revealed that multilobular necrosis (hazard ratio, 3.675; 95% confidence interval, 1.322-10.211) and lower body mass index (hazard ratio, 0.916; 95% confidence interval, 0.848-0.991) independently predicted death or transplantation.

CONCLUSIONS

The results of this study provide novel insights into the important role of liver biopsy in sIAH patients, suggesting that the presence of multilobular necrosis is an early indicator of poor prognosis.

Nutrition priorities in obese critically ill patients

PURPOSE OF REVIEW

During critical illness, several neuroendocrine, inflammatory, immune, adipokine, and gastrointestinal tract hormone pathways are activated; some of which are more intensified among obese compared with nonobese patients. Nutrition support may mitigate some of these effects. Nutrition priorities in obese critically ill patients include screening for nutritional risk, estimation of energy and protein requirement, and provision of macronutrients and micronutrients.

RECENT FINDINGS

Estimation of energy requirement in obese critically ill patients is challenging because of variations in body composition among obese patients and absence of reliable predictive equations for energy expenditure. Whereas hypocaloric nutrition with high protein has been advocated in obese critically ill patients, supporting data are scarce. Recent studies did not show differences in outcomes between hypocaloric and eucaloric nutrition, except for better glycemic control. Sarcopenia is common among obese patients, and the provision of increased protein intake has been suggested to mitigate catabolic changes especially after the acute phase of critical illness. However, high-quality data on high protein intake in these patients are lacking. Micronutrient deficiencies among obese critically ill patients are common but the role of their routine supplementation requires further study.

SUMMARY

An individualized approach for nutritional support may be needed for obese critically ill patients but high-quality evidence is lacking. Future studies should focus on nutrition priorities in this population, with efficient and adequately powered studies.

Circulating Chemerin and Its Kinetics May Be a Useful Diagnostic and Prognostic Biomarker in Critically Ill Patients with Sepsis: A Prospective Study

Chemerin, a novel adipokine, is a potent chemoattractant molecule with antimicrobial properties, implicated in immune responses. Our aim was to investigate circulating chemerin and its kinetics, early in sepsis in critically ill patients and its association with severity and prognosis. Serum chemerin was determined in a cohort of 102 critically ill patients with sepsis during the first 48 h from sepsis onset and one week later, and in 102 age- and gender-matched healthy controls. Patients were followed for 28 days and their outcomes were recorded. Circulating chemerin was significantly higher in septic patients at onset compared to controls (342.3 ± 108.1 vs. 200.8 ± 40.1 μg/L, p < 0.001). Chemerin decreased significantly from sepsis onset to one week later (342.3 ± 108.1 vs. 308.2 ± 108.5 μg/L, p < 0.001), but remained higher than in controls. Chemerin was higher in patients presenting with septic shock than those with sepsis (sepsis onset: 403.2 ± 89.9 vs. 299.7 ± 99.5 μg/L, p < 0.001; one week after: 374.9 ± 95.3 vs. 261.6 ± 91.9 μg/L, p < 0.001), and in nonsurvivors than survivors (sepsis onset: 427.2 ± 96.7 vs. 306.9 ± 92.1 μg/L, p < 0.001; one week after: 414.1 ± 94.5 vs. 264.2 ± 79.9 μg/L, p < 0.001). Moreover, patients with septic shock and nonsurvivors, presented a significantly lower absolute and relative decrease in chemerin one week after sepsis onset compared to baseline (p < 0.001). Based on ROC curve analyses, the diagnostic performance of chemerin (AUC 0.78, 95% CI 0.69–0.87) was similar to C-reactive protein (CRP) (AUC 0.78, 95% CI 0.68–0.87) in discriminating sepsis severity. However, increased chemerin at sepsis onset and one week later was an independent predictor of 28-day mortality (sepsis onset: HR 3.58, 95% CI 1.48–8.65, p = 0.005; one week after: HR 10.01, 95% CI 4.32–23.20, p < 0.001). Finally, serum chemerin exhibited significant correlations with the severity scores, white blood cells, lactate, CRP and procalcitonin, as well as with biomarkers of glucose homeostasis, but not with cytokines and soluble urokinase-type plasminogen activator receptor (suPAR). Circulating chemerin is increased early in sepsis and its kinetics may have diagnostic and prognostic value in critically ill patients. Further studies are needed to shed light on the role of chemerin in sepsis.

SARS-CoV-2 adipose tissue infection and hyperglycemia: A further step towards the understanding of severe COVID-19

Numerous studies have highlighted the prognostic significance of hyperglycemia in the outcomes of SARS-CoV-2 infection. A number of mechanisms have been proposed as potential drivers of this association, which were, however, up until recently based rather on speculation than on investigational evidence. It has been recently come to light that the development of insulin resistance in the frame of COVID-19 is likely the driving force behind the development of overt hyperglycemia. This results through the infectious insult of the adipose tissue, and is observed in conjunction with aberrant adipokine secretion by host adipocytes, such as decreased adiponectin, as well as a switch towards an antiviral immune secretory profile. These data could have a considerable relevance not only for the management of hyperglycemia in the course of the infection but also for the overall understanding of the pathogenesis of severe COVID-19.

Interactions between diabetes and COVID-19: A narrative review

Diabetes, whether due to pancreatic beta cells insufficiency or peripheral resistance to insulin, has been suggested as a risk factor of developing severe acute respiratory disease coronavirus-2 (SARS-CoV-2) infections. Indeed, diabetes has been associated with a higher risk of infections and higher risk of developing severe forms of coronavirus disease 2019 (COVID-19) related pneumonia. Diabetic patients often present associated comorbidities such as obesity, hypertension and cardiovascular diseases, and complications of diabetes, including chronic kidney disease, vasculopathy and relative immune dysfunction, all of which make them more susceptible to infectious complications. Moreover, they often present low-grade inflammation with increased circulating interleukin levels, endothelial susceptibility to inflammation and dysfunction, and finally, hyperglycemia, which increases this risk. Additionally, corticosteroids, which count among the few medications which showed benefit on survival and mechanical ventilation requirement in COVID-19 pneumonia in large randomized controlled trials, are associated to new onsets of diabetes, and metabolic disorders in patients with previous history of diabetes. Finally, SARS-CoV-2 via the alternate effects of the renin-angiotensin system, mediated by the angiotensin-converting-enzyme 2, was also associated with insulin resistance in key tissues involved in glucose homeostasis, such as liver, skeletal muscles, and adipose tissue; and also, with impaired insulin secretion by pancreatic β-cells. In this work, we reviewed all elements which may help understand how diabetes affects patients with COVID-19, how treatments affect outcomes in patients with COVID-19, how they may cause new onsets of diabetes, and finally review how SARS-CoV-2 may inherently be a risk factor of developing diabetes, through immune-mediated diabetogenic mechanisms.

Understanding the Co-Epidemic of Obesity and COVID-19: Current Evidence, Comparison with Previous Epidemics, Mechanisms, and Preventive and Therapeutic Perspectives

PURPOSE OF REVIEW

A growing body of evidence suggests that obesity and increased visceral adiposity are strongly and independently linked to adverse outcomes and death due to COVID-19. This review summarizes current epidemiologic data, highlights pathogenetic mechanisms on the association between excess body weight and COVID-19, compares data from previous pandemics, discusses why COVID-19 challenges the "obesity paradox," and presents implications in prevention and treatment as well as future perspectives.

RECENT FINDINGS

Data from meta-analyses based on recent observational studies have indicated that obesity increases the risks of infection from SARS-CoV-2, severe infection and hospitalization, admission to the ICU and need of invasive mechanical ventilation (IMV), and the risk of mortality, particularly in severe obesity. The risks of IMV and mortality associated with obesity are accentuated in younger individuals (age ≤ 50 years old). The meta-inflammation in obesity intersects with and exacerbates underlying pathogenetic mechanisms in COVID-19 through the following mechanisms and factors: (i) impaired innate and adaptive immune responses; (ii) chronic inflammation and oxidative stress; (iii) endothelial dysfunction, hypercoagulability, and aberrant activation of the complement; (iv) overactivation of the renin-angiotensin-aldosterone system; (v) overexpression of the angiotensin-converting enzyme 2 receptor in the adipose tissue; (vi) associated cardiometabolic comorbidities; (vii) vitamin D deficiency; (viii) gut dysbiosis; and (ix) mechanical and psychological issues. Mechanistic and large epidemiologic studies using big data sources with omics data exploring genetic determinants of risk and disease severity as well as large randomized controlled trials (RCTs) are necessary to shed light on the pathways connecting chronic subclinical inflammation/meta-inflammation with adverse COVID-19 outcomes and establish the ideal preventive and therapeutic approaches for patients with obesity.

Impact of thermogenesis induced by chronic β3-adrenergic receptor agonist treatment on inflammatory and infectious response during bacteremia in mice

White adipocytes store energy differently than brown and brite adipocytes which dissipate energy under the form of heat. Studies have shown that adipocytes are able to respond to bacteria thanks to the presence of Toll-like receptors at their surface. Despite this, little is known about the involvement of each class of adipocytes in the infectious response. We treated mice for one week with a β3-adrenergic receptor agonist to induce activation of brown adipose tissue and brite adipocytes within white adipose tissue. Mice were then injected intraperitoneally with E. coli to generate acute infection. The metabolic, infectious and inflammatory parameters of the mice were analysed during 48 hours after infection. Our results shown that in response to bacteria, thermogenic activity promoted a discrete and local anti-inflammatory environment in white adipose tissue characterized by the increase of the IL-1RA secretion. More generally, activation of brown and brite adipocytes did not modify the host response to infection including no additive effect with fever and an equivalent bacteria clearance and inflammatory response. In conclusion, these results suggest an IL-1RA-mediated immunomodulatory activity of thermogenic adipocytes in response to acute bacterial infection and open a way to characterize their effect along more chronic infection as septicaemia.

The Impact of Obesity in Critical Illness

The prevalence of obesity is rising worldwide. Adipose tissue exerts anatomic and physiological effects with significant implications for critical illness. Changes in respiratory mechanics cause expiratory flow limitation, atelectasis, and V̇/Q̇ mismatch with resultant hypoxemia. Altered work of breathing and obesity hypoventilation syndrome may cause hypercapnia. Challenging mask ventilation and peri-intubation hypoxemia may complicate intubation. Patients with obesity are at increased risk of ARDS and should receive lung-protective ventilation based on predicted body weight. Increased positive end expiratory pressure (PEEP), coupled with appropriate patient positioning, may overcome the alveolar decruitment and intrinsic PEEP caused by elevated baseline pleural pressure; however, evidence is insufficient regarding the impact of high PEEP strategies on outcomes. Venovenous extracorporeal membrane oxygenation may be safely performed in patients with obesity. Fluid management should account for increased prevalence of chronic heart and kidney disease, expanded blood volume, and elevated acute kidney injury risk. Medication pharmacodynamics and pharmacokinetics may be altered by hydrophobic drug distribution to adipose depots and comorbid liver or kidney disease. Obesity is associated with increased risk of VTE and infection; appropriate dosing of prophylactic anticoagulation and early removal of indwelling catheters may decrease these risks. Obesity is associated with improved critical illness survival in some studies. It is unclear whether this reflects a protective effect or limitations inherent to observational research. Obesity is associated with increased risk of intubation and death in SARS-CoV-2 infection. Ongoing molecular studies of adipose tissue may deepen our understanding of how obesity impacts critical illness pathophysiology.

The Role of Obesity in the Immunopathogenesis of COVID-19 Respiratory Disease and Critical Illness

Coronavirus disease (COVID-19), the clinical syndrome caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a global health pandemic with substantial morbidity and mortality. COVID-19 has cast a shadow on nearly every aspect of society, straining health systems and economies across the world. Although it is widely accepted that a close relationship exists between obesity, cardiovascular disease, and metabolic disorders on infection, we are only beginning to understand ways in which the immunological sequelae of obesity functions as a predisposing factor related to poor clinical outcomes in COVID-19. As both the innate and adaptive immune systems are each primed by obesity, the alteration of key pathways results in both an immunosuppressed and hyperinflammatory state. The present review will discuss the cellular and molecular immunology of obesity in the context of its role as a risk factor for severe COVID-19, discuss the role of cytokine storm, and draw parallels to prior viral epidemics such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and 2009 H1N1.

Effects of different lipid emulsions on serum adipokines, inflammatory markers and mortality in critically ill patients with sepsis: A prospective observational cohort study

BACKGROUND & AIMS

Intravenous lipid emulsions in parenteral nutrition may cause different metabolic responses and immune effects in critically ill patients with sepsis. The aim of this study is to investigate the effects of different lipid emulsions on changes in concentrations of adipokine and cytokine and their relationship with mortality in patients.

METHODS

Patients enrolled in this prospective, single-center, observational cohort study, were estimated to require more than ten days of parenteral nutrition. They were treated with soybean oil-based or olive oil-based parenteral lipid emulsions. Adipokine and cytokine concentrations of septic patients were determined at enrollment and ten days after, in accordance with the diagnostic criteria of SEPSIS-3. The concentrations levels were measured in an enzyme-linked immunosorbent assay. Mortality was analyzed using the Kaplan-Meier method and Cox regressions.

RESULTS

Over a 25-month period, 145 patients were assessed for eligibility and consequently, 40 patients were analyzed. On admission, both groups had comparable physiological scores, comorbidities, malnutrition risk, anthropometric measurements, metabolic/hematologic biomarkers and concentrations of adipokines and cytokines (p > .05). Serum leptin, resistin, and cytokines (IL-6, IL-10, IL-1β and TNF-α) decreased significantly in the entire cohort over ten days following sepsis (p < .05). Serum resistin decreased in both olive oil-based and soybean oil-based lipid emulsions groups. Serum adiponectin only decreased in soybean oil-based lipid emulsions group (p < .05). There was association between survival and percentage changes in adiponectin, resistin and visfatin concentrations (log rank test: p < .05).

CONCLUSION

Adipokine and cytokine responses are affected by medical nutritional therapy in the sepsis process and adipokines may represent functional prognostic biomarkers in critically ill patients with sepsis.

Circulating leptin, soluble leptin receptor and free leptin index in critically ill patients with sepsis: a prospective observational study

BACKGROUND

Leptin, the prototype adipokine, exerts immunomodulatory actions being implicated in inflammatory responses during sepsis. Clinical evidence regarding its role in sepsis has been contradictory, while free leptin has not been studied. Our aim was to jointly investigate circulating total leptin, its soluble receptor (sOBR), and free leptin, as well as their kinetics in critically ill patients with sepsis regarding their diagnostic and prognostic value.

METHODS

In a prospective study, serum total leptin, sOBR and free leptin index (FLI) were determined in 102 critically ill patients with sepsis within 48 hours from sepsis onset and one week after enrollment, and in 102 age and gender-matched healthy controls.

RESULTS

Upon enrollment, total leptin, sOB-R and FLI were significantly higher in septic patients compared to controls and they were positively correlated with sepsis severity scores, while they presented a significant decrease during the first week (p<0.001). The decrease in total leptin and sOB-R was significantly higher in patients with sepsis compared to septic shock and in survivors compared to nonsurvivors at 28 days (p<0.001). Higher serum total leptin was independently associated with survival at 28 days (enrollment: HR 0.86, p=0.03; one week after: HR 0.77, p<0.001). Higher kinetics of total leptin (but not FLI) was independently associated with survival after adjustment (HR: 0.48, p=0.001).

CONCLUSIONS

Higher circulating total leptin and its higher kinetics during the first week from sepsis onset independently predict 28 day survival in critically ill patients. Free leptin did not present any additional diagnostic and prognostic value in sepsis.

Vitamin D and Obesity: Current Evidence and Controversies

PURPOSE OF REVIEW

Evidence from observational studies suggests that obesity is associated with low vitamin D. As both obesity and hypovitaminosis D present an alarmingly increased prevalence worldwide, there is an intense research interest to clarify all aspects of this association. This review summarizes current evidence from meta-analyses investigating vitamin D status in obesity, including the effects of weight loss and bariatric surgery on vitamin D status and the outcomes of vitamin D supplementation on body weight. We also discuss potential pathophysiologic mechanisms and important controversies.

RECENT FINDINGS

Data from meta-analyses consistently support an inverse association of vitamin D levels with body weight. However, the impact of weight loss on improving vitamin D status is small, while studies on the supplementation with vitamin D after bariatric surgery have shown conflicting results regarding vitamin D status. Moreover, interventional studies do not support a beneficial effect of vitamin D supplementation on body weight. These findings warrant a cautious interpretation due to important methodological limitations and confounding factors, such as high heterogeneity of studies, variable methods of determination of vitamin D and definition of deficiency/insufficiency, use of various adiposity measures and definitions of obesity, and inadequate adjustment for confounding variables influencing vitamin D levels. The underlying pathogenetic mechanisms associating low vitamin D in obesity include volumetric dilution, sequestration into adipose tissue, limited sunlight exposure, and decreased vitamin D synthesis in the adipose tissue and liver. Experimental studies have demonstrated that low vitamin D may be implicated in adipose tissue differentiation and growth leading to obesity either by regulation of gene expression or through modulation of parathyroid hormone, calcium, and leptin. Obesity is associated with low vitamin D status but weight loss has little effect on improving this; vitamin D supplementation is also not associated with weight loss. Evidence regarding vitamin D status after bariatric surgery is contradicting. The link between vitamin D and obesity remains controversial due to important limitations and confounding of studies. More research is needed to clarify the complex interplay between vitamin D and adiposity.

Serum bilirubin to fetuin-A ratio as a prognostic biomarker in critically ill patients with sepsis

Liver dysfunction during sepsis is associated with increased bilirubin and decreased fetuin-A, a major hepatokine. We aimed to explore the association of bilirubin to fetuin-A (B/F) ratio early in sepsis with severity and outcome in critically ill patients. Based on a previous prospective study, we analyzed data of 90 critically ill patients (52 males, age: 65 ± 15 years, APACHE II: 24 ± 7 and SOFA: 10 ± 3) with sepsis. Bilirubin and fetuin-A increased during the first week of sepsis, (median (IQR) 0.45 (0.32-1) vs 0.55 (0.29-0.78) mg/dL, p = 0.03 and 302 (248-336) vs 358 (307-399) μg/mL, p < 0.001, respectively) while the B/F ratio did not change significantly. However, the B/F ratio at baseline and one week later was significantly higher in patients with septic shock (N = 38) and nonsurvivors (N = 28) compared to patients with sepsis (N = 52) and survivors (N = 62), respectively. The B/F ratio was positively associated with severity scores and outperformed bilirubin as a predictor of mortality in ROC curve analysis (AUC 0.78 (0.69-0.88), p < 0.001 and 0.69 (0.57-0.8), p = 0.003 respectively). The B/F ratio may be a promising sepsis biomarker with possible predictive value in critically ill patients.

Protective Effect of MicroRNA-23b on Kidney Injury in Septic Rats Through Regulation of Mothers Against Decapentaplegic Homolog 3 (Smad3)

Our study aims to investigate the mechanism whereby microRNA (miRNA)-23b alleviates kidney damage in septic rats. Herein, we set up septic rat model, control group and sham-operated model to evaluate the kidney tissue damage. The glomerular mesangial cells isolated from rats were transfected with plasmids expressing miR-23b followed by analysis of the expression of miR-23b, Smad3, TLR4, HMGB1 and expression of autophagy-related proteins (LC3, beclin-1) by western blot and RT-qPCR. The level of TNF-α, IL-6 and BUN and SCr were significantly elevated in the model group and decreased after overexpression of miR-23b with elevated LC3-II, Smad3 and Beclin-1 expression. miR-23b mimic group presented highest expression of miR-23b, followed by miR-23b NC group, and miR-23b inhibitor group. The levels of TLR4, and HMGB1 and positive rate of NF-κBp65 in miR-23b mimic group were significantly lower than those in miR-23b inhibitor group (p < 0.05). Importantly, miR-23b has a targeted relationship with Smad3. Overexpression of miR- 23b induces autophagy by promoting the Smad3 expression, alleviates kidney damage in septic rats, and reduces inflammation and inactivates NF-κB signaling pathway.

An update on the pathophysiology of acute and recurrent pericarditis

Pericarditis is an inflammatory disease of the pericardium. Progress has been done in recent years in the understanding of its pathophysiology. In particular, pre-clinical and clinical studies have contributed to increasing our knowledge on the role of interleukin (IL)-1 and NLRP3 (NACHT, leucine- rich repeat, and pyrin domain- containing protein 3) inflammasome. Based on current evidence, pericarditis should be considered as an inflammatory reaction to various stimuli, including chemical/physical, infectious, or ischemic ones, with a viral infection being a common etiology. Interaction of pathogens or irritants with toll-like receptor (TLRs) and stimulation of IL-1 receptor by IL-1α and IL-1β lead to an increased transcription of pro-inflammatory genes, including those needed for NLRP3 inflammasome assembly. This pathway is confirmed indirectly by the beneficial effect of colchicine (an indirect NLRP3 inflammasome inhibitor) and IL-1 blockers in patients with recurrent pericarditis. More recently, a direct evidence of the NLRP3 inflammasome within the inflamed pericardium has been provided as well. It may, however, occur that selfantigens on the surface of mesothelial cells or microbial peptides may stimulate autoreactive T cells along with B cells producing anti-heart antibodies, although less evidence is available on this. Some uncertainties still remain about the role of neutrophils, neutrophil extracellular traps (NETs), and pericardial interstitial cells in recurrent and constrictive pericarditis. Unraveling these aspects might have a direct impact on the development of novel targeted therapies, especially considering the increasing number of drugs targeting NETs.

Modulation of the inflammatory response to LPS by the recruitment and activation of brown and brite adipocytes in mice

Numerous studies have shown that the recruitment and activation of thermogenic adipocytes, which are brown and beige/brite, reduce the mass of adipose tissue and normalize abnormal glycemia and lipidemia. However, the impact of these adipocytes on the inflammatory state of adipose tissue is still not well understood, especially in response to endotoxemia, which is a major aspect of obesity and metabolic diseases. First, we analyzed the phenotype and metabolic function of white and brite primary adipocytes in response to lipopolysaccharide (LPS) treatment in vitro. Then, 8-wk-old male BALB/c mice were treated for 1 wk with a β3-adrenergic receptor agonist (CL316,243, 1 mg/kg/day) to induce recruitment and activation of brown and brite adipocytes and were subsequently injected with LPS (Escherichia coli lipopolysaccharide, 100 μg/mouse ip) to generate acute endotoxemia. The metabolic and inflammatory parameters of the mice were analyzed 6 h later. Our results showed that in response to LPS, thermogenic activity promoted a local anti-inflammatory environment with high secretion of IL-1 receptor antagonist (IL-1RA) without affecting other anti- or proinflammatory cytokines. Interestingly, activation of brite adipocytes reduced the LPS-induced secretion of leptin. However, thermogenic activity and adipocyte function were not altered by LPS treatment in vitro or by acute endotoxemia in vivo. In conclusion, these results suggest an IL-1RA-mediated immunomodulatory activity of thermogenic adipocytes specifically in response to endotoxemia. This encourages potential therapy involving brown and brite adipocytes for the treatment of obesity and associated metabolic diseases.NEW & NOTEWORTHY Recruitment and activation of brown and brite adipocytes in the adipose tissue of mice lead to a local low-grade anti-inflammatory phenotype in response to acute endotoxemia without alteration of adipocyte phenotype and function.

The role of resistin and myeloperoxidase in severe sepsis and septic shock: Results from the ALBIOS trial

BACKGROUND

Inflammatory biomarkers are useful in detecting patients with sepsis. The prognostic role of resistin and myeloperoxidase (MPO) has been investigated in sepsis.

MATERIALS AND METHODS

Plasma resistin and MPO were measured on days 1, 2 and 7 in 957 patients enrolled in the Albumin Italian Outcome Sepsis (ALBIOS) trial. The association between resistin and MPO levels on day 1, 2 and 7 and 90-day mortality was assessed.

RESULTS

Plasma resistin and MPO concentrations were higher at day 1 and decreased until day 7. Both biomarkers were positively correlated with each other and with physiological parameters. Higher levels of resistin and MPO on day 1 were associated with the development of new organ failures. Patients experiencing death at 90 days showed higher levels of resistin and MPO compared with survivors. At day 1, only MPO in the 4th quartile (Q4), but not resistin, was found to predict 90-day death (adjusted hazard ratio [aHR] 1.55 vs Q1). At day 2, resistin in the Q3 and Q4 predicted a > 40% increase in mortality as also did MPO in the Q4. On day 7, Q4 resistin was able to predict 90-day mortality, while all quartiles of MPO were not.

CONCLUSIONS

High levels of MPO, but not of resistin, on day 1 were able to predict 90-day mortality. These findings may either suggest that early hyper-activation of neutrophils is detrimental in patients with sepsis or reflect the burden of the inflammatory process caused by sepsis. Further studies are warranted to deepen these aspects (ALBIOS ClinicalTrials.gov Identifier: NCT00707122).

Autoantibody Production in Obesity: Is There Evidence for a Link Between Obesity and Autoimmunity?

PURPOSE OF REVIEW

During the last decades, obesity and autoimmune disorders have shown a parallel significant rise in industrialized countries. This review aims at providing a comprehensive update of the relationship between the adipose tissue in obesity and autoimmune disorders, highlighting the underlying mechanisms with a particular emphasis on adipokines and pro-inflammatory cytokines, the impaired B cell activity, and the production of natural and pathogenic autoantibody repertoire in the context of obesity.

RECENT FINDINGS

Obesity is related to a higher risk of rheumatoid arthritis, psoriasis and psoriatic arthritis, multiple sclerosis, and Hashimoto's thyroiditis, while it may promote inflammatory bowel disorders and type 1 diabetes mellitus. Interestingly, subjects with obesity present more severe forms of these autoimmune disorders as well as decreased therapeutic response. Both obesity and autoimmune disorders present elevated levels of leptin, resistin, and visfatin. Autoantibody production, a hallmark of autoimmune disorders, has been demonstrated in obese animal models and human subjects. Obesity results in deficiencies of the human self-tolerance mechanisms by promoting pro-inflammatory processes, reducing Bregs as well as Tregs, and the latter resulting in increased Th17 and Th1 cells, creating the perfect milieu for the development of autoimmune disorders. More mechanistic, animal, and clinical studies are required to delineate the exact mechanisms underlying auto-reactivity in obesity as well as the adipose-immune crosstalk for potential successful therapeutic strategies.

Deciphering the Association Between Psoriasis and Obesity: Current Evidence and Treatment Considerations

PURPOSE OF REVIEW

Obesity and psoriasis represent chronic inflammatory states that are interconnected in a vicious cycle, sharing also a degree of synergy. In this review, we aim to decipher the various lines of evidence supporting the bidirectional association between psoriasis and obesity highlighting their pathophysiologic connections as well as we attempt to strategize a therapeutic holistic approach for obese psoriatic patients.

RECENT FINDINGS

Recent meta-analyses have shown that (1) genetically higher BMI increased the odds of psoriasis occurrence; (2) obesity is associated with higher incidence and prevalence of psoriasis as well as psoriasis severity; (3) obesity is associated with lower efficacy to anti-TNF agents and may predict biologic treatment discontinuation; and (4) weight loss through diet and physical exercise may improve pre-existing psoriasis and prevent from de novo psoriasis. Methotrexate, acitretin, and cyclosporine could worsen hypertension, liver steatosis, and dyslipidemia. Since infliximab and ustekinumab are weight adjusted, they may be ideal drugs to treat obese psoriatic patients. IL-17 inhibitors are very effective independently from body weight; however, they tend to present better clearance rates in normal weight patients. There is a paucity on weight data regarding the efficacious IL-23 inhibitors. Apremilast may induce weight loss as an adverse effect presenting also some beneficial metabolic actions. Finally, simvastatin and some antidiabetic drugs could decrease psoriasis severity. More mechanistic, observational studies and well-conducted RCTs are necessary to decipher the enigmatic link between psoriasis and obesity, and to provide evidence-based specific guidelines for the screening and management of obese psoriatic patients.