Circulating resistin is a significant predictor of mortality independently from cardiovascular comorbidities in elderly, non-diabetic subjects with chronic kidney disease

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.

Serum and urinary levels of MIF, CD74, DDT and CXCR4 among patients with type 1 diabetes mellitus, type 2 diabetes and healthy individuals: Implications for further research

Background

Macrophage migration inhibitory factor (MIF) is a highly conserved cytokine with pleiotropic properties, mainly pro-inflammatory. MIF seems to exert its pro-inflammatory features by binding to its transmembrane cellular receptor CD74. MIF also has CXCR4, which acts as a co-receptor in this inflammatory process. Apart from MIF, D-dopachrome tautomerase (DDT) or MIF2, which belongs to the MIF superfamily, also binds to receptor CD74. Therefore, these molecules, MIF, CD74, DDT and CXCR4 are suggested to work together orchestrating an inflammatory process. Diabetes mellitus is characterised by chronic low-grade inflammation. Therefore, the aim of the present study was to evaluate serum and urinary levels of the aforementioned molecules among patients with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM) and among healthy controls.

Methods

We enrolled 13 patients with T1DM, 74 patients with T2DM and 25 healthy individuals as controls. Levels of CD74, CXCR4, DDT, and MIF were measured using ELISA Kits according to the manufacturer's instructions.

Results

We documented increased serum MIF levels together with higher urinary CD74 levels among patients with T1DM, when compared to patients with T2DM and healthy adults. In particular, patients with T1DM showed significantly increased levels of MIF compared to T2DM (p = 0.011) and healthy controls (p = 0.0093). CD74 in urine were significantly higher in patients with T1DM compared to those affected with T2DM (p = 0.0302) and healthy group (p = 0.0099). On the contrary, serum CD74 were similar among the three groups. No statistical differences were identified in CXCR4 levels both in serum and in urine of all groups. Patients with T2DM and overweight/obesity had increased urinary levels of CD74, when compared to lean patients with T2DM.

Conclusion

The increased serum MIF levels and urinary CD74 levels among patients with T1DM may be attributed to the autoimmune milieu, which characterises patients with T1DM, when compared to patients with T2DM. These two findings merit further attention as they could pave the way for further research regarding the potential beneficial effects of inhibitors of MIF among patients with T1DM, especially in the early stages of T1DM. Finally, the role of inhibitors of MIF could be further explored in the context of obesity among patients with T2DM.

Paraneoplastic hypoglycemia: An overview for optimal clinical guidance

Paraneoplastic hypoglycemia, also known as non-islet cell tumor hypoglycemia (NICTH), is a rare but critical condition occurring in patients with different types of malignancy. This condition is commonly linked to tumors producing insulin-like growth (IGF) factors, particularly IGF-2 and its precursors, which disrupt glucose homeostasis and lead to excessive glucose consumption. The diagnosis typically involves documenting symptomatic hypoglycemia and ruling out other potential causes. Essential diagnostic tools include imaging studies and laboratory tests, specifically measuring IGF-2 levels and the IGF-2:IGF-1 ratio. Treatment strategies for NICTH are multifaceted and may include surgical resection of the tumor if feasible, pharmacological interventions such as corticosteroids to suppress IGF-2 production, or supportive measures to manage acute hypoglycemic episodes. Novel therapeutic approaches targeting IGF-2, such as monoclonal antibodies or siRNA, are also being explored and hold promise for future treatment options. This review aims to enhance understanding of paraneoplastic hypoglycemia, focusing on its pathogenesis and diagnosis, to guide optimal medical treatment.

The role of kidney biopsy in deciphering diabetic versus non-diabetic origin of kidney disease among patients with type 2 diabetes mellitus and nephrotic range proteinuria: A retrospective study

Background

Diabetes mellitus (DM) is tightly associated with the increased prevalence of diabetic kidney disease (DKD). Nonetheless, severe renal function impairment and/or nephrotic range-proteinuria could also result from non-diabetic renal disease (non-DRD) among patients with DM. The 'Gold standard' for the differential diagnosis between DKD and non-DRD is kidney biopsy, although no real consensus exists. Thus, this study intends to associate the clinical and biochemical profile of patients with DM and renal disease with the histopathological data of kidney biopsy.In addition, we aimed to evaluate the role of kidney biopsy, especially when other causes, other than DM, are highly suspected among patients with DM and kidney disease.

Methods

Thirty two patients with T2DM and nephrotic range levels of proteinuria or with co-existing factors pointing towards a non-diabetic origin of kidney disease were studied, retrospectively. All 32 patients underwent kidney biopsy and were classified according to histopathological findings into 3 groups: a) isolated diabetic kidney disease (DKD), b) non-diabetic kidney disease (NDKD) and c) mixed kidney disease (MKD).

Results

Fifteen out of the 32 patients had findings of an isolated DKD, while 17 out of 32 patients suffered from NDKD (13 patients) or MKD (4 patients). DKD patients were younger (p = 0.016) and had a higher HbA1c value (p = 0.069, borderline statistical significance), while the NDKD patients had significantly shorter disease duration (p = 0.04). Furthermore, the incidence of diabetic retinopathy (DR) was lower among the NDKD patients (p < 0.001), who had also significantly less interstitial fibrosis (p = 0.02). Finally, the presence of DR, higher levels of interstitial fibrosis and longer T2DM duration were recognized as factors, which were positively associated with DKD.

Conclusion

This study advocates the usefulness of kidney biopsy in patients with T2DM and nephrotic range levels of proteinuria, especially when DR is absent and shorter disease duration is observed.

Incidental detection of hereditary bisalbuminemia in a patient with positive DAT coombs: A case-based review

Bisalbuminemia is a rare, typically benign condition marked by the presence of a bifid albumin band on serum protein electrophoresis. It can either be inherited due to a point mutation or acquired in association with various medical conditions, most commonly diabetes mellitus. Bisalbuminuria, the presence of bifid albumin in urine, may or may not accompany bisalbuminemia. Both conditions are often discovered incidentally during screening for monoclonal gammopathy. Bisalbuminemia and related variants provide insights into albumin's genetic diversity and functional roles, influencing clinical diagnostics and research in human genetics. Understanding these variants aids in distinguishing benign conditions from potential disease states, guiding appropriate clinical management. In this case-based review, we present a case of hereditary bisalbuminemia identified unexpectedly during an investigation of a positive Direct Antiglobulin Test Coombs in an adult female patient. This review aims to highlight the key features of bisalbuminemia, a rare condition that should be recognized by clinicians.

Diet patterns, gut microbiota and metabolic disorders: Perspectives and challenges

The worldwide surge in obesity and associated metabolic disorders is emerging as a significant public health issue for societies and healthcare systems. Available evidence has shown that alterations in the gut microbiota could be implicated in the pathogenesis of obesity and associated disorders. A healthy gut microbiome is characterized by richness and high microbial diversity. Gut microbiota affect how the host responds to diet, and conversely, the host may modify the gut microbiota through changes in dietary habits. Diet can impact and alter the composition, diversity, and species richness of the gut microbiota over time. An unhealthy diet, high in fat and sugar, may lead to decreased microbial diversity, reduced synthesis of metabolites that maintain gut permeability, damage to the mucus layer, increased bacterial translocation and lipopolyssacharide which can trigger endotoxemia, chronic subclinical inflammation and metabolic disorders. Currently, the impact of diet on gut microbial composition and its involvement in the pathogenic mechanisms underlying metabolic disorders is one of the most promising areas of research in nutrition. This special issue has gathered original research articles in topics related to diet patterns, gut microbiota, obesity and associated metabolic disorders as well as brief reports, reviews and perspectives in the wider field of translational and clinical metabolic research. In particular, the aim of this Special Issue was to present evidence connecting gut microbiota with metabolic disorders, explore the underlying mechanisms of this association, and examine how diet patterns may influence this relationship.

Resistin Contribution to Cardiovascular Risk in Chronic Kidney Disease Male Patients

BACKGROUND

Resistin is a molecule that belongs to the Resistin-Like Molecules family (RELMs), the group of proteins taking part in inflammatory processes. Increased resistin concentrations are observed in cardiovascular complications. Resistin contributes to the onset of atherosclerosis and intensifies the atherosclerotic processes. The aim of this study was to investigate the relationship between resistin and cardiovascular (CV) risk in men with chronic kidney disease (CKD) not treated with dialysis.

MATERIALS AND METHODS

One hundred and forty-two men were included in the study: 99 men with eGFR lower than 60 mL/min/1.73 m² and 43 men with eGFR ≥ 60 mL/min/1.73 m². CV risk was assessed. Serum resistin, tumor necrosis factor-alpha (TNF-alpha) and plasminogen activator inhibitor-1 (PAI-1) were measured among other biochemical parameters.

RESULTS

We observed that resistin concentrations were significantly higher in patients with CKD compared to individuals with eGFR ≥ 60 mL/min/1.73 m² (p = 0.003). In CKD, after estimating the general linear model (GLM), we found that resistin is associated with CV risk (p = 0.026) and PAI-1 serum concentrations (0.012). The relationship of PAI-1 with resistin depends on the level of CV risk in CKD (p = 0.048).

CONCLUSIONS

Resistin concentrations rise with the increase of CV risk in CKD patients and thus resistin may contribute to the progression of cardiovascular risk in this group of patients. The relationship between resistin and CV risk is modified by PAI-1 concentrations.

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.

Lower circulating omentin-1 is independently linked to subclinical hypothyroidism reflecting cardiometabolic risk: an observational case-control and interventional, longitudinal study

BACKGROUND

Omentin-1, a newly discovered adipokine, is implicated in the modulation of the adipose phenotype, ameliorating systemic metabolism and exhibiting anti-atherogenic, anti-oxidative, cardioprotective, anti-inflammatory and insulin-sensitizing properties. Our goal was to explore circulating omentin-1 in subclinical hypothyroidism (SH) and determine its correlations with cardiometabolic risk factors.

METHODS

In a large case-control and interventional longitudinal study, serum omentin-1, metabolic and lipid parameters, inflammatory biomarkers, classic adipocytokines and cardiovascular risk factors were assessed in 120 consecutive patients with SH and 120 healthy controls matched on age, gender and date of blood draw. Sixteen patients with SH were administered L-T4 and, after six months, circulating omentin-1 and other biomarkers were determined.

RESULTS

SH subjects presented significantly decreased circulating omentin-1 than control individuals (P<0.001). In all study participants, omentin-1 was negatively correlated with TSH, anti-thyroid antibodies, HOMA-IR, C-peptide, lipid and inflammatory biomarkers, adipokines and cardiovascular risk factors, including Framingham score and apolipoprotein B. Omentin-1 was positively associated with adiponectin and HDL-C. Circulating omentin-1 was independently associated with SH occurrence, above and beyond clinical and cardiometabolic factors (P=0.04). TSH was a negative independent predictor of serum omentin-1 levels (P<0.001). L-T4 treatment did not alter considerably the lower omentin-1 levels in treated SH patients (P=0.07).

CONCLUSIONS

Omentin-1 may be a useful non-invasive biomarker reflecting cardiometabolic risk as well as a promising therapeutic target. More mechanistic and larger prospective studies shedding light on the pathogenetic role of omentin-1 in SH are required to confirm these findings.

A chromatin remodeling checkpoint of diet-induced macrophage activation in adipose tissue

The interplay between the environment and the immune cells is linked to metabolic homeostasis under physiologic and pathophysiologic conditions. Diabetes mellitus type 2 (T2D) is considered an immune-related inflammatory disorder, in which the adipose tissue macrophages (ATMs) are key players orchestrating metabolic chronic meta-inflammation and contributing to the pathogenesis of metabolic disease. However, the molecular regulators that integrate the environmental signals to control ATM activation and adipose inflammation during obesity and T2D remain unclear. Epigenetic mechanisms constitute important parameters in metabolic homeostasis, obesity and T2D via the integration of the environmental factors to the transcriptional regulation of gene programs. In a very recent study published in Diabetes by Kong et al., BAF60a has been identified as a key chromatin remodeling checkpoint factor that associates obesity-associated stress signals with meta-inflammation and systemic homeostasis. Furthermore, this work uncovers Atf3 as an important downstream effector in BAF60a-mediated chromatin remodeling and transcriptional reprogramming of macrophage activation in adipose tissue. The findings of this research may contribute to the development of new therapeutic approaches for obesity-induced metabolic inflammation and associated metabolic disorders.

Of mice and men: Considerations on adipose tissue physiology in animal models of obesity and human studies

The ever-increasing burden of obesity demands a better pathophysiological understanding, especially regarding adipose tissue pathophysiology. Animal models of obesity are of great importance in investigating potential mechanisms and implications of obesity. Many issues should be considered while interpreting the preclinical results as anatomical and pathophysiological differences exist among species. Importantly, the natural history of obesity development differs considerably. An important example of conflicting results among preclinical models and human physiological studies is that of adipose tissue oxygenation, where rodent models almost unanimously have shown the presence of hypoxia in the adipose tissue of obese animals while human studies have yielded conflicting results to date. Other issues which require further clarification before generalizing preclinical data in humans include adipose tissue browning, endocrine function and fibrosis. The aim of this mini-review is to synopsize similarities and differences between rodent models and humans, which should be taken into consideration in obesity studies.

Could gut mycobiome play a role in NAFLD pathogenesis? Insights and therapeutic perspectives

The entire spectrum of nonalcoholic fatty liver disease (NAFLD) ranging from fatty liver to cirrhosis has been considered as the result of specific metabolic pathways and mediators, gut barrier function alterations and inflammatory responses. Previous studies have associated intestinal microbiota with NAFLD pathogenesis, focusing mostly on bacteria. In a recent study by Demir et al. in the Journal of Hepatology, researchers characterized the fecal mycobiome of patients with NAFLD and controls. NAFLD severity was linked to a specific fecal mycobiome signature, particularly in patients without obesity, highlighting previously undescribed aspects of the non obese phenotype of NAFLD. There has recently been a growing interest in the pathophysiology and progression of non obese NAFLD, as its actual incidence seems to be higher than previously described. Moreover, the authors demonstrated that in subjects with NAFLD and advanced fibrosis, there was an augmented systemic immune response to Candida albicans. Amphotericin B, which has been widely regarded as an antifungal with a good safety profile, low rate of resistance and high efficacy, has already been shown to prevent liver injury and steatosis in mice. Similarly in this study when germ-free mice colonized with feces from patients with NASH were fed with a Western diet, treatment with amphotericin B protected against steatohepatitis and liver fibrosis. In conclusion, this study has provided novel insights into the fecal mycobiome composition in advanced NAFLD especially in the non obese population while suggesting a role for antifungal therapy in the management of NAFLD.

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.

Understanding the enigmatic association between mycosis fungoides and psoriasis: Report of two cases and review of the literature

Psoriatic patients present an increased risk for developing lymphoma, particularly cutaneous T-cell lymphoma (CTCL). To what degree psoriasis itself through chronic immune stimulation, or the immunosuppressive medications used for its treatment or comorbidities (obesity, diabetes mellitus, etc), or lifestyle (smoking, alcohol, diet, etc) may play a role in the onset of MF is not yet clear. Psoriasis and Mycosis Fungoides (MF), the most common variant of CTCL, represent two distinct entities sharing common pathogenetic mechanisms and a wide spectrum of common clinical features associated with the abnormal activation of T-cells. The aim of this study is to explore the relationship between MF and psoriasis by presenting two cases with clinical and histopathologic features of both psoriasis and MF with a particular emphasis on the time of presentation of both disorders, the use of previous immunosuppressive drugs as well as the therapeutic management of patients. Biopsy of the cutaneous lesions before the introduction of biologics should be incorporated in clinical practice. Biopsy of the cutaneous lesion should also be performed in the case of appearance of psoriasiform lesions during biologic treatment for autoimmune disorders because this may represent an indolent form of MF. Psoriatic patients with poor or no-response to treatment should be examined thoroughly for MF using immunochemistry and, if necessary, molecular biology techniques. In concomitant MF and psoriasis, combination treatment may be beneficial for both entities. Finally, a large multicentric registry of MF patients who were treated for benign dermatoses (i.e. eczema, psoriasis) with classic immunosuppressive drugs and/or biologics is needed to collect data and further clarify the enigmatic relationship between psoriasis, MF and immunosuppressive treatment.

The Pathogenesis of End-Stage Renal Disease from the Standpoint of the Theory of General Pathological Processes of Inflammation

Chronic kidney disease can progress to end-stage chronic renal disease (ESRD), which requires the use of replacement therapy (dialysis or kidney transplant) in life-threatening conditions. In ESRD, irreversible changes in the kidneys are associated with systemic changes of proinflammatory nature and dysfunctions of internal organs, skeletal muscles, and integumentary tissues. The common components of ESRD pathogenesis, regardless of the initial nosology, are (1) local (in the kidneys) and systemic chronic low-grade inflammation (ChLGI) as a risk factor for diabetic kidney disease and its progression to ESRD, (2) inflammation of the classical type characteristic of primary and secondary autoimmune glomerulonephritis and infectious recurrent pyelonephritis, as well as immune reactions in kidney allograft rejection, and (3) chronic systemic inflammation (ChSI), pathogenetically characterized by latent microcirculatory disorders and manifestations of paracoagulation. The development of ChSI is closely associated with programmed hemodialysis in ESRD, as well as with the systemic autoimmune process. Consideration of ESRD pathogenesis from the standpoint of the theory of general pathological processes opens up the scope not only for particular but also for universal approaches to conducting pathogenetic therapies and diagnosing and predicting systemic complications in severe nephropathies.

The role of resistin and its relation to other pathogenetic factors of the chronic kidney disease development

Chronic kidney disease (CKD) is the leading cause of death from non-communicable diseases, and its prevalence in 2017 ranged from 8.5 to 9.8%. Depending on the stage of CKD, stage 1 was diagnosed in 3.5%, stage 2 in 3.2% and stage 3 in 7.6%, while stages 4 and 5 took place in 0.4 and 0.1% of the world’s population respectively. Obesity also contributes to the increase in the prevalence and severity of CKD, and their combination occurs in 3.1% of patients. Kidney damage and their structural and functional changes in patients with obesity are associated with high metabolic activity of adipose tissue, due to the synthesis of adipocytokines, including resistin.

The purpose of the work: to study changes of resistin level in the blood in patients with early stages of chronic kidney disease, its relation to the level of endothelin, markers of lipid metabolism and inflammation.

Materials and methods: 70 patients with stage 1 and 88 patients with stage 2 of CKD with different stages of obesity were examined. Glomerular filtration rate (GFR) was calculated by the formula CKD-EPI based on creatinine, cystatin C and their combination (CKD-EPIcysC / cr). The levels of cystatin C, resistin, tumor necrosis factor-alpha (TNF-α) and endothelin-1 were determined by enzyme-linked immunosorbent assay. Determination of total cholesterol and low-density lipoprotein cholesterol levels in the blood serum was performed by colorimetric method. Statistical analysis of the results was performed with the help of Statistica 6.0 statistical software package using Student’s t-test and Spearman’s rank correlation coefficient.

Results: an increase of the resistin level in the blood by 1.3 times in the patients with stage 1 CKD and by 1.6 times in the patients with stage 2 CKD and obesity was determined (p1.2 &lt; 0.05), and there was a weak correlation between its concentration in the blood and body mass index. A significant average negative correlation between resistin and GFR was detected. Increased serum resistin level correlates with increased TNF-α. In patients of both groups, the level of resistin and LDL increases simultaneously, and the correlation between them increases as CKD progresses. Similar changes are observed with respect to increasing concentrations of resistin and endothelin-1. Thus, an increase of resistin level in the blood in patients with the early stages of CKD initiates a number of pathological changes, such as systemic inflammation, hyperlipidemia and endothelial dysfunction.

Prognostic models for chronic kidney disease: a systematic review and external validation

BACKGROUND

Accurate risk prediction is needed in order to provide personalized healthcare for chronic kidney disease (CKD) patients. An overload of prognosis studies is being published, ranging from individual biomarker studies to full prediction studies. We aim to systematically appraise published prognosis studies investigating multiple biomarkers and their role in risk predictions. Our primary objective was to investigate if the prognostic models that are reported in the literature were of sufficient quality and to externally validate them.

METHODS

We undertook a systematic review and appraised the quality of studies reporting multivariable prognosis models for end-stage renal disease (ESRD), cardiovascular (CV) events and mortality in CKD patients. We subsequently externally validated these models in a randomized trial that included patients from a broad CKD population.

RESULTS

We identified 91 papers describing 36 multivariable models for prognosis of ESRD, 50 for CV events, 46 for mortality and 17 for a composite outcome. Most studies were deemed of moderate quality. Moreover, they often adopted different definitions for the primary outcome and rarely reported full model equations (21% of the included studies). External validation was performed in the Multifactorial Approach and Superior Treatment Efficacy in Renal Patients with the Aid of Nurse Practitioners trial (n = 788, with 160 events for ESRD, 79 for CV and 102 for mortality). The 24 models that reported full model equations showed a great variability in their performance, although calibration remained fairly adequate for most models, except when predicting mortality (calibration slope >1.5).

CONCLUSIONS

This review shows that there is an abundance of multivariable prognosis models for the CKD population. Most studies were considered of moderate quality, and they were reported and analysed in such a manner that their results cannot directly be used in follow-up research or in clinical practice.

Adipocytokines: Are they the Theory of Everything?

INTRODUCTION

Adipose tissue secretes various bioactive peptides/proteins, immune molecules and inflammatory mediators which are known as adipokines or adipocytokines. Adipokines play important roles in the maintenance of energy homeostasis, appetite, glucose and lipid metabolism, insulin sensitivity, angiogenesis, immunity and inflammation. Enormous number of studies from all over the world proved that adipocytokines are involved in the pathogenesis of diseases affecting nearly all body systems, which raises the question whether we can always blame adipocytokines as the triggering factor of every disease that may hit the body.

OBJECTIVE

Our review targeted the role played by adipocytokines in the pathogenesis of different diseases affecting different body systems including diabetes mellitus, kidney diseases, gynecological diseases, rheumatologic disorders, cancers, Alzheimer's, depression, muscle disorders, liver diseases, cardiovascular and lung diseases.

METHODOLOGY

We cited more than 33 recent literature reviews that discussed the role played by adipocytokines in the pathogenesis of different diseases affecting different body systems.

CONCLUSION

More evidence is being discovered to date about the role played by adipocytokines in more diseases and extra research is needed to explore hidden roles played by adipokine imbalance on disease pathogenesis.

Fatty Acid Binding Protein-4 and Risk of Cardiovascular Disease: The Cardiovascular Health Study

Background

FABP‐4 (fatty acid binding protein‐4) is a lipid chaperone in adipocytes and has been associated with prognosis in selected clinical populations. We investigated the associations between circulating FABP‐4, risk of incident cardiovascular disease (CVD), and risk of CVD mortality among older adults with and without established CVD.

Methods and Results

In the Cardiovascular Health Study, we measured FABP4 levels in stored specimens from the 1992–993 visit and followed participants for incident CVD if they were free of prevalent CVD at baseline and for CVD mortality through June 2015. We used Cox regression to estimate hazard ratios for incident CVD and CVD mortality per doubling in serum FABP‐4 adjusted for age, sex, race, field center, waist circumference, blood pressure, lipids, fasting glucose, and C‐reactive protein. Among 4026 participants free of CVD and 681 with prevalent CVD, we documented 1878 cases of incident CVD and 331 CVD deaths, respectively. In adjusted analyses, FABP‐4 was modestly associated with risk of incident CVD (mean, 34.24; SD, 18.90; HR, 1.10 per doubling in FABP‐4, 95% CI, 1.00–1.21). In contrast, FABP‐4 was more clearly associated with risk of CVD mortality among participants without (HR hazard ratio 1.24, 95% CI, 1.10–1.40) or with prevalent CVD (HR hazard ratio 1.57, 95% CI, 1.24–1.98). These associations were not significantly modified by sex, age, and waist circumference.

Conclusions

Serum FABP‐4 is modestly associated with risk of incident CVD even after adjustment for standard risk factors, but more strongly associated with CVD mortality among older adults with and without established CVD.

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

PURPOSE

Sepsis has become a global health problem with rising incidence and high mortality, creating a substantial social and economic burden. Early diagnosis and treatment can improve outcome, but reliable sepsis biomarkers are lacking. This review summarizes current evidence of the pathophysiological mechanisms linking adipose tissue to sepsis and presents experimental and clinical data on adipokines and sepsis along with important insights into the obesity paradox in sepsis survival.

RECENT FINDINGS

Sepsis is characterized by significant alterations in circulating cytokines and adipokines, biologically active molecules produced by the adipose tissue, being implicated in metabolic and inflammatory processes. Although data are inconclusive regarding classic adipokines such as leptin and adiponectin, recent evidence have highlighted the striking elevation of resistin and visfatin in critical illness and sepsis as well as their association with sepsis severity and outcomes. Given that inflammatory and metabolic pathways are involved in sepsis, studying adipokines presents an attractive, innovative, and promising research field that may provide more powerful diagnostic and prognostic biomarkers as well as novel therapeutic targets, empowering the therapeutic armamentarium for sepsis management in order to improve survival.

Physical activity increases the resistin concentration in hemodialyzed patients without metabolic syndrome

BACKGROUND

Resistin (RES) concentration increases in end-stage renal disease patients. However, there have been no studies defining the role of physical activity in RES concentrations in hemodialyzed (HD) patients. This study was aimed to determine metabolic and inflammatory effects, including RES, of 4-week supervised rehabilitation program in HD patients, with or without metabolic syndrome (MS).

METHODS

The study was completed by 28 patients aged 56.9±13.3 years ( x ¯ ± SD ) who were HD for 50.6±73.4 months, and 30 controls aged 61.5±8.3 years with normal renal function. Both the groups were divided into two subgroups with respect to MS. Individualized supervised rehabilitation program based on physiotherapy, including exercises, was provided to each subject for 4 weeks. Baseline and post-intervention complete blood count, glycated hemoglobin (HbA1c) and levels of serum RES, leptin, adiponectin, cystatin C, erythropoietin, high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6, transforming growth factor- β1, plasminogen activator inhibitor-1 homocysteine, insulin, albumin, parathyroid hormone (PTH), and phosphorus were measured.

RESULTS

Compared to controls, HD patients showed higher baseline leucocytes count and higher serum concentrations of RES, leptin, cystatin C, hs-CRP, TNF-α, homocysteine, phosphorus, PTH while hemoglobin, glucose, and albumin concentrations. A positive correlation between serum albumin and RES concentrations was observed in HD patients. Post-intervention RES increase was observed in HD patients without MS (post-intervention 34.22±8.89 vs baseline 30.16±11.04 ng/mL; P=0.046) while no change was observed in patients with MS and in the control group.

CONCLUSION

MS modifies a RES response to the rehabilitation program in HD patients.

Plasma Resistin Levels in Patients with Acute Aortic Dissection: A Propensity Score-Matched Observational Case-Control Study

Background

The aim of this observational case-control study was to compare the levels of plasma resistin between patients with acute aortic dissection and matched controls, and to use propensity score matching (PSM) to reduce case selection bias and clinical confounders.

Material/Methods

With the use of PSM, this study included 43 pairs of patients with acute aortic dissection (type-A and type-B dissection) and matched controls. Plasma resistin levels and other laboratory parameters were compared between the two groups, including white blood cell (WBC) count, glucose, high sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and D-dimer. The correlations between resistin and other laboratory parameters were evaluated in patients with acute aortic dissection.

Results

Following PSM adjustment for clinical variables, including age, sex, body mass index, smoking, alcohol drinking, hypertension, diabetes mellitus, coronary heart disease and stroke, plasma resistin levels were significantly increased in patients with acute aortic dissection when compared with controls (35.2±13.8 vs. 18.4±9.1 ng/ml) (p<0.001). WBC counts, and levels of glucose, hs-CRP, IL-6, TNF-α and D-dimer were also significantly increased in the patients with aortic dissection compared with the control group. After adjustment for these variables, the association between plasma resistin levels and acute aortic dissection remained significant (OR, 1.114; 95% CI, 1.036–1.224) (p<0.001). Plasma resistin levels was positively correlated with WBC count (r=0.368, p=0.015), hs-CRP (r=0.359, p=0.022), IL-6 (r=0.306, p=0.046) and TNF-α levels (r=0.315, p=0.040) in patients with acute aortic dissection.

Conclusions

Acute aortic dissection is associated with elevated levels of plasma resistin and other pro-inflammatory cytokines. Plasma resistin levels is positively associated with other pro-inflammatory cytokines in acute aortic dissection.

Kinetics of circulating fetuin-A may predict mortality independently from adiponectin, high molecular weight adiponectin and prognostic factors in critically ill patients with sepsis: A prospective study

PURPOSE

Fetuin-A and adiponectin, major hepatokine and adipokine respectively, have been implicated in systematic inflammation. Our aim was to jointly investigate whether kinetics of circulating fetuin-A, adiponectin and its isoform HMWA predict 28-day mortality in sepsis.

MATERIALS AND METHODS

In a prospective study, serum fetuin-A, adiponectin and HMWA were determined in 102 ICU patients fulfilling the diagnostic criteria of SEPSIS-3, at enrollment and one week after, and in 102 healthy controls matched on age and gender.

RESULTS

Serum fetuin-A was significantly lower in septic patients than controls (p<0.001). Among septic patients, those with septic shock and nonsurvivors presented lower fetuin-A, but higher adiponectin and HMWA compared to patients with sepsis and survivors respectively, both at baseline and day 7 (p<0.001). Fetuin-A exhibited negative correlations with APACHE II, CRP, procalcitonin, adiponectin and IL-6 but a positive one with albumin. Reduced fetuin-A as well as lower serum kinetics of fetuin-A (HR: 0.55, 95% C.I. 0.34-0.91, p=0.02), adiponectin but not HMWA were independently associated with 28-day mortality adjusting for age, gender, BMI, APACHE II, septic shock and laboratory biomarkers.

CONCLUSIONS

Circulating fetuin-A kinetics may be a prognostic biomarker in septic patients. More research is essential to elucidate fetuin-A's ontological role in sepsis pathophysiology.

Serum resistin is causally related to mortality risk in patients with type 2 diabetes: preliminary evidences from genetic data

Resistin has been firmly associated with all-cause mortality. We investigated, whether, in patients with type 2 diabetes (T2D), this association is sustained by a cause-effect relationship. A genotype risk score (GRS), created by summing the number of resistin increasing alleles of two genome-wide association studies (GWAS)-derived single nucleotide polymorphisms (SNPs), serum resistin measurements and all-cause death records were obtained in 1,479 (403 events/12,454 person-years), patients with T2D from three cohorts, Gargano Heart Study-prospective design (n = 350), Gargano Mortality Study (n = 698) and Foggia Mortality Study (n = 431), from Italy. GRS was strongly associated with serum resistin in a non-linear fashion (overall p = 3.5 * 10^-7) with effect size modest for GRS = 1 and 2 and much higher for GRS >3, with respect to GRS = 0. A significant non-linear association was observed also between GRS and all-cause mortality (overall p = 3.3 * 10^-2), with a low effect size for GRS = 1 and 2, and nearly doubled for GRS ≥ 3, with respect to GRS = 0. Based on the above-reported associations, each genetic equivalent SD increase in log-resistin levels showed a causal hazard ratio of all-cause mortality equal to 2.17 (95%CI: 1.22-3.87), thus providing evidence for a causal role of resistin in shaping the risk of mortality in diabetic patients.