Large Yellow Tea Attenuates Macrophage-Related Chronic Inflammation and Metabolic Syndrome in High-Fat Diet Treated Mice

Large yellow tea is a traditional beverage in China with a unique toasty flavor. A preliminary study using 3T3-L1 cells indicated that large yellow tea possessed more potent lipid-lowering efficacy than green, black, dark, and white teas. In the present study we further investigated its influence on metabolic syndrome in a high-fat diet (HFD) mouse model with an emphasis on dose response. Thirty-two C57BL/6 male mice were randomly divided into 4 groups: low-fat diet (LFD), HFD, HFD + 2.5% large yellow tea hot-water extract (YT, equivalent to 10 cups of tea daily for humans), HFD + 0.5% YT. Our data indicated that YT treatment for 12 weeks significantly reduced body weight, liver weight, and adipose tissue weight of the mice; lowered serum insulin and leptin; and raised serum adiponectin with dose effect. H&E staining showed that the HFD group exhibited significant enlargement of adipose cell sizes and the corresponding decrease of adipose cell numbers, which were dose-dependently attenuated in both YT groups. IHC results revealed that YT decreased macrophage recruitment in the liver, epididymal adipose tissue, and subcutaneous adipose tissue and depressed serum inflammatory cytokines including TNF-α, MCP-1, IFN-γ, IL-6, and IL-1β, in a dose-dependent manner. In addition, YT decreased serum glucose, TC, TG, LDL-C, and HDL-C, as well as ameliorated glucose intolerance and insulin resistance independent of dose. Overall, YT would be a unique tea with dose-independent antihyperglycemic and robust lipid-lowering efficacies.

Mice harboring pathobiont-free microbiota do not develop intestinal inflammation that normally results from an innate immune deficiency

BACKGROUND

Inability to maintain a stable and beneficial microbiota is associated with chronic gut inflammation, which classically manifests as colitis but may more commonly exist as low-grade inflammation that promotes metabolic syndrome. Alterations in microbiota, and associated inflammation, can originate from dysfunction in host proteins that manage the microbiota, such as the flagellin receptor TLR5. That the complete absence of a microbiota (i.e. germfree conditions) eliminates all evidence of inflammation in TLR5-deficient mice demonstrates that this model of gut inflammation is microbiota-dependent. We hypothesize that such microbiota dependency reflects an inability to manage pathobionts, such as Adherent-Invasive E. coli (AIEC). Herein, we examined the extent to which microbiota mismanagement and associated inflammation in TLR5-deficient mice would manifest in a limited and pathobiont-free microbiota. For this purpose, WT and TLR5-deficient mice were generated and maintained with the 8-member consortium of bacteria referred to as "Altered Schaedler Flora" (ASF). Such ASF animals were subsequently inoculated with AIEC reference strain LF82. Feces were assayed for bacterial loads, fecal lipopolysaccharide and flagellin loads, fecal inflammatory marker lipocalin-2 and microbiota composition.

RESULTS

Relative to similarly maintained WT mice, mice lacking TLR5 (T5KO) did not display low-grade intestinal inflammation nor metabolic syndrome under ASF conditions. Concomitantly, the ASF microbial community was similar between WT and T5KO mice, while inoculation with AIEC strain LF82 resulted in alteration of the ASF community in T5KO mice compared to WT control animals. AIEC LF82 inoculation in ASF T5KO mice resulted in microbiota components having elevated levels of bioactive lipopolysaccharide and flagellin, a modest level of low-grade inflammation and increased adiposity.

CONCLUSIONS

In a limited-complexity pathobiont-free microbiota, loss of the flagellin receptor TLR5 does not impact microbiota composition nor its ability to promote inflammation. Addition of AIEC to this ecosystem perturbs microbiota composition, increases levels of lipopolysaccharide and flagellin, but only modestly promotes gut inflammation and adiposity, suggesting that the phenotypes previously associated with loss of this innate immune receptor require disruption of complex microbiota.

Commensal Fungi in Health and Disease

Fungi are increasingly being recognized as common members of the microbiomes found on nearly all mucosal surfaces, and interest is growing in understanding how these organisms may contribute to health and disease. In this review, we investigate recent developments in our understanding of the fungal microbiota or "mycobiota" including challenges faced in characterizing it, where these organisms are found, their diversity, and how they interact with host immunity. Growing evidence indicates that, like the bacterial microbiota, the fungal microbiota is often altered in disease states, and increasingly studies are being designed to probe the functional consequences of such fungal dysbiosis on health and disease.

Metabolic Syndrome and Associated Diseases: From the Bench to the Clinic

Metabolic Syndrome and Associated Diseases: From the Bench to the Clinic, a Society of Toxicology Contemporary Concepts in Toxicology (CCT) workshop was held on March 11, 2017. The meeting was convened to raise awareness of metabolic syndrome and its associated diseases and serve as a melting pot with scientists of multiple disciplines (eg, toxicologists, clinicians, regulators) so as to spur research and understanding of this condition. The criteria for metabolic syndrome include obesity, dyslipidemia (low high-density lipoprotein and/or elevated triglycerides), elevated blood pressure, and alterations in glucose metabolism. It can lead to a greater potential of type 2 diabetes, lipid disorders, cardiovascular disease, hepatic steatosis, and other circulatory disorders. Although there are no approved drugs specifically for this syndrome, many drugs target diseases associated with this syndrome thus potentially increasing the likelihood of drug-drug interactions. There is currently significant research focusing on understanding the key pathways that control metabolism, which would be likely targets of risk factors (eg, exposure to xenobiotics, genetics) and lifestyle factors (eg, microbiome, nutrition, and exercise) that contribute to metabolic syndrome. Understanding these pathways could also lead to the development of pharmaceutical interventions. As individuals with metabolic syndrome have signs similar to that of toxic responses (eg, oxidative stress and inflammation) and organ dysfunction, these alterations should be taken into account in drug development. With the increasing frequency of metabolic syndrome in the general population, the idea of a "normal" individual may need to be redefined. This paper reports on the substance and outcomes of this workshop.

JAK/STAT - Emerging Players in Metabolism

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is crucial for transducing signals from a variety of metabolically relevant hormones and cytokines including growth hormone, leptin, erythropoietin, IL4, IL6 and IFNγ. A growing body of evidence suggests that this pathway is dysregulated in the context of obesity and metabolic disease. Recent development of animal models has been instrumental in identifying the role of JAK/STAT signaling in the peripheral metabolic organs including adipose, liver, muscle, pancreas, and the immune system. In this review we summarize current knowledge about the function of JAK/STAT proteins in the regulation of metabolism, and highlight new potential therapeutic targets for the treatment of obesity and diabetes.

Dysregulated Network of Immune, Endocrine and Metabolic Markers is Associated to More Severe Human Chronic Chagas Cardiomyopathy

Individuals who are infected with Trypanosoma cruzi develop chronic Chagas cardiomyopathy (CCC), which is a complication involving a series of immune pathogenetic mechanisms, although an association between immune and metabolic alterations was more recently proposed. Accordingly, we investigated the immuno-metabolic response in chagasic patients and their possible influence on CCC pathogenesis. To this end, T. cruzi-seropositive (asymptomatic or with CCC) and sero-negative individuals were studied. Serum tumour necrosis factor (TNF)-α, interleukin (IL)-6, adipocytokines and the expression of their receptors in peripheral blood mononuclear cell (PBMC) were evaluated, together with other factors influencing the immune response. CCC patients showed major metabolic and hormonal abnormalities, in parallel with increased IL-6 and leptin serum levels. TNF-α receptor s, leptin and adiponectin receptors (ObR and Adipo-Rs respectively), as well as PPAR-γ expression in PBMCs from CCC patients were compatible with a counteracting response leading to an unfavourable immune-metabolic profile. These results suggest that persistently increased levels of immune-metabolic pro-inflammatory mediators along with the adverse endocrine anti-inflammatory response of CCC individuals, may contribute to the underlying mechanisms dealing with myocardial tissue damage.

Effect of Dietary Lipids on Endotoxemia Influences Postprandial Inflammatory Response

Metabolic syndrome (MetS) results in postprandial metabolic alterations that predisposes one to a state of chronic low-grade inflammation and increased oxidative stress. We aimed to assess the effect of the consumption of the quantity and quality of dietary fat on fasting and postprandial plasma lipopolysaccharides (LPS). A subgroup of 75 subjects with metabolic syndrome was randomized to receive 1 of 4 diets: HSFA, rich in saturated fat; HMUFA, rich in monounsaturated fat; LFHCC n-3, low-fat, rich in complex carbohydrate diet supplemented with n-3 polyunsaturated fatty acids; LFHCC low-fat, rich in complex carbohydrate diet supplemented with placebo, for 12 weeks each. We administered a fat challenge reflecting the fatty acid composition of the diets at postintervention. We determined the plasma lipoproteins and glucose and gene expression in peripheral blood mononuclear cells (PBMC) and adipose tissue. LPS and LPS binding protein (LBP) plasma levels were determined by ELISA, at fasting and postprandial (4 h after a fat challenge) states. We observed a postprandial increase in LPS levels after the intake of the HSFA meal, whereas we did not find any postprandial changes after the intake of the other three diets. Moreover, we found a positive relationship between the LPS plasma levels and the gene expression of IkBa and MIF1 in PBMC. No statistically significant differences in the LBP plasma levels at fasting or postprandial states were observed. Our results suggest that the consumption of HSFA diet increases the intestinal absorption of LPS which, in turn, increases postprandial endotoxemia levels and the postprandial inflammatory response.

The effect of increasing body mass index on cardio-metabolic risk and biomarkers of oxidative stress and inflammation in nascent metabolic syndrome

The effect of BMI defined obesity on cardio-metabolic features and biomarkers of oxidative stress and inflammation in patients with nascent metabolic Syndrome (MetS) is poorly defined. Hence the aim of this study was to examine the effect of increasing obesity on the cardio metabolic risk profile, pro-oxidant state and pro-inflammatory features in nascent MetS patients without Diabetes or CVD. MetS was diagnosed by ATPIII criteria using waist circumference (WC) as the measure of adiposity. Patients (n=58) were stratified into overweight, obese and extreme obesity groups using BMI cut offs of 25-29.9, 30-39.9kg/m² and ≥40kg/m² and cardio-metabolic features, circulating and cellular biomarkers of oxidative stress and inflammation were determined and correlated with BMI. None of the main cardio-metabolic features including blood pressure, blood glucose, HDL-cholesterol, triglycerides, HOMA-IR, free fatty acids were increased with increasing BMI. Also none of the biomarkers of oxidative stress (ox-LDL, nitrotyrosine and monocyte superoxide anion release) were increased with increasing BMI. However, significant increase in hsCRP, the soluble TNFR1 and sTNFR2 and leptin, were observed with increasing adiposity. Other inflammatory bio-mediators (IL-1β, IL-6, IL-8, MCP-1, Toll-like receptors 2-4), endotoxin, LBP, sCD14 and HMGB1, adiponectin, and chemerin did not show significant increases with increasing BMI. Leptin, hsCRP, sTNFR1, and sTNFR2 correlated significantly with BMI. In conclusion, capturing the cardio-metabolic cluster of MetS that predisposed to both increased risk of diabetes and CVD, using waist circumference, as one of the 5 diagnostic criteria is sufficient and BMI does not appear to afford any major incremental benefit on the cardio-metabolic risk factors, increased oxidative stress and the majority of both cellular and circulating biomarkers of inflammation.

No Beneficial Effects of Resveratrol on the Metabolic Syndrome: A Randomized Placebo-Controlled Clinical Trial

CONTEXT

Low-grade inflammation is associated with obesity and the metabolic syndrome (MetS). Preclinical evidence suggests that resveratrol (RSV) has beneficial metabolic and anti-inflammatory effects that could have therapeutic implications.

OBJECTIVE

To investigate effects of long-term RSV treatment on inflammation and MetS.

SETTING AND DESIGN

A randomized, placebo-controlled, double-blind, parallel group clinical trial conducted at Aarhus University Hospital.

PARTICIPANTS

Middle-aged community-dwelling men (N = 74) with MetS, 66 of whom completed all visits (mean ± standard error of the mean): age, 49.5 ± 0.796 years; body mass index, 33.8 ± 0.44 kg/m2; waist circumference, 115 ± 1.14 cm.

INTERVENTION

Daily oral supplementation with 1000 mg RSV (RSVhigh), 150 mg RSV, or placebo for 16 weeks.

MAIN OUTCOME MEASURES

Plasma levels of high-sensitivity C-reactive protein (hs-CRP), circulating lipids, and inflammatory markers in circulation and adipose/muscle tissue biopsy specimens; glucose metabolism; and body composition including visceral fat and ectopic fat deposition.

RESULTS

RSV treatment did not lower circulating levels of hs-CRP, interleukin 6, or soluble urokinase plasminogen activator receptor in plasma, and inflammatory gene expression in adipose and muscle tissues also remained unchanged. RSV treatment had no effect on blood pressure, body composition, and lipid deposition in the liver or striated muscle. RSV treatment had no beneficial effect on glucose or lipid metabolism. RSVhigh treatment significantly increased total cholesterol (P < 0.002), low-density lipoprotein (LDL) cholesterol (P < 0.006), and fructosamine (P < 0.013) levels compared with placebo.

CONCLUSION

RSV treatment did not improve inflammatory status, glucose homeostasis, blood pressure, or hepatic lipid content in middle-aged men with MetS. On the contrary, RSVhigh significantly increased total cholesterol, LDL cholesterol, and fructosamine levels compared with placebo.

Mast cell specific immunological biomarkers and metabolic syndrome among middle-aged and older Chinese adults

The main aim of this study is to explore whether these mast cell specific immunological biomarkers [immunoglobulin E (IgE), chymase and tryptase] is an independent risk factor of MetS and whether the combined action of these biomarkers increased the associations with MetS. Three mast cell-specific immunological biomarkers were measured using enzyme linked immunosorbent assay (ELISA). One-way analysis of covariance and logistic regression models were used for analyzing the associations between immunological biomarkers with MetS. A total of 340 participants, 82 (24.1%) individuals had diabetes mellitus, 31 (9.1%) had MetS (without diabetes mellitus) and 110 had MetS plus diabetes mellitus. After adjusting by multivariable (age, gender, smoking, and family history for hypertension), compared with no diabetes mellitus or MetS group (reference group), hs-CRP was associated with diabetes mellitus [OR (odds ratio): 2.29 (1.15-4.57, 95% CI (confidence interval), p=0.019] and MetS plus diabetes mellitus [OR: 2.20 (1.05-4.61, 95% CI), p=0.036], IgE was associated with MetS plus diabetes mellitus [OR: 2.38 (1.13-5.02, 95% CI), p=0.023]. After adjusting by multivariable, compared with reference group, most of combined elevated inflammatory or immunological biomarkers were significantly associated with diabetes mellitus or MetS with or without diabetes mellitus. Patients with established diabetes mellitus or MetS had different inflammatory or immunological cytokine profile (such as hs-CRP, IgE, chymase, tryptase), which indicated that there is an alteration in the function of the immune system in diabetes mellitus or MetS patient. But these results are requested to be further demonstrated for large sample population-based cohort study.

[Comorbidity in psoriasis]

Psoriasis is a systemic chronic inflammatory disease associated with comorbidity. Many epidemiological studies have shown that psoriasis is associated with psoriatic arthritis as well as cardiovascular and metabolic diseases. Furthermore, obesity and psychological diseases such as depression and anxiety disorders are linked with psoriasis and play a central role in its management. The association of psoriasis and its comorbidity can be partly explained by genetic and pathophysiological mechanisms. Approximately 40 psoriasis susceptibility loci have been described with the majority linked to the innate and adaptive immune system. In some associated diseases, such as psoriatic arthritis, an overlap of their genetic susceptibility exists. Pathophysiologically the "psoriatic march" is a model that describes the development of metabolic and cardiovascular diseases due to the presence of underlying systemic inflammation. Dermatologists are the gatekeepers to treatment for patients with psoriasis. The early detection and the management of comorbidity is part of their responsibility. Concepts for the management of psoriasis and tools to screen for psoriatic comorbidity have been developed in order to support dermatologists in daily practice.

Changes of lipidic and the immunological state at patients with a metabolic syndrome in Ukraine

INTRODUCTION

The metabolic syndrome has become pandemic nature and tends to rejuvenation in the world. Elucidation of the pathogenic mechanisms on membrane-cell level will optimize the treatment of patients with metabolic syndrome and prevention of metabolic syndrome on the level of pre-clinical manifestations.

AIM

to study the immunological status and lipid metabolism in the patients with metabolic syndrome and the pathogenetic mechanisms of metabolic syndrome were established.

MATERIAL AND METHODS

There were 4 groups of pacients (110) with: metabolic syndrome, ischemic heart disease and hypertension, hypertention; control group. General clinical, instrumental, laboratory and statistical methods were used.

RESULTS

The levels of immune factors - interleukin-6 in supernatants of mononuclear cells by 65%, sICAM-1 by 20% is elevated in patients with metabolic syndrome compared with the control group. The increasing of the content of saturated fatty acids by 9.4% and polyunsaturated fatty acid by 36.6% lead to fundamental breach of structural and functional properties of membranes. There is significant common carotid artery intima media thickness on average twice at the patients with metabolic syndrome and with ischemic heart disease and hypertension.

CONCLUSIONS

The immunoinflammatory reactions were more revealed in the group of patients with metabolic syndrome than in other groups. The lipid state at patients with metabolic syndrome was changed more than in patients with hypertension or patients with ischemic heart disease and hypertension both. Moreover our data indicate the presence of structural changes in the vessel wall in patients with metabolic syndrome.

Linking the Microbiota, Chronic Disease, and the Immune System

Chronic inflammatory diseases (CIDs) are the most important causes of mortality in the world today and are on the rise. We now know that immune-driven inflammation is critical in the etiology of these diseases, though the environmental triggers and cellular mechanisms that lead to their development are still mysterious. Many CIDs are associated with significant shifts in the microbiota toward inflammatory configurations, which can affect the host both by inducing local and systemic inflammation and by alterations in microbiota-derived metabolites. This review discusses recent findings suggesting that shifts in the microbiota may contribute to chronic disease via effects on the immune system.

Investigation of the inflammatory biomarkers of metabolic syndrome in adolescents

BACKGROUND

Metabolic syndrome (MetS) is a chronic and multifactorial syndrome characterized by a low-grade chronic inflammation, and a major risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). In our study, we aimed to investigate the serum levels of high sensitive C-reactive protein (hs-CRP), haptoglobin (Hp), α2-macroglobulin (α2-MG), platelet factor-4 (PF-4), fetuin-A, serum amyloid P (SAP) and α1-acid glycoprotein (AGP) in an adolescent population with MetS.

METHODS

This study was performed in 43 (18 males, 25 females) MetS adolescents between the ages of 13 and 17 years (14.70±1.15) and 43 lean controls were matched for age and sex. The serum levels of Hp, α2-MG, PF-4, fetuin-A, SAP and AGP were measured by using a multi-ELISA technique.

RESULTS

Serum Hp, fetuin-A (p<0.01) and PF-4, hs-CRP, SAP, AGP (p<0.001) values of the MetS subjects were significantly higher than those of the controls. No difference was found in serum α2-MG levels between the MetS and control groups (p=0.184).

CONCLUSIONS

This finding suggests the possibility of using these markers in diagnosis of MetS in adolescents to prevent future complications.

Do worms protect against the metabolic syndrome? A systematic review and meta-analysis

AIMS

There is increasing evidence on the role of helminth infections in modifying autoimmune and allergic diseases. These infections may have similar effect in other inflammatory processes, such as insulin resistance. This review aims to examine the literature on the effect of helminthic infections on metabolic outcomes in humans.

METHODS

Using the PRISMA protocol, we searched the literature using PubMed, MEDLINE, and a manual review of reference lists. Human studies published in English after 1995 were included. Four papers were included in this review. Data was extracted and a meta-analysis was conducted using a random-effects model. Heterogeneity was assessed using Tau(2) and I(2) tests.

RESULTS

The included studies found that infection was associated with lower glucose levels, less insulin resistance, and/or a lower prevalence of metabolic syndrome (MetS) or type 2 diabetes mellitus (T2DM). Meta-analysis showed that participants with a previous or current helminth infection were 50% less likely to have an endpoint of metabolic dysfunction in comparison to uninfected participants (OR 0.50; 95% CI 0.38-0.66).

CONCLUSION

This review has shown that helminth infections can be associated with improved metabolic outcomes. Understanding of the mechanisms underlying this relationship could facilitate the development of novel strategies to prevent or delay T2DM.

Macrophage alterations within the mesenteric lymphatic tissue are associated with impairment of lymphatic pump in metabolic syndrome

OBJECTIVE

The intrinsic lymphatic pump is critical to proper lymph transport and is impaired in models of the MetSyn. Lymphatic contractile inhibition under inflammatory conditions has been linked with elevated NO production by activated myeloid-derived cells. Hence we hypothesized that inhibition of the MLV pump function in MetSyn animals was dependent on NO and was associated with altered macrophage recruitment and polarization within the MLV.

METHODS

We used a high fructose-fed rat model of MetSyn. Macrophage polarization was determined by whole mount immunofluorescence in mesenteric neurovascular bundles based on expression of CD163, CD206, and MHCII. We also utilized isolated vessel isobaric preparations to determine the role for elevated NO production in the inhibition of MLV contractility. Both LECs and LMCs were used to assess the cytokines and chemokines to test how the lymphatic cells response to inflammatory conditions.

RESULTS

Data demonstrated a greater accumulation of M1-skewed (CD163+ MHCII+ ) macrophages that were observed both within the perivascular adipose tissue and invested along the lymphatic vessels in MetSyn rats when compared to control rats. LECs and LMCs basally express the macrophage maturation polarization cytokines monocyte colony-stimulating factor and dramatically up regulate the M1 promoting cytokine granulocyte/monocyte colony-stimulating factor in response to lipopolysaccharide stimulation. MetSyn MLVs exhibited altered phasic contraction frequency. Incubation of MetSyn MLVs with LNAME or Glib had a partial restoration of lymphatic contraction frequency.

CONCLUSION

The data presented here provide the first evidence for a correlation between alterations in macrophage status and lymphatic dysfunction that is partially mediated by NO and KATP channel in MetSyn rats.

Biomarkers of systemic inflammation in pathogenesis of syntropic occupational bronchial asthma and metabolic syndrome

In search of inflammatory molecular markers helpful in detection of increased risk and prognosis of severity of syntropic occupational bronchial asthma and metabolic syndrome, the authors conducted a study covering 140 examinees with confirmed occupational bronchial asthma. According to IDF criteria (2005), the patients were assigned into a group with combined occupational bronchial asthma and metabolic syndrome, and a group of occupational bronchial asthma without metabolic syndrome. All the examinees underwent studies of inflammation markers - biochemical (C-reactive protein, leptine) and molecular-genetic ( polymorphism of Gln223Arg gene of leptine receptor (LEPR), polymorphism of C174G gene of interleukin-6 (IL-6), polymorphism of G308A gene of (TNF-a) tumor necrosis factor alpha). Evidences are that the patients with combined bronchial asthma and metabolic syndrome demonstrate higher activity of inflammatory processes (higher level of C-reactive protein, leptine) - that manifests in clinically more severe course of bronchopulmonary disease. Moleculary-genetic markers revealed are associated with higher activity of inflammation and therefore with increased risk of occupational bronchial asthma associated with metabolic syndrome and diabetess mellitus 2 type (polymorphisms of LEPR gene, IL-6 gene).

The Role of Dietary Inflammatory Index in Cardiovascular Disease, Metabolic Syndrome and Mortality

Inflammation is an underlying pathophysiological process in chronic diseases, such as obesity, type 2 diabetes mellitus and cardiovascular disease. In fact, a number of systematic reviews have shown the association between inflammatory biomarkers, such as CRP, IL-1β, IL-6, TNF-α, IL-4, or IL-10, and cardio-metabolic diseases. Diet is one of the main lifestyle-related factors which modulates the inflammatory process. Different individual foods and dietary patterns can have a beneficial health effect associated with their anti-inflammatory properties. The dietary inflammatory index (DII) was recently developed to estimate the inflammatory potential of overall diet. The aim of this review is to examine the findings of recent papers that have investigated the association between the DII, cardio-metabolic risk factors and cardiovascular disease. The relevance of the DII score in the association between inflammation and cardio-metabolic diseases is critically appraised, as well as its role in the context of healthy dietary patterns. We conclude that the DII score seems to be a useful tool to appraise the inflammatory capacity of the diet and to better understand the relationships between diet, inflammation, and cardio-metabolic diseases.

Type B insulin resistance syndrome

PURPOSE OF REVIEW

To review the epidemiology, pathophysiology, clinical features, and management of type B insulin resistance syndrome.

RECENT FINDINGS

Type B insulin resistance syndrome is a rare disorder caused by autoantibodies to the insulin receptor. This disorder is most frequently reported in middle-aged black women and is invariably associated with other autoimmune diseases. Typically, refractory transient hyperglycemia and extreme insulin resistance are the cardinal features, but hypoglycemia may also occur. Traditionally, the high reported mortality rate was typically attributed to the hypoglycemia. There is no well standardized treatment regimen. However, recent therapeutic advances with combination immunomodulatory therapy have led to significant reported improvements in hypoglycemia-associated mortality and durability of remission.

SUMMARY

We review the literature on the pathophysiology and clinical features of type B insulin resistance syndrome and highlight the complexities and recent advances in the management of this disorder.

Depressive and anxiety disorders and short leukocyte telomere length: mediating effects of metabolic stress and lifestyle factors

BACKGROUND

Depressive and anxiety disorders are associated with shorter leukocyte telomere length (LTL), an indicator of cellular aging. It is, however, unknown which pathways underlie this association. This study examined the extent to which lifestyle factors and physiological changes such as inflammatory or metabolic alterations mediate the relationship.

METHOD

We applied mediation analysis techniques to data from 2750 participants of the Netherlands Study of Depression and Anxiety. LTL was assessed using quantitative polymerase chain reaction. Independent variables were current depressive (30-item Inventory of Depressive Symptoms - Self Report) and anxiety (21-item Beck's Anxiety Inventory) symptoms and presence of a depressive or anxiety disorder diagnosis based on DSM-IV; mediator variables included physiological stress systems, metabolic syndrome components and lifestyle factors.

RESULTS

Short LTL was associated with higher symptom severity (B = -2.4, p = 0.002) and current psychiatric diagnosis (B = -63.3, p = 0.024). C-reactive protein, interleukin-6, waist circumference, triglycerides, high-density lipoprotein cholesterol and cigarette smoking were significant mediators in the relationship between psychopathology and LTL. When all significant mediators were included in one model, the effect sizes of the relationships between LTL and symptom severity and current diagnosis were reduced by 36.7 and 32.7%, respectively, and the remaining direct effects were no longer significant.

CONCLUSIONS

Pro-inflammatory cytokines, metabolic alterations and cigarette smoking are important mediators of the association between depressive and anxiety disorders and LTL. This calls for future research on intervention programs that take into account lifestyle changes in mental health care settings.

Effects of acute exercise on monocyte subpopulations in metabolic syndrome patients

OBJECTIVE

Acute exercise induces numerous changes in peripheral blood, e.g. counts of leukocytes. CD16^pos monocytes, which play a role in the pathogenesis of arteriosclerosis and the metabolic syndrome (MetS), are among the blood cells with the highest fold increase through exercise. So far no studies have investigated the effect of exercise on the blood cell composition of patients with MetS.

APPROACH AND RESULTS

Blood cell counts, a wide panel of laboratory tests, as well as lipid and protein content of monocytes and granulocytes were determined in healthy subjects, persons with metabolic risk and MetS patients before and after one minute of exercise at 400 W. Leukocyte counts increased significantly in all groups with CD14^pos CD16^pos monocytes showing the highest fold-change. In MetS patients the fold increase was smaller. They had a higher resting level of CD14^pos CD16^pos monocytes and a lower basal ratio of CD16^neg /CD16^pos monocytes. A similar ratio of these cells was induced in control and risk subjects after exercise. However, absolute counts of mobilized pro-inflammatory monocytes did not differ significantly. Furthermore, we detected a decrease in protein content of monocytes in controls, but not in MetS patients.

CONCLUSIONS

As strenuous exercise is able to mobilize the same amount of pro-inflammatory monocytes in MetS patients as in healthy persons, the elevated basal level of these cells in MetS patients is likely to be caused by enhanced maturation rather than chronic mobilization. The removal of these monocytes from the endothelium might be part of the beneficial effect of exercise on vascular disease. © 2016 International Clinical Cytometry Society.

Neuroinflammatory and autonomic mechanisms in diabetes and hypertension

Interdisciplinary studies in the research fields of endocrinology and immunology show that obesity-associated overnutrition leads to neuroinflammatory molecular changes, in particular in the hypothalamus, chronically causing various disorders known as elements of metabolic syndrome. In this process, neural or hypothalamic inflammation impairs the neuroendocrine and autonomic regulation of the brain over blood pressure and glucose homeostasis as well as insulin secretion, and elevated sympathetic activation has been appreciated as a critical mediator. This review describes the involved physiology and mechanisms, with a focus on glucose and blood pressure balance, and suggests that neuroinflammation employs the autonomic nervous system to mediate the development of diabetes and hypertension.

Insulin resistance, postprandial GLP-1 and adaptive immunity are the main predictors of NAFLD in a homogeneous population at high cardiovascular risk

BACKGROUND AND AIMS

The role of the different factors associated with fatty liver is still poorly defined. We evaluated the relationships between liver fat content (LF) and metabolic, inflammatory and nutritional factors in a homogeneous cohort of individuals at high cardio-metabolic risk.

METHODS AND RESULTS

In 70 individuals with high waist circumference and at least one more criterion for metabolic syndrome enrolled in a nutritional intervention study, LF was evaluated at baseline by hepatic/renal echo intensity ratio (H/R), together with dietary habits (7-day dietary record), insulin sensitivity and β-cell function (fasting and OGTT-derived indices), fasting and postprandial plasma GLP-1 and lipoproteins, and plasma inflammatory markers. H/R correlated positively with fasting and OGTT plasma glucose and insulin concentrations, HOMA-IR and β-cell function, and IL-4, IL-17, IFN-γ, TNF-α, FGF and GCSF plasma concentrations (p < 0.05 for all), and negatively with insulin sensitivity (OGIS), dietary, polyphenols and fiber (p < 0.05 for all). By multiple stepwise regression analysis, the best predictors of H/R were OGIS (β = -0.352 p = 0.001), postprandial GLP-1 (β = -0.344; p = 0.001), HDL-cholesterol (β = -0.323; p = 0.002) and IFN-γ (β = 0.205; p = 0.036).

CONCLUSION

A comprehensive evaluation of factors associated with liver fat, in a homogeneous population at high cardio-metabolic risk, indicated a pathogenic combination of the same pathways underlying the atherosclerotic process, namely whole body insulin sensitivity and inflammation. The higher predictive value of postprandial variables suggests that liver fat is essentially a postprandial phenomenon, with a relevant role possibly played by GLP-1.

REGISTRATION NUMBER FOR CLINICAL TRIALS

NCT01154478.

Metabolic Syndrome and Cardiovascular Risk in HIV-Infected Patients with Lipodystrophy

In this cross-sectional study, we evaluate potential predictors of Metabolic Syndrome (MS) in a group of 54 Caucasian chronically HIV-infected patients with lipodystrophy. According to ATP-III criteria, 22 patients were affected by MS and 32 were not. The mean age of the sample was 41.2 ± 8.6 years, and most patients were males (74.1%); the two groups were homogeneous for gender, age, viro-immunologic status and the duration of antiviral therapy. The independent association between MS and several factors including demographic characteristics, type of highly-active antiviral therapy (HAART), viro-immunologic response, common cardiovascular risk factors (including Framingham scores), and selected cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10 and IL-18), was investigated using stepwise forward logistic regression. At multivariate analysis, the only independent predictors of the metabolic syndrome were triglycerides and IL-18. A10 mg/dL increase in triglycerides corresponds to an adjusted risk ratio for MS of 1.11 (95% IC: 1.04–1.19); and patients in the top tertile of IL-18 (those with IL-18 ≥ 530 pg/L) had more than three times the likelihood of MS, as compared to the bottom and medium fertiles of IL-18 (patients with IL-18 < 530 pg/L). This relationship was not attenuated by the inclusion of any other variable in the multivariate model. However, the association between metabolic syndrome and IL-18 is no longer significant when IL-18 is treated as a continuous variable (trend p = 0.087). Our results on HIV patients with lipodystrophy confirm previous findings on a strong independent association between IL-18 and MS in the general population. Further research is needed to clarify the mechanism of this association and its role in the development of cardiovascular disease in HIV patients.

Does lipopolysaccharide-mediated inflammation have a role in OA?

The nature of the gastrointestinal microbiome determines the reservoir of lipopolysaccharide, which can migrate from the gut into the circulation, where it contributes to low-grade inflammation. Osteoarthritis (OA) is a low-grade inflammatory condition, and the elevation of levels of lipopolysaccharide in association with obesity and metabolic syndrome could contribute to OA. A 'two- hit' model of OA susceptibility and potentiation suggests that lipopolysaccharide primes the proinflammatory innate immune response via Toll-like receptor 4 and that progression to a full-blown inflammatory response and structural damage of the joint results from coexisting complementary mechanisms, such as inflammasome activation or assembly by damage-associated molecular patterns in the form of fragmented cartilage-matrix molecules. Lipopolysaccharide could be considered a major hidden risk factor that provides a unifying mechanism to explain the association between obesity, metabolic syndrome and OA.