Variations in circulating inflammatory factors are related to changes in calorie and carbohydrate intakes early in the course of surgery-induced weight reduction

Effects of Weight Loss on Key Obesity-Related Biomarkers Linked to the Risk of Endometrial Cancer: A Systematic Review and Meta-Analysis

Endometrial cancer (EC) includes various histologic types, with estrogen-dependent endometrioid carcinoma being the most common. Obesity significantly increases the risk of developing this type, especially in postmenopausal women, due to elevated estrogen production by adipocytes. This review examines the impact of weight loss from different interventions on reducing obesity-related risk factors for endometrioid EC. A systematic review and meta-analysis were conducted on three weight loss interventions: bariatric surgery, pharmacotherapy, and lifestyle changes. The effects of these interventions on inflammatory biomarkers (CRP, TNF-α, IL-6) and hormones (leptin, estrogen) were analyzed. Data from controlled studies were pooled to assess the significance of weight loss in reducing these biomarkers. Despite heterogeneity, bariatric surgery resulted in an overall 25.8% weight reduction, outperforming lifestyle and pharmacotherapy interventions. Weight loss reduced CRP levels by 33.5% and IL-6 levels by 41.9%. TNF-α levels decreased by 13% with percent weight loss over 7%. Leptin levels also decreased significantly, although the exact weight loss percentage was not statistically significant. Weight loss effectively reduces proinflammatory markers and hormones associated with increased risk of endometrioid EC. The strengths of this review include a comprehensive examination of different weight-loss interventions and a large pool of participants. However, limitations include high heterogeneity among studies and only 43% of the participants being postmenopausal. Limited data on sex hormones and racial disparities underscore the need for further research.

Circulating adipose tissue proteins involved in atrial fibrillation: An explorative scoping review

Obesity increases the risk of atrial fibrillation (AF), potentially through proteins secreted by adipose tissue (AT) that affect atrial electrical and structural remodeling. We aim to give a comprehensive overview of circulating AT proteins involved in inflammation and fibrosis, that are associated with prevalent AF (paroxysmal or persistent) and the risk on developing new-onset AF. These include adipokines, defined as proteins enriched in AT as adiponectin, but also proteins less specific to AT. We systematically performed an explorative search for studies reporting associations between proteins secreted from cells residing in the AT and AF, and additionally assessed the effect of obesity on these proteins by a secondary search. The AT proteins involved in inflammation were mostly increased in patients with prevalent and new-onset AF, and with obesity, while the AT enriched adipokines were mostly not associated with AF. This review provides insight into circulating adipose tissue proteins involved in AF substrate formation.

Osteoarthritis in patients with obesity: The bariatric surgery impacts on its evolution

Obesity is one of the main modifiable risk factors for osteoarthritis (OA). Moreover, obesity is associated with greater pain intensity and functional limitation, but also with a significantly lower responder rate to intra-articular treatments. Consequently, an arthroplasty is indicated earlier and more frequently in patients with obesity. However, pain and functional symptoms improve slightly less after arthroplasty in patients with obesity, who display higher incidence of early and late complications following prosthetic surgery. Bariatric surgery (BS) has increased worldwide and is efficient to induce major and sustainable weight-loss. Importantly, BS significantly reduces pain and functional limitation in patients with symptomatic knee OA. Biomarkers analysis also revealed a decrease in catabolic factors and an increase in anabolic one after BS suggesting a structural protective effect in knee OA. Nevertheless, the impact of BS prior to arthroplasty remains unclear. BS seems to decrease short- and mid-term complications such as infections or thrombosis. However, BS does not appear to modify long-term complications rate, and may even increase it, especially revisions and infections. Although few studies have compared the symptomatic and functional outcomes of joint replacement with or without BS, these are not significantly improved by prior BS. Despite these heterogeneous results, medico-economic studies found that BS prior to arthroplasty was cost-effective. To conclude, BS could significantly reduce the symptoms of OA and potentially slow its progression, but appears more disappointing in preventing long-term complications of arthroplasties and improving their functional results.

Serum Versus Fecal Calprotectin Levels in Patients with Severe Obesity Before and 6 Months After Roux-Y-Gastric Bypass: Report of the Prospective Leaky-Gut Study

INTRODUCTION

Obesity is associated with low-grade inflammation, including intestinal inflammation based on fecal or serum calprotectin (FC-SC) measurement. Roux-en-Y gastric bypass (RYGB) improves obesity-related parameters. However, the association between FC-SC levels and postoperative course and the link with metabolic and inflammatory phenotypes before and after RYGB remains unclear.

METHODS

We determined SC levels in 48 patients before (T0) and 6 months after (T6M) RYGB. We then analyzed postoperative changes in FC-SC levels and the relationship with inflammation and metabolic status.

RESULTS

Twenty-three patients (48%) had elevated SC levels (˃2.9 μg/mL) at T0 and T6M. Six of 29 patients (20.7%) had elevated FC concentrations (>50 μg/g) at T0 vs. 16 of 17 patients (94.1%) at T6M (p=0.006). At T0, FC levels correlated with BMI (Rho=0.63; p=0.001) and systemic inflammation (CRP: Rho=0.66, p=0.0006; IL-6: Rho=0.48, p=0.03; haptoglobin: Rho=0.75; p= 0.0006). SC tended to be positively associated with triglyceride levels (Rho=0.34; p=0.08), BMI (Rho=0.34; p=0.08), and inflammatory markers (CRP: Rho=0.33; p=0.09; IL-6: Rho=0.36; p=0.06). FC levels were associated with increased jejunal IL-17+CD8+ T-cell densities (Rho:0.90; p=0.0002). FC and SC were correlated together at T0 (Rho=0.83; p<0.001) but not at T6M. At T6M, SC decreased by 53.6%, whereas FC increased by 79.7%. SC and FC were not associated with any of the variables studied at T6M.

CONCLUSION

FC is a surrogate marker of systemic and intestinal inflammation and adiposity, whereas SC only tends to correlate with systemic inflammation. At 6 months after RYGB, SC-based systemic inflammation decreased, whereas FC-based intestinal inflammation increased. FC and SC levels follow different trajectories and are unrelated to improvements following bariatric surgery.

Metaflammation in obesity and its therapeutic targeting

Obesity-associated inflammation is a systemic process that affects all metabolic organs. Prominent among these is adipose tissue, where cells of the innate and adaptive immune system are markedly changed in obesity, implicating these cells in a range of processes linking immune memory to metabolic regulation. Furthermore, weight loss and weight cycling have unexpected effects on adipose tissue immune populations. Here, we review the current literature on the roles of various immune cells in lean and obese adipose tissue. Within this context, we discuss pharmacological and nonpharmacological approaches to obesity treatment and their impact on systemic inflammation.

Variation of modulation and expression of biomarkers associated with inflammation in bariatric surgery patients: A systematic review and meta-analysis

BACKGROUND

Bariatric surgery is an effective intervention that causes a series of metabolic changes related to inflammatory processes; however, the variation of biomarkers related to these processes is not entirely understood. Our objective was to investigate the variation of modulation and expression of biomarkers associated with inflammation in patients who underwent bariatric surgery.

METHODS

We searched the MEDLINE (via PubMed), EMBASE (via Elsevier), Cochrane Central Register of Controlled Trials, Latin American and Caribbean Literature on Health Sciences (via virtual health library), Cumulative Index to Nursing and Allied Health Literature (via EBSCO), Web of Science core collection, and Scopus (via Elsevier) databases, and the gray literature was examined from inception to January 2022. Three pairs of reviewers performed data screening, extraction, and quality assessment independently. Meta-analysis with random effects models was used for general, subgroup, and sensitivity analyses. The I2 statistic was used to assess heterogeneity between studies.

RESULTS

In total, 96 articles were included in this systematic review; of these, 87 studies met the criteria for the meta-analysis, involving 3,533 participants. Five biomarkers were included in the meta-analysis (tumor necrosis factor alpha; interleukin 6; leptin; interleukin 1 beta, and lipopolysaccharides). Only leptin showed a significant decrease in the first month after surgery (mean difference -20.71; [95% confidence interval: -28.10 to -13.32, P < .0001; I2 = 66.7%), with moderate heterogeneity. The 12 months after surgery showed a significant decrease in tumor necrosis factor alpha (mean difference -0.89; [95% confidence interval: -1.37 to -0.42], P = .0002; I2 = 94.7%), interleukin 6 (mean difference -1.62; [95% confidence interval: -1.95 to -1.29], P < .0001; I2 = 94.9%), leptin (mean difference -28.63; [95% confidence interval: -34.02 to -23.25], P < .0001; I2 = 92.7%), and interleukin 1 beta (mean difference -2.46; [95% confidence interval: -4.23 to -0.68], P = .006; I2 = 98.3%), all with high heterogeneity. The type of surgery did not show significant differences for the biomarkers at the first month and 12 months, and the results have not changed with high-quality studies. In the 12-month measurement, variations in tumor necrosis factor alpha and leptin were associated with body mass index.

CONCLUSION

The findings of this meta-analysis suggest that Roux-en-Y gastric bypass and sleeve gastrectomy bariatric surgeries are associated with a significant reduction in leptin at 1 month after bariatric surgical intervention and tumor necrosis factor alpha, leptin, and interleukin 1 beta after 12 months.

Inflammatory and Anti-Inflammatory Parameters in PCOS Patients Depending on Body Mass Index: A Case-Control Study

BACKGROUND

it has been suggested that chronic low-grade inflammation plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). According to previous studies, it remains unclear which cytokines influence the development of this syndrome and whether their increase is associated with the presence of excess weight/obesity or is an independent factor. The aim of our research was to determine the parameters of chronic inflammation in women with PCOS in comparison with healthy women in the normal weight and the overweight subgroups.

METHODS

This case-control study included 44 patients with PCOS (19 women with a body mass index (BMI) < 25 kg/m² and 25 women with a BMI ≥ 25 kg/m²) and 45 women without symptoms of PCOS (22 women with a BMI < 25 kg/m² and 23 women with a BMI ≥ 25 kg/m²). Thirty-two cytokines were analyzed in the plasma of the participants using Immunology multiplex assay HCYTA-60K-PX48 (Merck Life Science, LLC, Germany).

RESULTS

Cytokines: interleukin-1 receptor antagonist (IL-1 RA), IL-2, IL-6, IL-17 E, IL-17 A, IL-18, and macrophage inflammatory protein-1 alpha (MIP-1 α) were increased in women with PCOS compared to controls, both in lean and overweight/obese subgroups (p < 0.05). Moreover, only lean women with PCOS had higher levels of IL-1 alpha, IL-4, IL-9, IL-12, IL-13, IL-15, tumor necrosis factor (TNF- α) alpha and beta, soluble CD40 and its ligand (SCD40L), fractalkine (FKN), monocyte-chemotactic protein 3 (MCP-3), and MIP-1 β compared to the control group (p < 0.05). IL-22 was increased in the combined group of women with PCOS (lean and overweight/obese) compared to the control group (p = 0.012).

CONCLUSION

Chronic low-grade inflammation is an independent factor affecting the occurrence of PCOS and does not depend on the presence of excess weight/obesity. For the first time, we obtained data on the increase in such inflammatory parameters as IL-9, MCP-3, and MIP-1α in women with PCOS.

Higher IL-9 Level is Associated with Psoriasis Vulgaris Complicated by Metabolic Syndrome

Purpose

The underlying pathophysiology linking psoriasis vulgaris (PV) and metabolic syndrome (MetS) is not fully understood. The present study aimed to investigate the serum level of interleukin (IL)-9 and tissue levels of IL-9 and its receptor in PV patients with MetS and analyze the correlation of IL-9 levels with psoriasis disease severity and MetS.

Methods

This study enrolled 75 PV patients with MetS, 57 PV patients without MetS, 20 healthy blood donors, and 7 healthy skin donors. Clinical, socio-demographic, and anthropometric data were obtained from all individuals. Fasting blood glucose, insulin, lipid profile levels, and serum levels of IL-9 and IL-17A were measured. The expression of IL-9 and its receptor in skin specimens in PV patients and healthy controls was determined using immunohistochemistry. Normal human epidermal keratinocytes were stimulated with five pro-inflammatory cytokines (tumor necrosis factor-α, oncostatin M, IL-22, IL-17A, and IL-1α) to establish a psoriatic keratinocyte model and subsequently treated with IL-9. Their mRNA levels of antimicrobial peptides and chemokines were measured using quantitative real-time polymerase chain reaction.

Results

Serum level of IL-9 and tissue levels of IL-9 and its receptor were upregulated in PV patients with MetS. IL-9 level was positively correlated to IL-17A level; however, no significant correlation of IL-9 level with psoriasis area severity index was observed. IL-9 level had a positive correlation with the presence of MetS and its components. Correspondingly, IL-9 level positively correlated with waist circumference, body mass index, homeostasis model assessment-insulin resistance, blood pressure, and triglyceride level and negatively correlated with high-density lipoprotein cholesterol level. Additionally, IL-9 stimulated the expression of antimicrobial peptides and chemokines in a psoriatic keratinocyte model.

Conclusion

Our findings confirmed that higher IL-9 level is associated with PV complicated by MetS, suggesting that IL-9 may be a link between PV and MetS.

Changes in Lipid Metabolism Enzymes in Rat Epididymal Fat after Chronic Central Leptin Infusion Are Related to Alterations in Inflammation and Insulin Signaling

Leptin inhibits food intake and reduces the size of body fat depots, changing adipocyte sensitivity to insulin to restrain lipid accrual. This adipokine may modulate the production of cytokines that could diminish insulin sensitivity, particularly in visceral adipose tissue. To explore this possibility, we examined the effects of chronic central administration of leptin on the expression of key markers of lipid metabolism and its possible relationship with changes in inflammatory- and insulin-signaling pathways in epididymal adipose tissue. Circulating non-esterified fatty acids and pro- and anti-inflammatory cytokines were also measured. Fifteen male rats were divided into control (C), leptin (L, icv, 12 μg/day for 14 days), and pair-fed (PF) groups. We found a decrease in the activity of glucose-6-phosphate dehydrogenase and malic enzyme in the L group, with no changes in the expression of lipogenic enzymes. A reduction in the expression of lipoprotein lipase and carnitine palmitoyl-transferase-1A, together with a decrease in the phosphorylation of insulin-signaling targets and a low-grade inflammatory pattern, were detected in the epididymal fat of L rats. In conclusion, the decrease in insulin sensitivity and increased pro-inflammatory environment could regulate lipid metabolism, reducing epididymal fat stores in response to central leptin infusion.

Change in Adipokines and Gastrointestinal Hormones After Bariatric Surgery: a Meta-analysis

PURPOSE

The study aimed to perform a meta-analysis about the change in adipokines and gastrointestinal hormones after bariatric surgery in patients with obesity.

MATERIALS AND METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE, and PubMed for related articles and used Review Manager 5.4 for data aggregation. Sensitivity and subgroup analysis were also conducted when feasible.

RESULTS

As a result, 95 articles involving 6232 patients were included in the meta-analysis. After bariatric surgery, the levels of leptin, ghrelin, C-reactive protein (CRP), interleukin-6 (IL-6), high-sensitivity C-reactive protein (Hs-CRP), tumor necrosis, factor-α (TNF-α), and interleukin-1β (IL-1β) reduced, while adiponectin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) levels increased significantly. Subgroup analysis indicated that there was a more significant reduction in leptin level with a longer follow-up time. OAGB had a greater effect on increasing adiponectin level compared with other procedures. SG procedure would bring about reduced ghrelin, while BPD resulted in increased ghrelin. Meta-regression analysis found that publication year, study design, number of patients, preoperative age, preoperative BMI, and quality assessment score were not significantly related to change in leptin, adiponectin, and ghrelin levels.

CONCLUSION

Bariatric surgery was associated with a significant decrease in leptin, ghrelin, CRP, IL-6, Hs-CRP, TNF-α, and IL-1β, as well as increase in adiponectin, GLP-1, and PYY levels.

Leptin Increases: Physiological Roles in the Control of Sympathetic Nerve Activity, Energy Balance, and the Hypothalamic-Pituitary-Thyroid Axis

It is well established that decreases in plasma leptin levels, as with fasting, signal starvation and elicit appropriate physiological responses, such as increasing the drive to eat and decreasing energy expenditure. These responses are mediated largely by suppression of the actions of leptin in the hypothalamus, most notably on arcuate nucleus (ArcN) orexigenic neuropeptide Y neurons and anorexic pro-opiomelanocortin neurons. However, the question addressed in this review is whether the effects of increased leptin levels are also significant on the long-term control of energy balance, despite conventional wisdom to the contrary. We focus on leptin's actions (in both lean and obese individuals) to decrease food intake, increase sympathetic nerve activity, and support the hypothalamic-pituitary-thyroid axis, with particular attention to sex differences. We also elaborate on obesity-induced inflammation and its role in the altered actions of leptin during obesity.

Mouse Models of Obesity to Study the Tumor-Immune Microenvironment

Obesity is associated with chronic, low-grade systemic inflammation and leads to changes in the immune microenvironment of various tissues. As a result, obesity is associated with increased risk of cancer and a worse prognosis in patients. Given the prevalence of obesity worldwide, understanding the fundamental biology governing the relationship between obesity and cancer is critical. In this chapter, we describe preclinical models of obesity that can be combined with standard tumor models and techniques to study the tumor-immune microenvironment. We also discuss important considerations when planning experiments involving these models.

The Effect of Bariatric Surgery on Circulating Levels of Monocyte Chemoattractant Protein-1: A Systematic Review and Meta-Analysis

Background: MCP-1 (monocyte chemoattractant protein) plays an important role in early phases of atherogenesis as well as in plaque destabilization, which causes cardiovascular events to play an important role in low-grade inflammation. Obesity, particularly extreme obesity, is a pivotal risk factor for atherosclerosis and many other diseases. In the early stages, bariatric surgery might stop or slow atherogenesis by suppressing inflammation, but also in later stages, preventing plaque destabilization. The aim of this meta-analysis was to provide an answer as to whether bariatric surgery has a significant effect on circulating MCP-1 level or not. Methods: A systematic literature search in PubMed, Scopus, Embase, and Web of Science was performed from inception to 1 January 2022. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. In order to heterogeneity compensation of studies in terms of study design and treatment duration, the characteristics of the studied populations random-effects model and the generic inverse variance weighting method were used. To investigate the relationship with the estimated effect size, a random-effect meta-regression model was used. To assess the exitance of publication bias in the meta-analysis, the funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used. Results: Meta-analysis of 25 studies with 927 subjects included demonstrated a significant decrease of MCP-1 concentration after bariatric surgery. The data of meta-regression did not indicate any association between the alterations in body mass index (BMI) and absolute difference in MCP-1 levels, but a linear relationship between the changes in MCP-1 and length of follow-up was proven. Conclusions: Bariatric surgery significantly decreases MCP-1 concentration, but there was no association between the changes in BMI and absolute difference in MCP-1 levels before and after the surgery.

T and B Cell Composition and Cytokine Producing Capacity Before and After Bariatric Surgery

Morbid obesity is associated with a chronic state of low-grade inflammation, which may lead to accelerated differentiation of T and B cells. These differentiated immune cells are strongly cytotoxic and have an increased pro-inflammatory cytokine producing capacity. Furthermore, the anti-inflammatory function of the T and B cells decreases. The aim of this study was to evaluate the effect of morbid obesity on the subset profile and cytokine producing capacity of T and B cells. Subsequently, we assessed whether bariatric surgery affected the subset profile and cytokine producing capacity of these cells. We determined the proportion of T and B cell subsets and their cytokine producing capacity in peripheral blood collected from 23 morbidly obese patients before and three months after bariatric surgery using flow-cytometry. We compared this with the results of 25 lean controls. Both CD4+ and CD8+ T cells showed a more differentiated subset profile in morbidly obese patients as compared to lean controls, which was not recovered three months after bariatric surgery. The B cell composition of morbidly obese patients after bariatric surgery adjusted towards the profile of lean controls. However, the IL-2 and IFN-γ producing capacity of CD8+ T cells and the IL-2, IFN-γ, TNF-α and IL-10 producing capacity of B cells was not restored three months after bariatric surgery. In conclusion, the data suggest that the immune system has the capacity to recover from the detrimental effects of morbid obesity within three months after bariatric surgery in terms of cell composition; however, this was not seen in terms of cytokine producing capacity. The full restoration of the immune system after bariatric surgery may thus take longer.

Neurohormonal Changes in the Gut–Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut–brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut–brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.

Insulin resistance per se drives early and reversible dysbiosis-mediated gut barrier impairment and bactericidal dysfunction

OBJECTIVE

A common feature of metabolic diseases is their association with chronic low-grade inflammation. While enhanced gut permeability and systemic bacterial endotoxin translocation have been suggested as key players of this metaflammation, the mechanistic bases underlying these features upon the diabesity cascade remain partly understood.

METHODS

Here, we show in mice that, independently of obesity, the induction of acute and global insulin resistance and associated hyperglycemia, upon treatment with an insulin receptor (IR) antagonist (S961), elicits gut hyperpermeability without triggering systemic inflammatory response.

RESULTS

Of note, S961-treated diabetic mice display major defects of gut barrier epithelial functions, such as increased epithelial paracellular permeability and impaired cell-cell junction integrity. We also observed in these mice the early onset of a severe gut dysbiosis, as characterized by the bloom of pro-inflammatory Proteobacteria, and the later collapse of Paneth cells antimicrobial defense. Interestingly, S961 treatment discontinuation is sufficient to promptly restore both the gut microbial balance and the intestinal barrier integrity. Moreover, fecal transplant approaches further confirm that S961-mediated dybiosis contributes at least partly to the disruption of the gut selective epithelial permeability upon diabetic states.

CONCLUSIONS

Together, our results highlight that insulin signaling is an indispensable gatekeeper of intestinal barrier integrity, acting as a safeguard against microbial imbalance and acute infections by enteropathogens.

Lipocalin, Resistin and Gut Microbiota-Derived Propionate Could Be Used to Predict Metabolic Bariatric Surgery Selected Outcomes

Many patients with clinically severe obesity (CSO) need to undergo bariatric surgery, with possible side effects, so individualized predictive methods are required. Adipocytokines and gut/intestinal microbiota-derived metabolites could be predictive biomarkers of metabolic success post- surgery, but the knowledge in this field is undefined. The objective of this work was to determine whether adipocytokines and microbiota-derived metabolites can be used to predict the metabolic improvement post- surgery in women with CSO. We analyzed circulating levels of some cytokines and some microbiota-derived metabolites at baseline and 12 months post-surgery from 44 women with CSO and 21 women with normal weight. Results showed that glucose, insulin, glycosylated hemoglobin A1c (HbA1c), low-density lipoprotein (LDL-C), and triglycerides levels were decreased post-surgery, while high density lipoprotein increased. Twelve months later, leptin, resistin, lipocalin, PAI-1, TNF-α, and IL-1β levels were lower than baseline, meanwhile adiponectin, IL-8, and IL-10 levels were increased. Moreover, baseline lipocalin levels were associated with HbA1c reduction post-surgery; meanwhile baseline resistin was related to postoperative HOMA2 (insulin resistance) and baseline propionate was associated with LDL-C decrease. To conclude, the detection of lipocalin, resistin, and propionate levels may be used to predict the metabolic success following bariatric surgery, although new knowledge is needed.

An immediate post op and follow up assessment of circulating adipo-cytokines after bariatric surgery in morbid obesity

Background

Bariatric surgery has emerged as a promising treatment for improving adipose tissue dysfunction in obesity, but the mechanisms for such amelioration are still not known. This study comprehensively explores a panel of adipo-cytokines in individuals with obesity undergoing bariatric surgery, in conjunction with markers of insulin resistance, at three time points i.e., pre-op, immediate post-op and 6 months post-surgery.

Methods

It is a case-control prospective study among obese individuals undergoing bariatric surgery (BMI ≥35 kg/m2, n=30) and non-obese subjects (BMI <25 kg/m2, n=30), comparing the levels of serum adiponectin, resistin, C-Reactive Protein (CRP), Interleukin (IL)-6 and 8, Monocyte chemoattractant protein (MCP)-1 and Tumor necrosis factor (TNF)-α between them. The same were followed at immediate and 6-month post-op periods in the former group. The serum markers were correlated with the markers of Insulin resistance like HOMA-IR, HOMA-β and QUICKI.

Results

A significant increase in adiponectin was seen after weight loss in obese group (17.54 ± 1.31 μg/mL at baseline vs 68.76 ± 1.84 μg/mL at 6- month post-surgery). CRP being an acute phase protein showed significant higher levels at immediate post-op period but declined even below its baseline at 6 months after surgery (33.34 ± 16.85 μg/mL at baseline vs 59.85 ± 23.12 μg/mL at immediate post-op vs 9.66 ± 1.84 μg/mL at 6 months post-operatively). Few inconsistencies were observed in the trajectories of IL-6 and TNF-α, while other pro-inflammatory markers indicated resolution after surgery.

Conclusion

Bariatric surgery alleviated the systemic inflammation, correlating with improved insulin resistance in individuals with obesity.

What is already known about this subject?•

There is an altered expression of inflammatory cytokines and adipokines in obesity, contributing to a low-grade chronic inflammation, culminating in adipose tissue dysfunction.

•

Bariatric surgery leads to a considerable reduction in the adipose tissue mass which leads in resolution of inflammation, in terms of circulating adipocytokines.

•

The adipokines and cytokine profiles have been investigated pre and post bariatric surgery but inconsistencies have been reported in their serum levels in various studies.

What this study adds?•

This study takes into account the immediate post-operative serum cytokine profile, which has not been reported in the literature yet.

•

This study reports the significant changes in said parameters, right from the beginning of the post-surgical period, and correlates it with clinical profile of subjects.

•

This further enhances the knowledge about translation of bariatric surgery induced biochemical alterations, into a significant clinical benefit with regard to obesity related morbidity and mortality.

Impact of Bariatric Surgery on Adipose Tissue Biology

Bariatric surgery (BS) procedures are actually the most effective intervention to help subjects with severe obesity achieve significant and sustained weight loss. White adipose tissue (WAT) is increasingly recognized as the largest endocrine organ. Unhealthy WAT expansion through adipocyte hypertrophy has pleiotropic effects on adipocyte function and promotes obesity-associated metabolic complications. WAT dysfunction in obesity encompasses an altered adipokine secretome, unresolved inflammation, dysregulated autophagy, inappropriate extracellular matrix remodeling and insufficient angiogenic potential. In the last 10 years, accumulating evidence suggests that BS can improve the WAT function beyond reducing the fat depot sizes. The causal relationships between improved WAT function and the health benefits of BS merits further investigation. This review summarizes the current knowledge on the short-, medium- and long-term outcomes of BS on the WAT composition and function.

Opposite Effects of Chronic Central Leptin Infusion on Activation of Insulin Signaling Pathways in Adipose Tissue and Liver Are Related to Changes in the Inflammatory Environment

Leptin modulates insulin signaling and this involves the Akt pathway, which is influenced by changes in the inflammatory environment and with leptin regulating cytokine synthesis. We evaluated the association between activation of the insulin-signaling pathway and alterations in pro- and anti-inflammatory cytokine levels in inguinal fat and liver of chronic central leptin infused (L), pair-fed (PF), and control rats. Signal transducer and activator of transcription 3 (STAT3) phosphorylation was increased in inguinal fat and reduced in liver of L rats. Phosphorylation of c-Jun N-terminal kinase (JNK) and nuclear factor kappa B (NFkB) was increased in inguinal fat of L rats, together with a pro-inflammatory cytokine profile, while in the liver activation of JNK and NFkB were reduced and an anti-inflammatory pattern was found. Phosphorylation of the insulin receptor, Akt and mechanistic target of rapamycin was decreased in inguinal fat and increased in liver of L rats. There was a direct relationship between pSTAT3 and JNK and a negative correlation of Akt with pSTAT3 and JNK in both tissues. These results indicate that the effects of chronically increased leptin on insulin-related signaling are tissue-specific and suggest that inflammation plays a relevant role in the crosstalk between leptin and insulin signaling.

Cytokine Patterns in Maternal Serum From First Trimester to Term and Beyond

Pregnancy implies delicate immunological balance between two individuals, with constant changes and adaptions in response to maternal capacity and fetal demands. We performed cytokine profiling of 1149 longitudinal serum samples from 707 pregnant women to map immunological changes from first trimester to term and beyond. The serum levels of 22 cytokines and C-reactive protein (CRP) followed diverse but characteristic trajectories throughout pregnancy, consistent with staged immunological adaptions. Eotaxin showed a particularly robust decrease throughout pregnancy. A strong surge in cytokine levels developed when pregnancies progressed beyond term and the increase was amplified as labor approached. Maternal obesity, smoking and pregnancies with large fetuses showed sustained increase in distinct cytokines throughout pregnancy. Multiparous women had increased cytokine levels in the first trimester compared to nulliparous women with higher cytokine levels in the third trimester. Fetal sex affected first trimester cytokine levels with increased levels in pregnancies with a female fetus. These findings unravel important immunological dynamics of pregnancy, demonstrate how both maternal and fetal factors influence maternal systemic cytokines, and serve as a comprehensive reference for cytokine profiles in normal pregnancies.

In severe obesity, subcutaneous adipose tissue cell-derived cytokines are early markers of impaired glucose tolerance and are modulated by quercetin

BACKGROUND

Excessive adiposity provides an inflammatory environment. However, in people with severe obesity, how systemic and local adipose tissue (AT)-derived cytokines contribute to worsening glucose tolerance is not clear.

METHODS

Ninty-two severely obese (SO) individuals undergoing bariatric surgery were enrolled and subjected to detailed clinical phenotyping. Following an oral glucose tolerance test, participants were included in three groups, based on the presence of normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes (T2D). Serum and subcutaneous AT (SAT) biopsies were obtained and mesenchymal stem cells (MSCs) were isolated, characterized, and differentiated in adipocytes in vitro. TNFA and PPARG mRNA levels were determined by qRT-PCR. Circulating, adipocyte- and MSC-released cytokines, chemokines, and growth factors were assessed by multiplex ELISA.

RESULTS

Serum levels of IL-9, IL-13, and MIP-1β were increased in SO individuals with T2D, as compared with those with either IGT or NGT. At variance, SAT samples obtained from SO individuals with IGT displayed levels of TNFA which were threefold higher compared to those with NGT, but not different from those with T2D. Elevated levels of TNFα were also found in differentiated adipocytes, isolated from the SAT specimens of individuals with IGT and T2D, compared to those with NGT. Consistent with the pro-inflammatory milieu, IL-1β and IP-10 secretion was significantly higher in adipocytes from individuals with IGT and T2D. Moreover, increased levels of TNFα, both mRNA and secreted protein were detected in MSCs obtained from IGT and T2D, compared to NGT SO individuals. Exposure of T2D and IGT-derived MSCs to the anti-inflammatory flavonoid quercetin reduced TNFα levels and was paralleled by a significant decrease of the secretion of inflammatory cytokines.

CONCLUSION

In severe obesity, enhanced SAT-derived inflammatory phenotype is an early step in the progression toward T2D and maybe, at least in part, attenuated by quercetin.

Effects of Morbid Obesity and Metabolic Syndrome on the Composition of Circulating Immune Subsets

Morbid obesity is characterized by chronic, low-grade inflammation, which is associated with ‘inflamm-aging’. The presence of metabolic syndrome (MetS) might accelerate this phenomenon of metaflammation. In this study, we assessed the effects of morbid obesity and MetS on the composition of a broad spectrum of immune cells present within the circulation. A total of 117 morbidly obese patients (MOP) without MetS (MetS-), 127 MOP with MetS (MetS+) and 55 lean controls (LC) were included in this study. Absolute numbers of T cell, B cell, NK cell and monocyte subsets were assessed within peripheral blood using flow cytometry. Both absolute cell numbers and proportion of cells were evaluated correcting for covariates age, body mass index and cytomegalovirus serostatus. Although the absolute number of circulating CD4+ T cells was increased in the MetS+ group, the CD4+ T cell composition was not influenced by MetS. The CD8+ T cell and B cell compartment contained more differentiated cells in the MOP, but was not affected by MetS. Even though the absolute numbers of NK cells and monocytes were increased in the MOP as compared to LC, there was no difference in proportions of NK and monocyte subsets between the three study groups. In conclusion, although absolute numbers of CD4+ and CD8+ T cells, B cells, NK cells and monocytes are increased in MOP, obesity-induced effects of the composition of the immune system are confined to a more differentiated phenotype of CD8+ T cells and B cells. These results were not affected by MetS.

The Positive Impact of Resistance Training on Muscle Mass and Serum Leptin Levels in Patients 2-7 Years Post-Roux-en-Y Gastric Bypass: A Controlled Clinical Trial

PURPOSE

Resistance training program (RTP) assist the maintenance of optimal body composition and inflammatory response modulation in individuals in late Roux-en-Y gastric bypass (RYGB). This study aimed to investigate the effect of RTP on body composition and serum inflammatory profile in individuals 2-7 years post-RYGB.

METHODS

Volunteers were matched on body mass index (BMI), age, sex, and years after surgery, and they were allocated as control or RTP group. Body composition, visceral fat area (VFA), and inflammatory serum markers were measured at baseline and after 12 weeks of RTP.

RESULTS

The sample baseline characteristics (n = 63; BMI = 29.7 ± 5.3 kg/m²) were similar between the groups. After intervention, the RTP group presented higher fat-free mass (Δ 1.17 ± 1.12 kg, p = 0.003) and skeletal muscle mass (Δ 0.77 ± 0.66 kg, p = 0.002) and decreased leptin levels (Δ -0.15 ± 0.60 pg/mL, p = 0.028). Ultrasensitive C-reactive protein (CRPus), interleukin-6, adiponectin, and monocyte chemotactic protein-1 showed no significant time-by-group interaction. After the categorization of RTP group individuals by VFA median values (129.8 cm², IQR 90.9; 152.5), participants with VFA values above the median presented a significant decrease in CRPus (Δ -0.20 mg/L, IQR -7.59; -0.03, p = 0.022) when compared to the participants with VFA values below the median.

CONCLUSION

The RTP improved individuals' body composition by a modest but significant enhancing muscle mass and decreasing serum leptin and CRPus levels, especially in individuals with VFA values above the median. RTPs assist in maintaining the adequate body composition as they contribute to a decrease in proinflammatory markers in long-term RYGB.

Evaluation of Blood Levels of C-Reactive Protein Marker in Obstructive Sleep Apnea: A Systematic Review, Meta-Analysis and Meta-Regression

(1) Introduction: High sensitivity C-reactive protein (hs-CRP) and CRP are inflammatory biomarkers associated with several inflammatory diseases. In both pediatric and adult individuals with Obstructive Sleep Apnea (OSA) higher hs-CRP and CRP were observed, compared to controls. With the present systematic review, meta-analysis and meta-regression we expand upon previous meta-analyses in four ways: (1) We included 109 studies (96 in adults and 13 in children); (2) we reported subgroup and meta-regression analyses in adults with OSA compared to controls on the serum and plasma levels of hs-CRP; (3) we reported subgroup and meta-regression analyses in adults with OSA compared to controls on the serum and plasma levels of CRP; (4) we reported serum and plasma levels of both hs-CRP and CRP in children with OSA, always compared to controls. (2) Materials and Methods: The PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases were searched to retrieve articles published until 31 May 2020, with no restrictions. The data included basic information involving the first author, publication year, country of study, ethnicity of participants in each study, age, BMI, and AHI of both groups, and mean and standard deviation (SD) of plasma and serum levels of CRP and hs-CRP. (3) Results: A total of 1046 records were retrieved from the databases, and 109 studies were selected for the analysis (96 studies reporting the blood levels of hs-CRP/CRP in adults and 13 studies in children). For adults, 11 studies reported plasma hs-CRP, 44 serum hs-CRP, 9 plasma CRP, and 32 serum CRP levels. For children, 6 studies reported plasma hs-CRP, 4 serum hs-CRP, 1 plasma CRP, and 2 serum CRP levels. Compared to controls, the pooled MD of plasma hs-CRP levels in adults with OSA was 0.11 mg/dL (p < 0.00001). Compared to controls, the pooled MD of serum hs-CRP levels in adults with OSA was 0.09 mg/dL (p < 0.00001). Compared to controls, the pooled MD of plasma CRP levels in adults with OSA was 0.06 mg/dL (p = 0.72). Compared to controls, the pooled MD of serum CRP levels in adults with OSA was 0.36 mg/dL (p < 0.00001). Compared to controls, the pooled MD of plasma hs-CRP, serum hs-CRP, plasma hs-CRP, and serum hs-CRP in children with OSA was 1.17 mg/dL (p = 0.005), 0.18 mg/dL (p = 0.05), 0.08 mg/dL (p = 0.10), and 0.04 mg/dL (p = 0.33), respectively. The meta-regression showed that with a greater apnea-hypapnea index (AHI), serum hs-CRP levels were significantly higher. (4) Conclusions: The results of the present systematic review, meta-analysis and meta-regression showed that compared to healthy controls plasma and serum levels of hs-CRP and serum CRP level were higher in adults with OSA; for children, and compared to controls, just plasma hs-CRP levels in children with OSA were higher.

Preoperative Chemerin Level Is Predictive of Inflammatory Status 1 Year After Bariatric Surgery

BACKGROUND

Obesity is associated with chronic low-grade inflammation, which has been linked to increased morbidity. However, inflammation variably and unpredictably improves after bariatric surgery. This study aimed at (1) evaluating the relationship between amplitude of weight loss and variation of inflammatory parameters after bariatric surgery, and (2) identifying, among clinical and biological baseline parameters, predictive factors of variation in inflammatory parameters.

METHODS

In a prospective cohort of patients who underwent bariatric surgery, serum concentrations of interleukin (IL)-6, IL-10, resistin, leptin, adiponectin chemerin, and C-reactive protein (CRP) were measured preoperatively and 1 year after surgery, and routine clinical and biochemical parameters were retrieved. Univariate and multivariate analyses (partial least square method) were performed to assess how parameters were associated with weight loss and to predict improvement of inflammatory parameters.

RESULTS

Eighty-seven patients were included (mean weight ± SD 136.3 ± 3.2 kg, 35 gastric bypasses, 52 sleeve gastrectomies). In parallel with weight loss (39.5 ± 13.8 kg), pro-inflammatory markers (IL-6, CRP, leptin, resistin) significantly decreased, and anti-inflammatory markers (IL-10, adiponectin) increased. Multivariate analysis revealed a significant association between weight loss and improvement in inflammatory parameters. Among all the clinical and biological preoperative parameters, baseline chemerin level was the only parameter that was significantly associated with global improvement of the inflammatory status after surgery.

CONCLUSION

The amplitude of weight loss 1 year after bariatric surgery was strongly correlated with improvement of inflammatory profile, which could be predicted by baseline plasma level of chemerin. This suggests a key role of chemerin in obesity-driven inflammation, and a potential use as a biomarker.

Serum Adipocytokines Levels and Their Association with Insulin Sensitivity in Morbidly Obese Individuals Undergoing Bariatric Surgery

Background

Obese adipose tissue secretes a variety of adipocytokines that act as metabolic regulators with complex mechanisms. Our objective was to compare serum concentration of a panel of adipocytokines between obese and non-obese individuals and identify any distinct patterns correlating with insulin sensitivity in obesity.

Methods

We designed a cross-sectional study among obese (body mass index [BMI] ≥30 kg/m², n=62) and non-obese (BMI <25 kg/m², n=32) individuals to compare circulating levels of the adipokines, such as adiponectin and resistin in conjunction with the measurement of the levels of inflammatory cytokines including C-reactive protein (CRP), interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α using Luminex multiplex immunoassay with drop array technology. Correlations between circulating adipocytokine levels and those of multiple well-established markers of insulin resistance including homeostatic model assessment of insulin resistance (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β) and quantitative insulin sensitivity check index were also established.

Results

CRP, IL-8, MCP-1, and TNF-α levels were higher in obese than non-obese individuals; the CRP and IL-8 differences were statistically significant. CRP correlated significantly with markers of insulin resistance (fasting plasma insulin, HOMA-IR, and QUICKI), and adiponectin correlated with HOMA-β in obese individuals. We divided the group of obese individuals on the basis of HOMA-IR levels into insulin-resistant (IR; HOMA-IR ≥2.5) and insulin-sensitive (IS; HOMA-IR <2.5) groups; and 43 out of 62 participants were IR despite comparable BMIs. An overall proinflammatory profile was compared between IR and IS obese, though the values were higher in IR obese but the difference was not significant.

Conclusion

Obesity is associated with a general inflammatory milieu and a crosstalk between adipocytokines and insulin resistance is complex as well as multifactorial.

Inflammation initiates a vicious cycle between obesity and nonalcoholic fatty liver disease

Low‐level of chronic inflammation activation is characteristic of obesity. Nonalcoholic fatty liver disease (NAFLD) is closely linked to obesity and is an emerging health problem, it originates from abnormal accumulation of triglycerides in the liver, and sometimes causes inflammatory reactions that could contribute to cirrhosis and liver cancer, thus its pathogenesis needs to be clarified for more treatment options. Once NAFLD is established, it contributes to systemic inflammation, the low‐grade inflammation is continuously maintained during NAFLD causing impaired resolution of inflammation in obesity, which subsequently exacerbates its severity. This study focuses on the effects of obesity‐induced inflammations, which are the underlying causes of the disease progression and development of more severe inflammatory and fibrotic stages. Understanding the relationship between obesity and NAFLD could help in establishing attractive therapeutic targets or diagnostic markers in obesity‐induced inflammation response and provides new approaches for the prevention and treatment of NAFLD in obesity.

Functional variations of NFKB1 and NFKB1A in inflammatory disorders and their implication for therapeutic approaches

Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) is a sophisticated transcription factor that is particularly important in the inflammatory response, but it regulates more than 400 individual and dependent genes for parts of the apoptotic, angiogenic, and proliferative, differentiative, and cell adhesion pathways. NF-κB function is directly inhibited by the binding of inhibitor of κB (IκB), and the imbalance between NF-κB and IκB has been linked to the development and progression of cancer and a variety of inflammatory disorders. These observations might broaden the horizon of current knowledge, particularly on the pathogenesis of inflammatory diseases considering the roles of NF-κB and IκB. In this context, we focus this narrative review on a comparative discussion of our findings with other literature regarding variations of NFKB1 and NFKB1A and their association with susceptibility to widespread inflammatory disorders (such as atherosclerosis, morbid obesity, Behçet syndrome, Graves disease, Hashimoto disease) and common cancers (such as gliomas).

Vascular Risk Reduction in Obesity through Reduced Granulocyte Burden and Improved Angiogenic Monocyte Content following Bariatric Surgery

Bariatric surgery, in addition to the benefit of sustained weight loss, can also reduce cardiometabolic risk and mortality. Lifelong vessel maintenance is integral to the prevention of cardiovascular disease. Using aldehyde dehydrogenase activity, an intracellular detoxifying enzyme present at high levels within pro-vascular progenitor cells, we observed an association between chronic obesity and “regenerative cell exhaustion” (RCE), a pathology whereby chronic assault on circulating regenerative cell types can result in adverse inflammation and diminished vessel repair. We also describe that, at 3 months following bariatric surgery, systemic inflammatory burden was reduced and pro-angiogenic macrophage precursor content was improved in subjects with severe obesity, suggesting the restoration of a microenvironment to support vessel homeostasis. These data suggest that bariatric surgery may reverse deleterious events that predispose patients with morbid obesity to cardiovascular risk.

Obesity features a low frequency of ALDH and CD133 co-expressing cells

Bariatric surgery results in lower granulocyte precursors expressing ALDH

Macrophage balance favors M2 polarization following bariatric surgery

Cellular changes after bariatric surgery give insight into reducing CV risk

AhR activation defends gut barrier integrity against damage occurring in obesity

Objective

Obesity is characterized by systemic and low-grade tissue inflammation. In the intestine, alteration of the intestinal barrier and accumulation of inflammatory cells in the epithelium are important contributors of gut inflammation. Recent studies demonstrated the role of the aryl hydrocarbon receptor (AhR) in the maintenance of immune cells at mucosal barrier sites. A wide range of ligands of external and local origin can activate this receptor. We studied the causal relationship between AhR activation and gut inflammation in obesity.

Methods

Jejunum samples from subjects with normal weight and severe obesity were phenotyped according to T lymphocyte infiltration in the epithelium from lamina propria and assayed for the mRNA level of AhR target genes. The effect of an AhR agonist was studied in mice and Caco-2/TC7 cells. AhR target gene expression, permeability to small molecules and ions, and location of cell-cell junction proteins were recorded under conditions of altered intestinal permeability.

Results

We showed that a low AhR tone correlated with a high inflammatory score in the intestinal epithelium in severe human obesity. Moreover, AhR activation protected junctional complexes in the intestinal epithelium in mice challenged by an oral lipid load. AhR ligands prevented chemically induced damage to barrier integrity and cytokine expression in Caco-2/TC7 cells. The PKC and p38MAPK signaling pathways were involved in this AhR action.

Conclusions

The results of these series of human, mouse, and cell culture experiments demonstrate the protective effect of AhR activation in the intestine targeting particularly tight junctions and cytokine expression. We propose that AhR constitutes a valuable target to protect intestinal functions in metabolic diseases, which can be achieved in the future via food or drug ligands.

•

Intestinal inflammation in obese subjects correlates with low AhR activity.

•

AhR activation protects intestinal epithelium from damages.

•

AhR activation prevents cytokine induction in response to damages.

•

Protective role of AhR activation targets junctional complexes.

•

Protein kinases-dependent signaling pathways are involved in AhR action.

Obstructive sleep apnea and liver injury in severely obese patients with nonalcoholic fatty liver disease

OBJECTIVES

Obstructive sleep apnea (OSA) and nonalcoholic fatty liver disease (NAFLD) are common in subjects with severe obesity. It has been suggested that insulin resistance and systemic inflammation may play a role in the development of nonalcoholic steatohepatitis (NASH), but the mechanisms remain controversial. The aim of this study was to explore the influence of OSA on liver injury and its potential mechanisms in severely obese patients with NAFLD.

METHODS

Severely obese patients requiring bariatric surgery were consecutively recruited between November 2017 and June 2018. Demographic, biochemical, liver ultrasound, and ambulatory polygraph data were collected.

RESULTS

One hundred fifty-three subjects with liver ultrasound-verified NAFLD were classified into three groups according to the apnea-hypopnea index (AHI). The level of serum alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase (GGT) tended to increase with more severe OSA (P = 0.024 and P = 0.004, respectively). In the unadjusted analysis, both ALT and GGT were positively correlated with AHI, oxygen desaturation index, percentage of total sleep time spent with oxyhemoglobin saturation below 90%, male sex, homeostasis model assessment of insulin resistance (HOMA-IR), and total cholesterol, while liver enzymes were negatively related to lowest oxygen saturation. In multiple regression analysis, AHI (odds ratio (OR) = 1.052, P = 0.044) and HOMA-IR (OR = 1.135, P = 0.001) were independent risk factors for an elevated ALT level. High-sensitivity C-reactive protein (hs-CRP) was positively associated with BMI and GGT (r = 0.349 and r = 0.164 (P < 0.05), respectively), and no correlation was found between hs-CRP and AHI or other parameters of hypoxia. hs-CRP and GGT remained significantly correlated after adjusting for confounding parameters (OR = 2.509, P = 0.013).

CONCLUSIONS

OSA may play a role in liver injury among severely obese individuals with NAFLD. Insulin resistance and systemic inflammation were possible contributing factors in this process.

The immune remodel: Weight loss-mediated inflammatory changes to obesity

Obesity is an escalating world problem that contributes to the complexity and cost of treatment of metabolic disorders. Obesity is the result of increased storage of energy in the form of adipose tissue, reducing the quality of daily life, and interfering with longevity. Obesity is also a chronic, low-grade inflammatory disorder. The inflammatory processes affect many organ systems with expanded numbers of immune cells and increased cytokine production. Long-term weight loss is difficult to achieve and maintain. Lifestyle modifications, pharmacologic treatments, and surgical methods are increasingly utilized to ameliorate excess body weight and the comorbidities of obesity, such as diabetes, cardiovascular disease, dyslipidemia, and cancers. Weight loss is also touted to reduce inflammation. Here we review the current literature on human obesity-related systemic and local changes to the immune system and circulating inflammatory mediators. Further, we consider the impact of weight loss to reduce the burden of inflammation, bearing in mind the different methods of weight loss—behavioral change vs. surgical intervention.

Association Between BMI and Inflammation Among Diabetic Polyneuropathy Patients

Background:

Inflammation is defined as body tissues response to harmful stimuli. Obesity-related inflammation leads to increased risk chronic diseases including diabetic polyneuropathy (DPN). The present study was performed to determine association between body mass index (BMI) and inflammatory markers including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in DPN patients.

Methods:

In this cross-sectional study, 200 DPN patients with a mean (SD) of age 58.76 (9.53) years were selected. All patients completed the questionnaire including demographic data and chronic disease history. In addition, anthropometric measures and clinical laboratory tests were taken. Multivariate linear regression was used to detect the association between BMI, CRP, and ESR levels.

Results:

BMI was associated with increase in ESR and CRP levels (β-ESR = 4.67, P < 0.001 and β-CRP = 0.71, P < 0.001). Also, this association remained after adjustment for other different variables.

Conclusions:

These findings indicate that higher BMI is related to increase inflammatory markers including CRP and ESR in DPN patients. Therapies for DPN and reducing inflammation should target the weight loss among obese patients.

Monitoring Vitamin B12 in Women Treated with Metformin for Primary Prevention of Breast Cancer and Age-Related Chronic Diseases

Metformin (MET) is currently being used in several trials for cancer prevention or treatment in non-diabetics. However, long-term MET use in diabetics is associated with lower serum levels of total vitamin B₁₂. In a pilot randomized controlled trial of the Mediterranean diet (MedDiet) and MET, whose participants were characterized by different components of metabolic syndrome, we tested the effect of MET on serum levels of B₁₂, holo transcobalamin II (holo-TC-II), and methylmalonic acid (MMA). The study was conducted on 165 women receiving MET or placebo for three years. Results of the study indicate a significant overall reduction in both serum total B₁₂ and holo-TC-II levels according with MET-treatment. In particular, in the MET group 26 of 81 patients and 10 of the 84 placebo-treated subjects had B₁₂ below the normal threshold (<221 pmol/L) at the end of the study. Considering jointly all B₁₂, Holo-TC-II, and MMA, 13 of the 165 subjects (10 MET and 3 placebo-treated) had at least two deficits in the biochemical parameters at the end of the study, without reporting clinical signs. Although our results do not affect whether women remain in the trial, B₁₂ monitoring for MET-treated individuals should be implemented.

Novel Insights into Sensorimotor and Cardiovascular Autonomic Neuropathy from Recent-Onset Diabetes and Population-Based Cohorts

The most prevalent chronic complications of diabetes are diabetic neuropathies, among which distal sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN) are the best studied. Their major clinical sequelae such as foot ulcers, neuropathic pain, and orthostatic hypotension are associated with lower quality of life and increased risk of mortality. Here we discuss the recent insights into DSPN and CAN focusing on two prospective cohorts; that is, the German Diabetes Study (GDS) including recent-onset diabetes patients and the population-based Cooperative Health Research in the Region of Augsburg, Germany (KORA) surveys. The insights from these studies investigating novel tools for early detection and prediction of (pre)diabetic neuropathy as well as biomarkers of oxidative stress and inflammation should ultimately culminate in improving the health care of patients affected by this serious condition.

Effect of low energy diet for eight weeks to adults with overweight or obesity on folate, retinol, vitamin B12, D and E status and the degree of inflammation: a post hoc analysis of a randomized intervention trial

Background

Obesity is associated with vitamin insufficiency and low grade inflammation. The purpose of this study was to investigate the effect of weight loss on folate, retinol, vitamin B₁₂, D and E status and the degree of inflammation.

Methods

Out of 110, 85 individuals (75% women) aged 39 ± 11 years with a mean ± SD BMI of 33 ± 4 kg/m², completed an eight-week low energy diet (LED). Serum concentration of folate, retinol, B₁₂, D and E and C-reactive protein and homocysteine (Hcy) were measured at baseline and at end of the LED.

Results

At baseline, 8% of the participants were deficient in folate, 13% in vitamin B₁₂, 2% in retinol, 28% in vitamin D (72% were insufficient in vitamin D), and none were deficient in vitamin E. At baseline, BMI was inversely associated with retinol (P < 0.05) as was total and abdominal fat percentage with folate (P < 0.05); further BMI and measures of adiposity were positively associated with CRP (P < 0.01) and Hcy (P < 0.05). Homocysteine was inversely associated with all vitamins but retinol (P < 0.001). After the LED, the participants lost a mean [95% confidence intervals] of 12.3 [− 13.1,-11.6] kg. The serum concentration of folate, vitamin B₁₂ and D were increased (P < 0.001) after the LED whereas the concentration of retinol and vitamin E were reduced (P < 0.001).

Conclusion

Eight-weeks LED resulted in 13% weight loss and an increase in the serum concentrations of folate, vitamin B₁₂ and D. Baseline adiposity was inversely associated with folate and retinol, and positively associated with markers of inflammation.

Trial registration

Ethical Committee of Copenhagen as no. H-4-2013-135, NCT01561131.

Sex Differences in Adipose Tissue CD8+ T Cells and Regulatory T Cells in Middle-Aged Mice

The prevalence of cardiovascular disease has increased among middle-aged women in the United States, yet has declined in middle-aged men. In experimental stroke, middle-aged females have larger strokes and greater inflammation than age-matched males or younger females. The mechanism underlying this shift from an “ischemia-protected” to an “ischemia-sensitive” phenotype in aging females is unknown. One potential factor is an age-related increase in systemic factors that induce inflammation. Increased abdominal fat deposition is seen in women during middle age. Adipose tissue plays a key role in obesity-induced systemic inflammation, including increased pro-inflammatory cytokines. We hypothesized that age and sex differences in adipose immune cells promote an augmented pro-inflammatory milieu in middle-aged females driven by a balance shift between pro-inflammatory and anti-inflammatory T cells. Abdominal adipose tissue immune cells from young (3–4 months) and middle-aged (15–16 months) male and female C57BL/6J mice were analyzed by flow cytometry. Plasma triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels were determined with colorimetric assays. Middle-aged mice had higher adipose tissue mass compared to young mice. Lipid profiling showed no sex differences in TG and LDL, but middle-aged females had lower HDL (0.84 ± 0.07 μg/μl) than middle-aged males (1.35 ± 0.06 μg/μl). Flow cytometry data demonstrated an age-associated increase in adipose tissue CD8⁺ T cells that was augmented by female sex, with middle-aged females having a higher percentage of CD8⁺ cells (34.4 ± 3.2% of CD3⁺ T cells) than middle-aged males (24.4 ± 2.2%). This increase in CD8⁺ T-cell proportion was adipose tissue-specific, as this change was not observed in blood. Middle-aged females had higher numbers of activated (CD69⁺) CD8⁺ T cells than males. In addition, female CD8⁺ T cells produced higher levels of IFN-γ, TNF-α, and granzyme B ex vivo, and females had higher adipose levels of IFN-γ, RANTES and MIP-1β than middle-aged males. In parallel, females had lower levels of regulatory T cells (Tregs), an anti-inflammatory T-cell subtype, compared to age-matched males. In conclusion, middle-aged females have a detrimental combination of elevated pro-inflammatory T cells and decreased anti-inflammatory Tregs in adipose tissue, which may promote a pro-inflammatory milieu and contribute to increased cardiovascular disease burden in aging females.

Which cytokine is the most related to weight loss-induced decrease in arterial stiffness in overweight and obese men?

Obesity and increased arterial stiffness are risk factors for cardiovascular disease. A well-known characteristic of obesity is the chronic low-grade inflammatory state, and it causes elevation of arterial stiffness. Weight-loss reduces arterial stiffness and inflammatory level in obese individuals. However, it is unclear which inflammatory factor is most related to weight loss-induce decreases in arterial stiffness in overweight and obese men. Thus, the aim of this study was to determine which circulating cytokine level has the most effect on decreasing arterial stiffness after lifestyle modification. Twenty overweight and obese men completed a 12-week period of lifestyle modifications (combination of aerobic exercise training and dietary modification). We measured brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness, and circulating cytokine levels using comprehensive analysis. After the 12-week lifestyle modifications, body mass was markedly decreased. Also, baPWV and the levels of several circulating cytokines significantly decreased after the lifestyle modifications. We observed a positive correlation between changes in baPWV and circulating interleukin-6 (IL-6) levels. Furthermore, multiple liner regression analysis revealed that change in baPWV was significantly associated with that in IL-6 levels after consideration of changes in systolic blood pressure and body mass index. These results suggest that for overweight and obese men, a 12-week period of lifestyle modifications-induced a decrease in circulating cytokine levels (especially IL-6 levels), leads to decreased baPWV.

T Cell Populations and Functions Are Altered in Human Obesity and Type 2 Diabetes

PURPOSE OF THE REVIEW

Obesity and type 2 diabetes (T2D) are considered chronic inflammatory diseases. While early publications have reported the implication of innate immune cells such as macrophages to promote systemic inflammation and metabolic dysfunctions, recent publications underline the alterations of the T cell compartment in human obesity and type 2 diabetes. These recent findings are the focus of this review.

RECENT FINDINGS

In humans, obesity and T2D induce the expansion of proinflammatory T cells such as CD4 Th1, Th17, and CD8 populations, whereas innate T cells such as MAIT and iNKT cells are decreased. These alterations reflect a loss of total T cell homeostasis that may contribute to tissue and systemic inflammation. Whether these changes are adaptive to nutritional variations and/or contribute to the progression of metabolic diseases remains to be clarified. T cell phenotyping may improve obese and/or T2D patient stratification with therapeutic and prognostic implications.

Different Intestinal Microbial Profile in Over-Weight and Obese Subjects Consuming a Diet with Low Content of Fiber and Antioxidants

Obesity has been related to an increased risk of multiple diseases in which oxidative stress and inflammation play a role. Gut microbiota has emerged as a mediator in this interaction, providing new mechanistic insights at the interface between fat metabolism dysregulation and obesity development. Our aim was to analyze the interrelationship among obesity, diet, oxidative stress, inflammation and the intestinal microbiota in 68 healthy adults (29.4% normal-weight). Diet was assessed through a food frequency questionnaire and converted into nutrients and dietary compounds using food composition tables. The intestinal microbiota was assessed by quantitative PCR, fecal short chain fatty acids by gas chromatography and serum biomarkers by standard protocols. Higher levels of malondialdehyde (MDA), C reactive protein (CRP), serum leptin, glucose, fat percentage and the intestinal Lactobacillus group were found in the obese people. Cluster analysis of body mass index, fat mass, glucose, LDL/HDL ratio, leptin, MDA and CRP classified the subjects into two groups. The levels of the intestinal Bacteroides-Prevotella-Porphyromonas group were lower in the cluster and linked to a higher pro-oxidant and pro-inflammatory status, whose individuals also had lower intake of fruits, dried fruits, and fish. These results could be useful for designing strategies targeted to obesity prevention.

Interleukin-1 Antagonism Decreases Cortisol Levels in Obese Individuals

CONTEXT

Increased cortisol levels in obesity may contribute to the associated metabolic syndrome. In obesity, the activated innate immune system leads to increased interleukin (IL)-1β, which is known to stimulate the release of adrenocorticotropin hormone (ACTH).

OBJECTIVES

We hypothesized that in obesity IL-1 antagonism would result in downregulation of the hypothalamo-pituitary-adrenal axis, leading to decreased cortisol levels.

DESIGN AND PARTICIPANTS

In this prospective intervention study, we included 73 patients with obesity (body mass index [BMI] ≥30 kg/m2) and at least one additional feature of the metabolic syndrome.

OUTCOME MEASURES

The primary end point was change in morning cortisol from baseline to after the administration of the IL-1 receptor antagonist (anakinra/Kineret®, total dose 3 × 100 mg). Secondary end points were effects on salivary cortisol and ACTH.

RESULTS

Median age was 56 years, 50.7% of patients were female, and median BMI was 36.3 kg/m2. Median morning serum cortisol levels (nmol/L) decreased significantly after IL-1 antagonism [from baseline, 452 to 423; absolute difference, -38.7; 95% confidence interval (CI), -64 to -13.4; P = 0.0019]. Similar effects were found for salivary cortisol levels (-2.8; 95% CI, -4.4 to -1.3; P = 0.0007), ACTH levels (-2.2; 95% CI; -4.2 to -0.1; P = 0.038), systolic blood pressure (-5.2, 95% CI, -8.5 to -1.8; P = 0.0006), and heart rate (-2.9; 95% CI, -4.7 to -1.0; P = 0.0029).

CONCLUSION

IL-1 antagonism in obese individuals with features of the metabolic syndrome leads to a decrease in serum cortisol, salivary cortisol, and ACTH levels along with a reduction in systolic blood pressure and heart rate.

Obesity promotes prolonged ovalbumin-induced airway inflammation modulating T helper type 1 (Th1), Th2 and Th17 immune responses in BALB/c mice

Clinical and epidemiological studies indicate that obesity affects the development and phenotype of asthma by inducing inflammatory mechanisms in addition to eosinophilic inflammation. The aim of this study was to assess the effect of obesity on allergic airway inflammation and T helper type 2 (Th2) immune responses using an experimental model of asthma in BALB/c mice. Mice fed a high-fat diet (HFD) for 10 weeks were sensitized and challenged with ovalbumin (OVA), and analyses were performed at 24 and 48 h after the last OVA challenge. Obesity induced an increase of inducible nitric oxide synthase (iNOS)-expressing macrophages and neutrophils which peaked at 48 h after the last OVA challenge, and was associated with higher levels of interleukin (IL)-4, IL-9, IL-17A, leptin and interferon (IFN)-γ in the lungs. Higher goblet cell hyperplasia was associated with elevated mast cell influx into the lungs and trachea in the obese allergic mice. In contrast, early eosinophil influx and lower levels of IL-25, thymic stromal lymphopoietin (TSLP), CCL11 and OVA-specific immunoglobulin (IgE) were observed in the obese allergic mice in comparison to non-obese allergic mice. Moreover, obese mice showed higher numbers of mast cells regardless of OVA challenge. These results indicate that obesity affects allergic airway inflammation through mechanisms involving mast cell influx and the release of TSLP and IL-25, which favoured a delayed immune response with an exacerbated Th1, Th2 and Th17 profile. In this scenario, an intense mixed inflammatory granulocyte influx, classically activated macrophage accumulation and intense mucus production may contribute to a refractory therapeutic response and exacerbate asthma severity.