Increase in the mediators of asthma in obesity and obesity with type 2 diabetes: reduction with weight loss

Combined Training Improves Gene Expression Related to Immunosenescence in Obese Type 2 Diabetic Individuals

Purpose: The aim of this study was to investigate the effects of moderate combined training (CT) on both the gene expression of pro- and anti-inflammatory markers and senescence in the immune system in peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissue (SAT) of obese middle-aged individuals with type 2 diabetes (T2D). Methods: Thirty obese individuals (50.2 ± 9.4 years; body mass index: 31.8 ± 2.3 kg/m²) with T2D underwent 16 weeks of a CT group [CT; aerobic (50-60% of VO2max) plus resistance (50-75% of 1RM) training; 3 times/week, 70 min/session; n = 16)] or a control group (CG, n = 14). Nutritional patterns, muscle strength (1RM), cardiorespiratory fitness (VO2max), waist circumference (WC), body composition (Air Displacement Plethysmograph) and blood collections for biochemical (serum leptin, IL-2, IL-4, IL-6, IL-10, TNF-α and anti-CMV) and molecular (gene expression of leptin, IL-2, IL-4, IL-6, IL-10, TNF-α, PD-1, P16ink4a, CCR7, CD28 and CD27 in PBMCs and SAT) analyses were assessed before (Pre) and after (Post) the 16 weeks of the experimental period. Results: Significant decreases were observed in WC and IL4, TNF-α, PD-1 and CD27 expression in PBMCs for CT. Furthermore, significant increases were observed in 1RM and VO2max for CT after the experimental period. Conclusion: Moderate CT contributed to a reduction in the gene expression of markers associated to chronic inflammation and immunosenescence in PBMCs of obese middle-aged individuals with T2D.

Bariatric Surgery in Asthma: A Narrative Review

Nearly 60% of asthmatics in the USA suffer from obesity. Asthma is a comorbid condition alongside obesity, commonly accompanied by conditions such as hypertension and type 2 diabetes. The positive effect of bariatric surgery on patients suffering from hypertension and type 2 diabetes, which leads to either a reduction in the dose of medication taken for the aforementioned diseases or the withdrawal of the disease, is quite well proven in the literature. Currently, the impact of bariatric operations on the control and course of bronchial asthma and pharmacological treatment has not been fully recognized and described, requiring further research; therefore, the following review of the literature was conducted.

Obesity-induced blood-brain barrier dysfunction: phenotypes and mechanisms

Obesity, a burgeoning global health issue, is increasingly recognized for its detrimental effects on the central nervous system, particularly concerning the integrity of the blood-brain barrier (BBB). This manuscript delves into the intricate relationship between obesity and BBB dysfunction, elucidating the underlying phenotypes and molecular mechanisms. We commence with an overview of the BBB's critical role in maintaining cerebral homeostasis and the pathological alterations induced by obesity. By employing a comprehensive literature review, we examine the structural and functional modifications of the BBB in the context of obesity, including increased permeability, altered transport mechanisms, and inflammatory responses. The manuscript highlights how obesity-induced systemic inflammation and metabolic dysregulation contribute to BBB disruption, thereby predisposing individuals to various neurological disorders. We further explore the potential pathways, such as oxidative stress and endothelial cell dysfunction, that mediate these changes. Our discussion culminates in the summary of current findings and the identification of knowledge gaps, paving the way for future research directions. This review underscores the significance of understanding BBB dysfunction in obesity, not only for its implications in neurodegenerative diseases but also for developing targeted therapeutic strategies to mitigate these effects.

LIGHT/TNFSF14 Affects Adipose Tissue Phenotype

LIGHT/TNFSF14 is linked to several signaling pathways as a crucial member of a larger immunoregulatory network. It is primarily expressed in inflammatory effector cells, and high levels of LIGHT have been reported in obesity. Thus, with the aim of deepening the knowledge of the role of LIGHT on adipose tissue phenotype, we studied wild-type (WT), Tnfsf14-/-, Rag-/- and Rag-/Tnfsf14- (DKO) mice fed a normal diet (ND) or high-fat diet (HFD). Our results show that, although there is no significant weight gain between the mice with different genotypes, it is significant within each of them. We also detected an increase in visceral White Adipose Tissue (vWAT) weight in all mice fed HFD, together with the lowest levels of vWAT weight in Tnfsf14-/- and DKO mice fed ND with respect to the other strain. Inguinal WAT (iWAT) weight is significantly affected by genotype and HFD. The least amount of iWAT was detected in DKO mice fed ND. Histological analysis of vWAT showed that both the genotype and the diet significantly affect the adipocyte area, whereas the number is affected only by the genotype. In iWAT, the genotype and the diet significantly affect mean adipocyte area and number; interestingly, the area with the least adipocyte was detected in DKO mice fed ND, suggesting a potential browning effect due to the simultaneous lack of mature lymphocytes and LIGHT. Consistently, Uncoupling Protein 1 (UCP1) staining of iWAT demonstrated that few positive brown adipocytes appeared in DKO mice. Furthermore, LIGHT deficiency is associated with greater levels of UCP1, highlighting the lack of its expression in Rag-/- mice. Liver examination showed that all mice fed HFD had a steatotic liver, but it was particularly evident for DKO mice. In conclusion, our study demonstrates that the adipose tissue phenotype is affected by LIGHT levels but also much more by mature lymphocytes.

High levels of LIGHT/TNFSF14 in patients with Prader-Willi syndrome

PURPOSE/METHODS

Prader-Willi syndrome (PWS) is a rare genetic disorder displaying different clinical features, including obesity and bone impairment. LIGHT/TNFSF14 is a cytokine produced by immune cells affecting both fat and bone metabolism. The present study aimed to evaluate LIGHT serum levels in 28 children and 52 adult PWS patients compared to age and sex-matched controls, as well as correlations with parameters of bone and fat metabolism.

RESULTS

Median serum LIGHT levels were significantly increased in pediatric PWS with respect to controls [255.82 (284.43) pg/ml vs 168.11 (76.23) pg/ml, p ≤ 0.02] as well as in adult PWS compared to controls [296.85 (895.95) pg/ml vs 134.18 (141.18) pg/ml, p ≤ 0.001]. In pediatric PWS, LIGHT levels were positively correlated with weight-SDS, height-SDS, and glucose levels, and negatively with total 25 (OH) vitamin D, cholesterol, LDL cholesterol and triglycerides. Additionally, LIGHT levels were negatively correlated with total BMD and fat mass. In adult PWS, LIGHT levels were positively correlated with weight, HDL cholesterol and PTH, and negatively with glucose, insulin, HOMA-IR, total cholesterol, LDL cholesterol, triglycerides, calcium, phosphorus, 25(OH)Vitamin D as well as with instrumental parameters of bone and fat quality. Consistently, multiple regression analysis showed that LIGHT serum levels in pediatric and adult PWS were predicted by different parameters including 25 (OH) Vitamin D as well as DXA parameters of bone and fat quality.

CONCLUSIONS

In PWS children and adults the high levels of LIGHT could represent a marker of the altered bone and fat metabolism.

Diabetic Ferroptosis and Pancreatic Cancer: Foe or Friend?

Significance: Pancreatic cancer and diabetes have a reciprocal causation relationship. As a potential risk factor, diabetes increases morbidity and promotes pancreatic cancer progression. The main mechanisms include islet dysfunction-induced systemic metabolic disorder, pancreatic stellate cell activation, and immunosuppression. Ferroptosis is regarded as regulated cell death, which participates in chemotherapy resistance and is refractory to radiation therapy and immunotherapy. Diabetes-induced ferroptosis causes many complications, but the underlying mechanism of diabetes-related ferroptosis in pancreatic cancer has not been discussed. Recent Advances: Ferroptosis alleviates pancreatic intraepithelial neoplasia (PanIN) progression by activating chronic inflammation. The specific drugs that cause ferroptosis achieve tumor suppression by inducing lipid peroxidation. Ferroptosis plays pro and con roles in cancer. Both the ferroptosis inhibitor and inducer exhibit antitumor effects through killing cancer cells or directly affecting tumor growth. Diabetes-induced ferroptosis contributes to tumor cell death by different components, including tumor cells, fibroblasts, immune cells, and adipocytes. A better understanding of its role in modulating the tumor microenvironment will reveal diabetes-associated ferroptotic features in cancer development, which can be used to figure out possible treatment strategies for cancer patients with hyperglycemia. Critical Issues: We demonstrate the potential roles of diabetes-related ferroptosis in pancreatic cancer progression and discuss ferroptosis-related antitumor effects and therapeutics for pancreatic cancer treatment. Future Directions: Further studies are required to highlight mechanisms of diabetes-mediated ferroptosis in pancreatic cancer tumorigenesis and progression. The antitumor effects of ferroptosis regulators combined with chemotherapy, targeted therapy, or immunotherapy in diabetic patients should be investigated. We hope that pancreatic cancer patients with diabetes will benefit from ferroptosis-related therapies. Antioxid. Redox Signal. 37, 1206-1221.

Differential gene expression in nasal airway epithelium from overweight or obese youth with asthma

BACKGROUND

The mechanisms underlying the known link between overweight/obesity and childhood asthma are unclear. We aimed to identify differentially expressed genes and pathways associated with obesity-related asthma through a transcriptomic analysis of nasal airway epithelium.

METHODS

We compared the whole transcriptome in nasal airway epithelium of youth with overweight or obesity and asthma with that of youth of normal weight and asthma, using RNA sequencing data from a cohort of 235 Puerto Ricans aged 9-20 years (EVA-PR) and an independent cohort of 66 children aged 6-16 years in Pittsburgh (VDKA). Differential expression analysis adjusting for age, sex, sequencing plate number, and sample sorting protocol, and the first five principal components were performed independently in each cohort. Results from the two cohorts were combined in a transcriptome-wide meta-analysis. Gene enrichment and network analyses were performed on top genes.

RESULTS

In the meta-analysis, 29 genes were associated with obesity-related asthma at an FDR-adjusted p <.05, including pro-inflammatory genes known to be differentially expressed in adipose tissue of obese subjects (e.g., CXCL11, CXCL10, and CXCL9) and several novel genes. Functional enrichment analyses showed that pathways for interferon signaling, and innate and adaptive immune responses were down-regulated in overweight/obese youth with asthma, while pathways related to ciliary structure or function were up-regulated. Upstream regulatory analysis predicted significant inhibition of the IRF7 pathway. Network analyses identified "hub" genes like GBP5 and SOCS1.

CONCLUSION

Our transcriptome-wide analysis of nasal airway epithelium identified biologically plausible genes and pathways for obesity-related asthma in youth.

Concentration of Selected Metalloproteinases and Osteocalcin in the Serum and Synovial Fluid of Obese Women with Advanced Knee Osteoarthritis

The aim of the study was to evaluate the levels of selected MMPs (matrix metalloproteinases) and osteocalcin in the serum and synovial fluid of obese women with osteoarthritis and their correlations with clinical status. The studied group consisted of 39 overweight females undergoing primary total knee arthroplasty due to osteoarthritis (OA). The staging of knee OA was evaluated according to the Ahlbӓck and Kellgren–Lawrence scores. Synovial fluid and peripheral blood samples were obtained. The levels of selected MMPs and osteocalcin were assessed using commercial ELISA kits. The mean value of MMP3 was significantly higher in patients with more advanced disease in both serum (p = 0.0067) and synovial fluid (p = 0.0328). The pro-MMP13 level tended to be higher in synovial fluid in the case of more advanced stages (p = 0.0882), with no tendency regarding the serum level (p = 0.9595). The synovial level of pro-MMP1 was significantly correlated with the synovial concentration of MMP9 and MMP3. The synovial level of MMP9 also showed a significant correlation with the synovial level of MMP3 and pro-MMP13. Furthermore, it was found that the serum level of MMP3 was significantly correlated with the synovial pro-MMP13 level. A correlation between the osteocalcin level in serum and its synovial level was determined. The serum MMP9 level showed a significant correlation with BMI, whereas the synovial MMP9 level was notably correlated with age. Our results showed that the levels of MMP3, MMP9, and pro-MMP13 increased in more advanced radiological stages of OA, indicating the underlying inflammatory process of OA.

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.

Glycoprotein levels and oxidative lung injury in experimental diabetes: effect of oxovanadium(IV) complex based on thiosemicarbazone

Diabetes mellitus (DM) is chronic and metabolic disorder, which is mainly attributed by hyperglycemia. Vanadium salts and their oxo-complexes have been shown to possess insulin-mimetic and anti-diabetic activities in animal models and diabetic patients. The main goal of this study was to investigate the protective effect of oxovanadium(IV) complex based on thiosemicarbazone (VOL) [L: (N(1)-2,4-dihydroxybenzylidene-N-(4)-2-hydroxybenzylidene-S-methyl-isothiosemicarbazidato-oxovanadium(IV)] on glycoprotein components levels and oxidative lung injury of streptozotocin (STZ)-induced diabetic rats. Male Swiss albino rats were separated into four groups. Group I (n = 5): Control (normal) animals, Group II (n = 5): Control animals administered with VOL, Group III (n = 6): STZ-induced diabetic animals, and Group IV (n = 5): STZ-induced diabetic rats treated with VOL. VOL was given to the experimental animals by gavage at a dose of 0.2 mM/kg body weight every day for 12 days. Diabetes was induced by single intraperitoneal injection of STZ (65 mg/kg body weight). On the 12th day, lung tissue samples were taken. Glycoprotein components, advanced oxidation protein products, protein carbonyl, hydroxyproline levels, and prolidase, arginase, xanthine oxidase, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and adenosine deaminase activities significantly increased whereas aryl esterase, paraoxonase-1, carbonic anhydrase, Na⁺/K⁺-ATPase activities remarkably decreased in lung tissue of diabetic rats. Treatment with VOL reversed these effects showing a beneficial effect. The present study shows that VOL has a protective effect against diabetes-induced lung damage as well as on abnormal glycoprotein component levels.

Factors Influencing Total Serum IgE in Adults: The Role of Obesity and Related Metabolic Disorders

BACKGROUND AND AIM

Few reports have investigated the association between metabolic abnormalities (obesity and related metabolic syndrome) and total serum IgE concentrations.

METHODS

This cross-sectional study included a random sample of 1,516 adult individuals (44.7% men, aged 18-91 years, median 52 years) from a single municipality in Spain. Serum IgE was measured in the ADVIA Centaur system. Atopy was defined by the presence of positive skin prick tests to a panel of common aeroallergens in the area. Body mass index and data related to the definition of metabolic syndrome were obtained from all participants. Alcohol consumption, smoking, and regular physical exercise were assessed by a questionnaire.

RESULTS

Atopy (present in 21.9% of 1,514 evaluable individuals) was the strongest factor determining serum IgE concentrations. Male sex and heavy alcohol drinking were independently associated with higher IgE concentrations, particularly in the non-atopic individuals. Body mass index was positively associated with IgE concentrations, independent of potential confounders, although the effect was only evident among non-atopic individuals. In that group, median IgE concentrations in normal-weight and obese individuals were 15 and 24 kU/L, respectively (p < 0.001); likewise, obesity was associated with high (>100 kU/L) IgE concentrations after adjusting for potential confounders (odds ratio: 1.79, 95% confidence interval: 1.26-2.56, p = 0.001). The presence of metabolic syndrome and its components, particularly abdominal obesity and hyperglycaemia, was also positively and independently associated with higher IgE concentrations in non-atopic individuals.

CONCLUSIONS

Obesity and metabolic syndrome components are associated with high total serum IgE concentrations, particularly in non-atopic individuals.

Bariatric Surgery: Remission of Inflammation, Cardiometabolic Benefits, and Common Adverse Effects

Obesity is associated with increased mortality as a result of several comorbidities which occur in tandem with the obese state. Chronic inflammation is well documented in obesity, and evidence from numerous studies support the notion that the increased inflammation in individuals with obesity accentuates the comorbidities seen in this condition. The remission of comorbidities such as metabolic, cardiovascular, and neurological complications occurs following bariatric procedures. Bariatric surgery significantly reduces mortality and results in remarkable weight loss and reversal in several obesity-related comorbidities. There is indisputable evidence that the resolution of inflammation that occurs after bariatric surgery mitigates some of these comorbidities. With the increasing use of bariatric surgery for the treatment of severe obesity, it is pivotal to elucidate the underlying mechanisms responsible for the notable improvements seen after the procedure. This review summarizes underlying mechanisms responsible for the remission of obesity-related abnormalities and discusses the common adverse effects of bariatric surgery. Well-stratified, large-scale studies are still needed for a proper evaluation of these underlying mechanisms.

Shedding "LIGHT" on the Link between Bone and Fat in Obese Children and Adolescents

Obesity may affect bone health, but literature reports are contradictory about the correlation of body mass index (BMI) and bone markers. LIGHT, one of the immunostimulatory cytokines regulating the homeostasis of bone and adipose tissue, could be involved in obesity. The study involved 111 obese subjects (12.21 ± 3.71 years) and 45 controls. Patients underwent the evaluation of bone status by quantitative ultrasonography (QUS). LIGHT amounts were evaluated in sera by ELISA, whereas its expression on peripheral blood cells was evaluated by flow cytometry. Osteoclastogenesis was performed by culturing peripheral blood mononuclear cells (PBMCs) with or without anti-LIGHT antibodies. Obese patients showed significant high BMI-standard deviation score (SDS), weight-SDS, and Homeostatic model assessment for insulin resistance (HOMA-IR) that negatively correlated with the reduced Amplitude Dependent Speed of Sound (AD-SoS)-Z-score and Bone Transmission Time (BTT-Z)-score. They displayed significantly higher serum levels of LIGHT compared with controls (497.30 ± 363.45 pg/mL vs. 186.06 ± 101.41 pg/mL, p < 0.001). LIGHT expression on monocytes, CD3+-T-cells, and neutrophils was also higher in obese patients than in the controls. Finally, in PBMC cultures, the addition of anti-LIGHT antibodies induced a significant osteoclastogenesis inhibition. Our study highlighted the high serum levels of LIGHT in obese children and adolescents, and its relationship with both the grade of obesity and bone impairment.

Asthma and metabolic syndrome: a comprehensive systematic review and meta-analysis of observational studies

Introduction: This study aimed to perform a meta-analysis on the prevalence of metabolic syndrome (MetS) among patients with asthma and to measure the association asthma has with MetS.

Methods: The Web of Science, Medline, Scopus, Embase and Google Scholar were searched using the "Asthma", "Metabolic Syndrome", "Dysmetabolic Syndrome", "Cardiovascular Syndrome", "Insulin Resistance Syndrome", "Prevalence", "Odds Ratio", "Cross-Sectional Studies", and "Case-Control Studies" keywords. All observational studies reporting the prevalence of MetS among people with and without asthma were included in the study. In the presence of heterogeneity, random-effects models were used to pool the prevalence and odds ratios (OR), as measures of association in cross-sectional and case-control/ cohort studies, respectively.

Results: The prevalence of MetS among patients with asthma (8 studies) and the OR comparing the prevalence of MetS among patients with and without asthma (5 studies) were pooled separately. The pooled prevalence of MetS among patients with asthma was found to be 25% (95% confidence interval (CI): 13%–38%). In contrast, the overall pooled OR for MetS in patients with asthma, compared to healthy controls, was 1.34 (95% CI: 0.91–1.76), which was not statistically significant.

Conclusion: The prevalence of MetS was relatively high in patients with asthma. Furthermore, the odds of MetS was higher in patients with asthma, compared to healthy controls, although this difference was not statistically significant. More original studies among different populations are needed in order to more accurately examine the association between asthma and MetS, as well as the relationship asthma has with the individual components of MetS.

Macronutrient-Mediated Inflammation and Oxidative Stress: Relevance to Insulin Resistance, Obesity, and Atherogenesis

CONTEXT

The intake of macronutrients as components of a Western dietary pattern leads to oxidative stress and inflammation.

EVIDENCE ACQUISITION

Data were largely retrieved from our previous and most recent work. PubMed and Google Scholar were searched for recent articles on the effect of macronutrients/dietary intake on inflammation, insulin resistance, obesity, and atherogenesis. The most relevant, high-quality articles were included in our review.

EVIDENCE SYNTHESIS

Our previous work has demonstrated the molecular mechanisms of macronutrient-mediated oxidative stress and inflammation. With the induction of inflammation, proinflammatory molecules potentially interfere with insulin signal transduction, thus causing insulin resistance. In addition, other molecules promote atherogenic inflammation. More recently, our work has also shown that certain foods are noninflammatory or anti-inflammatory and thus, do not interfere with insulin signaling. Finally, as obesity is induced by chronic excessive caloric intake, it is characterized by an increase in the expression of proinflammatory molecules, which are induced acutely by a Western diet. Caloric restriction, including fasting, is associated with a reduction in oxidative and inflammatory stress.

CONCLUSIONS

This review summarizes and attempts to provide an up-to-date profile of the molecular mechanisms involved in macronutrient-mediated oxidative/inflammatory stress and its potential consequences. An understanding of these underlying mechanisms is crucial for making appropriate dietary choices.

Dietary β-Cryptoxanthin Inhibits High-Refined Carbohydrate Diet-Induced Fatty Liver via Differential Protective Mechanisms Depending on Carotenoid Cleavage Enzymes in Male Mice

BACKGROUND

β-Cryptoxanthin (BCX), a provitamin A carotenoid shown to protect against nonalcoholic fatty liver disease (NAFLD), can be cleaved by β-carotene-15,15'-oxygenase (BCO1) to generate vitamin A, and by β-carotene-9',10'-oxygenase (BCO2) to produce bioactive apo-carotenoids. BCO1/BCO2 polymorphisms have been associated with variations in plasma carotenoid amounts in both humans and animals.

OBJECTIVES

We investigated whether BCX feeding inhibits high refined-carbohydrate diet (HRCD)-induced NAFLD, dependent or independent of BCO1/BCO2.

METHODS

Six-week-old male wild-type (WT) and BCO1-/-/BCO2-/- double knockout (DKO) mice were randomly fed HRCD (66.5% of energy from carbohydrate) with or without BCX (10 mg/kg diet) for 24 wk. Pathological and biochemical variables were analyzed in the liver and mesenteric adipose tissues (MATs). Data were analyzed by 2-factor ANOVA.

RESULTS

Compared to their respective HRCD controls, BCX reduced hepatic steatosis severity by 33‒43% and hepatic total cholesterol by 43‒70% in both WT and DKO mice (P < 0.01). Hepatic concentrations of BCX, but not retinol and retinyl palmitate, were 33-fold higher in DKO mice than in WT mice (P < 0.001). BCX feeding increased the hepatic fatty acid oxidation protein peroxisome proliferator-activated receptor-α, and the cholesterol efflux gene ATP-binding cassette transporter5, and suppressed the lipogenesis gene acetyl-CoA carboxylase 1 (Acc1) in the MAT of WT mice but not DKO mice (P < 0.05). BCX feeding decreased the hepatic lipogenesis proteins ACC and stearoyl-CoA desaturase-1 (3-fold and 5-fold) and the cholesterol synthesis genes 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and HMG-CoA synthase 1 (2.7-fold and 1.8-fold) and increased the cholesterol catabolism gene cholesterol 7α-hydroxylase (1.9-fold) in the DKO but not WT mice (P < 0.05). BCX feeding increased hepatic protein sirtuin1 (2.5-fold) and AMP-activated protein kinase (9-fold) and decreased hepatic farnesoid X receptor protein (80%) and the inflammatory cytokine gene Il6 (6-fold) in the MAT of DKO mice but not WT mice (P < 0.05).

CONCLUSION

BCX feeding mitigates HRCD-induced NAFLD in both WT and DKO mice through different mechanisms in the liver-MAT axis, depending on the presence or absence of BCO1/BCO2.

Obesity and adiposity indicators in asthma and allergic rhinitis in children

PURPOSE OF REVIEW

The prevalence of obesity and allergic diseases, such as asthma and allergic rhinitis, is increasing worldwide not only in adults, but also in children. Experimental and clinical studies have demonstrated the effect of obesity not only on asthma, but also on other allergic diseases.

RECENT FINDINGS

Allergic diseases, such as asthma and allergic rhinitis, are common chronic inflammatory diseases of the airways. Obesity is an increasingly common pediatric disease and is a risk factor for the development of asthma in that obese patients with asthma tend to have more severe asthma that does not respond well to standard asthma therapy. On the contrary, children with asthma maybe at a high risk of obesity, suggesting that the relationship of asthma and obesity seems to be interrelated. The role of obesity on the development of allergic rhinitis is not well defined, whereas allergic rhinitis may have an impact on obesity.

SUMMARY

Childhood obesity is often considered to be less serious than obesity in adults because of the greater risk of complications in obese adults. In this review, we discuss the allergic confounders of obesity and the impact of allergic diseases on obesity. Proper control of the BMI within the normal range in children with allergic diseases is important.

Bariatric surgery: a potential cure for asthma?

Asthma incidence and severity are increased in obese populations. Systematic reviews have shown benefit from weight-loss interventions on asthma outcomes, but the role of bariatric surgery is still unclear. In this review, cohorts of obese asthmatic patients undergoing bariatric surgery were examined regarding different asthma outcomes. The available data on patients who were followed up showed improvements in asthma control, exacerbation risk, asthma-related hospitalisation, medication use and airway hyperresponsiveness, with some patients not requiring further treatment for asthma. Follow-up duration was variable, being mostly of 1 year, with some studies reporting long-term outcomes after 5 years. The studies reviewed had many limitations, including small numbers of patients, lack of control arm in some studies and lack of standardisation of asthma diagnosis, classification and outcome measures, in addition to possible reporting bias. Data on small numbers of patients also show the possibility of benefit exclusively in nonallergic asthma. Larger, more stringent clinical trials are needed before recommending bariatric surgery for treatment of asthma.

Role of Leptin in the Association Between Body Adiposity and Persistent Asthma: A Longitudinal Study

OBJECTIVE

Obesity is a likely risk factor for asthma. However, underlying mechanisms by which obesity affects asthma activity remain poorly understood. This study aimed to investigate the role of leptin, an adipocyte-derived proinflammatory protein, as a mediator in the association between body adiposity (assessed using BMI, waist circumference, and body fat percentage) and persistent asthma.

METHODS

A causal approach to mediation analysis was used to disentangle total and direct effects and the indirect effect mediated by leptin, using data from the French prospective French Epidemiological Study on the Genetics and Environment of Asthma (EGEA) (baseline: 2003-2007; follow-up: 2011-2013; mean follow-up time: 7 years). A total of 331 participants with current asthma at baseline were included.

RESULTS

Per 1-SD increment in BMI, waist circumference, and body fat percentage, the adjusted odds ratios of the total effect were 1.59 (95% CI: 0.95-2.97), 2.06 (1.06-4.00), and 3.25 (1.01-9.41), respectively; the odds ratios of the indirect effect mediated by leptin were 1.68 (1.09-2.46), 1.55 (0.99-2.57), and 1.99 (0.94-4.83), respectively.

CONCLUSIONS

Leptin partly (> 60%) mediated the association between high body adiposity and persistent asthma over time. Using a newly developed analytic approach, this longitudinal study brought new insight into one mechanism by which obesity may affect asthma activity.

The effects of diet-induced weight loss on asthma control and quality of life in obese adults with asthma: a randomized controlled trial

Objective: While the effects of obesity on asthma are yet to be fully clarified, increased fat tissue is known to increase the severity of asthma and to impair asthma control. This study evaluated the effects of diet-induced weight loss on the characteristics of asthma in obese adults with asthma.Methods: A total of 55 obese individuals (BMI ≥ 30.0) with asthma were enrolled in the study and randomized into the diet or control groups. The anthropometric measurements, asthma control test (ACT) scores, asthma quality of life questionnaire (AQLQ) scores, pulmonary function tests (PFT) and daily food consumption of the participants were recorded and compared at the baseline and at study completion.Results: The changes recorded in body weight (diet -5.2 (4, 5); control, -0.1 (1.3)), ACT score (diet 2.0 (2.0); control 0.0 (1.7)) and AQLQ score (diet 0.8 ± 0.1; control -0.02 ± 0.5) of the participants in the diet group were significantly higher than in the control group (p = 0.00). The increases in forced expiratory volume in one second (FEV₁) and the forced vital capacity (FVC) measurements of the participants with weight loss of ≥5.0 percent were significant when compared to those with weight loss of <5.0 percent (p < 0.05). While total energy uptake and carbohydrate consumption at the end of study were found to be decreased in the diet group, they had increased in the control group (p < 0.05).Conclusion: Diet intervention improved asthma control and quality of life in obese patients with controlled asthma in this study. However to generalize this finding to all asthma patients, further studies including uncontrolled asthmatics are needed.

Diabetes and Lung Disease: A Neglected Relationship

BACKGROUND

Diabetes mellitus is a systemic disorder associated with inflammation and oxidative stress which may target many organs such as the kidney, retina, and the vascular system. The pathophysiology, mechanisms, and consequences of diabetes on these organs have been studied widely. However, no work has been done on the concept of the lung as a target organ for diabetes and its implications for lung diseases.

AIM

In this review, we aimed to investigate the effects of diabetes and hypoglycemic agent on lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, pulmonary hypertension, and lung cancer. We also reviewed the potential mechanisms by which these effects may affect lung disease patients.

RESULTS

Our results suggest that diabetes can affect the severity and clinical course of several lung diseases.

CONCLUSIONS

Although the diabetes-lung association is epidemiologically and clinically well-established, especially in asthma, the underlying mechanism and pathophysiology are not been fully understood. Several mechanisms have been suggested, mainly associated with the pro-inflammatory and proliferative properties of diabetes, but also in relation to micro- and macrovascular effects of diabetes on the pulmonary vasculature. Also, hypoglycemic drugs may influence lung diseases in different ways. For example, metformin was considered a potential therapeutic agent in lung diseases, while insulin was shown to exacerbate lung diseases; this suggests that their effects extend beyond their hypoglycemic properties.

Mechanisms Involved in Childhood Obesity-Related Bone Fragility

Childhood obesity is one of the major health problems in western countries. The excessive accumulation of adipose tissue causes inflammation, oxidative stress, apoptosis, and mitochondrial dysfunctions. Thus, obesity leads to the development of severe co-morbidities including type 2 diabetes mellitus, liver steatosis, cardiovascular, and neurodegenerative diseases which can develop early in life. Furthermore, obese children have low bone mineral density and a greater risk of osteoporosis and fractures. The knowledge about the interplay bone tissue and between adipose is still growing, although recent findings suggest that adipose tissue activity on bone can be fat-depot specific. Obesity is associated to a low-grade inflammation that alters the expression of adiponectin, leptin, IL-6, Monocyte Chemotactic Protein 1 (MCP1), TRAIL, LIGHT/TNFSF14, OPG, and TNFα. These molecules can affect bone metabolism, thus resulting in osteoporosis. The purpose of this review was to deepen the cellular mechanisms by which obesity may facilitate osteoporosis and bone fractures.

Inflammation in human adipose tissues-Shades of gray, rather than white and brown

Chronic inflammation in adipose tissues has been associated with obesity and metabolic syndrome over the years. Various studies using animal models have contributed to our knowledge on the pro- and anti- inflammatory mediators that regulate obesity. Analyses of cytokine profiles in humans have not revealed a clear scenario. Likewise, treatments targeting inflammation to control obesity and insulin resistance has not yielded promising results. In this review we summarize the data available in human obesity and discuss the possible reasons that could explain the difficulties in treating obesity and insulin resistance by targeting pro-inflammatory cytokines.

An Official American Thoracic Society Workshop Report: Obesity and Metabolism. An Emerging Frontier in Lung Health and Disease

The world is in the midst of an unprecedented epidemic of obesity. This epidemic has changed the presentation and etiology of common diseases. For example, steatohepatitis, directly attributable to obesity, is now the most common cause of cirrhosis in the United States. Type 2 diabetes is increasingly being diagnosed in children. Pulmonary researchers and clinicians are just beginning to appreciate the impact of obesity and altered metabolism on common pulmonary diseases. Obesity has recently been identified as a major risk factor for the development of asthma and for acute respiratory distress syndrome. Obesity is associated with profound changes in pulmonary physiology, the development of pulmonary hypertension, sleep-disordered breathing, and altered susceptibility to pulmonary infection. In short, obesity is leading to dramatic changes in lung health and disease. Simultaneously, the rapidly developing field of metabolism, including mitochondrial function, is shifting the paradigms by which the pathophysiology of many pulmonary diseases is understood. Altered metabolism can lead to profound changes in both innate and adaptive immunity, as well as the function of structural cells. To address this emerging field, a 3-day meeting on obesity, metabolism, and lung disease was convened in October 2015 to discuss recent findings, foster research initiatives, and ultimately guide clinical care. The major findings arising from this meeting are reported in this document.

Inflammatory Cytokine Profiles in Visceral and Subcutaneous Adipose Tissues of Obese Patients Undergoing Bariatric Surgery Reveal Lack of Correlation With Obesity or Diabetes

Population studies have linked insulin resistance to systemic low-grade chronic inflammation and have reported elevated levels of inflammatory cytokines such as TNFα, IL-1β and IL-6, individually or in certain combinations, in adipose tissues or in the serum. We undertook this comprehensive study to simultaneously evaluate the expression of several pro-inflammatory and anti-inflammatory cytokines in serum and in the visceral and subcutaneous adipose tissues from obese patients undergoing bariatric surgery. We observed that several inflammatory cytokines implicated in obesity-associated inflammation showed no significant difference in protein or gene expression between obese patients with or without diabetes and control groups. IL1B gene expression was significantly elevated in the visceral adipose tissues of obese patients, but did not correlate with their diabetes status. Despite the significant increase in IL1B expression in the obese group, a significant proportion of obese patients did not express TNFA, IL1B or IL6 in visceral adipose tissues. Certain inflammatory cytokines showed correlation with the chemokine CCL2 and VEGF-A in visceral adipose tissues. Our findings suggest that the inflammatory cytokine profile in metabolic syndrome is more complex than what is currently perceived and that chronic inflammation in obese patients likely results from incremental contribution from different cytokines and possibly other inflammatory mediators from within and outside the adipose tissues. It is possible that this obesity associated chronic inflammation is not predicted by a single mediator, but rather includes a large spectrum of possible profiles.

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Visceral and subcutaneous adipose tissues do not express similar pattern of cytokines.

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VAT and SAT tissues from 30% of the obese patients do not express TNFA, IL6 or IL1B.

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Protein levels and gene expression do not necessarily correlate in VAT or SAT.

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The expression pattern of inflammatory mediators may present a larger spectrum than predicted from animal models.

Obesity, type 2 diabetes and cardiometabolic diseases are associated with a low-grade chronic inflammation. Various inflammatory mediators have been shown to mediate this inflammation. In this study we analyzed the expression of many of these inflammatory mediators in the visceral and subcutaneous adipose tissues obtained from patients undergoing bariatric surgery. Our results suggest that the profile of inflammatory mediators expressed in adipose tissue is diverse and varies from one patient to another.

Late-onset asthma: current perspectives

Because the pathophysiology of asthma has diverse characteristics, to manage the disease effectively, it is important for clinicians to distinguish among the clinical phenotypes. Among them, adult-onset asthma, that is, late-onset asthma (LOA), is increasing because of the aging of the population. The phenotype of LOA is largely divided into two types according to the presence or absence of eosinophilic inflammation, T-helper (Th)2- and non-Th2-associated LOA. Especially in Th2 LOA related to rhinosinusitis, as pulmonary function at onset is poor and asthma exacerbations occur frequently, it is important to detect this phenotype in the early phase by using a biomarker of Th2-type inflammation such as fractional exhaled nitric oxide (FENO). As non-Th2-LOA is often resistant to corticosteroids, this phenotype often requires another treatment strategy such as macrolide, diet, or smoking cessation. We often struggle with the management of LOA patients due to a lack of evidence; therefore, the elucidation of the mechanism of LOA contributes to increased efficiency of diagnosis and treatment of LOA. Age-related immune system and structural changes are thought to be associated with the pathophysiology of LOA. In the former case, changes in inflammatory cell function such as variations in the innate immune response and acquisition of autoimmunity or upregulation of oxidative stress are thought to be involved in the mechanism. Meanwhile, the latter can also become triggers or exacerbating factors of LOA via enhancement of airway hyperresponsiveness, decline in lung function, increased air trapping, and reduction in chest wall compliance. Therefore, appropriate individualized management in LOA may be possible through precisely assessing the pathophysiology based on age-related functional changes, including the immune and structural system.

Obesity and Asthma: A Missing Link

Obesity and asthma are two chronic conditions that affect millions of people. Genetic and lifestyle factors such as diet, physical activity, and early exposure to micro-organisms are important factors that may contribute to the escalating prevalence of both conditions. The prevalence of asthma is higher in obese individuals. Recently, two major phenotypes of asthma with obesity have been described: one phenotype of early-onset asthma that is aggravated by obesity, and a second phenotype of later-onset asthma that predominantly affects women. Systemic inflammation and mechanical effect, both due to the expansion of the adipose tissue, have been proposed as the main reasons for the association between obesity and asthma. However, the mechanisms involved are not yet fully understood. Moreover, it has also been suggested that insulin resistance syndrome can have a role in the association between these conditions. The intestinal microbiota is an important factor in the development of the immune system, and can be considered a link between obesity and asthma. In the obese state, higher lipopolysaccharide (LPS) serum levels as a consequence of a microbiota dysbiosis have been found. In addition, changes in microbiota composition result in a modification of carbohydrate fermentation capacity, therefore modifying short chain fatty acid (SCFA) levels. The main objective of this review is to summarize the principal findings that link obesity and asthma.

Effects of sleeve gastrectomy and rs9930506 FTO variants on angiopoietin/Tie-2 system in fat expansion and M1 macrophages recruitment in morbidly obese subjects

Angiogenesis in inflammation are hallmarks for adipose tissue expansion in obesity. The role of angiopoietin/Tie-2 system in adipose tissue expansion and immune cell recruitment is unclear. We studied the effect of sleeve gastrectomy and the influence of FTO rs9930506 polymorphism on Tie-2, angiopoietin-1 and angiopoietin-2 expression in morbid obesity. Fifteen morbidly obese subjects (4 men and 11 women) aged 24-55 years were followed-up 3 and 6 months after sleeve gastrectomy. Serum sTie-2, angiopoietin-1, angiopoietin-2, and hypoxia-inducible factor-1α concentrations were determined by ELISA. Tie-2 and its ligands in visceral and subcutaneous adipose tissue were localized by immunohistochemistry. Tie-2 expression was measured by flow cytometry in circulating monocytes and infiltrated macrophages. Comparisons before and after sleeve gastrectomy were carried out using ANOVA for repeated measures. rs9930506FTO genotyping was performed by PCR-RFLP. Circulating sTie-2 and angiopoietin-2 were higher before sleeve gastrectomy. Tie-2 and angiopoietin-2 mRNA levels were higher in subcutaneous adipose tissue than visceral and both decreased after surgery. Monocytes and infiltrated macrophages showed a pro-inflammatory phenotype, with increased Tie-2 expression that decreased 3 and 6 months after sleeve gastrectomy. Baseline sTie-2 correlated inversely with adiponectin levels. At baseline the rs9930506FTO AG ó GG genotypes carriers had more 34 kg than genotype carriers of rs9930506 AA. Weight and body mass index decreased at 6 months. We found that angiopoietin/Tie-2 system is mainly expressed in subcutaneous adipose tissue, contributing to expandability, fat accumulation, and monocytes attachment in obesity. Bariatric surgery favorably modifies the pro-angiogenic profile, allowed a reduced angiogenic expression in the circulation and adipose tissue.

New concepts in asthma: clinical phenotypes and pathophysiological mechanisms

Asthma is among the most common chronic inflammatory diseases worldwide. Recent evidence indicates that the pathogenesis shows a high degree of heterogeneity. Patient subsets have been identified that exhibit different cellular and molecular patterns of dysregulation. A prominent example is eosinophilic Th2-driven asthma. These unique and molecular patterns are termed endotypes. Characterization of endotypes has broad implications for therapeutic interventions. Although ∼80% of asthmatic patients respond well to standard anti-inflammatory therapies, the remaining subset particularly consisting of severe patients requires a more specialized endotype-specific approach. This interrelationship between clinical phenotypes, molecular endotypes and endotype-specific therapies is the focus of this review.

Reactive oxygen species and bacterial biofilms in diabetic wound healing

Chronic wounds are a common and debilitating complication for the diabetic population. It is challenging to study the development of chronic wounds in human patients; by the time it is clear that a wound is chronic, the early phases of wound healing have passed and can no longer be studied. Because of this limitation, mouse models have been employed to better understand the early phases of chronic wound formation. In the past few years, a series of reports have highlighted the importance of reactive oxygen species and bacterial biofilms in the development of chronic wounds in diabetics. We review these recent findings and discuss mouse models that are being utilized to enhance our understanding of these potentially important contributors to chronic wound formation in diabetic patients.

LIGHT/TNFSF14 is increased in patients with type 2 diabetes mellitus and promotes islet cell dysfunction and endothelial cell inflammation in vitro

AIMS/HYPOTHESIS

Activation of inflammatory pathways is involved in the pathogenesis of type 2 diabetes mellitus. On the basis of its role in vascular inflammation and in metabolic disorders, we hypothesised that the TNF superfamily (TNFSF) member 14 (LIGHT/TNFSF14) could be involved in the pathogenesis of type 2 diabetes mellitus.

METHODS

Plasma levels of LIGHT were measured in two cohorts of type 2 diabetes mellitus patients (191 Italian and 40 Norwegian). Human pancreatic islet cells and arterial endothelial cells were used to explore regulation and relevant effects of LIGHT in vitro.

RESULTS

Our major findings were: (1) in both diabetic cohorts, plasma levels of LIGHT were significantly raised compared with sex- and age-matched healthy controls (n = 32); (2) enhanced release from activated platelets seems to be an important contributor to the raised LIGHT levels in type 2 diabetes mellitus; (3) in human pancreatic islet cells, inflammatory cytokines increased the release of LIGHT and upregulated mRNA and protein levels of the LIGHT receptors lymphotoxin β receptor (LTβR) and TNF receptor superfamily member 14 (HVEM/TNFRSF14); (4) in these cells, LIGHT attenuated the insulin release in response to high glucose at least partly via pro-apoptotic effects; and (5) in human arterial endothelial cells, glucose boosted inflammatory response to LIGHT, accompanied by an upregulation of mRNA levels of HVEM (also known as TNFRSF14) and LTβR (also known as LTBR).

CONCLUSIONS/INTERPRETATION

Our findings show that patients with type 2 diabetes mellitus are characterised by increased plasma LIGHT levels. Our in vitro findings suggest that LIGHT may contribute to the progression of type 2 diabetes mellitus by attenuating insulin secretion in pancreatic islet cells and by contributing to vascular inflammation.

Differential association of plasma monocyte chemoattractant protein-1 with systemic inflammatory and airway remodeling biomarkers in type-2 diabetic patients with and without asthma

BACKGROUND

Chronic inflammation is a hallmark of type-2 diabetes (T2D) and asthma. Monocyte chemoattractant protein (MCP)-1 or CCL-2 is a key regulator of monocytic infiltration into the sites of inflammation. The changes in systemic MCP-1 levels and its relationship with other inflammatory/immune markers in T2D patients with asthma remain unclear and have been addressed in this study.

METHODS

Plasma samples from 10 asthmatic T2D patients (Group I: BMI = 37.82 ± 9.75 kg/m²), 13 non-asthmatic T2D patients (Group II: BMI = 32.68 ± 4.63 kg/m²), 23 asthma patients without T2D (Group III: BMI = 30.14 ± 6.74 kg/m²), and 25 non-asthmatic non-diabetic controls (Group IV: BMI = 27.99 ± 5.86 kg/m²) were used to measure levels of MCP-1 and multiple cytokine/chemokine biomarkers with bead-based multiplex assays using Luminex technology. IgE/ECP were measured using commercial ELISA kits. Data (mean ± SEM) were compared using unpaired Student's t-test and linear dependence between two variables was assessed by Pearson's correlation coefficient (r) and P ≤ 0.05 was considered as significant.

RESULTS

Plasma MCP-1 levels were significantly higher in Group I (337.95 ± 46.40 pg/mL) as compared with Group II (216.69 ± 17.30 pg/mL), Group III (251.76 ± 19.80 pg/mL), and Group IV (223.52 ± 133.36 pg/mL). MCP-1 showed differential association with tested biomarkers by correlating positively with: (i) IFN-α2, IL-10, fractalkine, and VEGF in T2D patients with asthma; (ii) IL-6 and GRO-α in T2D patients without asthma; (iii) MDC, IP-10, GM-CSF, FGF-2, and PDGF-AA/BB in patients with asthma only; and (iv) FPG and TG in non-asthmatic non-diabetic controls. MCP-1 associated with IL-1RA only in subjects with asthma.

CONCLUSION

The systemic MCP-1 levels were significantly elevated in T2D patients with asthma as compared with those without asthma and/or diabetes while these changes correlated differentially with important biomarkers of inflammation and airway remodeling.

Abdominal Obesity and Type 2 Diabetes Mellitus are Associated With Higher Seric Levels of IL 4 in Adults

Aims: Study of IL4 in relation to the anthropometric, biochemical and immunological parameters in patients with obesity and/or diabetes. Methods: The relationship between IL4 and clinical and biological parameters was studied in 76 patients divided into 4 groups: obese diabetics (OD), n = 25; obese without diabetes (O), n = 25; non obese diabetics (NOD), n = 11; controls (M), n = 15. IL4 was determined using the ELISA method. Statistical analysis was done using the MedCalc statistical software, version 16.1. Results: Serum IL4 was 0.38 ±0,40 pg / mL in the Control group, 0.366 (0,100-2,35) pg / ml in group O, 4.66±3.73 pg / ml in group OD, 0.30 (0.10-1.35) pg / ml in NOD. When IL4 levels were compared between the four groups, statistical significance was reached for the comparison between groups OD and M. Statistically significant correlations were detected between IL4 and age, waist circumference and hip circumference, blood glucose, glycated hemoglobin (HbA1c), VLDL, triglycerides and serum protein fraction β1. In univariate regression, the IL4 level predictors were age, height, BMI, abdominal circumference, hip circumference, beta 1% glucose, HbA1c, total lipids, total cholesterol, VLDL triglycerides, CRP. In multivariate regression, waist circumference and glycemia were significant predictors of levels of IL4 (p = 0.0001).

Plasma matrix metalloproteinase-9 levels, MMP-9 gene haplotypes, and cardiovascular risk in obese subjects

Plasma matrix metalloproteinase (MMP)-9 is a predictor of cardiovascular mortality, and MMP-9 polymorphisms affect plasma MMP-9 levels. However, no study examined whether MMP-9 haplotypes affect MMP-9 levels in obese adults. We examined whether MMP-9 polymorphisms and haplotypes are associated with obesity, and whether they affect MMP-9 levels in obese subjects. We examined the plasma levels of MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in 105 subjects with normal weight (controls), 100 obese subjects, and 156 obese subjects with ≥3 metabolic risk factors (MRFs). We determined genotypes for three polymorphisms: C-1562T (rs3918242), Q279R (A>G, rs17576), and R668Q (G>A, rs17577). MMP-9 levels and activity (MMP-9/TIMP-1 ratio) were higher in obese subjects than in controls (P < 0.05). However, MMP-9 levels were higher in obese subjects with ≥3 MRFs than in obese subjects (P < 0.05). Obese subjects with ≥3 MRFs carrying the GA+AA genotypes for R668Q (G>A) polymorphism had higher MMP-9 levels than subjects carrying the AA genotype (P < 0.05). The "T, G, A" haplotype was more common in both groups of obese subjects than in controls (OR 3.95 and 4.39, respectively; P < 0.01). Notably, obese subjects with ≥3 MRFs carrying the "T, G, A" haplotype had higher MMP-9 levels than subjects carrying the "C, A, G" reference haplotype (P < 0.05). The "T, G, A" haplotype was associated with an increased risk of obesity and affected MMP-9 levels in obese subjects with ≥3 MRFs. Our findings suggest that plasma MMP-9 levels and MMP-9 haplotypes may help to discriminate obese subjects at an increased cardiovascular risk.

Asthma and metabolic syndrome: Current knowledge and future perspectives

Asthma and obesity are epidemiologically linked; however, similar relationships are also observed with other markers of the metabolic syndrome, such as insulin resistance and dyslipidemia, which cannot be accounted for by increased body mass alone. Obesity appears to be a predisposing factor for the asthma onset, both in adults and in children. In addition, obesity could make asthma more difficult to control and to treat. Although obesity may predispose to increased Th2 inflammation or tendency to atopy, other mechanisms need to be considered, such as those mediated by hyperglycaemia, hyperinsulinemia and dyslipidemia in the context of metabolic syndrome. The mechanisms underlying the association between asthma and metabolic syndrome are yet to be determined. In the past, these two conditions were believed to occur in the same individual without any pathogenetic link. However, the improvement in asthma symptoms following weight reduction indicates a causal relationship. The interplay between these two diseases is probably due to a bidirectional interaction. The purpose of this review is to describe the current knowledge about the possible link between metabolic syndrome and asthma, and explore potential application for future studies and strategic approaches.

Suppressive effect of insulin on the gene expression and plasma concentrations of mediators of asthmatic inflammation

BACKGROUND AND HYPOTHESIS

Following our recent demonstration that the chronic inflammatory and insulin resistant state of obesity is associated with an increase in the expression of mediators known to contribute to the pathogenesis of asthma and that weight loss after gastric bypass surgery results in the reduction of these genes, we have now hypothesized that insulin suppresses the cellular expression and plasma concentrations of these mediators.

METHODS

The expression of IL-4, LIGHT, LTBR, ADAM-33, and TSLP in MNC and plasma concentrations of LIGHT, TGF-β1, MMP-9, MCP-1, TSLP, and NOM in obese patients with T2DM were measured before, during, and after the infusion of a low dose (2 U/h) infusion of insulin for 4 hours. The patients were also infused with dextrose or saline for 4 hours on two separate visits and served as controls. Results. Following insulin infusion, the mRNA expression of IL-4, ADAM-33, LIGHT, and LTBR mRNA expression fell significantly (P < 0.05 for all). There was also a concomitant reduction in plasma NOM, LIGHT, TGF-β1, MCP-1, and MMP-9 concentrations.

CONCLUSIONS

Insulin suppresses the expression of these genes and mediators related to asthma and may, therefore, have a potential role in the treatment of asthma.

The importance of the cellular stress response in the pathogenesis and treatment of type 2 diabetes

Organisms have evolved to survive rigorous environments and are not prepared to thrive in a world of caloric excess and sedentary behavior. A realization that physical exercise (or lack of it) plays a pivotal role in both the pathogenesis and therapy of type 2 diabetes mellitus (t2DM) has led to the provocative concept of therapeutic exercise mimetics. A decade ago, we attempted to simulate the beneficial effects of exercise by treating t2DM patients with 3 weeks of daily hyperthermia, induced by hot tub immersion. The short-term intervention had remarkable success, with a 1 % drop in HbA1, a trend toward weight loss, and improvement in diabetic neuropathic symptoms. An explanation for the beneficial effects of exercise and hyperthermia centers upon their ability to induce the cellular stress response (the heat shock response) and restore cellular homeostasis. Impaired stress response precedes major metabolic defects associated with t2DM and may be a near seminal event in the pathogenesis of the disease, tipping the balance from health into disease. Heat shock protein inducers share metabolic pathways associated with exercise with activation of AMPK, PGC1-a, and sirtuins. Diabetic therapies that induce the stress response, whether via heat, bioactive compounds, or genetic manipulation, improve or prevent all of the morbidities and comorbidities associated with the disease. The agents reduce insulin resistance, inflammatory cytokines, visceral adiposity, and body weight while increasing mitochondrial activity, normalizing membrane structure and lipid composition, and preserving organ function. Therapies restoring the stress response can re-tip the balance from disease into health and address the multifaceted defects associated with the disease.