Adipose tissue-mediated inflammation: the missing link between obesity and cardiovascular disease?

The Effects of Yoga on Key Adipocytokines in Obesity: A Narrative Review of Leptin and Adiponectin

Obesity is a global health concern that increases the risk of numerous complications, including type 2 diabetes, hypertension, and cardiovascular diseases. Conventional obesity treatments, such as lifestyle modifications, pharmacotherapy, and surgical interventions, are often insufficient, highlighting the need for more efficient and effective approaches. Yoga, an ancient mind-body practice incorporating physical postures (asanas), breathing exercises (pranayama), and meditation, has emerged as a potential therapeutic intervention for obesity management. This review examines the functions of leptin and adiponectin, two key adipocytokines central to obesity, and evaluates the impact of yoga on these hormones. A literature search was conducted using PubMed, Scopus, and Google Scholar with the keywords "yoga" and "adipocytokine" as of May 5, 2024, resulting in the selection of 12 relevant studies. The majority of studies reviewed demonstrated that yoga significantly decreases leptin levels and increases adiponectin levels. Intensive yoga sessions and combined dietary interventions were found to contribute notably to improvements in these hormonal levels. These findings suggest that yoga may improve the balance between leptin and adiponectin, offering beneficial effects on anti-obesity and chronic inflammation reduction. Yoga, as an economical and non-invasive treatment option, presents a promising approach to managing obesity. Further research is expected to elucidate the underlying mechanisms and explore potential clinical applications.

Associations of body mass index and weight change with circulating levels of high-sensitivity C-reactive protein, proinflammatory cytokines, and adiponectin among breast cancer survivors

AIM

This study examined the associations of body mass index (BMI) and weight change with inflammatory markers among breast cancer survivors in Korea.

METHODS

A total of 495 women were included who had been diagnosed with primary breast cancer and survived for at least 6 months since the surgery. Information on the body weight and height of the participants was collected both at the study enrollment and diagnosis. The plasma levels of inflammatory markers were measured, including high-sensitivity C-reactive protein, interleukin (IL)-6, IL-8, tumor necrosis factor-α, and adiponectin. A summary z-score was calculated by summing up the z-scores of each biomarker. The least-square means and 95% confidence intervals (CIs) were calculated using a generalized linear model and odds ratios (ORs) and 95% CIs for the elevated levels of inflammatory markers with a multivariate logistic regression model.

RESULTS

Participants with a BMI ≥27.5 kg/m² at the study enrollment and at diagnosis were significantly associated with elevated summary z-scores compared to those with a BMI < 23 kg/m² ; the ORs (95% CIs) were 5.42 (2.15-13.71) for current BMI and 3.66 (1.68-7.98) for BMI at diagnosis, respectively. Additionally, a weight loss > 5% since diagnosis was associated with a lower prevalence of high summary z-scores; the OR (95% CI) was .20 (.08-.52) compared to a stable weight.

CONCLUSIONS

A high BMI at diagnosis and current BMI with a greater degree were associated with unfavorable levels of inflammatory markers among breast cancer survivors. Additionally, weight loss since diagnosis was inversely associated with these markers.

Protective effects of calorie restriction and 17-β estradiol on cardiac hypertrophy in ovariectomized obese rats

Obesity and menopause lead to cardiovascular diseases. Calorie restriction (CR) can modulate estrogen deficiency and obesity-related cardiovascular diseases. The protective effects of CR and estradiol on cardiac hypertrophy in ovariectomized obese rats were explored in this study. The adult female Wistar rats were divided into sham and ovariectomized (OVX) groups that received a high-fat diet (60% HFD) or standard diet (SD) or 30% CR for 16 weeks, and then, 1mg/kg E2 (17-β estradiol) was injected intraperitoneally every 4 days for four weeks in OVX-rats. Hemodynamic parameters were evaluated before and after each diet. Heart tissues were collected for biochemical, histological, and molecular analysis. HFD consumption led to weight gain in sham and OVX rats. In contrast, CR and E2 led to body weight loss in these animals. Also, heart weight (HW), heart weight/body weight (HW/BW) ratio, and left ventricular weight (LVW) were enhanced in OVX rats that received SD and HFD. E2 reduced these indexes in both diet conditions but reduction effects of CR were seen only in HFD groups. HFD and SD feeding increased hemodynamic parameters, ANP (atrial natriuretic peptide) mRNA expression, and TGF-β1(transforming growth factor-beta 1) protein level in the OVX animals, while CR and E2 reduced these factors. Cardiomyocyte diameter and hydroxyproline content were increased in the OVX-HFD groups. Nevertheless, CR and E2 decreased these indicators. The results showed that CR and E2 treatment reduced obesity-induced-cardiac hypertrophy in ovariectomized groups (20% and 24% respectively). CR appears to have almost as reducing effects as estrogen therapy on cardiac hypertrophy. The findings suggest that CR can be considered a therapeutic candidate for postmenopausal cardiovascular disease.

Etanercept Prevents Endothelial Dysfunction in Cafeteria Diet-Fed Rats

Obesity is associated with endothelial dysfunction and this relationship is probably mediated in part by inflammation. Objective: The current study evaluated the effects of etanercept, a tumor necrosis factor-alpha (TNF-α) inhibitor, on endothelial and vascular reactivity, endothelial nitric oxide synthase (eNOS) immunoreactivity, and serum and aortic concentrations of TNF-α in a diet-induced rat model. Design and results: Male weanling Wistar rats were exposed to a standard diet and cafeteria diet (CD) for 12 weeks and etanercept was administered during CD treatment. Isolated aortas of the rats were used for isometric tension recording. Carbachol-induced relaxant responses were impaired in CD-fed rats, while etanercept treatment improved these endothelium-dependent relaxations. No significant change was observed in papaverine- and sodium nitroprusside (SNP)-induced relaxant responses. eNOS expression decreased in CD-fed rats, but no change was observed between etanercept-treated CD-fed rats and control rats. CD significantly increased both the serum and the aortic levels of TNF-α, while etanercept treatment suppressed these elevated levels. CD resulted in a significant increase in the body weight of the rats. Etanercept-treated (ETA) CD-fed rats gained less weight than both CD-fed and control rats.

Measurement of Plasma Resistin Concentrations in Horses with Metabolic and Inflammatory Disorders

Simple Summary

Obesity and its associated complications, such as metabolic syndrome, are an increasing problem in both humans and horses in the developed world. Adipose tissue is a key endocrine organ that communicates with other organs by multiple endocrine substances called adipokines. There is evidence to suggest that adipokines may contribute to the regulation of biological processes, such as metabolism, immunity, and inflammation. The aim of this study was to investigate the usefulness of one of these adipokines in horses, resistin, and its relationship with insulin dysregulation (ID) and inflammation. Seventy-two horses, included in one of the four following groups, were studied: healthy controls, horses with inflammatory conditions, horses with mild, and horses with severe ID. Plasma resistin concentrations were significantly different between groups, and the highest values were recorded in the inflammatory and severe ID groups. The lack of correlation of resistin with basal insulin concentration and the significant correlation of resistin with the inflammatory marker serum amyloid A suggest that, as is the case in humans, plasma resistin concentrations in horses are predominantly related to inflammatory conditions and not to ID.

Abstract

Obesity and its associated complications, such as metabolic syndrome, are an increasing problem in both humans and horses in the developed world. The expression patterns of resistin differ considerably between species. In rodents, resistin is expressed by adipocytes and is related to obesity and ID. In humans, resistin is predominantly produced by inflammatory cells, and resistin concentrations do not reflect the degree of obesity, although they may predict cardiovascular outcomes. The aim of this study was to investigate the usefulness of resistin and its relationship with ID and selected indicators of inflammation in horses. Seventy-two horses, included in one of the four following groups, were studied: healthy controls (C, n = 14), horses with inflammatory conditions (I, n = 21), horses with mild ID (ID1, n = 18), and horses with severe ID (ID2, n = 19). Plasma resistin concentrations were significantly different between groups and the higher values were recorded in the I and ID2 groups (C: 2.38 ± 1.69 ng/mL; I: 6.85 ± 8.38 ng/mL; ID1: 2.41 ± 2.70 ng/mL; ID2: 4.49 ± 3.08 ng/mL). Plasma resistin was not correlated with basal insulin concentrations. A significant (r = 0.336, p = 0.002) correlation was found between resistin and serum amyloid A. Our results show that, as is the case in humans, plasma resistin concentrations in horses are predominantly related to inflammatory conditions and not to ID. Horses with severe ID showed an elevation in resistin that may be secondary to the inflammatory status associated with metabolic syndrome.

Prognostic Role of Subcutaneous and Visceral Adiposity in Hospitalized Octogenarians with COVID-19

BACKGROUND

We investigated the prognostic significance of visceral and subcutaneous adiposity in octogenarians with COVID-19.

METHODS

This paper presents a monocentric retrospective study that was conducted in acute geriatric wards with 64 hospitalized patients aged 80+ who had a diagnosis of COVID-19 and who underwent a chest CT scan. A quantification of the subcutaneous, visceral, and total fat areas was performed after segmentations on the first abdominal slice caudal to the deepest pleural recess on a soft-tissue window setting. Logistic regression models were applied to investigate the association with in-hospital mortality and the extent of COVID-19 pneumonia.

RESULTS

The patients had a mean age of 86.4 ± 6.0 years, and 46.9% were male, with a mean BMI of 24.1 ± 4.4Kg/m² and mortality rate of 32.8%. A higher subcutaneous fat area had a protective effect against mortality (OR 0.416; 0.183-0.944 95% CI; p = 0.036), which remained significant after adjustments for age, sex, and BMI (OR 0.231; 0.071-0.751 95% CI; p = 0.015). Inversely, higher abdominal circumference, total fat area, subcutaneous fat area, and visceral fat were associated with worse COVID-19 pneumonia, with the latter presenting the strongest association after adjustments for age, sex, and BMI (OR 2.862; 1.523-5.379 95% CI; p = 0.001).

CONCLUSION

Subcutaneous and visceral fat areas measured on chest CT scans were associated with prognosis in octogenarians with COVID-19.

New Insights on the Relationship between Leptin, Ghrelin, and Leptin/Ghrelin Ratio Enforced by Body Mass Index in Obesity and Diabetes

Currently, adipose tissue is considered an endocrine organ, however, there are still many questions regarding the roles of adipokines—leptin and ghrelin being two adipokines. The purpose of the study was to assess the relationship between the adipokines and their ratio with obesity and diabetes. Methods: Sixty patients (mean age 61.88 ± 10.08) were evaluated. Cardiovascular risk factors, leptin, ghrelin, and insulin resistance score values were assessed. The patients were classified according to their body mass index (BMI) as normal weight, overweight, and obese. Results: 20% normal weight, 51.7% overweight, 28.3% obese, and 23.3% diabetic. Obese patients had higher leptin values (in obese 34,360 pg/mL vs. overweight 18,000 pg/mL vs. normal weight 14,350 pg/mL, p = 0.0049) and leptin/ghrelin ratio (1055 ± 641 vs. 771.36 ± 921 vs. 370.7 ± 257, p = 0.0228). Stratifying the analyses according to the presence of obesity and patients’ gender, differences were found for leptin (p = 0.0020 in women, p = 0.0055 in men) and leptin/ghrelin ratio (p = 0.048 in women, p = 0.004 in men). Mean leptin/BMI and leptin/ghrelin/BMI ratios were significantly higher, and the ghrelin/BMI ratio was significantly lower in obese and diabetic patients. In conclusion, obesity and diabetes are associated with changes not only in the total amount but also in the level of adipokines/kg/m². Changes appear even in overweight subjects, offering a basis for early intervention in diabetic and obese patients.

Pathophysiological role of major adipokines in Atrial Fibrillation

Background

The adipokines, secreted from adipose tissue or body fats, are also called adipocytokines which are cytokines, cell signaling proteins or cell–cell communication. However, AF is a common cardiac arrhythmia in which the heart beats so fast by abnormal beating and is a serious public health disease associated with increased heart failure, systemic thromboembolism, and death. Adipokines are cardiovascular disease (CVD) mediators or biomarkers that affect the heart as well as blood vessels, by increasing the cardiac contractility and action potential duration, which result in the extent of left ventricular and atrial remodeling.

Main body

Google Scholar, PubMed, and science direct were used to review the literature. Many keywords were used for searching the literature such as Adipokines, Leptin, Apelin, Adiponectin, Omentin-1, Chemerin, CTRP3, TNF-α, IL-6, IL-10, and AF. According to the literature, much more data are available for numerous adipokines, but this review article only has taken few major adipokines which played their major role in Atrial Fibrillation. The review article did not limit the time frame.

Conclusion

In conclusion, adipokines play a significant role in the development and progress of atrial fibrillation. Also, there are major adipokines such as adiponectin, apelin, C1q/TNF-Related Protein 3 (CTRP3), Chemerin, Omentin-1, interleukin-6, Leptin, TNF-α, resistin, and interleukin-10, which played their pathophysiological role in atrial fibrillation by causing cardiac hypertrophy, increasing the cardiac contractility and action potential duration, atrial fibrosis, electrical and structural remodeling of atrial tissue.

The Centrality of Obesity in the Course of Severe COVID-19

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global public health challenge. Most patients do not experience severe complications, but approximately 25% of patients progress to acute respiratory distress syndrome (ARDS), and the mortality rate is approximately 5-7%. Clinical findings have determined several risk factors for severe complications and mortality in COVID-19 patients, such as advanced age, smoking, obesity, and chronic diseases. Obesity is a common and serious health problem worldwide that initiates a cascade of disorders, including hypertension, cardiovascular disease (CVD), diabetes mellitus, and chronic kidney disease (CKD). The presence of these disorders is linked to a more severe course of COVID-19. Given the "epidemic" of obesity worldwide and the importance of obesity in the progression of COVID-19, we investigated the mechanisms through which obesity increases the susceptibility to and severity of COVID-19 to support the selection of more appropriate therapies for individuals with obesity.

Sfrp5/Wnt5a and leptin/adiponectin levels in the serum and the periarterial adipose tissue of patients with peripheral arterial occlusive disease

BACKGROUND

Leptin, adiponectin, secreted frizzled-related protein 5 (Sfrp5) and wingless-type family member 5a (Wnt5a) are novel adipokines that are involved in insulin sensitivity and atherosclerosis. The aim of the present study was to investigate the serum and periarterial adipose tissue leptin/adiponectin and Sfrp5/Wnt5a levels in patients with peripheral arterial occlusive disease (PAOD).

METHODS

A total of 75 patients with PAOD and 39 control subjects were recruited. The serum concentrations of leptin, adiponectin, Sfrp5 and Wnt5a were measured by ELISAs, and the leptin, adiponectin, Sfrp5 and Wnt5a levels in the periarterial adipose tissue were observed by western blotting.

RESULTS

The serum Sfrp5 levels were significantly lower in the patients with PAOD than in the control subjects (p < 0.001) and Wnt5a levels were higher in the patients with PAOD (p < 0.001). The serum leptin levels were significantly higher in the patients with PAOD than in the control subjects (p < 0.001), and adiponectin levels were significantly lower in the patients with PAOD (p < 0.001). The serum Sfrp5 levels were associated with ABI (rs = 0.274; p = 0.018), Wnt5a (rs = -0.409; p < 0.001), adiponectin (rs = 0.244; p = 0.035) and Leptin/Adiponetin ratio (rs = -0.244; p = 0.037). The adiponectin and Sfrp5 protein levels were decreased in the periarterial adipose tissue of patients with PAOD compared with control subjects. The leptin and Wnt5a protein levels were increased in the periarterial adipose tissue of patients with PAOD compared with control subjects.

CONCLUSION

We demonstrated that the adiponectin and Sfrp5 levels in the serum and periarterial adipose tissue were significantly lower in the patients with PAOD than in the control subjects. The leptin and Wnt5a levels in the serum and periarterial adipose tissue were significantly higher in the patients with PAOD than in the control subjects.

Blood Plasma Resistin and Atrial Fibrillation in Patients With Cardiovascular Disease

BACKGROUND

Atrial fibrillation (AF) affects quality of life and prognosis of patients with cardiovascular disease. Resistin plays an important role in inflammatory response to internal and external factors. The aim of this study is to evaluate the association between resistin and permanent AF (PAF) in patients with cardiovascular disease.

METHODS

In our study, we included 146 patients with cardiovascular disease. Plasma resistin concentrations and demographic characteristics of patients were recorded. The patients were divided in two groups: 118 patients without a history of PAF (NonAF group), and 28 patients with a history of PAF (AF group). Association of resistin with PAF and other variables was examined by parametric and non-parametric tests, and multivariable linear and univariable logistic regression analysis.

RESULTS

No differences of demographic characteristics (gender, age and body mass index (BMI)) between two groups were observed (P > 0.05). Higher median levels of resistin were observed in group AF than in group NonAF (6.90 ng/mL vs. 5.83 ng/mL, P = 0.03). Multivariate linear regression analysis (adjusted to gender, age, BMI, hypertension, diabetes mellitus, coronary artery disease, and mitral valve disease) showed that resistin was associated with PAF (β = 0.79, 95% confidence interval (CI): 0.08 to 1.51, P = 0.03).

CONCLUSIONS

Our analysis showed that plasma resistin was associated with PAF, and resistin concentration was higher in patients with AF compared to those without AF.

Diabetes and Obesity-Cumulative or Complementary Effects On Adipokines, Inflammation, and Insulin Resistance

Background: Diabetes and obesity are increasingly significant public health issues. The aim of this study was to evaluate the relationship between adipocytokines (leptin, ghrelin, and chemerin), inflammation (sVCAM1—soluble vascular adhesion molecule 1, sICAM1—soluble intercellular adhesion molecule 1), and insulin resistance in the presence of obesity and diabetes mellitus. Methods: 88 subjects, with a mean age of 61.96 ± 10.15 years, 75% of whom were women, were evaluated (in order to consider different associations between obesity and diabetes, subjects were categorized into four groups). Results: Overall, we found significant correlations between sICAM1-sVCAM1 rho = 0.426 and ghrelin-chemerin rho = −0.224. In the obesity + diabetes group, leptin correlated with sICAM1 rho = 0.786, and sVCAM1 negatively with glycemia/insulin rho = −0.85. Significant differences were found between the groups regarding sVCAM1 (p = 0.0134), leptin (p = 0.0265) and all insulin resistance scores, with differences influenced by the subjects’ gender. In conclusion, although there are currently many unknown aspects of the release and the role of various adipokines, in particular chemerin, its implication in early glucose metabolism dysregulation disorders seems very likely.

Performance Evaluation of a Semi-automated Method for [18F]FDG Uptake in Abdominal Visceral Adipose Tissue

PURPOSE

Severity of abdominal obesity and possibly levels of metabolic activity of abdominal visceral adipose tissue (VAT) are associated with an increased risk for cardiovascular disease (CVD). In this context, the purpose of the current study was to evaluate the reproducibility and repeatability of a semi-automated method for assessment of the metabolic activity of VAT using 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography (PET)/x-ray computed tomography (CT).

PROCEDURES

Ten patients with lung cancer who underwent two baseline whole-body [¹⁸F]FDG PET/low-dose (LD) CT scans within 1 week were included. Abdominal VAT was automatically segmented using CT between levels L1-L5. The initial CT-based segmentation was further optimized using PET data with a standardized uptake value (SUV) threshold approach (range 1.0-2.5) and morphological erosion (range 0-5 pixels). The [¹⁸F]FDG uptake in SUV that was measured by the automated method was compared with manual analysis. The reproducibility and repeatability were quantified using intraclass correlation coefficients (ICCs).

RESULTS

The metabolic assessment of VAT on [¹⁸F]FDG PET/LDCT scans expressed as SUV_mean, using an automated method showed high inter and intra observer (all ICCs > 0.99) and overall repeatability (ICC = 0.98). The manual method showed reproducible inter observer (all ICCs > 0.92), but less intra observer (ICC = 0.57) and less overall repeatability (ICC = 0.78) compared with the automated method.

CONCLUSIONS

Our proposed semi-automated method provided reproducible and repeatable quantitative analysis of [¹⁸F]FDG uptake in VAT. We expect this method to aid future research regarding the role of VAT in development of CVD.

The prevalence of cardio-metabolic risk factors is differentially elevated in obesity-prone Osborne-Mendel and obesity-resistant S5B/Pl rats

AIMS

Individual susceptibility to develop obesity may impact the development of cardio-metabolic risk factors that lead to obesity-related comorbid conditions. Obesity-prone Osborne-Mendel (OM) rats expressed higher levels of visceral adipose inflammation than obesity-resistant, S5B/Pl (S5B) rats. However, the consumption of a high fat diet (HFD) differentially affected OM and S5B rats and induced an increase in visceral adipose inflammation in S5B rats. The current study examined the effects of HFD consumption on cardio-metabolic risk factors in OM and S5B rats.

MATERIALS & METHODS

Glucose regulation and circulating levels of lipids, adiponectin and C-reactive protein were assessed following 8 weeks of HFD or low fat diet (LFD) consumption. Left ventricle hypertrophy and mRNA expression of cardiovascular disease biomarkers were also quantified in OM and S5B rats.

KEY FINDINGS

Circulating levels of triglycerides were higher, while HDL cholesterol, adiponectin and glycemic control were lower in OM rats, compared to S5B rats. In the left ventricle, BNP and CTGF mRNA expression were higher in OM rats and IL-6, IL-1β, VEGF, and iNOS mRNA expression were higher in S5B rats.

SIGNIFICANCE

These findings support the hypothesis that cardio-metabolic risk factors are increased in obesity-prone individuals, which may increase the risk for the development of obesity-related comorbidities. In the current models, obesity-resistant S5B rats also exhibited cardiovascular risk factors supporting the importance of monitoring cardiovascular health in individuals characterized as obesity-resistant.

Association of Abdominal Adiposity with Cardiovascular Mortality in Incident Hemodialysis

BACKGROUND

The risk of cardiovascular mortality is high among adults with end-stage renal disease (ESRD) undergoing hemodialysis. Waist-to-hip ratio (WHR), a metric of abdominal adiposity, is a predictor of cardiovascular disease (CVD) and mortality in the general population; however, no studies have examined the association with CVD mortality, particularly sudden cardiac death (SCD), in incident hemodialysis.

METHODS

Among 379 participants incident (< 6 months) to hemodialysis enrolled in the Predictors of Arrhythmic and Cardiovascular Risk in ESRD study, we evaluated associations between WHR and risk of CVD mortality, SCD, and non-CVD mortality in Cox proportional hazards regression models.

RESULTS

At study enrollment, mean age was 55 years with 41% females, 73% African Americans, and 57% diabetics. Mean body mass index was 29.3 kg/m2, and mean WHR was 0.95. During a median follow-up time of 2.5 years, there were 35 CVD deaths, 15 SCDs, and 48 non-CVD deaths. Every 0.1 increase in WHR was associated with higher risk (hazard ratio [95% CI]) of CVD mortality (1.75 [1.06-2.86]) and SCD (2.45 [1.20-5.02]), but not non-CVD mortality (0.93 [0.59-1.45]), independently of demographics, body mass index, comorbidities, inflammation, and traditional CVD risk factors.

CONCLUSIONS

WHR is significantly associated with CVD mortality including SCD, independently of other CVD risk factors in incident hemodialysis. This simple, easily obtained bedside metric may be useful in dialysis patients for CVD risk stratification.

Role of Procalcitonin As an Inflammatory Marker in a Sample of Egyptian Children with Simple Obesity

BACKGROUND

Obesity is a multifactorial disease, associated with metabolic disorders and chronic low-grade inflammation. Procalcitonin (PCT) is well known as a biomarker of infection, and systemic inflammation. Recently, it has potential as a marker for chronic low-grade inflammation.

AIM

This study aims to evaluate the role of serum PCT as an inflammatory biomarker in the diagnosis of obesity-related low-grade inflammation.

METHOD

In this case-control study, 50 obese and 35 normal weight children and adolescents aged 5-15 years were enrolled. Anthropometric parameters were measured in all subjects. Blood samples were collected for measurement of lipid profile, blood glucose, insulin, high sensitivity-CRP (Hs-CRP) and serum procalcitonin. Serum (PCT) levels were assessed using enzyme-linked immunosorbent assay.

RESULTS

Obese participants had higher concentrations of serum PCT, total cholesterol, triglycerides, LDL-c, glucose and Hs-CRP than control group. On correlation analysis, procalcitonin had significant positive correlation with (BMI) z-score (P = 0.02), insulin (P = 0.00), insulin resistance (HOMA-IR) (P = 0.006), Hs-CRP (P = 0.02), total cholesterol (P = 0.04) and triglycerides (P = 0.00) in obese group.

CONCLUSION

The increased serum procalcitonin concentrations were closely related to measures of adiposity, Hs-CRP and insulin resistance, suggesting that PCT may be an excellent biomarker for obesity-related chronic low-grade inflammation in children and adolescents.

Do flavanols-rich natural products relieve obesity-related insulin resistance?

Growing evidence support that insulin resistance may occur as a severe problem due to chronic energetic overfeeding and subsequent obesity. When an abundance of glucose and saturated fat enter the cell, impaired blood flow, hypoxia, inflammation and macrophage infiltration in obese adipose tissue may induce oxidative stress and insulin resistance. Excessive circulating saturated fatty acids ectopically accumulate in insulin-sensitive tissues and impair insulin action. In this context, excessive hepatic lipid accumulation may play a central, pathogenic role in insulin resistance. It is thought that dietary polyphenols may ameliorate obesity-related insulin resistance by attenuating inflammatory responses and oxidative stress. The most often occurring natural polyphenolic compounds are flavonoids. In this review, the possible mechanistic effect of flavonoid-rich natural products on insulin resistance-related metabolic pathways is discussed. Polyphenol intake can prevent high-fat-diet-induced insulin resistance via cell surface G protein-coupled estrogen receptors by upregulating the expression of related genes, and their pathways, which are responsible for the insulin sensitivity.

Subcutaneous adipose tissue gene expression and DNA methylation respond to both short- and long-term weight loss

BACKGROUND

Few studies have examined both gene expression and DNA methylation profiles in subcutaneous adipose tissue (SAT) during long-term weight loss. Thus, molecular mechanisms in weight loss and regain remain elusive.

PARTICIPANTS/METHODS

We performed a 1-year weight loss intervention on 19 healthy obese participants (mean body mass index (BMI) 34.6 kg m^-2) and studied longitudinal gene expression (Affymetrix Human Genome U133 Plus 2.0) and DNA methylation (Infinium HumanMethylation450 BeadChip) in SAT at 0, 5 and 12 months. To examine whether weight loss and acquired obesity produce reciprocal profiles, we verified our findings in 26 BMI-discordant monozygotic twin pairs.

RESULTS

We found altered expression of 69 genes from 0 to 5' months (short-term) weight loss. Sixty of these genes showed reversed expression in acquired obesity (twins). Altogether 21/69 genes showed significant expression-DNA methylation correlations. Pathway analyses revealed increased high-density lipoprotein-mediated lipid transport characteristic to short-term weight loss. After the fifth month, two groups of participants evolved: weight losers (WLs) and weight regainers (WRs). In WLs five genes were differentially expressed in 5 vs 12 months, three of which significantly correlated with methylation. Signaling by insulin receptor pathway showed increased expression. We further identified 35 genes with differential expression in WLs from 0 to 12 months (long-term) weight loss, with 20 showing opposite expression patterns in acquired obesity, and 16/35 genes with significant expression-DNA methylation correlations. Pathway analyses demonstrated changes in signal transduction, metabolism, immune system and cell cycle. Notably, seven genes (UCHL1, BAG3, TNMD, LEP, BHMT2, EPDR1 and OSTM1) were found to be downregulated during both short- and long-term weight loss.

CONCLUSIONS

Our study indicates short- and long-term weight loss influences in transcription and DNA methylation in SAT of healthy participants. Moreover, we demonstrate that same genes react in an opposite manner in weight loss and acquired obesity.

Coronary microvascular disease as an early culprit in the pathophysiology of diabetes and metabolic syndrome

Metabolic syndrome (MetS) is a group of cardio-metabolic risk factors that includes obesity, insulin resistance, hypertension, and dyslipidemia; these are also a combination of independent coronary artery disease (CAD) risk factors. Alarmingly, the prevalence of MetS risk factors are increasing and a leading cause for mortality. In the vasculature, complications from MetS and type 2 diabetes (T2D) can be divided into microvascular (retinopathy and nephropathy) and macrovascular (cardiovascular diseases and erectile dysfunction). In addition to vascular and endothelial dysfunction, vascular remodeling and stiffness are also hallmarks of cardiovascular disease (CVD), and well-characterized vascular changes that are observed in the early stages of hypertension, T2D, and obesity [1-3]. In the heart, the link between obstructive atherosclerosis of coronary macrovessels and myocardial ischemia (MI) is well established. However, recent studies show that abnormalities in the coronary microcirculation are associated with functional and structural changes in coronary microvessels (classically defined as being ≤150-200μm internal diameter), which may cause or contribute to MI even in the absence of obstractive CAD. This suggests a prognostic value of an abnormal coronary microcirculation as an early sub-clinical culprit in the pathogenesis and progression of heart disease in T2D and MetS. The aim of this review is to summarize recent studies investigating the coronary microvascular remodeling in an early pre-atherosclerotic phase of MetS and T2D, and to explore potential mechanisms associated with the timing of coronary microvascular remodeling relative to that of the macrovasculature.

Association of hyperleptinemia with peripheral arterial disease in hypertensive patients

OBJECTIVE

Hypertension is a risk factor for peripheral artery disease (PAD). Serum leptin plays an important role in promoting endothelial dysfunction. The aim of this study is to investigate whether the leptin level is associated with PAD in hypertensive patients.

MATERIALS AND METHODS

Ninety-eight hypertensive patients were enrolled in this study. Ankle-brachial index (ABI) values were measured using an automated oscillometric device. Patients with an ABI value <0.9 were considered the low ABI group. C-reactive protein (CRP) was measured using standard enzymatic automated methods. Serum levels of human leptin were determined using a commercially available enzyme immunoassay.

RESULTS

Eighteen (18.4%) hypertensive patients were included in the low ABI group. Hypertensive patients in the low ABI group had higher serum creatinine (P < 0.001), CRP (P = 0.003), and leptin (P < 0.001) levels, higher prevalence of diabetes (P = 0.036), and current smoking (P = 0.034) than patients in the normal ABI group. Univariate linear regression analyses revealed that body weight (P = 0.014), waist circumference (P = 0.010), body mass index (P = 0.002), and logarithmically transformed CRP (log-CRP, P = 0.001) were positively correlated with serum log-leptin levels in hypertensive patients. Multivariate stepwise linear regression analysis showed that log-leptin (β = 0.439, adjusted R2 change = 0.224, P < 0.001) was also an associated factor of PAD in hypertensive patients.

CONCLUSION

A higher log-leptin value is an independent predictor of PAD in hypertensive patients.

Role of leptin as a link between metabolism and the immune system

Leptin is an adipocyte-derived hormone not only with an important role in the central control of energy metabolism, but also with many pleiotropic effects in different physiological systems. One of these peripheral functions of leptin is a regulatory role in the interplay between energy metabolism and the immune system, being a cornerstone of the new field of immunometabolism. Leptin receptor is expressed throughout the immune system and the regulatory effects of leptin include cells from both the innate and adaptive immune system. Leptin is one of the adipokines responsible for the inflammatory state found in obesity that predisposes not only to type 2 diabetes, metabolic syndrome and cardiovascular disease, but also to autoimmune and allergic diseases. Leptin is an important mediator of the immunosuppressive state in undernutrition status. Placenta is the second source of leptin and it may play a role in the immunomodulation during pregnancy. Finally, recent work has pointed to the participation of leptin and leptin receptor in the pathophysiology of inflammation in oral biology. Therefore, leptin and leptin receptor should be considered for investigation as a marker of inflammation and immune activation in the frontier of innate-adaptive system, and as possible targets for intervention in the immunometabolic mediated pathophysiology.

Common SIRT1 variants modify the effect of abdominal adipose tissue on aging-related lung function decline

Lung function is an independent predictor of mortality and serves as an aging marker in never smokers. The protein sirtuin-1 of gene SIRT1 has profound anti-inflammatory effects and regulates metabolic pathways. Its suggested longevity effects on lower organisms remain poorly studied in humans. In 1132 never smokers of the population-based SAPALDIA cohort, we investigated associations between single nucleotide polymorphisms (SNPs; rs730821, rs10997868, rs10823116) of SIRT1 and aging-related lung function decline over 11 years in terms of change in forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced expiratory flow between 25 and 75 % of FVC (FEF25-75) using multiple linear regression models. Interactions between the SIRT1 SNPs and adiposity parameters (body mass index (BMI), its change and weight gain) were tested by including multiplicative interaction terms into the models. SIRT1 polymorphisms exhibited no main effects, but modified the association between obesity measures and FEV1/FVC and FEF25-75 decline (p = 0.009-0.046). Per risk allele, FEV1/FVC decline was accelerated up to -0.5 % (95 % CI -1.0 to 0 %) and -0.7 % (-1.3 to -0.2 %) over interquartile range increases in BMI (2.4 kg/m(2)) or weight (6.5 kg), respectively. For FEF25-75 decline, corresponding estimates were -57 mL/s (-117 to 4 mL/s) and -76 mL/s (-1429 to -9 mL/s). Interactions were not present in participants with genetically lowered C-reactive protein concentrations. Genetic variation in SIRT1 might therefore affect lung function and human longevity by modifying subclinical inflammation arising from abdominal adipose tissue.

Effect of 3,4-dihydroxyacetophenone on endothelial dysfunction in obese rats

CONTEXT

3,4-Dihydroxyacetophenone (DHAP) has been reported to possess cardiovascular pharmacological effects.

OBJECTIVE

This study was designed to determine whether DHAP could improve endothelial function in obese rats.

MATERIALS AND METHODS

Wistar rats were randomly divided into control, obesity, and DHAP groups and fed a normal, high-fat, and high-fat plus DHAP (10 mg kg(-1) d(-1)) diet, respectively, for 8 weeks. Endothelial-dependent vasodilatation was assessed. Endothelial nitric oxide synthase (eNOS) activity and nitric oxide (NO) production in endothelial cells were determined. Nuclear transcription factor kappa B (NF-κB) expression and superoxide production in aorta were evaluated.

RESULTS

DHAP treatment significantly decreased plasma triglycerides (0.94 ± 0.31 mmol/l versus 1.36 ± 0.29 mmol/l, p < 0.05) and free fatty acids (0.53 ± 0.15 mmol/l versus 0.99 ± 0.24 mmol/l, p < 0.05), reduced serum tumor necrosis factor α (35.56 ± 9.28 pg/ml versus 68.3 ± 10.24 pg/ml, p < 0.05) and malondialdehyde (2.94 ± 0.58 pg/ml versus 6.45 ± 0.70 pg/ml, p < 0.05), and increased serum adiponectin levels (164.5 ± 34.5 μg/l versus 84.5 ± 20.4 μg/l, p < 0.05). DHAP enhanced endothelial-dependent vasodilatation and improved endothelial function in obese rats (p < 0.05). eNOS activity and NO production in endothelial cells significantly decreased and NF-κB activation and superoxide production in aorta significantly increased in obese rats compared with the control group (p < 0.05). However, DHAP treatment significantly up-regulated the eNOS-NO pathway and decreased NF-κB activation and superoxide production (p < 0.05).

CONCLUSION

DHAP improved endothelial function in obese rats. This beneficial effect may be associated with up-regulation of the eNOS-NO pathway by improving lipid metabolism and reducing oxidative stress and inflammation activity.

Peer effects, fast food consumption and adolescent weight gain

This paper aims at opening the black box of peer effects in adolescent weight gain. Using Add Health data on secondary schools in the U.S., we investigate whether these effects partly flow through the eating habits channel. Adolescents are assumed to interact through a friendship social network. We propose a two-equation model. The first equation provides a social interaction model of fast food consumption. To estimate this equation we use a quasi maximum likelihood approach that allows us to control for common environment at the network level and to solve the simultaneity (reflection) problem. Our second equation is a panel dynamic weight production function relating an individual's Body Mass Index z-score (zBMI) to his fast food consumption and his lagged zBMI, and allowing for irregular intervals in the data. Results show that there are positive but small peer effects in fast food consumption among adolescents belonging to a same friendship school network. Based on our preferred specification, the estimated social multiplier is 1.15. Our results also suggest that, in the long run, an extra day of weekly fast food restaurant visits increases zBMI by 4.45% when ignoring peer effects and by 5.11%, when they are taken into account.

ALTERED CIRCULATING LEVELS OF RETINOL BINDING PROTEIN 4 AND TRANSTHYRETIN IN RELATION TO INSULIN RESISTANCE, OBESITY, AND GLUCOSE INTOLERANCE IN ASIAN INDIANS

OBJECTIVE

Retinol binding protein 4 (RBP4) has been implicated in metabolic disorders including type 2 diabetes mellitus (T2DM), but few studies have looked at transthyretin (TTR) with which RBP4 is normally bound to in the circulation. We report on the systemic levels of RBP4 and TTR and their associations with insulin resistance, obesity, prediabetes, and T2DM in Asian Indians.

METHODS

Age-matched individuals with normal glucose tolerance (NGT, n = 90), impaired glucose tolerance (IGT, n = 70) and T2DM (n = 90) were recruited from the Chennai Urban Rural Epidemiology Study (CURES). Insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). RBP4 and TTR levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Circulatory RBP4 and TTR levels (in μg/mL) were highest in T2DM (RBP4: 13 ± 3.9, TTR: 832 ± 310) followed by IGT (RBP4: 10.5 ± 3.2; TTR: 720 ± 214) compared to NGT (RBP4: 8.7 ± 2.5; TTR: 551 ± 185; P<.001). Compared to nonobese NGT individuals, obese NGT, nonobese T2DM, and obese T2DM had higher RBP4 (8.1 vs. 10.6, 12.1, and 13.2 μg/mL, P<.01) and TTR levels (478 vs. 737, 777, and 900 μg/mL, P<.01). RBP4 but not TTR was significantly (P<.001) correlated with insulin resistance even among NGT subjects. In regression analysis, RBP4 and TTR showed significant associations with T2DM after adjusting for confounders (RBP4 odds ratio [OR]: 1.107, 95% confidence interval [CI]: 1.008-1.216; TTR OR: 1.342, 95% CI: 1.165-1.547).

CONCLUSION

Circulatory levels of RBP4 and TTR showed a significant associations with glucose intolerance, obesity, T2DM and RBP4 additionally, with insulin resistance.

Ageing and inflammation - A central role for mitochondria in brain health and disease

To develop successful therapies that prevent or treat neurodegenerative diseases requires an understanding of the upstream events. Ageing is by far the greatest risk factor for most of these diseases, and to clarify their causes will require an understanding of the process of ageing itself. Starting with the question Why do we age as individual organisms, but the line of pluripotent embryonic stem cells and germ cells carried by individuals and transmitted to descendants is immortal? this review discusses how the process of cellular differentiation leads to the accumulation of biological imperfections with ageing, and how these imperfections may be the cause of chronic inflammatory responses to stress that undermine cellular function. Both differentiation and inflammation involve drastic metabolic changes associated with alterations in mitochondrial dynamics that shift the balance between aerobic glycolysis and oxidative phosphorylation. With ageing, mitochondrial dysfunction can be both the cause and consequence of inflammatory processes and elicit metabolic adaptations that might be either protective or become progressively detrimental. It is argued here that an understanding of the relationship between metabolism, differentiation and inflammation is essential to understand the pathological mechanisms governing brain health and disease during ageing.

Changes in Weight and Cardiovascular Disease Risk Factors in Monozygotic Twins: The Healthy Twin Study

We aimed to assess the non-genetic contribution to the associations between the change in weight and changes in cardiovascular disease (CVD) risk factors. This analysis included 194 Korean monozygotic (MZ) twin pairs (116 men, 272 women; mean age, 38.5 ± 6.8 years) who were first examined for weight and CVD risk factors (blood pressure (BP), glucose, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL)) between December 2005 and December 2008, and returned for a repeat examination after 2.7 ± 0.9 years. The within-pair correlations were 0.21 for the change in weight and 0.05-0.42 for the changes in CVD risk factors. Bivariate analyses showed significant environmental correlations shared between the change in weight and the changes in CVD risk factors (p < .05), except for glucose, while there were no significant genetic effects shared between the phenotypes. After adjusting for baseline values of weight, smoking, and alcohol consumption, diastolic blood pressure (DBP), TG, TC, and LDL significantly increased by 1.6 mmHg, 0.09 mmol/L, 0.10 mmol/L, and 0.09 mmol/L, respectively, per 1 kg increase in within-pair differences in weight change. In Korean MZ twins, similarity between twins for changes in weight and CVD risk factors were small to moderate, and non-genetic factors were responsible for the associations between the change in weight and changes in DBP, TG, TC, and LDL.

Lipid accumulation product is associated with insulin resistance, lipid peroxidation, and systemic inflammation in type 2 diabetic patients

BACKGROUND

Lipid accumulation product (LAP) is a novel biomarker of central lipid accumulation related to risk of diabetes and cardiovascular disease. In this study, we assessed the association of LAP with glucose homeostasis, lipid and lipid peroxidation, and subclinical systemic inflammation in diabetic patients.

METHODS

Thirty-nine male and 47 female type 2 diabetic patients were assessed for anthropometrics and biochemical measurements. LAP was calculated as [waist circumference (cm)-65]×[triglycerides (mmol/L)] in men, and [waist circumference (cm)-58]×[triglycerides (mmol/L)] in women. Associations of LAP with fasting glucose, insulin, insulin resistance index, lipid and lipoprotein levels, malondialdehyde, and high-sensitive C-reactive protein (hs-CRP) were assessed.

RESULTS

Mean age and LAP index were 53.6±9.6 and 51.9±31.2 years, respectively. After adjustments for age, sex and body mass index status, a significant positive correlation was observed between LAP index and fasting glucose (r=0.39, P<0.001), and homeostasis model assessment of insulin resistance (r=0.31, P<0.05). After additional adjustment for fasting glucose levels, antidiabetic and antilipidemic drugs, the LAP index was also correlated to total cholesterol (r=0.45, P<0.001), high density lipoprotein cholesterol (HDL-C) levels (r=-0.29, P<0.05), triglycerides to HDL-C ratio (r=0.89, P<0.001), malondialdehyde (r=0.65, P<0.001), and hs-CRP levels (r=0.27, P<0.05).

CONCLUSION

Higher central lipid accumulation in diabetic patients was related to higher insulin resistance, oxidative stress and systemic inflammation.

Diet-induced obesity attenuates endotoxin-induced cognitive deficits

Activation of the immune system can impair cognitive function, particularly on hippocampus dependent tasks. Several factors such as normal aging and prenatal experiences can modify the severity of these cognitive deficits. One additional factor that may modulate the behavioral response to immune activation is obesity. Prior work has shown that obesity alters the activity of the immune system. Whether diet-induced obesity (DIO) influences the cognitive deficits associated with inflammation is currently unknown. The present study explored whether DIO alters the behavioral response to the bacterial endotoxin, lipopolysaccharide (LPS). Female C57BL/6J mice were fed a high-fat (60% fat) or control diet (10% fat) for a total of five months. After consuming their respective diets for four months, mice received an LPS or saline injection and were assessed for alterations in spatial learning. One month later, mice received a second injection of LPS or saline and tissue samples were collected to assess the inflammatory response within the periphery and central nervous system. Results showed that LPS administration impaired spatial learning in the control diet mice, but had no effect in DIO mice. This lack of a cognitive deficit in the DIO female mice is likely due to a blunted inflammatory response within the brain. While cytokine production within the periphery (i.e., plasma, adipose, and spleen) was similar between the DIO and control mice, the DIO mice failed to show an increase in IL-6 and CD74 in the brain following LPS administration. Collectively, these data indicate that DIO can reduce aspects of the neuroinflammatory response as well as blunt the behavioral reaction to an immune challenge.

Importance of serum adipokine and ghrelin levels in patients with Crimean-Congo hemorrhagic fever

Crimean-Congo Hemorrhagic Fever (CCHF) may present with a mild clinical course or else exhibit a severe profile with potentially fatal hemorrhaging. The pathogenesis of the disease has not yet been well described. Cytokines have recently been investigated in order to explain the pathogenesis. The latest reports show that adipokines are powerful inflammation modulators. This study investigated the effect of adipokines (resistin, leptin, and adiponectin) and ghrelin on disease severity in CCHF patients by testing their serum levels. This retrospective study was conducted with patients with CCHF hospitalized at the Karadeniz Technical University, Medical Faculty in Turkey. Patients were divided into severe and non-severe groups. Serum adipokine levels of patients with CCHF were measured using enzyme-linked immunosorbent assay (ELISA). Fifty-three patients with confirmed CCHF were investigated. Twenty-five (47.2%) of these patients constituted the severe group. Serum resistin levels in the severe and non-severe groups were 108.9 ± 24.7 ng/ml and 77.5 ± 27.7 ng/ml (P < 0.001), leptin levels 15.5 ± 9.8 and 11.2 ± 5.1 ng/ml (P = 0.074), adiponectin levels 26.8 ± 18.9 and 27.4 ± 16.3 ng/ml (P = 0.903) and ghrelin levels 57.1 ± 48.7 and 200.9 ± 182.7 ng/ml (P = 0.001), all respectively. This study confirms that significant changes in serum levels of resistin and ghrelin take place in severe CCHF.

Adipose tissue and vascular inflammation in coronary artery disease

Obesity has become an important public health issue in Western and developing countries, with well known metabolic and cardiovascular complications. In the last decades, evidence have been growing about the active role of adipose tissue as an endocrine organ in determining these pathological consequences. As a consequence of the expansion of fat depots, in obese subjects, adipose tissue cells develope a phenotypic modification, which turns into a change of the secretory output. Adipocytokines produced by both adipocytes and adipose stromal cells are involved in the modulation of glucose and lipid handling, vascular biology and, moreover, participate to the systemic inflammatory response, which characterizes obesity and metabolic syndrome. This might represent an important pathophysiological link with atherosclerotic complications and cardiovascular events. A great number of adipocytokines have been described recently, linking inflammatory mileu and vascular pathology. The understanding of these pathways is crucial not only from a pathophysiological point of view, but also to a better cardiovascular disease risk stratification and to the identification of possible therapeutic targets. The aim of this paper is to review the role of Adipocytokines as a possible link between obesity and vascular disease.

Subnormal peripheral blood leukocyte counts are related to the lowest prevalence and incidence of metabolic syndrome: Tianjin chronic low-grade systemic inflammation and health cohort study

Few studies have assessed the relationship between a subnormal inflammatory status and metabolic syndrome (MS). We therefore designed a cross-sectional and 5-year cohort study to evaluate how a subnormal peripheral blood leukocyte count is related to MS. Participants were recruited from Tianjin Medical University General Hospital-Health Management Centre. Both a baseline cross-sectional (n = 46,179) and a prospective assessment (n = 13,061) were performed. Participants without a history of MS were followed up for 5 years. Leukocyte counts and MS components were assessed at baseline and yearly during the follow-up. Adjusted logistic and Cox proportional hazards regression models were used to assess relationships between the categories of leukocyte counts and MS. The subnormal leukocyte counts group (1,100-3,900 cells/mm(3)) had the lowest prevalence and incidence of MS. The odds ratio and hazard ratio (95% confidence interval) of the highest leukocyte counts were 1.98 (1.57-2.49) and 1.50 (1.22-1.84) (both P for trend <0.0001), respectively, when compared to the subnormal leukocyte counts group after adjusting for potential confounders. This study has shown that subnormal leukocyte counts are independently related to the lowest prevalence and incidence of MS. The findings suggest that it is necessary to restudy and discuss the clinical or preventive value of subnormal leukocyte counts.

Serum immunoglobulin M concentration is positively related to metabolic syndrome in an adult population: Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) Cohort Study

Persistent low-grade systemic inflammation has been increasingly recognized as a common pathological process, and an important contributing factor to cardiovascular diseases and its risk factor, metabolic syndrome. Immunoglobulin M is reactive to multiple autoantigens and is inferred to be important for autoimmunity, implying that immunoglobulin M may be a potential risk factor for metabolic syndrome. However, few epidemiological studies are available which are related to this potential link. Therefore, we designed a cross-sectional study of 9,379 subjects to evaluate the relationship between immunoglobulin M and metabolic syndrome in an adult population. Subjects who received health examinations were recruited from the Tianjin Medical University General Hospital-Health Management Center in Tianjin, China. Immunoglobulin M was determined with an immunonephelometric technique. Metabolic syndrome was defined according to the criteria of the American Heart Association scientific statements of 2009. Multiple logistic regression analysis was used to examine the relationships between the quartiles of immunoglobulin M and the prevalence of metabolic syndrome. After adjustment for covariates, the odds ratio of having metabolic syndrome in the fourth quartile compared with the first quartile of immunoglobulin M was 1.19 times for males (95% confidence interval, 1.002-1.41) and 1.39 times for females (95% confidence interval, 1.07-1.80). Immunoglobulin M levels also showed positive relationships with the ratio of elevated triglycerides and reduced high-density lipoprotein cholesterol in males. The study is the first to show that immunoglobulin M is independently related to metabolic syndrome and its individual components (elevated triglycerides and reduced high-density lipoprotein cholesterol) in males, whereas immunoglobulin M is independently related to metabolic syndrome in females but not to its individual components. Further studies are needed to explore the causality and the exact role of immunoglobulin M in metabolic syndrome.

Arterial and fat tissue inflammation are highly correlated: a prospective 18F-FDG PET/CT study

PURPOSE

There is evidence that the link between obesity and cardiovascular disease might relate to inflammation in both fat tissue and the arterial wall. (18)F-FDG uptake on PET is a surrogate marker of vessel wall inflammation. The aim of the study was to measure FDG uptake in both regions using PET and identify links between adipose and arterial inflammation.

METHODS

Included in the study were 173 cardiovascular patients who were prospectively imaged with FDG PET/CT. Arterial FDG uptake was measured in the carotid arteries and ascending aorta. The same was done in fat tissue in the neck, the presternal region (both subcutaneous) and the pericardium. FDG uptake was quantified as average maximal target-to-background ratio (mean TBR max). Multivariate regression analyses were performed to identify significant associations between arterial and adipose tissue FDG uptake and clinical variables as given by the standardized correlation coefficient (β).

RESULTS

FDG uptake values in all fat tissue regions were highly predictive of vascular FDG uptake in both the carotids (β 0.262, p < 0.0001, in the neck subcutaneous region) and aorta (β 0.22, p = 0.008, in the chest pericardial region; β 0.193, p = 0.019, in the chest subcutaneous region). Obesity was significantly associated with elevated FDG uptake in adipose tissue (β 0.470, p < 0.0001, in the neck subcutaneous region; β 0.619, p = 0.028, in the chest subcutaneous region; β 0.978, p = 0.035, in the chest pericardial region).

CONCLUSION

FDG uptake in diverse fat tissue regions was significantly associated with arterial FDG uptake, a reasonable surrogate of inflammation. Increasing body weight significantly predicted the level of fatty inflammation. FDG PET therefore provides imaging evidence of an inflammatory link between fat tissue and the vasculature in patients with cardiovascular disease.

Berry anthocyanins suppress the expression and secretion of proinflammatory mediators in macrophages by inhibiting nuclear translocation of NF-κB independent of NRF2-mediated mechanism

The objectives of this study were to compare the anti-inflammatory effects of anthocyanins from blueberry (BBA), blackberry (BKA), and blackcurrant (BCA) and to determine the relationship between their antioxidant capacity and anti-inflammatory effect in macrophages. Major anthocyanins in BBA, BKA and BCA were malvidin-3-glucoside (16%), cyanidin-3-glucoside (98%) and delphinidin-3-rutinoside (44%), respectively. BKA showed higher total antioxidant capacity than BBA and BCA. RAW 264.7 macrophages were incubated with 0-20 μg/ml of BBA, BKA and BCA, and subsequently activated by lipopolysaccharide (LPS) to measure proinflammatory cytokine production. Interleukin 1β (IL-1β) messenger RNA (mRNA) levels were significantly decreased by all berry anthocyanins at 10 μg/ml or higher. Tumor necrosis factor α (TNFα) mRNA levels and secretion were also significantly decreased in LPS-treated macrophages. The levels of the repression were comparable for all berry anthocyanins. LPS-induced nuclear factor κB (NF-κB) p65 translocation to the nucleus was markedly attenuated by all of the berry anthocyanins. In bone marrow-derived macrophages (BMMs) from nuclear factor E2-related factor 2 wild-type (Nrf2(+/+)) mice, BBA, BKA and BCA significantly decreased cellular reactive oxygen species (ROS) levels with a concomitant decrease in IL-1β mRNA levels upon LPS stimulation. However, in the BMM from Nrf2(-/-) mice, the anthocyanin fractions were able to significantly decrease IL-1β mRNA despite the fact that ROS levels were not significantly affected. In conclusion, BBA, BKA and BCA exert their anti-inflammatory effects in macrophages, at least in part, by inhibiting nuclear translocation of NF-κB independent of the NRF2-mediated pathways.

Leptin, adiponectin and vascular stiffness parameters in women with systemic lupus erythematosus

The purpose of the present study was to determine levels of adipokines and their relationship with stiffness parameters and disease activity index in SLE patients in comparison with healthy controls. Sixty SLE patients and 29 control subjects were enrolled in the study. Serum leptin and adiponectin levels were determined by commercial sandwich ELISA kits. Colour-coded carotid duplex sonography was performed using a Siemens SONOLINE Antares machine equipped with linear 5-13 MHz. SLEDAI, ECLAM and SLICC were evaluated in all patients. Data were analysed by software for statistical analysis (Prism 5.0). Median leptin is higher among SLE patients compared with controls (p 0.035). Median values of vascular stiffness and PSEM are increased in SLE compared with controls (p = 0.0003 and p = 0.007). Vascular strain and vascular distensibility are lower in SLE patients in comparison with controls (p = 0.0001 and p = 0.0006, respectively). Considering SLE patients, leptin levels correlate with vascular stiffness (r = 0.64, p < 0.0001) and PSEM (r = 0.63, p < 0.0001). Adiponectin levels correlate with vascular strain (r = 0.28, p 0.039) and negatively correlate with vascular stiffness (r = -0.38, p 0.039). Leptin levels correlate with disease activity (SLEDAI and ECLAM) and cumulative damage (SLICC) indexes. This study demonstrates higher values of leptin in SLE patients. Moreover, SLE patients show increased levels of vascular stiffness and PSEM and reduced values of vascular strain and distensibility. These results globally indicate a decline in arterial elasticity. We find a positive correlation of leptin with stiffness parameters. According to its atheroprotective action, adiponectin inversely correlates with stiffness parameters.

PBMCs reflect the immune component of the WAT transcriptome--implications as biomarkers of metabolic health in the postprandial state

SCOPE

Food and nutrition studies often require accessing metabolically active tissues, including adipose tissue. This can involve invasive biopsy procedures that can be a limiting factor in study design. In contrast, peripheral blood mononuclear cells (PBMCs) are a population of circulating immune cells that are easily accessible through venipuncture. As transcriptomics is of growing importance in food and metabolism research, understanding the transcriptomic relationship between these tissue types can provide insight into the utility of PBMCs in this field.

METHODS AND RESULTS

We examine this relationship within eight subjects, in two postprandial states (following oral lipid tolerance test and oral glucose tolerance test). Multivariate analysis techniques were used to examine variation between tissues, samples, and subjects in order to define which genes havecommon/disparate expression profiles associated with highly defined metabolic phenotypes. We demonstrate global similarities in gene expression between PBMCs and white adipose tissue, irrespective of the metabolic challenge type. Closer examination of individual genes revealed this similarity to be strongest in pathways related to immune response/inflammation. Notably, the expression of metabolism-related nuclear receptors, including PPARs, LXR, etc. was discordant between tissues

CONCLUSION

The PBMC transcriptome may therefore provide a unique insight into the inflammatory component of metabolic health, as opposed to directly reflecting the metabolic component of the adipose tissue transcriptome.

Superparamagnetic iron oxide nanoparticles alter expression of obesity and T2D-associated risk genes in human adipocytes

Adipocytes hypertrophy is the main cause of obesity and its affliction such as type 2 diabetes (T2D). Since superparamagnetic iron oxide nanoparticles (SPIONs) are used for a wide range of biomedical/medical applications, we aimed to study the effect of SPIONs on 22 and 29 risk genes (Based on gene wide association studies) for obesity and T2D in human adipocytes. The mRNA expression of lipid and glucose metabolism genes was changed upon the treatment of human primary adipocytes with SPIONs. mRNA of GULP1, SLC30A8, NEGR1, SEC16B, MTCH2, MAF, MC4R, and TMEM195 were severely induced, whereas INSIG2, NAMPT, MTMR9, PFKP, KCTD15, LPL and GNPDA2 were down-regulated upon SPIONs stimulation. Since SEC16B gene assist the phagocytosis of apoptotic cells and this gene were highly expressed upon SPIONs treatment in adipocytes, it is logic to assume that SPIONs may play a crucial role in this direction, which requires more consideration in the future.

Injection of phosphatidylcholine and deoxycholic acid regulates gene expression of lipolysis-related factors, pro-inflammatory cytokines, and hormones on mouse fat tissue

Injection of phosphatidylcholine (PC) and deoxycholic acid (DA) preparation is widely used as an alternative to liposuction for the reduction of subcutaneous fat. Nevertheless, its physiological effects and mechanism of action are not yet fully understood. In this report, PC and deoxycholic acid (DA) were respectively injected into adipose tissue. PC decreased tissue mass on day 7, but DA did not. On the other hand, a decrement of DNA mass was observed only in DA-injected tissue on day 7. Both PC and DA reduced the mRNA expression of adipose tissue hormones, such as adiponectin, leptin, and resistin. In lipolysis-related gene expression profiles, PC increased hormone-sensitive lipase (HSL) transcription and decreased the expression other lipases, perilipin, and the lipogenic marker peroxisome proliferator-activated receptor-γ (PPARγ); DA treatment diminished them all, including HSL. Meanwhile, the gene expression of pro-inflammatory cytokines and a chemokine was greatly elevated in both PC-injected and DA-injected adipose tissue. Microscopic observation showed that PC induced lipolysis with mild PMN infiltration on day 7. However, DA treatment did not induce lipolysis but induced much amount of PMN infiltration. In conclusion, PC alone might induce lipolysis in adipose tissue, whereas DC alone might induce tissue damage.

Allosteric regulation of the calcium-sensing receptor in obese individuals

We have previously reported that the calcium-sensing receptor (CaSR) plays an important role in modulating lipid metabolism under low calcium conditions. The aim of this study was to identify possible regulators of CaSR and the mechanisms of action of CaSR in obese individuals. Subcutaneous fat samples were obtained from 10 obese and 10 non-obese males undergoing elective abdominal surgery. Visceral fat pads were obtained from 12 obese and 12 non-obese male rats. Serum lipid, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations, as well as the gene and protein expression of CaSR in the white adipose tissue of obese subjects and rats were determined. Serum total calcium, vitamin D, parathyroid hormone (PTH) and amino acid levels in human subjects were measured. Intracellular calcium and cyclic adenosine monophosphate (cAMP) levels in rat adipocytes were measured by laser scanning confocal microscopy and ELISA, respectively. The results revealed that serum triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), TNF-α, IL-6 and PTH levels were significantly higher in the obese individuals versus the controls. By contrast, serum vitamin D and amino acid concentrations were lower in the obese individuals versus the controls. In addition, intracellular calcium levels were higher, while cAMP levels were lower in the obese rat adipocytes compared with the control group. However, the gene and protein expression of CaSR in white adipose tissue did not differ between the obese groups and the controls. Thus, these results suggest that CaSR functions not through its expression, but rather through allosteric regulation in obese individuals.

Measurement of waist circumference predicts coronary atherosclerosis beyond plasma adipokines

OBJECTIVE

The association of plasma adipokines beyond waist circumference (WC) with coronary artery calcification (CAC), a measure of subclinical atherosclerosis, is unknown.

DESIGN AND METHODS

Asymptomatic Caucasian individuals from two community-based cross-sectional studies (n = 1,285) were examined and multivariate analysis of traditional risk factors was performed, then WC and adipokines (adiponectin and leptin) were added. Incremental value of each was tested with likelihood ratio testing.

RESULTS

Beyond traditional risk factors, WC (Tobit regression ratio 1.69, P < 0.001) and plasma leptin (1.57, P < 0.001) but not plasma adiponectin (P = 0.75) were independently associated with CAC. In nested models, neither adiponectin (χ(2) = 0.76, P = 0.38) nor leptin (χ(2) = 1.32, P = 0.25) added value to WC beyond traditional risk factors, whereas WC added incremental value to adiponectin (χ(2) = 28.02, P < 0.0001) and leptin (χ(2) = 13.58, P = 0.0002).

CONCLUSION

In the face of important biomarkers such as plasma adiponectin and leptin, WC remained a significant predictor of CAC beyond traditional risk factors underscoring the importance of WC measurement during cardiovascular risk assessment.

Correlation of resistin with inflammatory and cardiometabolic markers in obese adolescents with and without metabolic syndrome

OBJECTIVE

The link between plasma resistin and obesity-related cardiometabolic disorders in children remains debatable. This study assessed the relationships of plasma resistin with cardiovascular risk factors, pro-inflammatory markers and insulin resistance index (HOMA-IR) in obese (Ob) adolescents and obese adolescents with metabolic syndrome (Ob-MS) compared to healthy controls (CO).

METHODS

114 obese adolescents (60 Ob, age 13.6 ± 0.9 years, BMI 28.0 ± 2.2 kg/m(2), and 54 Ob-MS, age 13.8 ± 1.0 years, BMI 32.5 ± 4.8 kg/m(2)) and 37 CO (age 13.7 ± 0.8 years, BMI 22.8 ± 0.8 kg/m(2)) were studied. Anthropometrics, cardiac variables as well as fasting plasma concentrations of lipids, glucose, insulin, and adipocytokines (resistin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP)) were measured. HOMA-IR was calculated, and the presence of MS was assessed.

RESULTS

Plasma resistin was significantly higher in Ob-MS than in both Ob and CO and was correlated with anthropometric, cardiovascular, pro-inflammatory markers and several components of MS as was HOMA-IR in Ob and Ob-MS. With increasing the number of MS components, plasma resistin, pro-inflammatory markers, and HOMA-IR were also increased. Multiple regression models highlighted significant correlation between resistin and both HOMA-IR (r = 0.40, p < 0.05) and systolic blood pressure (r = 0.63, p < 0.01) in Ob-MS.

CONCLUSION

These results support the hypothesis that there is an association between circulating resistin and childhood obesity-related inflammatory and cardiometabolic events.

Calcium sensing receptor activation elevates proinflammatory factor expression in human adipose cells and adipose tissue

The proinflammatory status of adipose tissue has been linked to the metabolic and cardiovascular consequences of obesity. Human adipose cells express the calcium sensing receptor (CaSR), and its expression is elevated in inflammatory states, such as that associated with obesity. Given the CaSR's association with inflammation in other tissues, we evaluated its role elevating the adipose expression of inflammatory factors. The CaSR activation by the calcimimatic cinacalcet (5μM) in adipose tissue and in vitro cultured LS14 adipose cells elicited an elevation in the expression of the proinflammatory cytokines IL6, IL1β, TNFα, and the chemoattractant CCL2. This was in part reverted by SN50, an inhibitor of the inflammatory mediator nuclear factor kappa B (NFκB). Our observations suggest that CaSR activation elevates cytokine and chemokine production, partially mediated by NFκB. These findings support the relevance of the CaSR in the pathophysiology of obesity-induced adipose tissue dysfunction, with an interesting potential for pharmacological manipulation.

Evaluation of serum adipokines in peripheral arterial occlusive disease

Aim. Out study aimed to assess the serum levels of adipokines in patients with peripheral arterial occlusive disease (PAOD) caused by atherosclerosis. Methods. Serum samples were obtained from 221 patients. One hundred and forty patients, (26 females and 114 males) met the inclusion criteria and were assigned into the case group. Eighty one patients (17 females and 64 males), were included in the control group. Circulating plasma levels of adiponectin, leptin, resistin, and TNF-α were measured using the enzyme-linked immunosorbent assay (ELISA) method. Results. Significant lower levels of adiponectin were present (P = 0.0061) in PAOD patients (2380.23 ± 1634.42 pg/mL) compared to the control group (3065.06 ± 1901.2 pg/mL). The mean value of leptin (2844.42 ± 3301.08 pg/mL) and resistin (2047.81±3301.08 pg/mL) patients included in the PAOD group was higher, as compared to the control group. Statistically significant difference was found between the two groups for leptin (P = 0.0332) and for resistin (P = 0.0352). No statistically significant difference for TNF-α was found between the two groups (P > 0.05). Conclusion. The markers of inflammation secreted by the adipose tissue (adiponectin, leptin, resistin) showed significant differences in patients from the case group (with PAOD) compared to the control group.