The role of adiponectin in obesity, diabetes, and cardiovascular disease

Effect of Berberine on C-reactive protein: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Clinical evidence suggests the beneficial effects of Berberine (BER) on inflammatory markers. However, these results are controversial. The aim of this systematic review was to assess the effects of BER on C-reactive protein (CRP) using clinical trials in adults.

DESIGN

Systematic review and meta-analysis.

MAIN OUTCOME MEASURES

We searched randomized controlled trials in PubMed and Scopus up to November 2018. The mean differences (MD) and confidence interval (CI) of CRP (mg/L) concentrations were pooled with a random- or a fixed-effects model depending on the results of heterogeneity tests.

RESULTS

Of 1242 studies identified, 5 were included in the meta-analysis. Pooled analysis showed that serum levels of CRP were decreased after BER supplementation (MD:-0.64 mg/L, 95% CI(-0.67 to -0.61) P < 0.001)) without any significant heterogeneity (I² = 0.0% and P = 0.984).

CONCLUSION

This meta-analysis showed BER supplementation may ameliorate the state of chronic inflammation. Patients with cardiovascular disease and diabetes are two important groups which may benefit from BER supplementation. Further well-designed investigations with larger samples are needed to ascertain the long-term effects of BER on chronic inflammation.

Ascorbic acid attenuates cell stress by activating the fibroblast growth factor 21/fibroblast growth factor receptor 2/adiponectin pathway in HepG2 cells

Increasing prevalence of obesity‑induced non‑alcoholic fatty liver disease (NAFLD) and non‑alcoholic steatohepatitis (NASH) has been reported. Ascorbic acid (AA), also known as vitamin C, an excellent antioxidant, has been shown to exert beneficial effects on NAFLD; however, the underlying mechanisms are yet to be fully elucidated. In the present study, the role of AA on cell stress in tumor necrosis factor α (TNFα)‑treated HepG2 cells was investigated. Our findings revealed that exposure to AA effectively ameliorated TNFα‑induced cell stresses, including hypoxia, inflammation and endoplasmic reticulum (ER) stress by reducing the expression of Hif1α and its target genes (glucose transporter 1), pro‑inflammatory genes (monocyte chemoattractant 1) and ER stress‑related genes (glucose‑regulated protein, 78 kDa). AA also decreased the protein level of HIF1α. Additionally, AA significantly increased the secretion of total adiponectin and high molecular weight (HMW) adiponectin. Mechanistically, AA was determined to increase the expression of fibroblast growth factor 21 (FGF21) and its receptor, fibroblast growth factor receptor 2 (FGFR2). Knockdown of FGFR2 not only decreased the levels of total adiponectin and HMW adiponectin, but almost abolished the beneficial effects of AA in ameliorating cell stress. Collectively, the findings of our study demonstrated that AA may attenuate hepatocyte stress induced by TNFα via activation of the FGF21/FGFR2/adiponectin pathway. This could a novel mechanism of action of AA, and its potential for the treatment of NAFLD/NASH.

Risk Factors for Unhealthy Weight Gain and Obesity among Children with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a developmental disorder characterized by social and communication deficits and repetitive behaviors. Children with ASD are also at a higher risk for developing overweight or obesity than children with typical development (TD). Childhood obesity has been associated with adverse health outcomes, including insulin resistance, diabetes, heart disease, and certain cancers. Importantly some key factors that play a mediating role in these higher rates of obesity include lifestyle factors and biological influences, as well as secondary comorbidities and medications. This review summarizes current knowledge about behavioral and lifestyle factors that could contribute to unhealthy weight gain in children with ASD, as well as the current state of knowledge of emerging risk factors such as the possible influence of sleep problems, the gut microbiome, endocrine influences and maternal metabolic disorders. We also discuss some of the clinical implications of these risk factors and areas for future research.

Effects of nutritional status on serum fetuin-A level

Fetuin-A is a glycoprotein structured molecule which is mostly released by the liver. As a multifunctional protein, fetuin-A has positive effects on health such as calcification, cardiovascular diseases and tumor development processes with various mechanisms, whereas it plays a negative role in the processes of obesity, diabetes and fatty liver disease. There are a large number of studies reporting that serum fetuin-A levels are affected by several dietary factors. It is reported in some of these studies that several nutrients increase fetuin-A release, while some others have adverse effects. It is put forward that some nutrients such as dairy products, curcumin, niacin, palmitate, coffee and alcohol consumption decrease fetuin-A level, and dietary omega-3 fatty acids intake may increase fetuin-A concentration. In addition, it is indicated that high blood glucose levels increase hepatic fetuin-A release by activating extracellular signal-regulated kinase 1/2 enzymes and increased plasma free fatty acids do the same effect by increasing NF-_KB activity. Despite these studies in the literature, there is not any review evaluating fetuin-A, chronic diseases and nutrition together. Therefore, in this study, the relationship between serum fetuin levels and some diseases and the effects of nutrients on fetuin A levels were investigated with possible mechanisms.

Cyanidin-3-O-galactoside-enriched Aronia melanocarpa extract attenuates weight gain and adipogenic pathways in high-fat diet-induced obese C57BL/6 mice

Aronia melanocarpa are a rich source of anthocyanins that have received considerable interest for their relations to human health. In this study, the anti-adipogenic effect of cyanidin-3-O-galactoside-enriched Aronia melanocarpa extract (AM-Ex) and its underlying mechanisms were investigated in an in vivo system. Five-week-old male C57BL/6N mice were randomly divided into five groups for 8-week feeding with a control diet (CD), a high-fat diet (HFD), or a HFD with 50 (AM-Ex 50), 100 (AM-Ex 100), or 200 AM-Ex (AM-Ex 200) mg/kg body weight/day. HFD-fed mice showed a significant increase in body weight compared to the CD group, and AM-Ex dose-dependently inhibited this weight gain. AM-Ex significantly reduced the food intake and the weight of white fat tissue, including epididymal fat, retroperitoneal fat, mesenteric fat, and inguinal fat. Treatment with AM-Ex (50 to 200 mg/kg) reduced serum levels of leptin, insulin, triglyceride, total cholesterol, and low density lipoprotein (LDL)-cholesterol. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that AM-Ex suppressed adipogenesis by decreasing CCAAT/enhancer binding protein α, peroxisome proliferator-activated receptor γ, sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor gamma coactivator-1α, acetyl-CoA carboxylase 1, ATP-citrate lyase, fatty acid synthase, and adipocyte protein 2 messenger RNA (mRNA) expressions. These results suggest that AM-Ex is potentially beneficial for the suppression of HFD-induced obesity by modulating multiple pathways associated with adipogenesis and food intake.

Intermittent Fasting in Cardiovascular Disorders-An Overview

Intermittent fasting is a form of time restricted eating (typically 16 h fasting and 8 h eating), which has gained popularity in recent years and shows promise as a possible new paradigm in the approach to weight loss and the reduction of inflammation, and has many potential long term health benefits. In this review, the authors will incorporate many aspects of fasting, mainly focusing on its effects on the cardiovascular system, involving atherosclerosis progression, benefits for diabetes mellitus type 2, lowering of blood pressure, and exploring other cardiovascular risk factors (such as lipid profile and inflammation).

[Pharmacogenetic markers of metabolic disorders in the treatment with valproic acid]

The review includes studies on the association between the use of VA drugs and weight gain in patients with epilepsy as well as other valproate-induced adverse drug reactions, including insulin resistance. Understanding the mechanisms of significant weight gain of patients taking VA drugs will help personalize antiepileptic therapy and minimize the risk of valproate-induced obesity.

Adipose-on-a-chip: a dynamic microphysiological in vitro model of the human adipose for immune-metabolic analysis in type II diabetes

Infiltration of immune cells into adipose tissue is associated with chronic low-grade inflammation in obese individuals. To better understand the crosstalk between immune cells and adipocytes, in vivo-like in vitro models are required. Conventionally transwell culture plates are used for studying the adipocyte-immune cell interaction; however, the static culture nature of this approach falls short of closely recapitulating the physiological environment. Here we present a compartmentalized microfluidic co-culture system which provides a constant-rate of nutrient supply as well as waste removal, resembling the microvascular networks of the in vivo environment. Human adipocytes and U937 cells were co-cultured in close proximity in an enclosed system. The porous barrier between the adjacent compartments comprises an array of microchannels, which enables paracrine interaction between cells in adjacent compartments and improved perfusion-based long term cell feeding. Human pre-adipocytes were fully differentiated into adipocytes on the chip and remained viable for several weeks. Upon co-culturing with immune cells, adipocytes showed a tendency to develop insulin resistance. The immune-metabolic correlation has been studied by monitoring adiponectin and IL-6 expression, as well as glucose uptake upon treatment with insulin. Our microfluidic system can be potentially used to develop physiologically relevant adipose tissue models to study obesity-associated diseases such as insulin resistance and type 2 diabetes and therefore, facilitate drug development to treat these diseases.

Association and biomarker potential of elevated serum adiponectin with nephropathy among type 1 and type 2 diabetics: A meta-analysis

Background

Managing nephropathy associated with diabetes mellitus warrant investigation of relevant biomarkers in predicting this condition. Adiponectin (ADP) may hold promise as a biomarker for diabetic nephropathy (DN). In this study, we examine associations of ADP with DN by meta-analyzing relevant literature. We also examined the predictive potential of ADP and estimate progression of DN.

Methods

Multi-database literature searches and serial omissions of articles yielded 13 studies for inclusion in the meta-analysis. We compared ADP levels between controls/ normoalbuminuria and cases with micro- and macroalbuminuria (MI and MA, respectively) as well as MI versus MA using standardized mean differences (SMD). Associations of ADP with DN were indicated with the P-value considered significant at ≤ 0.05. Subgrouping was based on diabetes type (1 and 2). Predictive potential of ADP was explored with AUC (area under the curve) derived from Receiver Operating Characteristic curve analysis.

Results and conclusion

At high P-values of <10⁻⁵, overall and subgroup outcomes indicated ADP associations with DN (up to SMD = 1.89–2.26, respectively). However, heterogeneity of the initial SMD effects (up to I² = 99%) warranted examination of their sources which with the Galbraith plot method, either eliminated or reduced their heterogeneity, signifying combinability of the studies. This feature along with consistency of significant associations, robust outcomes and significant AUC values provide good evidence of the associative and predictive roles of ADP in DN.

Do probiotics, prebiotics and synbiotics affect adiponectin and leptin in adults? A systematic review and meta-analysis of clinical trials

BACKGROUND & AIMS

Human studies have reported controversial findings regarding the health promoting effects of probiotic, prebiotic and synbiotic on adiponectin and leptin levels. This systematic review and meta-analysis was conducted to understand the effect of probiotics, prebiotics or synbiotics on adiponectin and leptin levels in adults.

METHODS

Electronic searches were performed in PubMed, Scopus, Web of Science, Cochrane Library and Google scholar up to February 11, 2018 without any restriction. Controlled clinical trials, in any age of adults, which reported the effect of probiotic, prebiotic and synbiotic on serum level of adiponectin and leptin were included. As leptin and adiponectin were reported in different units across the studies, Hedges's adjusted g was used to calculate effect size. A random-effects model was used to pool calculated effect sizes.

RESULTS

Of 12 eligible studies, 10 publications focused on probiotics, and only 3 studies reported the effect of prebiotics (n = 2) or synbiotics (n = 1) on leptin and adiponectin. There were no significant changes in adiponectin (Hedges' g = -0.04; 95% CI: -0.27, 0.19) and leptin (Hedges' g = -0.30; 95% CI: -0.86, 0.26) in probiotic group compared with controls. Subgroup analyses ranged in heterogeneity from 0% to 93%, but no subgroup showed an effect of probiotics on adiponectin or leptin.

CONCLUSION

There were limited studies regarding the effect of prebiotic and synbiotic on adiponectin and leptin. Although previous studies reported several health promoting effects of probiotics, we could not find any pooled effect on adiponectin and leptin.

Development of an In Vitro Screening Platform for the Identification of Partial PPARγ Agonists as a Source for Antidiabetic Lead Compounds

Type 2 diabetes (T2D) is a metabolic disorder where insulin-sensitive tissues show reduced sensitivity towards insulin and a decreased glucose uptake (GU), which leads to hyperglycaemia. Peroxisome proliferator-activated receptor (PPAR)γ plays an important role in lipid and glucose homeostasis and is one of the targets in the discovery of drugs against T2D. Activation of PPARγ by agonists leads to a conformational change in the ligand-binding domain, a process that alters the transcription of several target genes involved in glucose and lipid metabolism. Depending on the ligands, they can induce different sets of genes that depends of their recruitment of coactivators. The activation of PPARγ by full agonists such as the thiazolidinediones leads to improved insulin sensitivity but also to severe side effects probably due to their behavior as full agonists. Partial PPARγ agonists are compounds with diminished agonist efficacy compared to full agonist that may exhibit the same antidiabetic effect as full agonists without inducing the same magnitude of side effects. In this review, we describe a screening platform for the identification of partial PPARγ agonists from plant extracts that could be promising lead compounds for the development of antidiabetic drugs. The screening platform includes a series of in vitro bioassays, such as GU in adipocytes, PPARγ-mediated transactivation, adipocyte differentiation and gene expression as well as in silico docking for partial PPARγ agonism.

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

The Relation of Light-to-Moderate Alcohol Consumption to Glucose Metabolism and Insulin Resistance in Nondiabetic Adults: the Moderating Effects of Depressive Symptom Severity, Adiposity, and Sex

PURPOSE

We examined the relation of alcohol consumption to glucose metabolism and insulin resistance (IR) as a function of depressive symptoms, adiposity, and sex.

METHOD

Healthy adults (aged 18-65 years) provided fasting blood samples and information on lifestyle factors. Alcohol intake was categorized as never, infrequent (1-3 drinks/month), occasional (1-7 drinks/week), and regular (≥2 drinks/day) drinkers. The Beck Depression Inventory (BDI) was used to assess symptom severity. Primary outcomes were fasting insulin, glucose, and IR assessed by the homeostasis model assessment (HOMA).

RESULTS

In univariate analysis, alcohol consumption was negatively associated with HOMA-IR (p = 0.03), insulin (p = 0.007), and body mass index (BMI) (p = 0.04), but not with glucose or BDI. Adjusting for potential confounders including BMI, alcohol consumption was associated with HOMA-IR (p = 0.01) and insulin (p = 0.009) as a function of BDI and sex. For women with minimal depressive symptoms, light-to-moderate alcohol consumption was associated with lower HOMA-IR and insulin. Alcohol consumption was not associated with metabolic markers in women with higher depressive symptoms and in men. In analysis using BMI as a continuous moderator, alcohol consumption was only associated with insulin (p = 0.004). Post-hoc comparisons between BMI groups (<25 vs ≥25 kg/m²⁾ revealed that light-to-moderate alcohol consumption was associated with lower insulin but only in subjects with BMI ≥ 25 kg/m².

CONCLUSIONS

The benefits of light-to-moderate alcohol consumption on fasting insulin and IR are sex dimorphic and appear to be independently moderated by adiposity and depressive symptom severity.

Lower Levels of Serum Adiponectin and the T Allele of rs1501299 of the ADIPOQ Gene Are Protective against Polycystic Ovarian Syndrome in Jordan

Background

Polycystic ovary syndrome (PCOS) is a common reproductive disorder. Obesity, which is linked with lower adiponectin levels, increases a woman's risk of developing PCOS; however, the association between adiponectin and PCOS is controversial. Adiponectin levels could be affected by single nucleotide polymorphisms (SNPs) in the ADIPOQ gene. This study aimed to test the relationship between serum adiponectin and PCOS in Jordan and the association between the rs2241766, rs1501299, and rs266729 SNPs in the ADIPOQ gene and PCOS.

Methods

One hundred and fifty-four women with PCOS and 149 age- and body mass index-matched normally menstruating controls were recruited. Serum adiponectin levels were measured using enzyme-linked immunosorbent assay. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis.

Results

Serum adiponectin levels were significantly lower (P=0.0064) in PCOS women and rs1501299 (+276 G/T) genotype distributions were significantly different (P=0.01) between them and normally menstruating women. Multivariate analysis revealed that adiponectin levels remained significantly lower in PCOS women (P=0.001; odds ratio [OR], 0.9; 95% confidence interval [CI], 0.84-0.96). The GT genotype of rs1501299 increased the risk of PCOS (P<0.001; OR, 5.46; 95% CI, 2.42-12.33) and increased the risk of PCOS by three-fold (P<0.001; OR, 3.00; 95% CI, 1.36-6.60) relative to the TT genotype. The GG genotype increased the risk of PCOS as well (P<0.001; OR, 3:00; 95% CI, 1.36-6.60).

Conclusion

PCOS is associated with lower serum adiponectin levels independent of age and body mass index. The T allele of the rs1501299 (+276 G/T) SNP of the ADIPOQ gene protects against PCOS.

Parallels in Immunometabolic Adipose Tissue Dysfunction with Ageing and Obesity

Ageing, like obesity, is often associated with alterations in metabolic and inflammatory processes resulting in morbidity from diseases characterised by poor metabolic control, insulin insensitivity, and inflammation. Ageing populations also exhibit a decline in immune competence referred to as immunosenescence, which contributes to, or might be driven by chronic, low-grade inflammation termed "inflammageing". In recent years, animal and human studies have started to uncover a role for immune cells within the stromal fraction of adipose tissue in driving the health complications that come with obesity, but relatively little work has been conducted in the context of immunometabolic adipose function in ageing. It is now clear that aberrant immune function within adipose tissue in obesity-including an accumulation of pro-inflammatory immune cell populations-plays a major role in the development of systemic chronic, low-grade inflammation, and limiting the function of adipocytes leading to an impaired fat handling capacity. As a consequence, these changes increase the chance of multiorgan dysfunction and disease onset. Considering the important role of the immune system in obesity-associated metabolic and inflammatory diseases, it is critically important to further understand the interplay between immunological processes and adipose tissue function, establishing whether this interaction contributes to age-associated immunometabolic dysfunction and inflammation. Therefore, the aim of this article is to summarise how the interaction between adipose tissue and the immune system changes with ageing, likely contributing to the age-associated increase in inflammatory activity and loss of metabolic control. To understand the potential mechanisms involved, parallels will be drawn to the current knowledge derived from investigations in obesity. We also highlight gaps in research and propose potential future directions based on the current evidence.

Lifestyle and the Prevention of Type 2 Diabetes: A Status Report

Diabetes is a costly disease affecting 387 million individuals globally and 28 million in the United States. Its precursor, prediabetes, affects 316 and 86 million individuals globally and in the United States, respectively. People living with elevated blood glucose levels are at high risk for all-cause mortality and numerous cardiometabolic ailments. Fortunately, diabetes can be prevented or delayed by maintaining a healthy lifestyle and a healthy body weight. In this review, we summarize the literature around lifestyle diabetes prevention programs and provide recommendations for introducing prevention strategies in clinical practice. Overall, evidence supports the efficacy and effectiveness of lifestyle diabetes prevention interventions across clinical and community settings, delivery formats (eg, individual-, group-, or technology-based), and implementers (eg, clinicians, community members). Evidence-based diabetes prevention strategies that can be implemented in clinical practice include brief behavior change counseling, group-based education, community referrals, and health information technologies. These strategies represent opportunities where practitioners, communities, and health care systems can work together to provide individuals with education, support and opportunities to maintain healthy, diabetes-free lifestyles.

Severe degenerative aortic stenosis with preserved ejection fraction does not change adipokines serum levels

BACKGROUND

The role of the adipokines in the pathogenesis of aortic stenosis (AS) is not well established. The aim was to evaluate the relationship between adipokines and clinical characteristics as well as echocardiographic indices and noninvasive markers of vascular remodeling in patients with severe AS with preserved ejection fraction (EF).

METHODS

Sixty-five patients (F/M: 38/27; age: 68.3 ± 9.0 years; body mass index [BMI]: 29.6 ± 4.3 kg/m2) with severe AS with preserved EF: 33 patients with paradoxical low-flow low-gradient AS (PLFLG AS) and 32 patients with normal flow high-gradient AS (NFHG AS) were prospectively enrolled into the study. Twenty-four subjects (F/M: 14/10; age: 65.4 ± 8.7 years; BMI: 29.6 ± 4.3 kg/m2) who matched as to age, sex, BMI and coronary artery disease (CAD) constituted the control group (CG). Clinical data and markers of vascular remodeling were related to the serum adipokines.

RESULTS

There were no differences in the adipokines concentrations in the AS/CG. Patients with AS and coexisting CAD were characterized by decreased serum adiponectin (9.9 ± 5.5 vs. 12.7 ± 5.8 μg/mL, p = 0.040) and leptin (8.3 ± 7.8 vs. 21.6 ± 17.1 ng/mL, p < 0.001) levels compared to subjects without CAD. There were no differences in the serum adipokines concentrations between patients with PLFLG AS and NFHG AS. Systemic hypertension, diabetes, hyperlipidemia or markers of vascular remodeling did not discriminate adipokines concentrations. Multivariate regression analysis indicated that age (F = 3.02; p = 0.015) and E/E' index (F = 0.87, p = 0.032) were independent predictors of the adiponectin level in the AS group.

CONCLUSIONS

The presence of AS with preserved EF did not change the adipokine serum profile. Adipokines levels were modified by coexisting atherosclerosis but not the typical cardiovascular risk factors or the hemodynamic type of AS.

Fat-enriched rather than high-fructose diets promote whitening of adipose tissue in a sex-dependent manner

Adipose tissue is a critical regulator of energy metabolism and an effector organ of excessive caloric intake. We studied the effects of high-fructose (HFruD), high-fat (HFD) and mixed high-sucrose and high-fat diet (HFHSD) on adipocyte morphology and biology and consecutive metabolic effects in male and female C57BL/6 mice. Forty male and 40 female mice were randomly assigned to one of four dietary groups and fed for 10 weeks ad libitum. After 10 weeks of feeding, mice were analyzed in regard to glucose metabolism, insulin sensitivity and alteration in adipocyte morphology and function. Weight gain and diminished insulin sensitivity in HFD- and HFHSD-fed mice were accompanied by increased adipocyte size and a shift in size distribution towards larger adipocytes in all mice. The latter effect was also found but less pronounced in HFruD-fed mice, while insulin sensitivity and body weight remained unaffected. In male mice, expansion of white adipocytes along with decreased uncoupling protein 1 (UCP-1) expression and alterations of mitochondrial biogenesis was found after HFD and HFHSD feeding, while in female mice, UCP-1 expression was also reduced in the HFruD dietary group. Diet-induced cellular alterations were less pronounced in female mice. Our data demonstrate that high-fat rather than high fructose consumption drives metabolically disadvantageous alterations of adipocyte differentiation involving whitening and insulin resistance in a sex-dependent manner with most deleterious effects seen upon administration of combined sucrose and fat-enriched diet in male mice.

Molecular mechanisms underlying metabolic syndrome: the expanding role of the adipocyte

The metabolic syndrome (MetS) is defined as a cluster of 3 or more metabolic and cardiovascular risk factors and represents a serious problem for public health. Altered function of adipose tissue has a significant impact on whole-body metabolism and represents a key driver for the development of these metabolic derangements, collectively referred as to MetS. In particular, increased visceral and ectopic fat deposition play a major role in the development of insulin resistance and MetS. A large body of evidence demonstrates that aging and MetS share several metabolic alterations. Of importance, molecular pathways that regulate lifespan affect key processes of adipose tissue physiology, and transgenic mouse models with adipose-specific alterations in these pathways show derangements of adipose tissue and other metabolic features of MetS, which highlights a causal link between dysfunctional adipose tissue and deleterious effects on whole-body homeostasis. This review analyzes adipose tissue-specific dysfunctions, including metabolic alterations that are related to aging, that have a significant impact on the development of MetS.-Armani, A., Berry, A., Cirulli, F., Caprio, M. Molecular mechanisms underlying metabolic syndrome: the expanding role of the adipocyte.

Effects of Coenzyme Q10 on Markers of Inflammation: A Systematic Review and Meta-Analysis

Background/Objective

Chronic inflammation contributes to the onset and development of metabolic diseases. Clinical evidence has suggested that coenzyme Q10 (CoQ10) has some effects on inflammatory markers. However, these results are equivocal. The aim of this systematic review was to assess the effects of CoQ10 on serum levels of inflammatory markers in people with metabolic diseases.

Methods

Electronic databases were searched up to February 2016 for randomized controlled trials (RCTs). The outcome parameters were related to inflammatory factors, including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and C reactive protein (CRP). RevMan software was used for meta-analysis. Meta-regression analysis, Egger line regression test and Begg rank correlation test were performed by STATA software.

Results

Nine trials involving 428 subjects were included in this meta-analysis. The results showed that compared with control group, CoQ10 supplementation has significantly improved the serum level of CoQ10 by 1.17μg/ml [MD = 1.17, 95% CI (0.47 to 1.87) μg/ml, I² = 94%]. Meanwhile, it has significantly decreased TNF-α by 0.45 pg/ml [MD = -0.45, 95% CI (-0.67 to -0.24) pg/ml, I² = 0%]. No significant difference was observed between CoQ10 and placebo with regard to CRP [MD = -0.21, 95% CI (-0.60 to 0.17) mg/L, I² = 21%] and IL-6 [MD = -0.89, 95% CI (-1.95 to 0.16) pg/ml, I² = 84%].

Conclusions

CoQ10 supplementation may partly improve the process of inflammatory state. The effects of CoQ10 on inflammation should be further investigated by conducting larger sample size and well-defined trials of long enough duration.

Serum Concentrations of Leptin and Adiponectin in Dogs with Myxomatous Mitral Valve Disease

Background

The concentrations of circulating adipokines in dogs with myxomatous mitral valve disease (MMVD) have not been investigated in detail.

Objectives

To determine whether serum concentrations of adipokines differ between healthy dogs and dogs with MMVD and whether circulating concentrations depend on the severity of heart failure resulting from MMVD.

Animals

In the preliminary study, 30 healthy dogs and 17 client‐owned dogs with MMVD, and in the subsequent study, 30 healthy dogs and 46 client‐owned dogs with MMVD.

Methods

Prospective case‐controlled observational study. In the preliminary study, serum concentrations of leptin, adiponectin, resistin, visfatin, interleukin (IL)‐1β, IL‐6, IL‐10, IL‐18, and tumor necrosis factor‐α were measured. In the subsequent study, MMVD dogs were divided into three groups according to the International Small Animal Cardiac Health Council (ISACHC) classification, and serum concentrations of leptin and adiponectin were measured.

Results

In the preliminary study, serum leptin and adiponectin concentrations differed significantly between dogs with MMVD and healthy dogs. Serum leptin (P = .0013) concentrations were significantly higher in dogs with MMVD than in healthy dogs, whereas adiponectin (P = .0009) concentrations were significantly lower in dogs with MMVD. However, we observed no significant differences in the other variables. In the subsequent study, dogs classified as ISACHC class 3 had higher serum concentrations of leptin (P = .0022) than healthy dogs but ISACHC class 1 or 2 dogs did not. Serum adiponectin concentrations were significantly lower in ISACHC class 1 (P < .0001) dogs than in healthy dogs, whereas adiponectin concentrations in ISACHC class 3 dogs were significantly higher than in ISACHC class 1 dogs (P = .0081).

Conclusions and Clinical Importance

Circulating concentrations of leptin and adiponectin might be altered in dogs with MMVD.

The role of autophagy in cardiac hypertrophy

Autophagy is conserved in nature from lower eukaryotes to mammals and is an important self-cannibalizing, degradative process that contributes to the elimination of superfluous materials. Cardiac hypertrophy is primarily characterized by excess protein synthesis, increased cardiomyocyte size, and thickened ventricular walls and is a major risk factor that promotes arrhythmia and heart failure. In recent years, cardiomyocyte autophagy has been considered to play a role in controlling the hypertrophic response. However, the beneficial or aggravating role of cardiomyocyte autophagy in cardiac hypertrophy remains controversial. The exact mechanism of cardiomyocyte autophagy in cardiac hypertrophy requires further study. In this review, we summarize the controversies associated with autophagy in cardiac hypertrophy and provide insights into the role of autophagy in the development of cardiac hypertrophy. We conclude that future studies should emphasize the relationship between autophagy and the different stages of cardiac hypertrophy, as well as the autophagic flux and selective autophagy. Autophagy will be a potential therapeutic target for cardiac hypertrophy.

Aortic valve sclerosis is associated with lower serum adiponectin levels

AIMS

The sclerotic lesions of the aortic valve share common features with atherosclerosis. An anti-inflammatory protein, adiponectin, seems to have a protective effect on the cardiovascular system. The goal of our study is to determine adiponectin levels in patients with aortic sclerosis and to compare these values with the control group with similar age and cardiovascular risk profile.

METHODS

Sixty-eight patients with aortic sclerosis and 40 controls were included. Serum adiponectin levels were measured by solid-phase enzyme-linked immunosorbent assay.

RESULTS

There were no significant differences regarding age, sex and other cardiovascular risk factors between groups. Also, mean body mass index values were similar. The rate of mitral annular calcification and left ventricular hypertrophy were significantly higher in patients with aortic sclerosis. Among laboratory variables, high-sensitive C-reactive protein (hsCRP) levels were significantly higher in patients with aortic sclerosis than in those without (4.0 ± 2.9 vs. 2.9 ± 2.3 mg/dl, P = 0.04). Adiponectin levels were found to be significantly lower in aortic sclerosis group than in controls (9.7 ± 4.4 vs. 11.7 ± 4.9 μg/ml, P = 0.034). In the whole group, adiponectin levels were significantly correlated with BMI (r = -0.22, P = 0.02), white blood cell count (r = -0.2, P = 0.03), hsCRP (r = -0.25, P = 0.008), total cholesterol (r = -0.18, P = 0.05), high-density lipoprotein (HDL) cholesterol (r = 0.31, P = 0.001) and triglyceride (r = -0.36, P < 0.001).

CONCLUSION

In patients with aortic sclerosis, serum adiponectin levels were significantly lower compared with those with normal aortic valves. Our findings suggested that adiponectin might play a role in the progression of degenerative aortic valve disease.

Molecular Regulation of Adipogenesis and Potential Anti-Adipogenic Bioactive Molecules

Adipogenesis is the process by which precursor stem cells differentiate into lipid laden adipocytes. Adipogenesis is regulated by a complex and highly orchestrated gene expression program. In mammalian cells, the peroxisome proliferator-activated receptor γ (PPARγ), and the CCAAT/enhancer binding proteins (C/EBPs) such as C/EBPα, β and δ are considered the key early regulators of adipogenesis, while fatty acid binding protein 4 (FABP4), adiponectin, and fatty acid synthase (FAS) are responsible for the formation of mature adipocytes. Excess accumulation of lipids in the adipose tissue leads to obesity, which is associated with cardiovascular diseases, type II diabetes and other pathologies. Thus, investigating adipose tissue development and the underlying molecular mechanisms is vital to develop therapeutic agents capable of curbing the increasing incidence of obesity and related pathologies. In this review, we address the process of adipogenic differentiation, key transcription factors and proteins involved, adipogenic regulators and potential anti-adipogenic bioactive molecules.

[Adiponectin in health and disease]

Over the past 20 years after the discovery of adiponectin, much knowledge about its effect in health and disease has been gained. Adiponectin has antidiabetic, antiatherogenic, anti-inflammatory, immunomodulatory, metabolic, vasoprotective, and antiapoptotic properties. However, an understanding stems from the given literature review that much remains to be explored. Adiponectin has not yet commonly used in clinical practice, but cardiologists, endocrinologists, pediatricians, oncologists, and physicians of many specialties are interested in its preventive and therapeutic applications.

Effect of adiponectin on expression of vascular endothelial growth factor and pigment epithelium-derived factor: an in vitro study

Aim:

This study was carried out to identify the role of adiponectin (APN) in modulating the expression of vascular endothelial growth factor (VEGF) and pigment epithelial-derived factor (PEDF) in relation to ocular angiogenesis.

Materials and Methods:

Human retinal pigment epithelial cell lines (ARPE-19) were cultured in Dulbeco's minimum essential medium with 10% fetal bovine serum (FBS) and exposed to varying concentrations of recombinant adiponectin (5–5 ng/ml) for 1 h. Analysis of VEGF and PEDF mRNA was done by reverse transcriptase and further quantified by quantitative polymerase chain reaction. VEGF and PEDF protein expression were studied using enzyme-linked immune sorbent assay (ELISA).

Statistical Analysis:

Unpaired Student's t-test was used to analyze the significance. P < 0.05 was accepted as statistically significant.

Results:

ARPE cells exposed to APN showed decreased expression of VEGF mRNA, protein whereas PEDF protein is unaltered and PEDF mRNA was increased.

Conclusion:

Our in vitro study on ARPE exposed to APN showed a negative correlation with VEGF levels. Thus indicating the protective role for APN in angiogenesis-related diseases.

Second-generation antipsychotics and adiponectin levels in schizophrenia: A comparative meta-analysis

People with schizophrenia treated with second-generation antipsychotics (SGAs) have lower plasma adiponectin levels, as compared with general population, that may lead to metabolic abnormalities. However, the contribution of different SGAs on adiponectin dysregulation is still unclear. The objective of this systematic review and meta-analysis was to estimate differences in adiponectin levels among people with schizophrenia treated with different SGAs. We systematically searched for observational studies published up to March 2015 in main electronic databases. Different SGAs were included if data on adiponectin were available from at least three different samples involving as a minimum five participants per treatment arm. Standardized mean differences with relevant 95% confidence intervals were generated. I(2) was used to test heterogeneity among studies. Eight studies were included with data suitable for carrying out four different comparisons: Clozapine vs. Olanzapine (including n=877 individuals with schizophrenia); Clozapine vs. Risperidone (n=660); Olanzapine vs. Risperidone (n=738); Quetiapine vs. Risperidone (n=186). There were no differences on adiponectin levels between people taking Clozapine and those taking Olanzapine (p=0.86), but high heterogeneity was detected (I(2)=82%). Both individuals taking Clozapine (p<0.001; I(2)=0%) and those taking Olanzapine (p=0.02; I(2)=9%), but not subjects treated with Quetiapine (p=0.47; I(2)=0%), had adiponectin levels significantly lower than people taking Risperidone. Our findings are consistent with previous evidence showing greater metabolic abnormalities attributable to Clozapine and Olanzapine, as compared with other SGAs. Although mechanisms whereby both these SGAs influence adiponectin remain unexplained, its reduction might mediate relevant abnormalities. Prospective evaluations of long-term effects of different SGAs on adiponectin are needed.

Deficiency in adiponectin exaggerates cigarette smoking exposure-induced cardiac contractile dysfunction: Role of autophagy

Second hand smoke is an independent risk factor for cardiovascular disease. Adiponectin (APN), an adipose-derived adipokine, has been shown to offer cardioprotective effect through an AMPK-dependent manner. This study was designed to evaluate the impact of adiponectin deficiency on second hand smoke-induced cardiac pathology and underlying mechanisms using a mouse model of side-stream smoke exposure. Adult wild-type (WT) and adiponectin knockout (APNKO) mice were placed in a chamber exposed to cigarette smoke for 1 hour daily for 40 days. Echocardiographic, cardiomyocyte function, and intracellular Ca2+ handling were evaluated. Autophagy and apoptosis were examined using western blot. 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) staining was used to evaluate reactive oxygen species (ROS) generation. Masson trichrome staining was employed to measure interstitial fibrosis. Our data revealed that adiponectin deficiency provoked smoke exposure-induced cardiomyopathy (compromised fractional shortening, disrupted cardiomyocyte function and intracellular Ca2+ homeostasis, apoptosis and ROS generation). In addition, these detrimental effects of side-stream smoke were accompanied by defective autophagolysosome formation, the effect of which was exacerbated by adiponectin deficiency. Blocking autophagolysosome formation using bafilomycin A1 (BafA1) negated the cardioprotective effect of rapamycin against smoke extract. Induction of autophagy using rapamycin and AMPKα activation using AICAR rescued against smoke extract-induced myopathic anomalies in APNKO mice. Our data suggest that adiponectin serves as an indispensable cardioprotective factor against side-stream smoke exposure-induced myopathic changes possibly through facilitating autophagolysosome formation.

Plasma adiponectin levels in schizophrenia and role of second-generation antipsychotics: a meta-analysis

BACKGROUND

People with schizophrenia are more likely than general population to suffer from metabolic abnormalities, with second-generation antipsychotics (SGAs) increasing the risk. Low plasma adiponectin levels may lead to metabolic dysregulations but evidence in people with schizophrenia, especially for the role of SGAs, is still inconclusive.

OBJECTIVE

To compare plasma adiponectin levels between people with schizophrenia and healthy controls, and to estimate the relative effect of schizophrenia and SGAs on adiponectin.

METHODS

We performed a systematic review and meta-analysis of observational studies published up to 13 June 2014 in main electronic databases. Pooled standardized mean differences (SMDs) between index and control groups were generated. Appropriate subanalyses and additional subgroup analyses were carried out.

RESULTS

Data from 2735 individuals, 1013 with and 1722 without schizophrenia, respectively, were analysed. Schizophrenia was not associated with lower adiponectin levels (SMD of -0.28, 95%CI: -0.59, 0.04; p=0.09). However, individuals with schizophrenia taking SGAs had plasma levels significantly lower than controls (p=0.002), which was not the case of drug free/drug naïve subjects (p=0.52). As regards single antipsychotic drugs clozapine (p<0.001) and olanzapine (p=0.04)--but not risperidone (p=0.88)--were associated with adiponectin levels lower than controls.

CONCLUSIONS

People with schizophrenia per se may not have levels of adiponectin lower than controls, though treatment with SGAs is associated with this metabolic abnormality. This bears clinical significance because of hypoadiponectinemia involvement in cardiovascular diseases, even if mechanisms whereby SGAs affect adiponectin remain unexplained. Longitudinal studies evaluating long-term effects of SGAs on adiponectin are needed.

Additive regulation of adiponectin expression by the mediterranean diet olive oil components oleic Acid and hydroxytyrosol in human adipocytes

Adiponectin, an adipocyte-derived insulin-sensitizing and anti-inflammatory hormone, is suppressed in obesity through mechanisms involving chronic inflammation and oxidative stress. Olive oil consumption is associated with beneficial cardiometabolic actions, with possible contributions from the antioxidant phenol hydroxytyrosol (HT) and the monounsaturated fatty acid oleic acid (OA, 18:1n-9 cis), both possessing anti-inflammatory and vasculo-protective properties. We determined the effects of HT and OA, alone and in combination, on adiponectin expression in human and murine adipocytes under pro-inflammatory conditions induced by the cytokine tumor necrosis factor(TNF)-α. We used human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes and murine 3T3-L1 adipocytes as cell model systems, and pretreated them with 1-100 μmol/L OA, 0.1-20 μmol/L HT or OA plus HT combination before stimulation with 10 ng/mL TNF-α. OA or HT significantly (P<0.05) prevented TNF-α-induced suppression of total adiponectin secretion (by 42% compared with TNF-α alone) as well as mRNA levels (by 30% compared with TNF-α alone). HT and OA also prevented-by 35%-TNF-α-induced downregulation of peroxisome proliferator-activated receptor PPARγ. Co-treatment with HT and OA restored adiponectin and PPARγ expression in an additive manner compared with single treatments. Exploring the activation of JNK, which is crucial for both adiponectin and PPARγ suppression by TNF-α, we found that HT and OA additively attenuated TNF-α-stimulated JNK phosphorylation (up to 55% inhibition). In conclusion, the virgin olive oil components OA and HT, at nutritionally relevant concentrations, have additive effects in preventing adiponectin downregulation in inflamed adipocytes through an attenuation of JNK-mediated PPARγ suppression.

Valproic acid and nonalcoholic fatty liver disease: A possible association?

Valproic acid (VPA) is one of the most prescribed drugs in children with newly diagnosed epilepsy. Weight gain and obesity have been observed as side effects of VPA. These are often linked with other metabolic disturbances such as development of insulin resistance, dyslipidemia, metabolic syndrome (MetS) and non-alcoholic fatty liver disease or nonalcoholic fatty liver disease (NAFLD). NAFLD refers to a group of liver disorders with marked hepatic steatosis. It is associated with an increased incidence of cardiovascular diseases and overall reduced life expectancy. NAFLD occurs in 20%-25% of the general population and it is known to be the most common cause of chronic liver disease. NAFLD therefore represents a major public health issue worldwide. This study reviews and summarizes relevant literature that supports the existence of an association between VPA therapy and the development of NAFLD in children. Long-term VPA-therapy appears to be associated with an increased risk of developing NAFLD. Further studies are needed to clarify the pathogenic mechanisms that lie behind this association and to standardize the options for the use of this drug in overweight patients and in those with risks for developing MetS and NAFLD.

The Role of Metformin in Metabolic Disturbances during Pregnancy: Polycystic Ovary Syndrome and Gestational Diabetes Mellitus

Maintenance of gestation implicates complex function of multiple endocrine mechanisms, and disruptions of the global metabolic environment prompt profound consequences on fetomaternal well-being during pregnancy and postpartum. Polycystic Ovary Syndrome (PCOS) and gestational diabetes mellitus (GDM) are very frequent conditions which increase risk for pregnancy complications, including early pregnancy loss, pregnancy-induced hypertensive disorders, and preterm labor, among many others. Insulin resistance (IR) plays a pivotal role in the pathogenesis of both PCOS and GDM, representing an important therapeutic target, with metformin being the most widely prescribed insulin-sensitizing antidiabetic drug. Although traditional views neglect use of oral antidiabetic agents during pregnancy, increasing evidence of safety during gestation has led to metformin now being recognized as a valuable tool in prevention of IR-related pregnancy complications and management of GDM. Metformin has been demonstrated to reduce rates of early pregnancy loss and onset of GDM in women with PCOS, and it appears to offer better metabolic control than insulin and other oral antidiabetic drugs during pregnancy. This review aims to summarize key aspects of current evidence concerning molecular and epidemiological knowledge on metformin use during pregnancy in the setting of PCOS and GDM.

Effect of therapeutic dose of vitamin d on serum adiponectin and glycemia in vitamin d-insufficient or deficient type 2 diabetic patients

Background:

Lower vitamin D status has been reported in diabetic patients. Serum 25-hydroxyvitamin D and adiponectin were inversely associated with type 2 diabetes and insulin resistance. Vitamin D may involve in regulation of the adiponectin levels, which is directly related to insulin sensitivity.

Objectives:

The aim of this study was to investigate the effect of therapeutic dose of vitamin D on serum adiponectin and insulin resistance in vitamin D-insufficient or deficient type 2 diabetic patients.

Materials and Methods:

This double-blind, randomized, clinical trial was conducted on 81 type 2 diabetic patients with vitamin D level of 10-30 ng/mL. Intervention was 50000 IU vitamin D or placebo once a week for 8 weeks. At the beginning and end of the study, blood samples were collected after 12 hours of fasting and serum glucose, insulin, 25-hydroxyvitamin D, and adiponectin were measured. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR).

Results:

After 8-week intervention, serum 25-hydroxyvitamin D significantly increased and reached the normal levels in patients receiving vitamin D (P < 0.001) and the levels of fasting serum glucose, insulin, and HOMA-IR were significantly decreased (P = 0.04, 0.02 and 0.007, respectively). No significant changes were observed in these levels in the placebo group. Significant differences were observed in mean changes in the above-mentioned variables between the two groups (P = 0.01, 0.04 and 0.006, respectively). No significant changes were found in serum adiponectin in the vitamin D and placebo groups (P = 0.83).

Conclusions:

Therapeutic dose of vitamin D can improve vitamin D status and glycemic indicators. But it seems that an 8-week intervention period was not sufficient to reveal the possible effects of vitamin D on serum adiponectin levels.

Vaspin and lipocalin-2 levels in severe obsructive sleep apnea

BACKGROUND

Vaspin and lipocalin-2 are less-known recent members of adipocytokine family. There are ongoing studies investigating the role of vaspin ve lipocalin-2 in metabolic syndrome (MS). Obstructive sleep apnea syndrome (OSAS) is independently associated with an increased prevalence of MS. We aimed to measure the levels of vaspin and lipocalin-2 which are secreted from adipocytes in patients with severe OSAS and examine the relationship between these two adipocytokines and OSAS.

METHODS

THE STUDY CONSISTED OF TWO GROUPS: severe OSAS patients with an apnea-hypopnea index (AHI) of >30/h (OSAS group, 34 subjects) and age-matched healthy volunteers with a AHI <5/h (control group, 25 subjects) Serum levels of vaspin and lipocalin-2 in these two groups were compared.

RESULTS

Serum levels of vaspin were significantly lower in OSAS group; patients with severe OSAS compared with control group; healthy volunteers (OSAS group: 0.69±0.5 vs. control group: 1.24±1.13; P=0.034). The difference between the two groups in terms of serum levels of lipocalin-2 has not reached statistical significance (OSAS group: 61.6±18.2 vs. control group: 68.5±20.1; P=0.17).

CONCLUSIONS

We found that serum vaspin levels were significantly lower in patients with severe OSAS compared with healthy controls. Lipocalin-2 levels were similar. The decrease in serum vaspin levels in severe OSAS patients may be important in diagnosis and follow-up of these patients.

Adiponectin: a manifold therapeutic target for metabolic syndrome, diabetes, and coronary disease?

Adiponectin is the most abundant peptide secreted by adipocytes, being a key component in the interrelationship between adiposity, insulin resistance and inflammation. Central obesity accompanied by insulin resistance is a key factor in the development of metabolic syndrome (MS) and future macrovascular complications. Moreover, the remarkable correlation between coronary artery disease (CAD) and alterations in glucose metabolism has raised the likelihood that atherosclerosis and type 2 diabetes mellitus (T2DM) may share a common biological background. We summarize here the current knowledge about the influence of adiponectin on insulin sensitivity and endothelial function, discussing its forthcoming prospects and potential role as a therapeutic target for MS, T2DM, and cardiovascular disease. Adiponectin is present in the circulation as a dimer, trimer or protein complex of high molecular weight hexamers, >400 kDa. AdipoR1 and AdipoR2 are its major receptors in vivo mediating the metabolic actions. Adiponectin stimulates phosphorylation and AMP (adenosin mono phosphate) kinase activation, exerting direct effects on vascular endothelium, diminishing the inflammatory response to mechanical injury and enhancing endothelium protection in cases of apolipoprotein E deficiency. Hypoadiponectinemia is consistently associated with obesity, MS, atherosclerosis, CAD, T2DM. Lifestyle correction helps to favorably modify plasma adiponectin levels. Low adiponectinemia in obese patients is raised via continued weight loss programs in both diabetic and nondiabetic individuals and is also accompanied by reductions in pro-inflammatory factors. Diet modifications, like intake of fish, omega-3 supplementation, adherence to a Mediterranean dietary pattern and coffee consumption also increase adiponectin levels. Antidiabetic and cardiovascular pharmacological agents, like glitazones, glimepiride, angiotensin converting enzyme inhibitors and angiotensin receptor blockers are also able to improve adiponectin concentration. Fibric acid derivatives, like bezafibrate and fenofibrate, have been reported to enhance adiponectin levels as well. T-cadherin, a membrane-associated adiponectin-binding protein lacking intracellular domain seems to be a main mediator of the antiatherogenic adiponectin actions. The finding of novel pharmacologic agents proficient to improve adiponectin plasma levels should be target of exhaustive research. Interesting future approaches could be the development of adiponectin-targeted drugs chemically designed to induce the activaton of its receptors and/or postreceptor signaling pathways, or the development of specific adiponectin agonists.

Adiponectin levels are reduced while markers of systemic inflammation and aortic remodelling are increased in intrauterine growth restricted mother-child couple

AIM OF THE STUDY

To investigate the relationships between the adipocytokine levels, markers of inflammation, and vascular remodelling in pregnancies complicated by intrauterine growth restriction (IUGR).

MATERIALS AND METHODS

This was a retrospective study. One hundred and forty pregnant patients were enrolled. Adiponectin, leptin, tumor necrosis factor α (TNFα), interleukin-6 (IL-6), and C reactive protein (CRP) were assessed in IUGR, small for gestational age (SGA), and appropriate for gestational age (AGA) mother-child couples at delivery. IUGR and SGA fetuses were defined as fetuses whose estimated fetal weight (EFW) was below 10th percentile for gestational age with and without umbilical artery (UA) Doppler abnormalities, respectively. Fetal aorta intima media thickness (aIMT) was evaluated by ultrasound in the same fetal groups. Data were analyzed by R (version 2.15.2).

RESULTS

There were 37 IUGR mother-child couples, 33 SGA, and 70 AGA. Leptin, TNFα, IL-6, and CRP serum levels were higher in IUGR pregnant patients (P < 0.05). Adiponectin levels were significantly reduced in IUGR fetuses compared to SGA and AGA, while leptin, TNFα, and IL-6 levels were higher in IUGR group (P ≤ 0.05). Fetal aIMT was significantly higher in IUGR (P < 0.05) and in this group there was a negative correlation between aIMT and adiponectin/leptin ratio (A/L ratio) (P < 0.05) and between adiponectin and IL-6 levels (P < 0.05).

CONCLUSIONS

In conclusion, compared to SGA and AGA, IUGR fetuses had reduced circulating levels of adiponectin and elevated measures of aIMT and several inflammatory markers. Moreover, adiponectin levels were negatively correlated with aIMT in IUGR fetuses suggesting a possible causal link between reduced adiponectin and vessel remodelling.

Adiponectin protects against hyperoxic lung injury and vascular leak

Adiponectin (Ad), an adipokine exclusively secreted by the adipose tissue, has emerged as a paracrine metabolic regulator as well as a protectant against oxidative stress. Pharmacological approaches of protecting against clinical hyperoxic lung injury during oxygen therapy/treatment are limited. We have previously reported that Ad inhibits the NADPH oxidase-catalyzed formation of superoxide from molecular oxygen in human neutrophils. Based on this premise, we conducted studies to determine whether (i) exogenous Ad would protect against the hyperoxia-induced barrier dysfunction in the lung endothelial cells (ECs) in vitro, and (ii) endogenously synthesized Ad would protect against hyperoxic lung injury in wild-type (WT) and Ad-overexpressing transgenic (AdTg) mice in vivo. The results demonstrated that exogenous Ad protected against the hyperoxia-induced oxidative stress, loss of glutathione (GSH), cytoskeletal reorganization, barrier dysfunction, and leak in the lung ECs in vitro. Furthermore, the hyperoxia-induced lung injury, vascular leak, and lipid peroxidation were significantly attenuated in AdTg mice in vivo. Also, AdTg mice exhibited elevated levels of total thiols and GSH in the lungs as compared with WT mice. For the first time, our studies demonstrated that Ad protected against the hyperoxia-induced lung damage apparently through attenuation of oxidative stress and modulation of thiol-redox status.

Comprehensive analysis of circulating adipokines and hsCRP association with cardiovascular disease risk factors and metabolic syndrome in Arabs

Background

Cardiovascular diseases (CVD) are a leading cause of death worldwide including the Middle East. This is caused in part by the dysregulation of adipose tissue leading to increased production of pro-inflammatory adipokines and reduction in cardio-protective adipokines such as adiponectin. Ethnicity has been recognized as a major factor in the association between CVD risk factors and the different circulating adipokines. In this study, for the first time, the relationship between traditional cardiovascular risk factors, Metabolic Syndrome (MetS) and circulating level of adipokines in Arab ethnicity was investigated.

Methods

We conducted a population-based cross-sectional survey on 379 adult Arab participants living in Kuwait. Traditional cardiovascular risk factors such as blood pressure (BP), low density lipoprotein (LDL) and triglyceride (TG) were measured. Plasma levels of circulating Leptin, Plasminogen Activator Inhibitor (PAI-1) visfatin, adiponectin, resistin and adipsin were assessed using the multiplexing immunobead-based assay.

Results

Circulating levels of High sensitivity C-Reactive Protein (hsCRP), Leptin, PAI-1 and adiponectin were significantly higher in Arab women than men (p < 0.0001). In multi-variate analysis, the homeostasis model assessment-insulin resistance (HOMA-IR) and body mass index (BMI) showed strong association with most of the biomarkers (p < 0.05). HsCRP showed significant association with all risk factors (p < 0.05). Leptin, PAI-1 and adipsin showed significant positive correlation with BMI, unlike adiponectin which showed inverse correlation (p < 0.05). Subjects in the highest tertile of leptin, PAI-1 and hsCRP had higher odds of having Metabolic Syndrome (MetS) (odd ratio [OR] = 3.02, 95% confidence interval [CI] = 1.47 – 6.19) and (OR = 2.52, 95% CI = 1.45 – 4.35), (OR = 4.26, 95% CI = 2.39 – 7.59) respectively. On the other hand subjects with highest tertile of adiponectin had lower odds of having MetS (OR = 0.22, 95% CI = 0.12 – 0.40). Leptin, PAI-1 and hsCRP showed significant positive association with increased MetS components (P-trend <0.05), while adiponectin was negatively associated with increased MetS components (P-trend <0.0001).

Conclusion

Our results show positive association between hsCRP, leptin, PAI-1 with increased MetS components and increase the odds of having MetS. Adiponectin on the other hand showed inverse correlation with MetS components and associated with reduction in MetS. Overall, our data highlights the significant clinical value these markers have in MetS especially hsCRP which can be used as good marker of low grade inflammation in Arabs.

Short-term physical inactivity impairs vascular function

BACKGROUND

Sedentarism, also termed physical inactivity, is an independent risk factor for cardiovascular diseases. Mechanisms thought to be involved include insulin resistance, dyslipidemia, hypertension, and increased inflammation. It is unknown whether changes in vascular and endothelial function also contribute to this excess risk. We hypothesized that short-term exposure to inactivity would lead to endothelial dysfunction, arterial stiffening, and increased vascular inflammation.

METHODS

Five healthy subjects (four men and one woman) underwent 5 d of bed rest (BR) to simulate inactivity. Measurements of vascular function (flow-mediated vasodilation to evaluate endothelial function; applanation tonometry to assess arterial resistance), inflammation, and metabolism were made before BR, daily during BR, and 2 d after BR recovery period. Subjects maintained an isocaloric diet throughout.

RESULTS

BR led to significant decreases in brachial artery and femoral artery flow-mediated vasodilation (brachial: 11 ± 3% pre-BR versus 9 ± 2% end-BR, P = 0.04; femoral: 4 ± 1% versus 2 ± 1%, P = 0.04). The central augmentation index increased with BR (-4 ± 9% versus 5 ± 11%, P = 0.03). Diastolic blood pressure increased (58 ± 7 mm Hg versus 62 ± 7 mm Hg, P = 0.02), whereas neither systolic blood pressure nor heart rate changed. 15-Hydroxyeicosatetraenoic acid, an arachidonic acid metabolite, increased but the other inflammatory and metabolic biomarkers were unchanged.

CONCLUSIONS

Our findings show that acute exposure to sedentarism results in decreased endothelial function, arterial stiffening, increased diastolic blood pressure, and an increase in 15-hydroxyeicosatetraenoic acid. We speculate that inactivity promotes a vascular "deconditioning" state characterized by impaired endothelial function, leading to arterial stiffness and increased arterial tone. Although physiologically significant, the underlying mechanisms and clinical relevance of these findings need to be further explored.

Additional effect of diabetes mellitus type 2 on the risk of coronary artery disease: role of serum adiponectin

Background:

Adiponectin, an adipocyte-derived hormone, is implicated in diabetes mellitus type 2 and atherosclerosis. The study was designed to investigate whether serum adiponectin levels in patients with both coronary artery disease (CAD) and diabetes mellitus type 2 (T2DM) are lower than in patients with CAD alone and control subjects.

Objectives:

In this present study, we measured serum adiponectin levels in consecutive CAD patients with and without T2DM and investigated whether decreased adiponectin is associated with risk factors of CAD.

Materials and Methods:

The study included 198 subjects, 138 patients with CAD (72 of whom had both CAD and T2DM), and 60 control subjects. We measured serum adiponectin, interleukin-6 (IL-6) and insulin by ELISA. In addition, Lipid profile, glucose and anthropometrical measurements were performed in all subjects.

Results:

The results revealed significant difference in serum adiponectin levels between patients with CAD+T2DM and patients with CAD alone (3.80 ± 1.52 vs. 5.25 ± 2.35, P = 0.007), between patients with CAD and control (5.25 ± 2.35 vs. 7.04 ± 3.32, P = 0.001), and between patients with CAD + T2DM and control (3.80 ± 1.52 vs. 7.04 ± 3.32, P < 0.001). Serum adiponectin level was significantly higher in women in contrast to men (5.97 ± 3.15 vs. 4.62 ± 2.81 µg/ml, P = 0.002). Serum adiponectin levels were correlated significantly with insulin (r = -0.178, P = 0.013), total cholesterol (r = -0.313, P < 0.001), low density lipoprotein (r = -0.154, P = 0.016), body mass index (r = -0.171, P = 0.016), glucose (r = -0.202, P = 0.006), HOMA-IR (r= -0.251, P = 0.001), and IL-6 levels (r = -0.321, P = 0.001). Adiponectin was correlated positively only with high density lipoprotein (r = 0.389, P < 0.001).

Conclusions:

It is speculated that increased insulin resistance and increase in other adipokines such as IL-6 may contribute to the decreased serum levels of adiponectin in patients with both CAD and T2DM.

The role of adiponectin gene variants in glycemic control in patients with Type 2 diabetes

The aim of this study was to investigate the association between glycemic control in Type 2 diabetes mellitus patients and common genetic variants of ADIPQO gene. A total of 427 Type 2 diabetes patients were recruited in the study and divided into two groups: 172 patients with good glycemic control and 249 with poor glycemic control. Genotyping of C11377G, G276T and T45G ADIPQO SNPs were carried out using restriction fragment length polymorphisms-polymerase chain reaction. The results showed that C11377G ADIPQO SNP is strongly associated with glycemic control in Type 2 diabetes patients. Patients with the GG genotype at adiponectin C11377G had better glycemic control than those with CC or CG genotypes. However, other examined SNPs were not correlated with glycemic control in Type 2 diabetes patients. Other parameters that impacted glycemic control include duration of the disease (p < 0.01), use of insulin therapy (p < 0.01) and presence of neuropathy complications (p < 0.01). However, no contribution was observed for gender, statin use, lipid profile and other oral medications to glycemic control (p > 0.05). Glycemic control among Type 2 diabetes patients might be affected by variants in ADIPQO gene.

Dietary fat differentially influences the lipids storage on the adipose tissue in metabolic syndrome patients

PURPOSE

Adipose tissue is now recognized as a highly active metabolic and endocrine organ. Our aim was to investigate the effect of the dietary fat on the two main adipose tissue functions, endocrine and lipid store, by analyzing the adipose tissue gene expression from metabolic syndrome patients.

METHODS

A randomized, controlled trial conducted within the LIPGENE study assigned 39 metabolic syndrome patients to 1 of 4 isoenergetic diets: (1) high-saturated fatty acid (HSFA), (2) high-monounsaturated fatty acid (HMUFA), (3) low-fat, high-complex carbohydrate diet supplemented with long-chain n-3 fatty acids (LFHCC n-3), and (4) low-fat, high-complex carbohydrate diet supplemented with placebo (LFHCC), for 12 weeks each. A fat challenge reflecting the fatty acid composition as the original diets was conducted post-intervention.

RESULTS

The long-term consumption of HSFA, LFHCC, and LFHCC n-3 diets, but not HMUFA diet, decreased the perilipin fasting mRNA levels. LFHCC diet consumption increased fasting FABP4 expression, while it was reduced by the consumption of LFHCC n-3 diet. LFHCC meal reduced, while LFHCC n-3 meal intake increased postprandial CAV1 expression.

CONCLUSION

The quantity and quality of dietary fat induce differential lipid storage and processing related gene expression, which may interact with the expression of adipokines through common regulatory mechanisms.

Adiponectin knockout accentuates high fat diet-induced obesity and cardiac dysfunction: role of autophagy

Adiponectin (APN), an adipose-derived adipokine, offers cardioprotective effects although the precise mechanism of action remains unclear. This study was designed to examine the role of APN in high fat diet-induced obesity and cardiac pathology. Adult C57BL/6 wild-type and APN knockout mice were fed a low or high fat diet for 22weeks. After 40day feeding, mice were treated with 2mg/kg rapamycin or vehicle every other day for 42days on respective fat diet. Cardiomyocyte contractile and Ca(2+) transient properties were evaluated. Myocardial function was evaluated using echocardiography. Dual energy X-ray absorptiometry was used to evaluate adiposity. Energy expenditure, metabolic rate and physical activity were monitored using a metabolic cage. Lipid deposition, serum triglyceride, glucose tolerance, markers of autophagy and fatty acid metabolism including LC3, p62, Beclin-1, AMPK, mTOR, fatty acid synthase (FAS) were evaluated. High fat diet intake induced obesity, systemic glucose intolerance, cardiac hypertrophy, dampened metabolic ability, cardiac and intracellular Ca(2+) derangements, the effects of which were accentuated by APN knockout. Furthermore, APN deficiency augmented high fat diet-induced upregulation in the autophagy adaptor p62 and the decline in AMPK without affecting high fat diet-induced decrease in LC3II and LC3II-to-LC3I ratio. Neither high fat diet nor APN deficiency altered Beclin-1. Interestingly, rapamycin negated high fat diet-induced/APN-deficiency-accentuated obesity, cardiac hypertrophy and contractile dysfunction as well as AMPK dephosphorylation, mTOR phosphorylation and p62 buildup. Our results collectively revealed that APN deficiency may aggravate high fat diet-induced obesity, metabolic derangement, cardiac hypertrophy and contractile dysfunction possibly through decreased myocardial autophagy.