Unravelling the adiponectin paradox: novel roles of adiponectin in the regulation of cardiovascular disease

The effect of resistance training and nandrolone decanoate administration on cardiac tissue in mice

PURPOSE

This study examined the effect of resistance training (RT) by itself and in combination with supraphysiological administration of nandrolone decanoate (ND) on the inflammatory, apoptotic, and oxidative stress response in cardiac tissue. The effect of the training and androgen intervention on adiponectin expression, a potential cardio protectant was also examined.

METHODS

Forty male C57Bl/6J mice, 3 months of age were randomized into four groups (n = 10 per group). Two groups of animals performed a 3-day per week RT program for 7-weeks, while the other two groups remained sedentary (SED). The RT and SED animals were further randomized into an androgen group (RTA and SEDA, respectively) or a sham group (RTS and SEDS, respectively). Animals in the RTA and SEDA groups received 38-mg·kg-1 injected once per week. Mice from RTS and SEDS received sham injections.

RESULTS

Main effects for group indicated that RT resulted in significant elevations in NFκβ (p < 0.001), glutamine peroxidase (GPX) (p = 0.007) and adiponectin (p < 0.001). Main effects for treatment indicated that ND administration resulted in greater elevations in NFκβ (p = 0.01) and TNF-α (p = 0.017). In addition, TNF-α expression was greater in RTA compared to RETS (p = 0.006) and the adiponectin response in RTA was greater (p's < 0.05) than all other groups. A significant correlation was noted between average training volume during the RT program and GPX expression (r = 0.716, p < 0.001).

CONCLUSION

Results indicate that RT and ND administration can increase markers of apoptosis and inflammation. Elevations in adiponectin expression suggest that it may act as a compensatory mechanism supporting cardiovascular health.

The Potential of Dehydrated Geniotrigona thoracica Stingless Bee Honey against Metabolic Syndrome in Rats Induced by a High-Carbohydrate, High-Fat Diet

BACKGROUND/OBJECTIVES

Metabolic syndrome (MS) is diagnosed when at least three out of five key risk factors are present: obesity, high blood pressure, insulin resistance, high triglycerides (TG) and low high-density lipoprotein (HDL). MS is often associated with chronic low-grade inflammation. Recent studies have shown that raw stingless bee honey (SBH) can alleviate MS risk factors. However, the high moisture content in raw SBH predisposes it to fermentation, which can degrade its quality. Therefore, dehydrating SBH is necessary to prevent the fermentation process. This study aimed to compare the effects of dehydrated (DeGT) and raw (RGT) SBH from Geniotrigona thoracica species on high-carbohydrate, high-fat diet (HCHF)-induced MS in rats.

METHODS

Twenty-four male Wistar rats were divided into four groups: control (C), HCHF-induced MS without treatment (MS), HCHF-induced MS treated with DeGT (MS+DeGT) and HCHF-induced MS treated with RGT (MS+RGT). Group C received standard rat chow, while the other groups were fed with HCHF diet for 16 weeks. In the final eight weeks, two HCHF-induced groups received their respective SBH treatments.

RESULTS

Both DeGT and RGT treatments reduced energy intake, fat mass, high blood pressure, inflammatory (tumour necrosis factor-alpha (TNF-α)) and obesity (the leptin/adiponectin (L/A) ratio, corticosterone, 11 beta-hydroxysteroid dehydrogenase type-1 (11βHSD1)) markers, as well as prevented histomorphometry changes (prevented adipocyte hypertrophy, increased the Bowman's space area and glomerular atrophy). Additionally, DeGT increased serum HDL levels, while RGT reduced serum TG, leptin and other inflammatory markers (interleukin-6 (IL-6) and interleukin-1 beta (IL-1β)), as well as hepatosteatosis.

CONCLUSIONS

While DeGT demonstrates potential as a preventive agent for MS, RGT exhibited more pronounced anti-MS effects in this study.

Serum Adiponectin Levels Increase in Acute Ischemic Stroke and Correlate with Patients' Outcomes: A Pilot Study

Stroke is a leading cause of death and severe disability worldwide. Rapid diagnosis is critical to ensure the timely administration of medical treatment. Given that in some cases CT scans fail to show the classic clinical signs of stroke, we aimed to evaluate the diagnostic capacity of adiponectin levels and their association with the clinical parameters of patients with acute ischemic stroke (AIS). Adiponectin was measured within 24 h (T1) and 48 h (T2) of AIS onset in 70 patients. A total of 68 control cases were included in the study. Adiponectin levels were significantly higher in the AIS patients than in the controls (16.64 (3.79; 16.69) vs. 3.78 (3.79; 16.69); p < 0.001), with an accuracy of 0.98 (AUC = 0.99). Lower levels were seen in males and in AIS patients with obesity. Higher levels of adiponectin at T1 were associated with a moderate/severe NIHSS score at patient discharge. Moreover, higher levels of borderline significance were seen in patients who died within 12 months of their AIS episode (p = 0.054). Adiponectin may be a useful biomarker for the identification of AIS patients who do not present classic CT signs and could be used to stratify severe cases. Further studies are needed to validate these results.

Human recombinant relaxin-2 (serelaxin) regulates the proteome, lipidome, lipid metabolism and inflammatory profile of rat visceral adipose tissue

Recombinant human relaxin-2 (serelaxin) has been widely proven as a novel drug with myriad effects at different cardiovascular levels, which support its potential therapeutic efficacy in several cardiovascular diseases (CVD). Considering these effects, together with the influence of relaxin-2 on adipocyte physiology and adipokine secretion, and the connection between visceral adipose tissue (VAT) dysfunction and the development of CVD, we could hypothesize that relaxin-2 may regulate VAT metabolism. Our objective was to evaluate the impact of a 2-week serelaxin treatment on the proteome and lipidome of VAT from Sprague-Dawley rats. We found that serelaxin increased 1 polyunsaturated fatty acid and 6 lysophosphatidylcholines and decreased 4 triglycerides in VAT employing ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) based platforms, and that regulates 47 phosphoproteins using SWATH/MS analysis. Through RT-PCR, we found that serelaxin treatment also caused an effect on VAT lipolysis through an increase in the mRNA expression of hormone-sensitive lipase (HSL) and a decrease in the expression of adipose triglyceride lipase (ATGL), together with a reduction in the VAT expression of the fatty acid transporter cluster of differentiation 36 (Cd36). Serelaxin also caused an anti-inflammatory effect in VAT by the decrease in the mRNA expression of tumor necrosis factor α (TNFα), interleukin-1β (IL-1β), chemerin, and its receptor. In conclusion, our results highlight the regulatory role of serelaxin in the VAT proteome and lipidome, lipolytic function, and inflammatory profile, suggesting the implication of several mechanisms supporting the potential benefit of serelaxin for the prevention of obesity and metabolic disorders.

Reevaluating Adiponectin's impact on obesity hypertension: a Chinese case-control study

BACKGROUND

Obesity and hypertension are major risk factors for cardiovascular diseases that affect millions of people worldwide. Both conditions are associated with chronic low-grade inflammation, which is mediated by adipokines such as adiponectin. Adiponectin is the most abundant adipokine that has a beneficial impact on metabolic and vascular biology, while high serum concentrations are associated with some syndromes. This "adiponectin paradox" still needs to be clarified in obesity-associated hypertension. The aim of this study was to investigate how adiponectin affects blood pressure, inflammation, and metabolic function in obesity hypertension using a Chinese adult case-control study.

METHODS

A case-control study that had finished recruiting 153 subjects divided as four characteristic groups. Adiponectin serum levels were tested by ELISA in these subjects among these four characteristic Chinese adult physical examination groups. Waist circumference (WC), body mass index (BMI), systolic blood pressure (SB), diastolic blood pressure (DB), and other clinical laboratory data were collected. Analyzation of correlations between the research index and differences between groups was done by SPSS.

RESULTS

Serum adiponectin levels in the| normal healthy group (NH group) were significantly higher than those in the newly diagnosed untreated just-obesity group (JO group), and negatively correlated with the visceral adiposity index. With multiple linear egression analysis, it was found that, for serum adiponectin, gender, serum albumin (ALB), alanine aminotransferase (ALT) and high-density lipoprotein cholesterol (HDLC) were the significant independent correlates, and for SB, age and HDLC were the significant independent correlates, and for DB, alkaline phosphatase (ALP) was the significant independent correlate. The other variables did not reach significance in the model.

CONCLUSIONS

Our study reveals that adiponectin's role in obesity-hypertension is multifaceted and is influenced by the systemic metabolic homeostasis signaling axis. In obesity-related hypertension, compensatory effects, adiponectin resistance, and reduced adiponectin clearance from impaired kidneys and liver all contribute to the "adiponectin paradox".

Improving our understanding of the paradoxical protective effect of obesity on radiographic damage: a large magnetic resonance imaging-study in early arthritis

OBJECTIVE

Obesity conveys a risk for RA development, while paradoxically, associating with less radiographic progression after RA diagnosis. Using MRI we can study this surprising association in detail from MRI-detected synovitis and osteitis to MRI-detected erosive progression, which precedes radiographic progression. Previous research suggested obesity associates with less osteitis and synovitis. We therefore aimed to (i) validate the previously suggested association between BMI and MRI-detected osteitis/synovitis; (ii) study whether this is specific for ACPA-positive or ACPA-negative RA or also present in other arthritides; (iii) study whether MRI-detected osteitis associates with MRI-detected erosive progression; and (iv) study whether obesity associates with MRI-detected erosive progression.

METHODS

We studied 1029 early arthritis patients (454 RA, 575 other arthritides), consecutively included in Leiden Early Arthritis Clinic. At baseline patients underwent hand-and-foot MRI that were RAMRIS-scored, and 149 RA patients underwent follow-up MRIs. We studied associations between baseline BMI and MRI-detected osteitis/synovitis (using linear regression), and erosive progression (using Poisson mixed models).

RESULTS

In RA, higher BMI associated with less osteitis at disease onset (β = 0.94; 95% CI: 0.93, 0.96) but not with synovitis. Higher BMI associated with less osteitis in ACPA-positive RA (β = 0.95; 95% CI: 0.93, 0.97), ACPA-negative RA (β = 0.97; 95% CI: 0.95, 0.99) and other arthritides (β = 0.98; 95% CI: 0.96, 0.99). Over 2 years, overweight and obesity associated with less MRI-detected erosive progression (P = 0.02 and 0.03, respectively). Osteitis also associated with erosive progression over 2 years (P < 0.001).

CONCLUSIONS

High BMI relates to less osteitis at disease onset, which is not confined to RA. Within RA, high BMI and less osteitis associated with less MRI-detected erosive progression. This suggests that the protective effect of obesity on radiographic progression is exerted via a path of less osteitis and subsequently fewer MRI-detected erosions.

Positive Effects of Adiponectin, BDNF, and GLP-1 on Cortical Neurons Counteracting Palmitic Acid Induced Neurotoxicity

The prevalence of metabolic syndrome caused by diets containing excessive fatty acids is increasing worldwide. Patients with metabolic syndrome exhibit abnormal lipid profiles, chronic inflammation, increased levels of saturated fatty acids, impaired insulin sensitivity, excessive fat accumulation, and neuropathological issues such as memory deficits. In particular, palmitic acid (PA) in saturated fatty acids aggravates inflammation, insulin resistance, impaired glucose tolerance, and synaptic failure. Recently, adiponectin, brain-derived neurotrophic factor (BDNF), and glucose-like peptide-1 (GLP-1) have been investigated to find therapeutic solutions for metabolic syndrome, with findings suggesting that they are involved in insulin sensitivity, enhanced lipid profiles, increased neuronal survival, and improved synaptic plasticity. We investigated the effects of adiponectin, BDNF, and GLP-1 on neurite outgrowth, length, and complexity in PA-treated primary cortical neurons using Sholl analysis. Our findings demonstrate the therapeutic potential of adiponectin, BDNF, and GLP-1 in enhancing synaptic plasticity within brains affected by metabolic imbalance. We underscore the need for additional research into the mechanisms by which adiponectin, BDNF, and GLP-1 influence neural complexity in brains with metabolic imbalances.

Interaction between Selected Adipokines and Musculoskeletal and Cardiovascular Systems: A Review of Current Knowledge

Adipokines are substances secreted by adipose tissue that are receiving increasing attention. The approach to adipose tissue has changed in recent years, and it is no longer looked at as just a storage organ but its secretion and how it influences systems in the human body are also looked at. The role of adipokine seems crucial in developing future therapies for pathologies of selected systems. In this study, we look at selected adipokines, leptin, adiponectin, chemerin, resistin, omentin-1, nesfatin, irisin-1, visfatin, apelin, vaspin, heparin-binding EGF-like growth factor (HB-EGF), and TGF-β2, and how they affect systems in the human body related to physical activity such as the musculoskeletal and cardiovascular systems.

Goldfish adiponectin: (I) molecular cloning, tissue distribution, recombinant protein expression, and novel function as a satiety factor in fish model

Adiponectin (AdipoQ) is an adipokine involved in glucose homeostasis and lipid metabolism. In mammals, its role in appetite control is highly controversial. To shed light on the comparative aspects of AdipoQ in lower vertebrates, goldfish was used as a model to study feeding regulation by AdipoQ in fish species. As a first step, goldfish AdipoQ was cloned and found to be ubiquitously expressed at the tissue level. Using sequence alignment, protein modeling, phylogenetic analysis and comparative synteny, goldfish AdipoQ was shown to be evolutionarily related to its fish counterparts and structurally comparable with AdipoQ in higher vertebrates. In our study, recombinant goldfish AdipoQ was expressed in E. coli, purified by IMAC, and confirmed to be bioactive via activation of AdipoQ receptors expressed in HepG2 cells. Feeding in goldfish revealed that plasma levels of AdipoQ and its transcript expression in the liver and brain areas involved in appetite control including the telencephalon, optic tectum, and hypothalamus could be elevated by food intake. In parallel studies, IP and ICV injection of recombinant goldfish AdipoQ in goldfish was effective in reducing foraging behaviors and food consumption. Meanwhile, transcript expression of orexigenic factors (NPY, AgRP, orexin, and apelin) was suppressed with parallel rises in anorexigenic factors (POMC, CART, CCK, and MCH) in the telencephalon, optic tectum and/or hypothalamus. In these brain areas, transcript signals for leptin receptor were upregulated with concurrent drops in the NPY receptor and ghrelin receptors. In the experiment with IP injection of AdipoQ, transcript expression of leptin was also elevated with a parallel drop in ghrelin mRNA in the liver. These findings suggest that AdipoQ can act as a novel satiety factor in goldfish. In this case, AdipoQ signals (both central and peripheral) can be induced by feeding and act within the brain to inhibit feeding behaviors and food intake via differential regulation of orexigenic/anorexigenic factors and their receptors. The feeding inhibition observed may also involve the hepatic action of AdipoQ by modulation of feeding regulators expressed in the liver.

Epicardial adipose tissue and cardiac lipotoxicity: A review

Epicardial adipose tissue (EAT) has morphological and physiological contiguity with the myocardium and coronary arteries, making it a visceral fat deposit with some unique properties. Under normal circumstances, EAT exhibits biochemical, mechanical, and thermogenic cardioprotective characteristics. Under clinical processes, epicardial fat can directly impact the heart and coronary arteries by secreting proinflammatory cytokines via vasocrine or paracrine mechanisms. It is still not apparent what factors affect this equilibrium. Returning epicardial fat to its physiological purpose may be possible by enhanced local vascularization, weight loss, and focused pharmacological therapies. This review centers on EAT's developing physiological and pathophysiological dimensions and its various and pioneering clinical utilities.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

Adiponectin as a therapeutic target for diabetic foot ulcer

The global burden of diabetic foot ulcers (DFUs) is a significant public health concern, affecting millions of people worldwide. These wounds cause considerable suffering and have a high economic cost. Therefore, there is a need for effective strategies to prevent and treat DFUs. One promising therapeutic approach is the use of adiponectin, a hormone primarily produced and secreted by adipose tissue. Adiponectin has demonstrated anti-inflammatory and anti-atherogenic properties, and researchers have suggested its potential therapeutic applications in the treatment of DFUs. Studies have indicated that adiponectin can inhibit the production of pro-inflammatory cytokines, increase the production of vascular endothelial growth factor, a key mediator of angiogenesis, and inhibit the activation of the intrinsic apoptotic pathway. Additionally, adiponectin has been found to possess antioxidant properties and impact glucose metabolism, the immune system, extracellular matrix remodeling, and nerve function. The objective of this review is to summarize the current state of research on the potential role of adiponectin in the treatment of DFUs and to identify areas where further research is needed in order to fully understand the effects of adiponectin on DFUs and to establish its safety and efficacy as a treatment for DFUs in the clinical setting. This will provide a deeper understanding of the underlying mechanisms of DFUs that can aid in the development of new and more effective treatment strategies.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

A case-cohort study of the association between adiponectin and mortality in EPIC-Heidelberg: NT-proBNP may explain the adiponectin paradox

BACKGROUND AND AIMS

NT-proBNP has been hypothesized as a possible explanation for the paradoxical association between adiponectin and cardiovascular and all-cause mortality. We examined the heterogeneities by NT-proBNP, sex, BMI, smoking status, hypertension and diabetes status in the association between adiponectin and cardiovascular disease risk and mortality.

METHODS AND RESULTS

We used a case-cohort design nested within the EPIC-Heidelberg cohort, including 1387 incident cases of myocardial infarction or stroke, 582 deaths from cardiovascular causes and 2352 total deaths. We estimated hazard ratios for the association between 1SD increase in log-transformed total adiponectin levels and cardiovascular disease risk, cardiovascular mortality and mortality using Prentice-weighted Cox-proportional hazard models and assessed heterogeneity of the associations across strata of covariates. Overall, adiponectin was significantly associated with all-cause mortality [HR = 1.09, 95% CI: 1.03-1.16, p = 0.004]. The association with cardiovascular mortality did not reach statistical significance [1.10 (0.99-1.37), p = 0.073]. There was significant heterogeneity by NT-proBNP in the association between total adiponectin and all-cause mortality (phet = 0.019) such that significant increase in hazards of mortality were restricted to participants in the highest tertile of NT-proBNP. Among these participants, adiponectin showed a dose-response relationship with total mortality such that; compared to participants in the lowest quintile, those in the third, fourth and fifth were at 1.22 (0.87-1.70), 1.50 (1.07-2.11), and 1.59 (1.15-2.21) higher hazards of mortality respectively.

CONCLUSIONS

Significant association between adiponectin and mortality was only observed in the context of high NT-proBNP. Our findings provide further support for hypothesis that NT-proBNP may explain the adiponectin paradox.

Mechanisms and Effect of Increased Physical Activity on General and Abdominal Obesity and Associated Metabolic Risk Factors in a Community with Very High Rates of General and Abdominal Obesity

Background: The growing prevalence of obesity and related type 2 diabetes is reaching epidemic proportions in the UAE. Physical inactivity is one of the possible factors linking obesity to diabetes and other related complications. However, the molecular mechanisms through which physical inactivity is contributing to increased obesity-related pathologies are not clear. Aims: to measure the effects of increased physical activity on obesity and related metabolic risk factors. Materials and Methods: We investigated the effects of physical activity on body weight, waist circumference (WC) and metabolic risk factors in 965 community free-living Emirati subjects. Physical activity, dietary intake, antioxidant enzymes and markers of oxidative damage and inflammation were measured both at baseline and follow up. A validated questionnaire was used to assess occupation and leisure-related physical activity. We compared metabolic risk factors between subjects stratified by physical activity levels. The Cox proportional hazards analysis was used to determine the independent effects of increased physical activity on presence and absence of obesity, body weight and waist circumference (WC) change at follow up. Results: A total of 965 community free-living subjects [801 (83%) females, mean (SD) age 39 ± 12 years] were recruited and followed up with for a period of 427 ± 223 days. Using WHO cut-of-points for body mass index (BMI), 284 (30%) subjects were overweight and 584 (62%) subjects were obese, compared to 69 (8%) at normal body weight. We found men to be more physically active than women at both leisure and work times. BMI, hip circumference, total body fat, HDL and inflammatory markers (us CRP, TNF) were significantly higher in female subjects, whilst fat free-mass, WC, blood pressure and HbA1c were higher in male subjects (p < 0.05). Hypertension and diabetes were more common in male subjects compared to female subjects (p < 0.05). Increased physical activity both at baseline and follow up were associated with decreased BMI, WC and inflammatory markers, including us-CRP and TNF. Increased physical activity was associated with significant decrease in abdominal obesity in female subjects and general obesity in both male and females after adjusting for important prognostic indicators [hazard ratio (95% CI): 0.531 (0.399, 0.707); p < 0.001; 0.475 (0.341, 0.662); p < 0.001 respectively]. Conclusion: Our findings suggest that increased physical activity may decrease the risk of obesity and also mitigate the associated oxidative damage and inflammatory responses.

Exploratory analysis of the effect of a controlled lifestyle intervention on inflammatory markers - the Healthy Lifestyle Community Programme (cohort 2)

BACKGROUND

Chronic low-grade inflammation is associated with an increased risk of chronic disease and mortality. The objective of the study was to test the effect of a healthy lifestyle intervention on biomarkers of inflammation (among other risk markers).

METHODS

We conducted a non-randomized controlled trial with mostly middle-aged and elderly participants from the general population in rural northwest Germany (intervention: n = 114; control: n = 87). The intervention consisted of a 1-year lifestyle programme focusing on diet (largely plant-based; strongest emphasis), physical activity, stress management, and social support. High-sensitivity C-reactive protein (hs-CRP) was assessed at baseline, 10 weeks, 6 months, and 1 year. Homocysteine (Hcy) was assessed at baseline, 10 weeks, and 1 year. Adiponectin (Apn) was assessed at baseline and 10 weeks. An exploratory analysis of these inflammatory markers assessing the between-group differences with ANCOVA was conducted.

RESULTS

The 1-year trajectory of hs-CRP was significantly lower in the intervention group compared to control (between-group difference: -0.8 (95% CI -1.2, -0.3) mg/l; p = 0.001; adjusted for baseline). The 1-year trajectory of Hcy was non-significantly higher in the intervention compared to control (between-group difference: 0.2 (95% CI -0.3, 0.7) µmol/l; p = 0.439; adjusted for baseline). From baseline to 10 weeks, Apn decreased significantly more in the intervention group compared to control (between-group difference: -1.6 (95% CI -2.7, -0.5) µg/ml; p = 0.004; adjusted for baseline).

CONCLUSIONS

Our study shows that healthy lifestyle changes can lower hs-CRP and Apn levels and are unlikely to significantly affect Hcy levels within 1 year.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS; reference: DRKS00018775 , registered 12 Sept 2019; retrospectively registered; www.drks.de ).

Adiponectin alleviates non-alcoholic fatty liver injury via regulating oxidative stress in liver cells

BACKGROUND

The aim of the present study was to investigate the role of adiponectin in non-alcoholic fatty liver cell model and its mechanism.

METHODS

The serum were collected from patients with non-alcoholic fatty liver disease and healthy controls. Then the expression of APN in the serum was detected using APN kit. Furthermore, an in vitro model of NAFLD was established using mixed fatty acids treated HepG2 cells, and APN was highly expressed in the culture solution to a concentration of 10 μg/mL. The normal control group (Normal) was normal cells, the model group (NAFLD) was mixed fatty acids treated HepG2 cells, the experimental group (NAFLD+APN) was model cells transfected with high APN expression, and the negative control group (NAFLD+PBS) was model cells transfected with PBS. The expression of NOX2 in each group was detected by Western blot. The corresponding kit was used to detect the level of triglyceride (TG), the activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA), and the ratio of GSH/GSSG in each group of cells.

RESULTS

The expression level of APN was greatly decreased in the serum of NAFLD patients (P<0.01), and the TG content was significantly increased in HepG2 cells treated with fatty acids (P<0.001), indicating successful modeling. The cells had high expression of APN (P<0.001) showed low expression of NOX2 (P<0.001). The kit test results showed that the high expression of APN could reverse the decrease of SOD activity, the increase of MDA level, the decrease of GSH/GSSG ratio and the increase of TG content (P<0.001), all of which were restored to the modeling level after application of NOX2's activator TBCA.

CONCLUSIONS

APN was lowly expressed in the serum of NAFLD patients. Its effect mechanism was to alleviate the injury of NAFLD cells by reducing oxidative stress via regulating NOX2 expression.

Associations between Body Mass Index, Waist Circumference, and Myocardial Infarction in Older Adults Aged over 75 Years: A Population-Based Cohort Study

Background and Objectives: Body mass index (BMI) is widely used as a standard screening method for obesity and an indicator of related diseases. However, its inability to distinguish between lean body mass and body fat limits its utility. This limitation may be more prominent in older populations, wherein age-related sarcopenia and increased visceral fat due to the redistribution of adipose tissue may preclude a precise estimation of obesity. Many studies suggest that waist circumference (WC) is more strongly related to obesity-related diseases. There are also different opinions on whether the obesity paradox is real or a result of confusing interpretations. This study seeks to determine the association between myocardial infarction (MI), BMI, and WC in older adults and to determine if BMI and WC can reliably predict the risk of cardiovascular disease. Materials and Methods: We conducted a cohort study of older Korean adults aged over 75 years registered in the National Health Insurance System Senior database. Results: The results from the analysis using model 5, which was adjusted for each study variable, showed that the lower the BMI, the higher the hazard ratio (HR) of MI and vice versa. On the other hand, groups with lower than normal WC showed lower HR; even if it was higher, the difference was not statistically significant. Those with abdominal obesity tended to have an increased HR of MI. Conclusions: This study found that HR for MI has a negative relationship with BMI, whereas it has a positive relationship with WC. Furthermore, WC is a more appropriate indicator for predicting the risk of MI in the older population.

Congenital adiponectin deficiency mitigates high-fat-diet-induced obesity in gonadally intact male and female, but not in ovariectomized mice

Epidemiological literature indicates that women are less susceptible to type II diabetes (T2D) than males. The general consensus is that estrogen is protective, whereas its deficiency in post-menopause is associated with adiposity and impaired insulin sensitivity. However, epidemiological data suggests that males are more prone to developing T2D, and at a lower BMI, compared to females during post-menopausal years; suggesting that another factor, other than estrogen, protects females. We proposed to determine if adiponectin (APN) serves as this protective factor. An initial experiment was performed in which gonadally intact male and female mice were fed either a purified low-fat diet (LFD) or high-fat diet (HFD) (40% kcals from fat) for 16 weeks. An additional group of HFD ovariectomy (OVX) mice were included to assess estrogen deficiency’s impact on obesity. Body composition, adipose tissue inflammation, ectopic lipid accumulation as well as glucose metabolism and insulin resistance were assessed. In corroboration with previous data, estrogen deficiency (OVX) exacerbated HFD-induced obesity in female mice. However, despite a higher body fat percentage and a similar degree of hepatic and skeletal muscle lipid accumulation, female OVX HFD-fed mice exhibited enhanced insulin sensitivity relative to HFD-fed males. Therefore, a subsequent HFD experiment was performed utilizing male and female (both gonadally intact and OVX) APN deficient mice (APN^−/−) and wildtype littermates to determine if APN is the factor which protects OVX females from the similar degree of metabolic dysfunction as males in the setting of obesity. Indirect calorimetry was used to determine observed phenotype differences. APN deficiency limited adiposity and mitigated HFD-induced insulin resistance and adipose tissue inflammation in gonadally intact male and female, but not in OVX mice. Using indirect calorimetry, we uncovered that slight, but non-statistically significant differences in food intake and energy expenditure leading to a net difference in energy balance likely explain the reduced body weight exhibited by male APN-deficient mice. In conclusion, congenital APN deficiency is protective against obesity development in gonadally intact mice, however, in the setting of estrogen deficiency (OVX) this is not true. These findings suggest that gonadal status dictates the protective effects of congenital APN deficiency in the setting of HFD-induced obesity.

Adiponectin reduces apoptosis of diabetic cardiomyocytes by regulating miR-711/TLR4 axis

OBJECTIVE

To investigate the regulation of adiponectin/miR-711 on TLR4/NF-κB-mediated inflammatory response and diabetic cardiomyocyte apoptosis.

METHODS

Diabetes models were established using rats and H9c2 cardiomyocytes. qRT-PCR was used to detect adiponectin, miR-711, and TLR4. MTT, β-galactosidase staining, and flow cytometry were utilized to assess cell viability, senescence, and apoptosis, respectively. The colorimetric method was used to measure caspase-3 activity, DCFH-DA probes to detect ROS, and western blotting to determine the protein levels of Bax, Bcl-2, TLR4, and p-NF-κB p65. ELISA was performed to measure the levels of adiponectin, ICAM-1, MCP-1, and IL-1β. Dual-luciferase reporter system examined the targeting relationship between miR-711 and TLR4. H&E and TUNEL staining revealed myocardial structure and apoptosis, respectively.

RESULTS

Adiponectin and miR-711 were underexpressed and TLR4/NF-κB signaling pathway was activated in high glucose-treated H9c2 cells. High glucose treatment reduced viability, provoked inflammatory response, and accelerated senescence and apoptosis in H9c2 cells. miR-711 could bind TLR4 mRNA and inactivate TLR4/NF-κB signaling. Adiponectin treatment increased miR-711 expression and blocked TLR4/NF-κB signaling. Adiponectin/miR-711 reduced myocardial inflammation and apoptosis in diabetic rats.

CONCLUSION

Adiponectin inhibits inflammation and alleviates high glucose-induced cardiomyocyte apoptosis by blocking TLR4/NF-κB signaling pathway through miR-711.

The Harm of Metabolically Healthy Obese and the Effect of Exercise on Their Health Promotion

Obesity and obesity-related diseases [type 2 diabetes, cardiovascular disease (CVD), and cancer] are becoming more common, which is a major public health concern. Metabolically healthy obesity (MHO) has become a type of obesity, accounting for a large proportion of obese people. MHO is still harmful to health. It was discovered that MHO screening criteria could not well reflect health hazards, whereas visceral fat, adiponectin pathway, oxidative stress, chronic inflammation, and histological indicators at the microlevel could clearly distinguish MHO from health control, and the biological pathways involved in these micro indicators were related to MHO pathogenesis. This review reveals that MHO’s micro metabolic abnormality is the initial cause of the increase of disease risk in the future. Exploring the biological pathway of MHO is important in order to develop an effective mechanism-based preventive and treatment intervention strategy. Exercise can correct the abnormal micro metabolic pathway of MHO, regulate metabolic homeostasis, and enhance metabolic flexibility. It is a supplementary or possible alternative to the traditional healthcare prevention/treatment strategy as well as an important strategy for reducing MHO-related health hazards.

Adiponectin System (Rescue Hormone): The Missing Link between Metabolic and Cardiovascular Diseases

The adipose tissue, regardless of its role in generating and storing energy, acts as a key player as an endocrine tissue, producing a wide scale of cytokines/hormones called adipokines. Adipokines such as leptin, resistin, visfatin and osteopontin own pro-inflammatory effects on the cardiovascular system in some cases. In contrast, some adipokines have cardioprotective and anti-inflammatory impacts including adiponectin, omentin, and apelin. One of the key adipokines is adiponectin, the abundant peptide regulating hormone that is released mainly by adipocytes and cardiomyocytes as well as by endothelial and skeletal cells. It acts through two main receptors: AdipoR1 and AdipoR2, forming the "Adiponectin system" which effectively exerts its cellular mechanisms and responses in target cells. It regulates various metabolic processes, while adiponectin is the adipocyte hormone known for its cardioprotective impact in clinical and experimental research. It is also a well-effector metabolic adipokine, since weight loss or diet restriction show a link with rises in adiponectin concentrations, which is accompanied with increasing insulin sensitivity, glucose, and lipids-regulation via adiponectin's antioxidant, anti-inflammatory, anti-fibrotic actions. The high adiponectin level made it an attractive player in developing therapeutical treatments for metabolic syndromes and cardiovascular disease. The elevated plasma levels of adiponectin are mostly attributed to its benefits on cardio-metabolism. In some cases, adiponectin has been paradoxically accompanied with elevated risk of cardiovascular disease, so higher adiponectin concentration is a marker of poor prediction. Thus, the adiponectin system is attractive to researchers as a biomarker of heart disease advancement and a predictor of prognosis during the term of some cardiovascular diseases and its mechanical functions in Hypertension and diabetic patients. This review highlights the physiological roles of adiponectin as an anti-inflammatory and cardioprotective hormone as well as how it plays as a biomarker and potential therapeutic tool in the cardiovascular system in adult, children, and adolescents. The adiponectin system may be seen as a rescue hormone aiding in remodeling of the cardiovascular system on both cellular and molecular levels. The paradox role of adiponectin relevant to cardiovascular mortality should be taken into consideration.

Metabolic Effects of the Left Atrial Appendage Exclusion (THE HEART HORMONE STUDY)

OBJECTIVE

The effect of epicardial LAA occlusion therapy on lipid and glucose metabolism in AF patients over the long term follow up is unclear.

METHODS

In a single-center prospective observational study, 60 patients with longstanding persistent AF with cardiovascular risk factors had undergone an epicardial exclusion procedure. Anthropometric parameters and glucose, glycated hemoglobin (HbA1c), insulin, leptin, adiponectin, free fatty acids, beta-hydroxybutyrate, and total cholesterol levels were evaluated on fasting at baseline before the procedure and compared with levels at 24 hours, 7 days, 1 month, 3 months, 6 months, and 24 months follow the procedure.

RESULTS

The mean age of the patients was 67.5 ± 8.1. Insulin levels significantly increased at 7 days, 1 month, 3 months, 6 months, 12 months, and 24 months follow-up. The leptin levels showed a significant increase in 6 months, 12 months, and 24 months when compared to baseline. Whereas the adiponectin levels showed a significant decrease at 3 months, 6 months, 12 months, and 24 months when compared to baseline levels. In patients with the epicardial procedure, when compared to baseline, glucose, glycated hemoglobin, total cholesterol, and beta-hydroxybutyrate levels did not show any significant changes at baseline and 24 months follow up.

CONCLUSION

The epicardial exclusion ligation in AF patients was associated with significant changes in insulin, leptin, and adiponectin over long follow up. This article is protected by copyright. All rights reserved.

Urine 11-Dehydro-Thromboxane B2 in Aspirin-Naive Males with Metabolic Syndrome

Urine 11-dehydro-thromboxane B2 (11-dehydro-TXB2), an indirect measure of platelet activity, is elevated in cardiovascular diseases and diabetes. The purpose of our study was to determine whether urine 11-dehydro-TXB2 is elevated in aspirin-naive males with metabolic syndrome (MS) and to determine predictors of 11-dehydro-TXB2 levels. The secondary aim was to evaluate whether these MS patients could be potential candidates for the aspirin-mediated prevention of atherosclerotic cardiovascular diseases (ASCVDs). In 82 males with MS (76 hypertensive), anthropometric measures, urine 11-dehydro-TXB2, platelet count, creatinine, glucose, insulin, estimated insulin resistance, lipid parameters, high-sensitivity C-reactive protein (hs-CRP), adiponectin, homocysteine, and ten-year risk of fatal cardiovascular disease (SCORE) were assessed. Urine 11-dehydro-TXB2 levels were elevated (≥2500 pg/mg creatinine) in two-thirds of patients, including 11 high-risk patients (SCORE ≥ 5%). Homocysteine, adiponectin, hs-CRP, waist-to-hip ratio, and total cholesterol were found to be predictors of urine 11-dehydro-TXB2. In conclusion, there is a high incidence of elevated urine 11-dehydro-TXB2 in males with MS, including in some patients who are at a high or very high risk of ASCVDs. 11-dehydro-TXB2 levels are associated with hyperhomocysteinemia, inflammation, fat distribution, hypercholesterolemia, and adiponectin concentrations. Elevated 11-dehydro-TXB2 levels may support the use of personalised aspirin ASCVD prevention in high-risk males with MS. Giuseppe Patti.

Interplay of Obesity, Ethanol, and Contaminant Mixture on Clinical Profiles of Cardiovascular and Metabolic Diseases: Evidence from an Animal Study

Obesity, ethanol, and contaminants are known risk factors of cardiovascular and metabolic diseases (CMD). However, their interplay on clinical profiles of these diseases remains unclear, and thus were investigated in this study. Male lean or obese JCR rats were given water or 10% ethanol and orally treated with or without a contaminant mixture (CM) dissolved in corn oil and loaded on two cookies at 0, 1.6, or 16 mg/kg BW/day dose levels for 4 weeks. The CM consisted 22 environmental contaminants found in human blood or serum of Northern populations. Over 60 parameters related to CMD were examined. The results revealed that obesity in JCR rats resembles the clinical profiles of non-alcoholic fatty liver disease in humans. Obesity was also associated with increased serum and organ retention of mercury, one of the chemical components of CM. Exposure to ethanol lightened hyperlipidemia, increased liver retention of mercury, and increased risk for hypertension in the obese rats. CM lessened hyperlipidemia and hyperenzymemia, worsened systemic inflammation and increased the risk for hypertension in the obese rats. CM markedly increased serum ethanol levels with or without ethanol exposure. Tissue total mercury contents significantly correlated with clinical parameters with altered profiles by both ethanol and obesity. These results suggest that obese individuals may be more prone to contaminant accumulation. Ethanol and CM exposure can alter clinical profiles associated with obesity, which may lead to misdiagnosis of CMD associated with obesity. CM can alter endogenous production and/or metabolism of ethanol, further complicating disease progression, diagnosis, and treatment.

Vascular Function and Distribution of Adiponectin Isomers during Puberty in Children and Adolescents with Obesity

INTRODUCTION

Youth with obesity have abnormal vascular function that relates to the anti-atherogenic adipose-derived hormone, adiponectin. The distribution of adiponectin isomers changes during normal puberty, but there are no data in relation to vascular function. We aimed to evaluate vascular function, adiponectin, and its isomers longitudinally in peri-pubertal youth with obesity and controls.

METHODS

The study is a cohort longitudinal study involving 30 children and adolescents with obesity (body mass index [BMI] z-score 2.31 ± 0.24; age 12.8 ± 3 years, 17 male participants) and 28 age-/sex-matched healthy controls (12.8 ± 3 years, 14 male participants). Vascular function (flow-mediated dilatation [FMD], glyceryl trinitrate-mediated dilatation [GTN]), total adiponectin and isomers, and laboratory and clinical variables were assessed at 0, 18, and 36 months.

RESULTS

FMD and GTN were stable during puberty in both groups, remaining consistently lower in obese children (p = 0.02, p < 0.001). The change in total (p = 0.02) and high-molecular weight (HMW) (p = 0.02) adiponectin differed between the groups: falling in controls by the end of puberty but not falling further during puberty in obesity. In obesity, impaired GTN was associated longitudinally with lower total (B = 7.85, p = 0.006) and HMW (B = 3.72, p = 0.03) adiponectin. In controls, more favourable GTN was longitudinally associated with a lower BMI z-score (B = -3.04, p = 0.027) and lower waist circumference (B = -0.35, p = 0.009).

CONCLUSIONS

Vascular dysfunction and lower levels of adiponectin are associated in children and adolescents with obesity during puberty and do not deteriorate further. Healthy children's better vascular function, within the normal range, is associated with a lower BMI z-score and waist circumference.

Hip BMD is associated with visceral fat change: a registry study of osteoporosis and sarcopenia

Background:

Osteoporosis increases the risk of fractures. Visceral fat is associated with cardiovascular disease (CVD). There is inadequate knowledge on the relationship between osteoporosis and visceral fat. The study aimed to evaluate the relationship between bone mineral density (BMD) and visceral fat mass in the elderly.

Methods:

This was a prospective cohort study. Subjects were enrolled from the Rheumatology Clinic. All subjects underwent baseline bone mineral density and body composition measurements using dual-energy X-ray absorptiometry.

Results:

A total of 321 patients including 288 females and 33 males were enrolled in this study. We followed up DEXA for 1 year for fat and muscle mass change and found that 162 (50.5%) had a decrease in fat mass, 129 (40.2%) had decreased visceral fat, and 138 (43%) had decreased muscle mass. Furthermore, we found that the baseline hip T score was correlated with visceral fat decrease. Using visceral fat decrease as the outcome, we found that hip T score could predict visceral fat loss: the higher the T score, the more visceral fat loss was found [ p < 0.001, OR: 1.6, CI: (1.3–2.1)].

Conclusion:

A high hip T score was associated with a future decrease in visceral fat, which may decrease the risk of atherosclerosis and CV risk. Therefore, evaluation of visceral fat may be useful for assessing CVD risk in patients with osteoporosis. Effective management of the risk of atherosclerosis and CVD is important in improving the life expectancy of these patients.

The Role of Anti-Inflammatory Adipokines in Cardiometabolic Disorders: Moving beyond Adiponectin

The global burden of obesity has multiplied owing to its rapidly growing prevalence and obesity-related morbidity and mortality. In addition to the classic role of depositing extra energy, adipose tissue actively interferes with the metabolic balance by means of secreting bioactive compounds called adipokines. While most adipokines give rise to inflammatory conditions, the others with anti-inflammatory properties have been the novel focus of attention for the amelioration of cardiometabolic complications. This review compiles the current evidence on the roles of anti-inflammatory adipokines, namely, adiponectin, vaspin, the C1q/TNF-related protein (CTRP) family, secreted frizzled-related protein 5 (SFRP5), and omentin-1 on cardiometabolic health. Further investigations on the mechanism of action and prospective human trials may pave the way to their clinical application as innovative biomarkers and therapeutic targets for cardiovascular and metabolic disorders.

Vitamin D is directly associated with favorable glycemic, lipid, and inflammatory profiles in individuals with at least one component of metabolic syndrome irrespective of total adiposity: Pró-Saúde Study, Brazil

Vitamin D insufficiency has been suggested as a risk factor for several metabolic disorders. The objective of the study was to investigate the association between serum 25 hydroxyvitamin D [25(OH)D] and metabolic health markers of Brazilian individuals with normal-weight, overweight or obesity. We hypothesized that serum 25(OH)D would be inversely associated with glycemic, lipid and inflammatory markers indicative of metabolic abnormality. Data of 511 individuals (33-79 years), recruited from a longitudinal investigation (Pró-Saúde Study), were analyzed cross-sectionally. Anthropometric, biochemical, body composition, socio-demographic and lifestyle data were collected. Based on body mass index (BMI; normal weight, overweight, obesity) and metabolic health (metabolically healthy (MH) and metabolically unhealthy (MU)) categories, the participants were classified into 6 phenotypes. Individuals having zero components of the metabolic syndrome were considered as "MH". MH obesity was frequent in 2.0% of the participants and 56.0% exhibited vitamin D insufficiency (<20 ng/mL). In the subgroups of the same BMI category, there were no significant differences in 25(OH)D concentrations between individuals classified as MH and MU. After adjustments (including %body fat and BMI), an inverse association was observed between 25(OH)D and visceral adipose tissue (B = -6.46, 95% confidence interval, CI: -12.87, -0.04), leptin (B = -0.09, 95% confidence interval, CI: -0.14, -0.03), insulin (B = -0.21, 95%CI: -0.34, -0.07), HOMA-IR (B = -0.06, 95%CI: -0.10, -0.02), triglycerides (B = -2.44, 95%CI: -3.66, -1.22), and TNF-α (B = -0.12, 95%CI: -0.24, -0.005) only in MU individuals. Our results indicate that the association of 25(OH)D concentrations with a favorable biochemical profile (glycemic, lipidic and inflammatory) seems to depend on the individual's overall metabolic health, suggesting more benefits from higher serum vitamin D in MU individuals, regardless of their adiposity.

An Explanation for the Adiponectin Paradox

The adipokine adiponectin improves insulin sensitivity. Functional signal transduction of adiponectin requires at least one of the receptors AdipoR1 or AdipoR2, but additionally the glycosyl phosphatidylinositol-anchored molecule, T-cadherin. Overnutrition causes a reduction in adiponectin synthesis and an increase in the circulating levels of the enzyme glycosyl phosphatidylinositol-phospholipase D (GPI-PLD). GPI-PLD promotes the hydrolysis of T-cadherin. The functional consequence of T-cadherin hydrolysis is a reduction in adiponectin sequestration by responsive tissues, an augmentation of adiponectin levels in circulation and a (further) reduction in signal transduction. This process creates the paradoxical situation that adiponectin levels are augmented, whereas the adiponectin signal transduction and insulin sensitivity remain strongly impaired. Although both hypoadiponectinemia and hyperadiponectinemia reflect a situation of insulin resistance, the treatments are likely to be different.

A Adiponectina Previne a Reestenose pela Inibição da Proliferação Celular em um Modelo de Enxerto Venoso em Ratos

Fundamento:

O enxerto de bypass na artéria coronária (CABG) continua a ser eficiente como tratamento para pacientes portadores de doença arterial coronariana; entretanto, o enxerto venoso tende a apresentar reestenose ou oclusão. A adiponectina (ADP) é uma proteína hormonal plasmática com a função de regular a proliferação celular.

Objetivo:

Foram utilizadas duas doses diferentes da proteína ADP em um modelo de enxerto venoso em ratos para estimular a alteração do enxerto venoso. O objetivo deste estudo foi investigar o efeito da ADP sobre a reestenose em enxerto venoso.

Métodos:

Veias jugulares autólogas foram implantadas como enxertos interposicionais de carótida pela técnica de anastomose de manga em ratos Sprague Dawley. A adiponectina (2,5 μg e 7,5 μg) foi entregue ao enxerto venoso por bypass de forma perivascular, suspensa em gel Pluronic-F127 a 30%. O grupo tratado apenas com bypass e o grupo tratado com gel veículo carregado apenas com Pluronic funcionaram como controle. Foram feitas comparações com análise de via única de variância e teste post-hoc, com p <0,05 sendo considerado significativo.

Resultados:

A proliferação celular (índice de PCNA) foi significativamente baixa no grupo tratado com adiponectina em comparação com o grupo de controle e o grupo tratado com o gel veículo na íntima e na adventícia dos enxertos a partir do dia 3 (p <0,01). VCAM-1 e ICAM-1 avaliados por imuno-histoquímica diminuíram significativamente em enxertos venosos tratados com adiponectina na quarta semana (p <0,01). O tratamento de enxertos venosos com gel carregado com adiponectina reduziu a espessura da íntima, da média e da adventícia, em comparação com os enxertos de controle e tratados com gel veículo no dia 28 (p <0,01).

Conclusões:

Este estudo oferece evidências adicionais do possível papel terapêutico da adiponectina na modulação de lesão vascular e seu reparo.

The prognostic role of RBP-4 and adiponectin in patients with peripheral arterial disease undergoing lower limb endovascular revascularization

BACKGROUND

RBP4 is an adipokine with an established role in atherosclerosis, while adiponectin has unique anti-inflammatory properties. We investigated the association of RBP4 and adiponectin with the presence of symptomatic peripheral artery disease (PAD) and their possible prognostic role in major adverse cardiovascular events (MACE).

METHODS

We enrolled 168 consecutive patients with symptomatic, established PAD, requiring revascularization by endovascular means of any or both of their lower limbs. 88 age- and sex-matched subjects with less than 2 classical cardiovascular risk factors served as controls. Clinical parameters, glycemic and lipid profile, RBP4 and adiponectin levels were assayed. The occurrence of MACE was recorded during the 6-month follow-up and patients were assigned to MACE and non-MACE subgroups.

RESULTS

The presence of symptomatic PAD was significantly correlated with age, diabetes, hsCRP, RBP4 and low adiponectin levels (p < 0.05). After adjustment for age, RBP4 (β = 0.498, p < 0.001), and adiponectin (β = -0.288, p < 0.001) levels remained as independent predictors of PAD presence in the whole study cohort. At baseline, MACE subgroup appeared with higher RBP-4 and hsCRP serum levels than non-MACE subgroup (p < 0.001), but no differences were detected for adiponectin (p = 0.758). Serum RBP4 levels remained independent predictor of MACE (β = 0.455, p < 0.001) after adjustment for traditional cardiovascular risk factors.

CONCLUSIONS

High RBP4 and low adiponectin serum levels are independently associated with PAD presence. In addition, RBP4 is an independent predictor of MACE incidence in symptomatic PAD patients.

Adiponectin: a pleiotropic hormone with multifaceted roles

Adipose tissue mostly composed of different types of fat is one of the largest endocrine organs in the body playing multiple intricate roles including but not limited to energy storage, metabolic homeostasis, generation of heat, participation in immune functions and secretion of a number of biologically active factors known as adipokines. The most abundant of them is adiponectin. This adipocite-derived hormone exerts pleiotropic actions and exhibits insulin-sensitizing, antidiabetic, anti-obesogenic, anti-inflammatory, antiatherogenic, cardio- and neuroprotective properties. Contrariwise to its protective effects against various pathological events in different cell types, adiponectin may have links to several systemic diseases and malignances. Reduction in adiponectin levels has an implication in COVID-19-associated respiratory failure, which is attributed mainly to a phenomenon called 'adiponectin paradox'. Ample evidence about multiple functions of adiponectin in the body was obtained from animal, mostly rodent studies. Our succinct review is entirely about multifaceted roles of adiponectin and mechanisms of its action in different physiological and pathological states.

Glutamine supplementation can reduce some atherosclerosis markers after exhaustive exercise in young healthy males

OBJECTIVES

Glutamine can be beneficial to athletes for its antiinflammatory and antioxidant effects. The present study was designed to investigate the effect of glutamine supplementation on some atherosclerosis markers after exhaustive exercise in young healthy males.

METHODS

In an intervention study, 30 healthy males (case = 15 and control = 15) were randomly assigned into two groups. For 14 d, the intervention group received 0.3 g of glutamine per kilogram of body weight per day, with 25 g of sugar in 250 mL of water, and the control group received 25 g of sugar per 250 mL of water. At the end of the intervention, the participants completed one session of exhaustive exercise, and then fasting blood samples were taken to test serum levels of atherosclerosis markers.

RESULTS

In the intervention group, the serum levels of leptin, cholesterol, and oxidized low-density lipoprotein were lower than in the control group after 2 wk of glutamine supplementation (P < 0.05). Interleukin-6 serum levels were lower in the intervention group compared to the control group after supplementation, but not significantly. Serum levels of leptin, interleukin-6, cholesterol, and oxidized low-density lipoprotein, as well as the ratio of oxidized low-density lipoprotein to high-density lipoprotein, were significantly decreased in the intervention group compared to the control group after exhaustive exercise (P < 0.05).

CONCLUSIONS

Glutamine supplementation has beneficial effects for athletes, particularly those doing strenuous physical exercise, through reducing atherosclerosis-related biomarkers and elevating serum adiponectin levels, and it can potentially play a role in decreasing the initiation and progression of atherosclerosis.

Non-Alcoholic Fatty Liver Disease in Lean and Non-Obese Individuals: Current and Future Challenges

Non-alcoholic fatty liver disease (NAFLD), which approximately affects a quarter of the world’s population, has become a major public health concern. Although usually associated with excess body weight, it may also affect normal-weight individuals, a condition termed as lean/non-obese NAFLD. The prevalence of lean/non-obese NAFLD is around 20% within the NAFLD population, and 5% within the general population. Recent data suggest that individuals with lean NAFLD, despite the absence of obesity, exhibit similar cardiovascular- and cancer-related mortality compared to obese NAFLD individuals and increased all-cause mortality risk. Lean and obese NAFLD individuals share several metabolic abnormalities, but present dissimilarities in genetic predisposition, body composition, gut microbiota, and susceptibility to environmental factors. Current treatment of lean NAFLD is aimed at improving overall fitness and decreasing visceral adiposity, with weight loss strategies being the cornerstone of treatment. Moreover, several drugs including PPAR agonists, SGLT2 inhibitors, or GLP-1 receptor agonists could also be useful in the management of lean NAFLD. Although there has been an increase in research regarding lean NAFLD, there are still more questions than answers. There are several potential drugs for NAFLD therapy, but clinical trials are needed to evaluate their efficacy in lean individuals.

Association of Adiponectin, Leptin and Resistin Plasma Concentrations with Echocardiographic Parameters in Patients with Coronary Artery Disease

The imbalanced network of adipokines may contribute to the development of systemic low-grade inflammation, metabolic diseases and coronary artery disease (CAD). In the last decade, three classic adipokines—adiponectin, leptin and resistin—have been of particular interest in studies of patients with CAD due to their numerous properties in relation to the cardiovascular system. This has directed our attention to the association of adipokines with cardiac structure and function and the development of heart failure (HF), a common end effect of CAD. Thus, the purpose of this study was to analyse the associations of plasma concentrations of adiponectin, leptin and resistin with parameters assessed in the echocardiographic examinations of CAD patients. The presented study enrolled 167 Caucasian patients (133 male; 34 female) with CAD. Anthropometric, echocardiographic and basic biochemical measurements, together with plasma concentrations of adiponectin, leptin and resistin assays, were performed in each patient. Adiponectin concentrations were negatively associated with left ventricular ejection fraction (LVEF) and shortening fraction (LVSF), and positively associated with mitral valve E/A ratio (E/A), left ventricular end-diastolic volume (LVEDV), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter LVESD, and left atrium diameter (LAD). Resistin concentrations were negatively associated with E/A. Leptin concentrations, although correlated with HF severity assessed by the New York Heart Association (NYHA) Functional Classification, were not independently associated with the echocardiographic parameters of cardiac structure or function. In conclusion, adiponectin and resistin, but not leptin, are associated with the echocardiographic parameters of cardiac remodelling and dysfunction. These associations suggest that adiponectin and resistin might be involved in mechanisms of cardiac remodelling or compensative response. We also suggest the possible benefits of adiponectin and resistin level measurements in the monitoring of patients with CAD.

Serum levels of adiponectin, resistin and tumour necrosis factor-alpha in Nigerian men with nuchal fat fold

BACKGROUND

Factors necessitating the propensity of adults with upper body fat deposition (UBFD) for developing insulin resistance and cardiovascular diseases (CVDs) are poorly understood. Therefore, understanding the roles of adipocytokines in the development of UBFD-associated pathologies could be of clinical importance.

AIM

To assess the levels of selected adipocytokines in males with nuchal fat fold (NFF).

METHODOLOGY

Eighty-six males (43 with NFF and 43 without NFF) were enrolled into this study. Serum levels of tumour necrosis factor-alpha (TNF-α), resistin and adiponectin were determined using ELISA.

RESULTS

Adiponectin level was significantly higher while resistin and TNF-α levels were significantly lower in NFF compared with the controls. TNF-α had significant positive correlation with systolic blood pressure (SBP) while adiponectin had significant positive correlation with the waist-hip ratio (WHR). Stratifying based on the obesity status, the mean body weight, BMI, waist circumference (WC), hip circumference (HC), WHR, neck circumference (NC), NFF and diastolic BP were significantly higher in NFF with obesity compared with those without obesity. However, levels of TNF-α, resistin and adiponectin were similar between the two groups.

CONCLUSIONS

NFF is associated with elevation in adiponectin level and increased CVD risk. NFF can therefore, serve as an index of early onset of cardiometabolic diseases.

Obesity and diabetes are major risk factors for epicardial adipose tissue inflammation

BACKGROUND

Epicardial adipose tissue (EAT) directly overlies the myocardium, with changes in its morphology and volume associated with myriad cardiovascular and metabolic diseases. However, EAT’s immune structure and cellular characterization remain incompletely described. We aimed to define the immune phenotype of EAT in humans and compare such profiles across lean, obese, and diabetic patients.

METHODS

We recruited 152 patients undergoing open-chest coronary artery bypass grafting (CABG), valve repair/replacement (VR) surgery, or combined CABG/VR. Patients’ clinical and biochemical data and EAT, subcutaneous adipose tissue (SAT), and preoperative blood samples were collected. Immune cell profiling was evaluated by flow cytometry and complemented by gene expression studies of immune mediators. Bulk RNA-Seq was performed in EAT across metabolic profiles to assess whole-transcriptome changes observed in lean, obese, and diabetic groups.

RESULTS

Flow cytometry analysis demonstrated EAT was highly enriched in adaptive immune (T and B) cells. Although overweight/obese and diabetic patients had similar EAT cellular profiles to lean control patients, the EAT exhibited significantly (P ≤ 0.01) raised expression of immune mediators, including IL-1, IL-6, TNF-α, and IFN-γ. These changes were not observed in SAT or blood. Neither underlying coronary artery disease nor the presence of hypertension significantly altered the immune profiles observed. Bulk RNA-Seq demonstrated significant alterations in metabolic and inflammatory pathways in the EAT of overweight/obese patients compared with lean controls.

CONCLUSION

Adaptive immune cells are the predominant immune cell constituent in human EAT and SAT. The presence of underlying cardiometabolic conditions, specifically obesity and diabetes, rather than cardiac disease phenotype appears to alter the inflammatory profile of EAT. Obese states markedly alter EAT metabolic and inflammatory signaling genes, underlining the impact of obesity on the EAT transcriptome profile.

FUNDING

Barts Charity MGU0413, Abbott, Medical Research Council MR/T008059/1, and British Heart Foundation FS/13/49/30421 and PG/16/79/32419.

Adiponectin in psoriasis and its comorbidities: a review

Psoriasis is a chronic, immune-mediated inflammatory skin disease characterized by abnormal T cell activation and excessive proliferation of keratinocytes. In addition to skin manifestations, psoriasis has been associated with multiple metabolic comorbidities, such as obesity, insulin resistance, and diabetes. An increasing amount of evidence has highlighted the core role of adipokines in adipose tissue and the immune system. This review focus on the role of adiponectin in the pathophysiology of psoriasis and its comorbidities, highlighting the future research avenues.

Altered Adiponectin Response in Older Women Following Dextrose and High-Fat Dietary Challenges

SCOPE

Despite its beneficial properties, higher adiponectin concentrations are paradoxically associated with mortality in advanced age. Several mechanisms are being discussed. However, little is known about postprandial regulation of adiponectin in older adults. We assessed age-specific differences of the adiponectin response to different test meals considering potential determinants.

METHODS AND RESULTS

Older (n = 20) and younger (n = 22) women are randomized to a dextrose (DEX) or high-fat (HF) dietary challenge. Postprandial adiponectin and fibroblast growth factor 21 (FGF21) concentrations are measured before and 60, 120, 240 min after ingestion. We assessed postprandial changes and group differences using linear mixed models controlled for possible determinants. In younger women, postprandial adiponectin remains stable after both test meals. In contrast, adiponectin increases following DEX and decreases after HF in older women, irrespective of control variables. Postprandial adiponectin is positively associated with malondialdehyde and inversely associated with interleukin-6 following DEX and also negatively associated with metabolic parameters after both test meals. In older women, elevated postprandial FGF21 concentrations are associated with a higher adiponectin response (β = 30.7, 95% CI 10.6-50.8, p = 0.007).

CONCLUSIONS

Adiponectin response is associated with type of dietary challenge, age, and FGF21 response. Age-group differences are partly attributable to metabolic parameters and oxidative stress.

Switching from boosted PIs to dolutegravir decreases soluble CD14 and adiponectin in high cardiovascular risk people living with HIV

BACKGROUND

Switching from boosted PIs to dolutegravir in people living with HIV (PLWH) with high cardiovascular risk improved plasma lipids at 48 weeks in the NEAT022 trial. Whether this strategy may have an impact on cardiovascular biomarkers is unknown.

METHODS

We assessed 48 week changes in biomarkers associated with inflammation, endothelial dysfunction, monocyte immune activation, oxidation, insulin resistance, hypercoagulability, heart failure, myocardial injury, and glomerular and tubular kidney injury.

RESULTS

Of 415 PLWH randomized in the NEAT022 study, 313 (75.4%) remained on allocated therapy and had paired samples available. Soluble CD14 (-11%, P < 0.001) and adiponectin (-11%, P < 0.001) significantly declined and high-sensitive C-reactive protein (-13%, P = 0.069) and oxidized LDL (-13%, P = 0.084) tended to decrease with dolutegravir. Switching to dolutegravir remained significantly associated with soluble CD14 and adiponectin reductions after adjustment for baseline variables. There were inverse correlations between soluble CD14 and CD4 count changes (P = 0.05), and between adiponectin and BMI changes (P < 0.001).

CONCLUSIONS

Switching from boosted PIs to dolutegravir in PLWH with high cardiovascular risk led to soluble CD14 and adiponectin reductions at 48 weeks. While decreasing soluble CD14 may entail favourable health effects in PLWH, adiponectin reduction may reflect less insulin sensitivity associated with weight gain.

Role of Perivascular Adipose Tissue-Derived Adiponectin in Vascular Homeostasis

Studies of adipose tissue biology have demonstrated that adipose tissue should be considered as both passive, energy-storing tissue and an endocrine organ because of the secretion of adipose-specific factors, called adipokines. Adiponectin is a well-described homeostatic adipokine with metabolic properties. It regulates whole-body energy status through the induction of fatty acid oxidation and glucose uptake. Adiponectin also has anti-inflammatory and antidiabetic properties, making it an interesting subject of biomedical studies. Perivascular adipose tissue (PVAT) is a fat depot that is conterminous to the vascular wall and acts on it in a paracrine manner through adipokine secretion. PVAT-derived adiponectin can act on the vascular wall through endothelial cells and vascular smooth muscle cells. The present review describes adiponectin's structure, receptors, and main signaling pathways. We further discuss recent studies of the extent and nature of crosstalk between PVAT-derived adiponectin and endothelial cells, vascular smooth muscle cells, and atherosclerotic plaques. Furthermore, we argue whether adiponectin and its receptors may be considered putative therapeutic targets.

AdipoRon: A Novel Insulin Sensitizer in Various Complications and the Underlying Mechanisms: A Review

BACKGROUND

AdipoRon is the first synthetic analog of endogenous adiponectin, an adipose tissue-derived hormone. AdipoRon possesses pharmacological properties similar to adiponectin and its ability to bind and activate the adipoR1 and adipoR2 receptors makes it a suitable candidate for the treatment of a multitude of disorders.

OBJECTIVE

In the present review, an attempt was made to compile and discuss the efficacy of adipoRon against various disorders.

RESULTS

AdipoRon is a drug that acts not only in metabolic diseases but in other conditions unrelated to energy metabolism. It is well- reported that adipoRon exhibits strong anti-obesity, anti-diabetic, anticancer, anti-depressant, anti-ischemic, anti-hypertrophic properties and also improves conditions like post-traumatic stress disorder, anxiety, and systemic sclerosis.

CONCLUSION

A lot is known about its effects in experimental systems, but the translation of this knowledge to the clinic requires studies which, for many of the potential target conditions, have yet to be carried out. The beneficial effects of AdipoRon in novel clinical conditions will suggest an underlying pathophysiological role of adiponectin and its receptors in previously unsuspected settings.

Cardiovascular Disease Prediction by Machine Learning Algorithms Based on Cytokines in Kazakhs of China

Background

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Accurately identifying subjects at high-risk of CVD may improve CVD outcomes. We sought to systematically examine the feasibility and performance of 7 widely used machine learning (ML) algorithms in predicting CVD risks.

Methods

The final analysis included 1508 Kazakh subjects in China without CVD at baseline who completed follow-up. All subjects were randomly divided into the training set (80%) and the test set (20%). L1-penalized logistic regression (LR), support vector machine with radial basis function (SVM), decision tree (DT), random forest (RF), k-nearest neighbors (KNN), Gaussian naive Bayes (NB), and extreme gradient boosting (XGB) were employed for prediction CVD outcomes. Ten-fold cross-validation was used during model developing and hyperparameters tuning in the training set. Model performance was evaluated in the test set in light of discrimination, calibration, and clinical usefulness. RF was applied to obtain the variable importance of included variables. Twenty-two variables, including sociodemographic characteristics, medical history, cytokines, and synthetic indices, were used for model development.

Results

Among 1508 subjects, 203 were diagnosed with CVD over a median follow-up of 5.17 years. All 7 models had moderate to excellent discrimination (AUC ranged from 0.770 to 0.872) and were well calibrated. LR and SVM performed identically with an AUC of 0.872 (95% CI: 0.829–0.907) and 0.868 (95% CI: 0.825–0.904), respectively. LR had the lowest Brier score (0.078) and the highest sensitivity (97.1%). Decision curve analysis indicated that SVM was slightly better than LR. The inflammatory cytokines, such as hs-CRP and IL-6, were identified as strong predictors of CVD.

Conclusion

SVM and LR can be applied to guide clinical decision-making in the Kazakh Chinese population, and further study is required to ensure their accuracies.

Inflammatory Gene Expression in Neck Perivascular and Subcutaneous Adipose Tissue in Men With Carotid Stenosis

The inflammatory phenotype of neck adipose tissue (NAT) might reflect its involvement in the pathogenesis of carotid atherosclerosis. We investigated inflammatory gene expression in the subcutaneous and the perivascular (pericarotid) adipose tissue from patients with carotid stenosis (CS) undergoing endarterectomy and a control group of patients without significant carotid atherosclerosis undergoing thyroid surgery. Only male patients were included (n = 13 in each study group). Clinical and biochemical data along with serum leptin, adiponectin, and monocyte chemoattractant protein 1 (MCP-1) were collected. Adipose tissue samples were obtained from both the subcutaneous and pericarotid compartments. Real-time polymerase chain reaction was used to measure gene expression of macrophage markers and adipokines. The CS group had higher subcutaneous and pericarotid visfatin gene expression and higher pericarotid expression of MCP-1 and CD68 genes. The ratio between pericarotid CD206 and CD68 gene expression was similar between study groups. Adiponectin gene expression in both NAT compartments did not differ between groups, but it was negatively associated with body weight. These observations suggest that NAT, and especially the pericarotid compartment, express enhanced inflammatory properties in patients with CS, but the proportion of anti-inflammatory macrophages in advanced atherosclerosis seems to be maintained.

Adiponectin: Structure, Physiological Functions, Role in Diseases, and Effects of Nutrition

Adiponectin (a protein consisting of 244 amino acids and characterized by a molecular weight of 28 kDa) is a cytokine that is secreted from adipose tissues (adipokine). Available evidence suggests that adiponectin is involved in a variety of physiological functions, molecular and cellular events, including lipid metabolism, energy regulation, immune response and inflammation, and insulin sensitivity. It has a protective effect on neurons and neural stem cells. Adiponectin levels have been reported to be negatively correlated with cancer, cardiovascular disease, and diabetes, and shown to be affected (i.e., significantly increased) by proper healthy nutrition. The present review comprehensively overviews the role of adiponectin in a range of diseases, showing that it can be used as a biomarker for diagnosing these disorders as well as a target for monitoring the effectiveness of preventive and treatment interventions.

Traditional Chinese Medicine formula FTZ protects against polycystic ovary syndrome through modulating adiponectin-mediated fat-ovary crosstalk in mice

ETHNOPHARMACOLOGICAL RELEVANCE

FuFang ZhenZhu TiaoZhi (FTZ) is a hospitalized traditional Chinese medicine herbal formula with documented metabolic benefits. Polycystic ovary syndrome (PCOS) characterized by ovarian dysfunction and insulin resistance represents one of the most common endocrine disorders in close association with metabolic dysfunction in premenopausal women.

AIM OF THE STUDY

The present study aimed to investigate the preventive effect of FTZ on letrozole-induced experimental PCOS and its associated insulin resistance in mice.

MATERIALS AND METHODS

Prepubertal female mice in the experimental groups (letrozole and FTZ) received continuous infusion of letrozole (50 μg/day) for 35 days. FTZ was administrated to mice by oral gavage daily at dosage of 2.892 g/kg body weight for 5 weeks. All groups of mice were fed a high-fat diet (HFD). Ovary and adipose tissue were collected from all mice after 5 weeks and adiponectin, testosterone, estradiol, and luteinizing hormone level determined.

RESULTS

Letrozole-induced morphological changes in the ovary, including a decreased number of corpora lutea and antral follicles, and increased cystic follicles, were significantly attenuated in FTZ-treated mice. Additionally, FTZ treatment notably reversed PCOS-related disruption of estrous status. PCOS-related insulin resistance was markedly alleviated. Mechanistically, FTZ treatment notably enhanced circulating level and transcriptional abundance of adiponectin in adipose tissue, thereby orchestrating fat-ovary crosstalk.

CONCLUSIONS

Our data collectively demonstrate that FTZ exerted preventive benefits in an experimental model of PCOS, at least partially by potentiating the production of adiponectin from adipose tissues. This suggests that FTZ is a promising treatment for PCOS.