Functional adiponectin resistance and exercise intolerance in heart failure

Relationship between adiponectin and muscle mass in patients with metabolic syndrome and obesity

BACKGROUND

Adiponectin is one of the most important adipokines in human beings. Obesity and sarcopenia are associated with a low-level chronic inflammatory status, and adiponectin plays an anti-inflammatory role.

AIMS

The objective of the current work was to study the association between muscle mass, determined via bioelectrical impedance (BIA), and circulating adiponectin levels among obese patients with metabolic syndrome who are older than 60 years of age.

METHODS

We performed a cross-sectional study incorporating 651 patients with obesity and metabolic syndrome. Anthropometric data, BIA data (total fat mass (FM), fat-free mass (FFM), fat-free mass index (FFMi), skeletal muscle mass (SMM) and skeletal muscle mass index (SMMi)), arterial pressure, HOMA-IR (homeostasis model assessment of insulin resistance), and biochemical parameters were recorded.

RESULTS

The patients were separated into two groups based on their median SMMi (skeletal muscle mass index) levels. The low-SMMi group presented adiponectin levels that were higher than those in the high-SMMi group (delta value: 4.8 + 0.7 ng/dl: p = 0.02). Serum adiponectin values were negatively correlated with fat mass (FM), fat-free mass (FFM), fat-free mass index (FFMi), SMM, and SMMi. Adiponectin presented a negative correlation with HOMA-IR and a positive correlation with HDL-cholesterol. In the final multivariate model using SMMi as a dependent variable, adiponectin levels explained 18 % of the variability (Beta -0.49, CI95% -0.89 to -0.16) after adjusting for age and gender.

CONCLUSIONS

Serum adiponectin levels are negatively associated with low skeletal muscle mass among obese subjects with metabolic syndrome who are older than 60 years of age.

The association of serum adiponectin level with activities of daily living in hospitalized elderly patients with heart failure

BACKGROUND

Several studies have reported a relationship between elevated serum adiponectin levels and poor outcomes in patients with heart failure (HF). However, data on the activities of daily living (ADL) in elderly patients with HF are limited.

METHODS

We evaluated 218 hospitalized elderly (≥65 years) patients with HF who underwent a comprehensive cardiac rehabilitation (CR) program during hospitalization. Serum adiponectin levels were measured before discharge. The Barthel index (BI) score was evaluated at discharge. Low ADL was defined as a BI score < 85.

RESULTS

Serum adiponectin levels were significantly associated with low ADL [p = 0.03; odds ratio (OR), 1.024, per 1.0 μg/mL increase]. In logistic or regression analyses adjusted for age, sex, body mass index, and estimated glomerular filtration rate, high adiponectin levels (≥16.2 μg/mL) were significantly associated with low ADL (p = 0.04; OR, 2.53), malnutrition (p < 0.01; OR, 2.88), and 6-min walk distance (p = 0.04; β = -17.5). In the multivariate analysis adjusted for conventional risk factors of low ADL, high adiponectin levels were also significantly associated with low ADL (p = 0.03; OR, 2.68). In the stepwise forward selection procedure, a high adiponectin level was an independent determinant of low ADL (p = 0.02; R2 = 0.0262). Both net reclassification improvement (0.53; p < 0.01) and integrated discrimination improvement (0.02; p = 0.01) improved significantly after the addition of high adiponectin level to conventional risk factors. In the regression analysis adjusted for age and sex, serum adiponectin levels were significantly (p < 0.0025) negatively associated with abdominal visceral and subcutaneous adipose tissue areas, body weight, body mass index, and serum triglyceride levels.

CONCLUSIONS

High serum adiponectin levels were not only significantly associated with an increased risk of low ADL, but also with an increased risk of malnutrition and low physical activity in elderly patients with HF after the in-hospital CR program.

Assessment of biomarkers and clinical parameters as predictors of survival in patients with chagasic heart failure

BACKGROUND

Chagas disease, endemic in Latin America and spreading globally due to emigration, has a significant health burden, particularly in relation to chagasic heart failure (HF). Chagasic cardiomyopathy (CCM) is characterized by chronic inflammatory myocardial disease. This study aimed to identify inflammatory parameters and biomarkers that could aid in the management of patients with chagasic HF.

METHODS AND FINDINGS

A cohort study was conducted at a tertiary cardiology single-center over a mean follow-up period of 2.4 years. The study included patients with HF secondary to CCM enrolled between October 2013 and July 2017. Various clinical parameters, echocardiography findings, parasitemia status, brain natriuretic peptide (BNP) and troponin T (TnT) levels, and inflammatory biomarkers (IL-6, IL-10, IL-12p70, IL-17A, adiponectin, and IFN-γ) were assessed. The study encompassed a cohort of 103 patients, with a median age of 53 years and 70% being male. The left ventricular ejection fraction (LVEF) was 28%, with 40% of patients classified as NYHA II functional class. The median BNP level was 291 pg/ml. The observed mortality rate during the study period was 38.8%. Predictors of lower survival were identified as elevated levels of BNP, TnT, reduced LVEF, and increased adiponectin (thresholds: BNP > 309 pg/ml, TnT > 27.5 ng/ml, LVEF < 25.5%, adiponectin > 38 μg/mL). Notably, there was no evidence indicating a relationship between parasitemia and the inflammatory parameters with lower survival in these patients, including INF-γ, IL-6, IL-10, IL12-(p70), and IL17a.

CONCLUSION

Despite the presence of a chronic inflammatory process, the evaluated inflammatory biomarkers in this cohort were not predictive of survival in patients with chagasic HF with reduced ejection fraction (HFrEF). However, reduced LVEF, elevated BNP, adiponectin levels, and troponin T were identified as predictors of lower survival in these patients.

Diminished AdipoR1/APPL1 Interaction Mediates Reduced Cardioprotective Actions of Adiponectin against Myocardial Ischemia/Reperfusion Injury in Type-2 Diabetic Mice

Background

Obesity-related diseases have important implications for the occurrence, severity, and outcome of ischemic heart disease. Patients with obesity, hyperlipidemia, and diabetes mellitus (metabolic syndrome) are at increased risk of heart attack with decreased plasma lipocalin levels, and lipocalin is negatively correlated with heart attack incidence. APPL1 is a signaling protein with multiple functional structural domains and plays an important role in the APN signaling pathway. There are two known subtypes of lipocalin membrane receptors, AdipoR1 and AdipoR2. AdioR1 is mainly distributed in skeletal muscle while AdipoR2 is mainly distributed in the liver.

Objective

To clarify whether the AdipoR1-APPL1 signaling pathway mediates the effect of lipocalin in reducing myocardial ischemia/reperfusion injury and its mechanism will provide us with a new approach to treat myocardial ischemia/reperfusion injury using lipocalin as an intervention and therapeutic target.

Methods

(1) Induction of hypoxia/reoxygenation in SD mammary rat cardiomyocytes to simulate myocardial ischemia/reperfusion; (2) downregulation of APPL1 expression in cardiomyocytes to observe the effect of lipocalin on myocardial ischemia/reperfusion and its mechanism of action.

Results

(1) Primary mammary rat cardiomyocytes were isolated and cultured and induced to simulate MI/R by hypoxia/reoxygenation; (2) lipocalin inhibited H/R-induced apoptosis in cardiomyocytes; and (3) APN attenuated MI/R injury through AdipoR1-APPL1 and the possible mechanism.

Conclusion

This study demonstrates for the first time that lipocalin can attenuate myocardial ischemia/reperfusion injury through the AdipoR1-APPL1 signaling pathway and that the reduction of AdipoR1/APPL1 interaction plays an important role in cardiac APN resistance to MI/R injury in diabetic mice.

Angiotensin II receptor blocker and statin combination therapy associated with higher skeletal muscle index in patients with cardiovascular disease: A retrospective study

WHAT IS KNOWN AND OBJECTIVE

Reduction in skeletal muscle mass is the most important component in diagnosing sarcopenia. Ageing and chronic heart failure due to cardiovascular diseases (CVDs) accelerate the reduction of skeletal muscles. However, there are no currently available drugs that are effective for sarcopenia. The purpose of this study was to explore the association between prescribed medications and skeletal muscle mass in patients with CVD.

METHODS

This was a single-centre, retrospective, cross-sectional study. The subjects were 636 inpatients with CVD who took prescribed medicines for at least 4 weeks at the time of admission. Skeletal muscle volume was assessed using a bioelectrical impedance assay.

RESULTS AND DISCUSSION

Single regression analysis showed that 10 and 3 medications were positively and negatively associated with skeletal muscle index (SMI), respectively. Stepwise multivariate regression analysis revealed that angiotensin II receptor blocker (ARB)/statin combination, dipeptidyl peptidase-4 inhibitor, and antihyperuricemic agents were positively associated with SMI while diuretics and antiarrhythmic agents were negatively associated with SMI. After adjustment using propensity score matching, the SMI was found to be significantly higher in ARB/statin combination users than in non-users.

WHAT IS NEW AND CONCLUSION

Combination use of ARB/statin was associated with a higher SMI in patients with CVD. A future randomised, controlled trial is warranted to determine whether the ARB/statin combination will increase the SMI and prevent sarcopenia in patients with CVD.

Cloves Regulate Na+-K+-ATPase to Exert Antioxidant Effect and Inhibit UVB Light-Induced Skin Damage in Mice

The purpose of this study was to observe the effect of cloves (Syzygium aromaticum (L.) Merr. & L.M. Perry) on the mouse skin using a UVB-induced skin injury mouse model. The serum, liver, and skin indexes of mice were determined by kits, H&E tissue staining, and qPCR assay. The compound composition of cloves was determined by HPLC. The results showed that cloves increased the activity of Na⁺-K⁺-ATPase in the skin and then maintained the sodium and potassium pump in the damaged skin muscle membrane. Cloves alleviated the oxidative stress injury induced by UVB irradiation by normalizing the related oxidative stress indexes (T-SOD, CAT, AGEs, and H₂O₂) in serum and skin. Inhibition of the proinflammatory cytokines TNF-α, IL-1β, and IL-6 and increased activation of anti-inflammatory cytokines IL-4 and IL-10 occurred after treatment with cloves, which ultimately reduced the inflammatory damage to the body. Further results showed that cloves upregulate SOD1, SOD2, CAT, GSH, IL-10, IκB-α, AMPK, SIRT1, LKB1, PGC-1α, APPL1, and FoxO1 and downregulate NF-κB p65, TNF-α, IL-6, and mTOR mRNA expression in the skin tissues of UVB-damaged mice. The results of composition analysis showed that the five most abundant compounds in cloves are rutin, isoquercitrin, ferulic acid, dihydroquercetin, and quercitrin. Cloves regulate the skin sarcomembrane Na⁺-K⁺-ATPase through these five compounds, and because they regulate the oxidation, inflammation, and ATP energy consumption of the body, they subsequently protect the skin from UVB damage.

Adiponectin Concentration and Chronic Stroke Individuals, Associations with Body Composition, Physical Activity Levels and Lipid Profile: A Cross-Sectional Explorative Study

OBJECTIVE

Higher adiponectin concentration has been associated with the presence of sarcopenia in individuals with cardiovascular diseases. Post-stroke individuals presented higher adiponectin concentrations than non-stroke ones. However, no previous study has investigated the association between the adiponectin concentration and skeletal muscle mass in post-stroke individuals. On the other hand, higher adiponectin concentration has been associated with a more favorable lipid profile and the physical activity level might regulate adiponectin concentration. These associations have not been studied in this population. Thus, the main objective of this study was to determine whether the adiponectin concentration is associated with: (1) body composition; (2) lipid profile; and (3) physical activity level in chronic post-stroke individuals.

MATERIALS AND METHODS

This study was a correlational, cross-sectional exploratory study. Data on body composition and lipid profile were collected using a bioelectrical impedance analyzer (InBody® 720) and an automated method analyzer (CELL-DYN Ruby), respectively. The physical activity level was measured by the StepWatch® Activity Monitor and the serum adiponectin concentration was analyzed using an enzyme-linked immunosorbent assay kit. Correlation analyses were made using Spearman's rank correlation coefficient (r_s).

RESULTS

Twenty-one post-stroke participants took part in the study. The adiponectin concentration was associated with the following: skeletal muscle mass (r_s = -0.78), skeletal muscle mass index (r_s = -0.75) and high-density lipoprotein (r_s = 0.43).

CONCLUSIONS

A greater adiponectin concentration is associated with a lower skeletal muscle mass and a higher high-density lipoprotein level in chronic post-stroke individuals, but not with physical activity levels.

Iron overload reduces adiponectin receptor expression via a ROS/FOXO1-dependent mechanism leading to adiponectin resistance in skeletal muscle cells

Iron overload (IO) is a common yet underappreciated finding in metabolic syndrome (MetS) patients. With the prevalence of MetS continuing to rise, it is imperative to further elucidate cellular mechanisms leading to metabolic dysfunction. Adiponectin has many beneficial effects and is a therapeutic target for the treatment of MetS and cardiovascular diseases. IO positively correlates with reduced circulating adiponectin levels yet the impact of IO on adiponectin action is unknown. Here, we established a model of IO in L6 skeletal muscle cells and found that IO-induced adiponectin resistance. This was shown via reduced p38 mitogen-activated protein kinase phosphorylation in response to the small molecule adiponectin receptor (AdipoR) agonist, AdipoRon, in presence of IO. This correlated with reduced messenger RNA and protein levels of AdipoR1 and its facilitative signaling binding partner, APPL1. IO caused phosphorylation, nuclear extrusion, and thus inhibition of FOXO1, a known transcription factor regulating AdipoR1 expression. The antioxidant N-acetyl cystine attenuated the production of reactive oxygen species (ROS) by IO, and blunted its effect on FOXO1 phosphorylation and removal from the nucleus, as well as subsequent adiponectin resistance. In conclusion, our study identifies a ROS/FOXO1/AdipoR1 axis as a cause of skeletal muscle adiponectin resistance in response to IO. This new knowledge provides insight into a cellular mechanism with potential relevance to disease pathophysiology in MetS patients with IO.

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

Adipose tissue (AT) has recently been identified as a dynamic endocrine organ secreting a wide range of adipokines. Adiponectin is one such hormone, exerting endocrine and paracrine effects on the cardiovascular system. At a cellular and molecular level, adiponectin has anti-inflammatory, antioxidant and anti-apoptotic roles, thereby mitigating key mechanisms underlying cardiovascular disease (CVD) pathogenesis. However, adiponectin expression in human AT as well as its circulating levels are increased in advanced CVD states, and it is actually considered by many as a 'rescue hormone'. Due to the complex mechanisms regulating adiponectin's biosynthesis in the human AT, measurement of its levels as a biomarker in CVD is highly controversial, given that adiponectin exerts protective effects on the cardiovascular system but at the same time its increased levels flag advanced CVD. In this review article, we present the involvement of adiponectin in CVD pathogenesis and we discuss its role as a clinical biomarker.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Prognostic value of adiponectin in coronary artery disease: Role of diabetes and left ventricular systolic dysfunction

OBJECTIVES

Adiponectin (AD) promotes insulin sensitivity and has anti-atherogenic properties. However, the role of AD on clinical outcomes in coronary artery disease (CAD) is controversial. We analyzed whether AD was an independent predictor of all-cause mortality and hospitalization in patients with CAD.

METHOD

We prospectively enrolled 138 patients with stable CAD, with or without type 2 diabetes and with or without left ventricular dysfunction. A telephone follow-up was conducted to register long term outcomes. Sensitivity/specificity ratio for AD was investigated with ROC analysis and the independent role of AD on outcome was evaluated with Cox regression model of analysis. The survival rate was represented by Kaplan Meyer curves.

RESULTS

Of 138 patients, 61 had type 2 diabetes and 71 left ventricular systolic dysfunction (EF<40%). Median time of follow-up was 1384days; mortality rate was 18.8% (26 deaths) and hospitalization rate was 47.1% (65 events). Mean concentration of AD was 9.87±7.53ng/ml; the analysis of the ROC curve identified an AD cut-off level of 13.2ng/ml (AUC 0.779; p<0.0001). Patients with AD >13.2ng/ml had a significantly higher risk of death (HR=6.50; 95% CI: 2.40-17.70), but not of cardiovascular hospitalization (HR=0.87; 95% CI: 0.31-2.44). AD predictivity remained significant also in patients with type 2 diabetes and with left ventricular systolic dysfunction.

CONCLUSION

In stable CAD, an AD value of >13.2ng/ml independently predicts a 6-fold increased risk of all-cause mortality.

Adiponectin resistance in skeletal muscle: pathophysiological implications in chronic heart failure

Skeletal muscle wasting is a common complication of chronic heart failure (CHF) and linked to poor patient prognosis. In recent years, adiponectin was postulated to be centrally involved in CHF-associated metabolic failure and muscle wasting. This review discusses current knowledge on the role of adiponectin in CHF. Particular emphasis will be given to the complex interaction mechanisms and the intracellular pathways underlying adiponectin resistance in skeletal muscle of CHF patients. In this review, we propose that the resistance process is multifactorial, integrating abnormalities emanating from insulin signalling, mitochondrial biogenesis, and ceramide metabolism.

Dysregulation of Autonomic Nervous System in Chagas' Heart Disease Is Associated with Altered Adipocytokines Levels

BACKGROUND

Chagas disease (CD) induces autonomic dysfunction and inflammatory activity, which may promote metabolic abnormalities. We studied metabolism and his correlation with Autonomic Nervous System (ANS) and inflammation in CD.

METHODS AND RESULTS

Sixty subjects were divided into 4 groups: control group (CG), IF (indeterminate form) group; ECG group (ECG abnormalities and normal left ventricular systolic function), and LVD group (left ventricular sistolic dysfunction). Levels of adiponectin, leptin, insulin, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were assayed in serum samples by ELISA. ANS was assessed by heart rate variability in frequency domain in 24-hour Holter and postural tilt test (rest and orthostatic position). High frequency (HFr) component values were used to estimate parasympathetic activity and low frequency (LFr) component, sympathetic activity. Analyzes were made of the correlations of each of the metabolic parameters (leptin and adiponectin) with the inflammatory cytokines (interleukin-6 and TNF- alpha) and with the ANS assessment measurements. No significant differences were observed in leptin and insulin levels. Adiponectin was higher in ECG and LVD groups: [CG = 4766.5 (5529.5), IF = 4003.5 (2482.5), ECG = 8376.5 (8388.5), LVD = 8798 (4188.0) ng/mL, p<0.001)]. IL-6 and TNF-alpha were higher in LVD group: [IL-6: CG = 1.85 (6.41); IF = 1.58 (1.91); ECG = 1.0 (1.57); LVD= 31.44 (72.19) pg/ml; p = 0.001. TNF-alpha: CG = 22.57 (88.2); IF = 19.31 (33.16); ECG = 12.45 (3.07); LVD = 75.15 (278.57) pg/ml; p = 0.04]. Adiponectin levels had a positive association with the HFr component (r = 0.539; p = 0.038) and an inverse association with the LFr component (r = - 0.539; p = 0.038) in ECG group. Leptin levels had a negative association with the HFr component (r= - 0.632; p = 0.011) and a positive association with the LFr component (r = 0.632; p = 0.011) in LVD group.

CONCLUSIONS

We found increased adiponectin levels in Chagas' heart disease with systolic dysfunction and in patients with ECG abnormalities and normal systolic function at rest. Adipocytokines levels (adiponectin and leptin) were associated with ANS parameters in Chagas' heart disease.

Effects of administration of omega-3 fatty acids with or without vitamin E supplementation on adiponectin gene expression in PBMCs and serum adiponectin and adipocyte fatty acid-binding protein levels in male patients with CAD

OBJECTIVE

Adiponectin is a unique anti-atherogenic adipocytokine. Regulation of adiponectin secretion is dysfunctional in cardiovascular diseases. The current trial study assessed the effects of omega-3 fatty acids with or without vitamin E on adiponectin gene expression in peripheral blood mononuclear cells and serum adiponectin and adipocyte fatty acid-binding protein (A-FABP; also called ap2 and FABP4) levels in patients with coronary artery disease (CAD).

METHODS

This randomized, double-blind, placebo-controlled trial included 67 male patients with CAD. First of the four group of participants received 4 g/day omega-3 fatty acids plus 400 IU/day vitamin E (OE), second group 4 g/day omega-3 fatty acids plus vitamin E placebo (OP), or both omega-3 fatty acid and vitamin E placebos (PP) for 8 weeks. Adiponectin gene expression and serum adiponectin and FABP4 levels were evaluated.

RESULTS

The combination of omega-3 fatty acids and vitamin E in patients with CAD affected their serum adiponectin and FABP4 levels and the adiponectin/FABP4 ratio significantly. In the OP group, serum adiponectin levels did not change significantly. Consumption of omega-3 fatty acids with and without vitamin E had no significant effect on adiponectin gene expression.

CONCLUSION

Omega-3 fatty acids with or without vitamin E improve adiponectin levels in patients, without any significant changes in adiponectin gene expression. This nutritional intervention may prevent complications in patients with CAD because of increased adiponectin levels.

Adiponectin: key role and potential target to reverse energy wasting in chronic heart failure

The concept of skeletal muscle myopathy as a main determinant of exercise intolerance in chronic heart failure (HF) is gaining acceptance. Symptoms that typify HF patients, including shortness of breath and fatigue, are often directly related to the abnormalities of the skeletal muscle in HF. Besides muscular wasting, alterations in skeletal muscle energy metabolism, including insulin resistance, have been implicated in HF. Adiponectin, an adipocytokine with insulin-sensitizing properties, receives increasing interest in HF. Circulating adiponectin levels are elevated in HF patients, but high levels are paradoxically associated with poor outcome. Previous analysis of m. vastus lateralis biopsies in HF patients highlighted a striking functional adiponectin resistance. Together with increased circulating adiponectin levels, adiponectin expression within the skeletal muscle is elevated in HF patients, whereas the expression of the main adiponectin receptor and genes involved in the downstream pathway of lipid and glucose metabolism is downregulated. In addition, the adiponectin-related metabolic disturbances strongly correlate with aerobic capacity (VO2 peak), sub-maximal exercise performance and muscle strength. These observations strengthen our hypothesis that adiponectin and its receptors play a key role in the development and progression of the "heart failure myopathy". The question whether adiponectin exerts beneficial rather than detrimental effects in HF is still left unanswered. This current research overview will elucidate the emerging role of adiponectin in HF and suggests potential therapeutic targets to tackle energy wasting in these patients.

Direct effects of adipokines on the heart: focus on adiponectin

Cardiovascular disease, including heart failure, is a principal cause of death in individuals with obesity and diabetes. However, the mechanisms of obesity- and diabetes-induced heart disease are multifaceted and remain to be clearly defined. Of relevance to this review, there is currently great research and clinical interest in the endocrine effects of adipokines on the myocardium and their role in heart failure. We will discuss the potential significance of adipokines in the pathogenesis of heart failure via their ability to regulate remodeling events including metabolism, hypertrophy, fibrosis, and cell death. As an excellent example, we will first focus on adiponectin which is best known to confer numerous cardioprotective effects. However, we comprehensively discuss the existing literature that highlights it would be naive to assume that this was always the case. We also focus on lipocalin-2 which mediates pro-inflammatory and pro-apoptotic effects. It is important when studying actions of adipokines to integrate cellular and mechanistic analyses and translate these to physiologically relevant in vivo models and clinical studies. However, assimilating studies on numerous cardiac remodeling events which ultimately dictate cardiac dysfunction into a unifying conclusion is challenging. Nevertheless, there is undoubted potential for the use of adipokines as robust biomarkers and appropriate therapeutic targets in heart failure.

Simultaneous characterization of metabolic, cardiac, vascular and renal phenotypes of lean and obese SHHF rats

Individuals with metabolic syndrome (MetS) are prone to develop heart failure (HF). However, the deleterious effects of MetS on the continuum of events leading to cardiac remodeling and subsequently to HF are not fully understood. This study characterized simultaneously MetS and cardiac, vascular and renal phenotypes in aging Spontaneously Hypertensive Heart Failure lean (SHHF(+/?) regrouping (+/+) and (+/cp) rats) and obese (SHHF(cp/cp), "cp" defective mutant allele of the leptin receptor gene) rats. We aimed to refine the milestones and their onset during the progression from MetS to HF in this experimental model. We found that SHHF(cp/cp )but not SHHF(+/?) rats developed dyslipidemia, as early as 1.5 months of age. This early alteration in the lipidic profile was detectable concomitantly to impaired renal function (polyuria, proteinuria but no glycosuria) and reduced carotid distensibility as compared to SHHF(+/?) rats. By 3 months of age SHHFcp/cp animals developed severe obesity associated with dislipidemia and hypertension defining the onset of MetS. From 6 months of age, SHHF(+/?) rats developed concentric left ventricular hypertrophy (LVH) while SHHF(cp/cp) rats developed eccentric LVH apparent from progressive dilation of the LV dimensions. By 14 months of age only SHHF(cp/cp) rats showed significantly higher central systolic blood pressure and a reduced ejection fraction resulting in systolic dysfunction as compared to SHHF(+/?). In summary, the metabolic and hemodynamic mechanisms participating in the faster decline of cardiac functions in SHHF(cp/cp) rats are established long before their physiological consequences are detectable. Our results suggest that the molecular mechanisms triggered within the first three months after birth of SHHF(cp/cp) rats should be targeted preferentially by therapeutic interventions in order to mitigate the later HF development.

Association of adiponectin with peripheral muscle status in elderly patients with heart failure

BACKGROUND

Reduced peripheral muscle mass was demonstrated in patients with chronic heart failure (HF). Adipokines may have potent metabolic effects on skeletal muscle. The associations between adipokines, peripheral muscle mass, and muscle function have been poorly investigated in patients with HF.

METHODS

We measured markers of fat and bone metabolism (adiponectin, leptin, 25-hydroxy vitamin D, parathyroid hormone, osteoprotegerin, RANKL), N-terminal pro B-type natriuretic peptide (NT-pro-BNP) in 73 non-cachectic, non-diabetic, male patients with chronic HF (age: 68 ± 7 years, New York Heart Association class II/III: 76/26%, left ventricular ejection fraction 29 ± 8%) and 20 healthy controls of similar age. Lean mass as a measure of skeletal muscle mass was measured by dual energy X-ray absorptiometry (DEXA), while muscle strength was assessed by hand grip strength measured by Jamar dynamometer.

RESULTS

Serum levels of adiponectin, parathyroid hormone, osteoprotegerin, RANKL, and NT-pro-BNP were elevated in patients with chronic HF compared to healthy controls (all p<0.0001), while no difference in serum levels of leptin, testosterone or SHBG was noted. Levels of 25-hydroxy vitamin D were reduced (p=0.002) in HF group. Peripheral lean mass and hand grip strength were reduced in patients with HF compared to healthy subjects (p=0.006 and p<0.0001, respectively). Using backward selection multivariable regression, serum levels of increased adiponectin remained significantly associated with reduced arm lean mass and muscle strength.

CONCLUSIONS

Our findings may indicate a cross-sectional metabolic association of increased serum adiponectin with reduced peripheral muscle mass and muscle strength in non-cachectic, non-diabetic, elderly HF patients.

Adiponectin in inflammatory and immune-mediated diseases

Circulating levels of adiponectin (APN) are reduced in obesity and associated comorbidities, with inflammation playing an important role in downregulating APN production. In contrast to obesity and metabolic disease, elevated systemic and local levels of APN are present in patients with inflammatory and immune-mediated diseases, including autoimmune and pulmonary conditions, heart and kidney failure, viral hepatitis, organ transplantation and perhaps critical illness. A positive association between inflammation and APN is usually reported in inflammatory/immune pathologies, in contrast with the negative correlation typical of metabolic disease. This review discusses the role of APN in modulation of inflammation and immunity and the potential mechanisms leading to increased levels of APN in inflammatory/immune diseases, including modification of adipose tissue physiology; relative contribution of different tissues and adipose depots; hormonal, pharmacological, nutritional and life style factors; the potential contribution of the microbiota as well as the role of altered APN clearance and release from T-cadherin-associated tissue reservoirs. Potential reasons for some of the apparently contradictory findings on the role of APN as a modulator of immunity and inflammation are also discussed, including a comparison of types of recombinant APN used for in vitro studies and strain-dependent differences in the phenotype of APN KO mice.

Unraveling new mechanisms of exercise intolerance in chronic heart failure: role of exercise training

Despite remarkable progress in the therapeutic approach of patients with chronic heart failure (CHF), exercise intolerance remains one of the hallmarks of the disease. During the past two decades, evidence has accumulated to underscore the key role of both endothelial dysfunction and skeletal muscle wasting in the process that gradually leads to physical incapacity. Whereas reverse ventricular remodeling has been attributed to aerobic exercise training, the vast majority of studies conducted in this specific patient population emphasize the reversal of peripheral abnormalities. In this review, we provide a general overview on underlying pathophysiological mechanisms. In addition, emphasis is put on recently identified pathways, which contribute to a deeper understanding of the main causes of exercise tolerance and the potential for reversal through exercise training. Recently, deficient bone marrow-related endothelial repair mechanisms have received considerable attention. Both acute exercise bouts, as well as exercise training, affect the mobilization of endothelial progenitor cells and their function. The observed changes following exercise training are believed to significantly contribute to improvement of peripheral endothelial function, as well as exercise capacity. With regard to skeletal muscle dysfunction and energy deprivation, adiponectin has been suggested to play a significant role. The demonstration of local skeletal muscle adiponectin resistance may provide an interesting and new link between the insulin resistant state and skeletal muscle wasting in CHF patients.

The influence of abdominal visceral fat on inflammatory pathways and mortality risk in obstructive lung disease

BACKGROUND

Low-grade systemic inflammation, particularly elevated IL-6, predicts mortality in chronic obstructive pulmonary disease (COPD). Although altered body composition, especially increased visceral fat (VF) mass, could be a significant contributor to low-grade systemic inflammation, this remains unexplored in COPD.

OBJECTIVE

The objective was to investigate COPD-specific effects on VF and plasma adipocytokines and their predictive value for mortality.

DESIGN

Within the Health, Aging, and Body Composition (Health ABC) Study, an observational study in community-dwelling older persons, we used propensity scores to match n = 729 persons with normal lung function to n = 243 persons with obstructive lung disease (OLD; defined as the ratio of forced expiratory volume in 1 s to forced vital capacity < lower limit of normal). Matching was based on age, sex, race, clinic site, BMI, and smoking status. Within this well-balanced match, we compared computed tomography-acquired visceral fat area (VFA) and plasma adipocytokines, analyzed independent associations of VFA and OLD status on plasma adipocytokines, and studied their predictive value for 9.4-y mortality.

RESULTS

Whereas whole-body fat mass was comparable between groups, persons with OLD had increased VFA and higher plasma IL-6, adiponectin, and plasminogen activator inhibitor 1 (PAI-1). Both OLD status and VFA were independently positively associated with IL-6. Adiponectin was positively associated with OLD status but negatively associated with VFA. PAI-1 was no longer associated with OLD status after VFA was accounted for. Participants with OLD had increased risk of all-cause, respiratory, and cardiovascular mortality, of which IL-6 was identified as an independent predictor.

CONCLUSION

Our data suggest that excessive abdominal visceral fat contributes to increased plasma IL-6, which, in turn, is strongly associated with all-cause and cause-specific mortality in older persons with OLD.