Implications of plasma concentrations of adiponectin in patients with coronary artery disease

Serum lectin-like oxidized-low density lipoprotein receptor-1 and adiponectin levels are associated with coronary artery disease accompanied with metabolic syndrome

Background:

Coronary artery disease (CAD) is a major public health problem for developed and developing countries and is the single leading cause of death worldwide.

Objectives:

There is very few evidence regarding changes of both serum Lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) and adiponectin in patients with CAD accompanied with metabolic syndrome (MS). Here we aimed to evaluate serum levels of LOX-1 and adiponectin in patients with CAD accompanied with MS.

Patients and Methods:

Thirty patients with coronary artery disease without metabolic syndrome, 30 patients with coronary artery disease and metabolic syndrome, 30 ones with metabolic syndrome and 30 healthy subjects were enrolled. For all subjects, a questionnaire was filled to collect data, and peripheral blood samples were collected aseptically from the antecubital vein to measure serum Lectin-like oxidized-low density lipoprotein receptor-1 and adiponectin levels by enzyme-linked immunosorbent assay.

Results:

Serum LOX-1 level was highest in CAD + MS group; the difference between control and disease groups was statistically significant (P < 0.001). Adiponectin level had the lowest value in CAD + MS group; the difference between control and disease groups was statistically significant (P < 0.05). No significant differences were observed in serum Lectin-like oxidized-low density lipoprotein receptor-1and adiponectin in patients with different ages and gender. Serum LOX-1 level was changed negatively and linearly (R2 = 0.721) correlated with adiponectin level in different groups.

Conclusions:

Patient with CAD and MS had higher risk than those with only CAD because of lipid and glucose metabolism abnormalities. Combination measurements of serum LOX-1 and adiponectin levels may be helpful to evaluate the severity of CAD together with MS.

Adiponectin regulates SR Ca(2+) cycling following ischemia/reperfusion via sphingosine 1-phosphate-CaMKII signaling in mice

The adipocyte-secreted hormone adiponectin (APN) exerts protective effects on the heart under stress conditions. Recent studies have demonstrated that APN induces a marked Ca(2+) influx in skeletal muscle. However, whether APN modulates [Ca(2+)]i activity, especially [Ca(2+)]i transients in cardiomyocytes, is still unknown. This study was designed to determine whether APN modulates [Ca(2+)]i transients in cardiomyocytes. Adult male wild-type (WT) and APN knockout (APN KO) mice were subjected to myocardial ischemia/reperfusion (I/R, 30min/30min) injury. CaMKII-PLB phosphorylation and SR Ca(2+)-ATPase (SERCA2) activity were downregulated in I/R hearts of WT mice and further decreased in those of APN KO mice. Both the globular domain of APN and full-length APN significantly reversed the decrease in CaMKII-PLB phosphorylation and SERCA2 activity in WT and APN KO mice. Interestingly, compared with WT littermates, single myocytes isolated from APN KO mice had remarkably decreased [Ca(2+)]i transients, cell shortening, and a prolonged Ca(2+) decay rate. Further examination revealed that APN enhances SERCA2 activity via CaMKII-PLB signaling. In in vivo and in vitro experiments, both APN receptor 1/2 and S1P were necessary for the APN-stimulated CaMKII-PLB-SERCA2 activation. In addition, S1P activated CaMKII-PLB signaling in neonatal cardiomyocytes in a dose dependent manner and improved [Ca(2+)]i transients in APN KO myocytes via the S1P receptor (S1PR1/3). Further in vivo experiments revealed that pharmacological inhibition of S1PR1/3 and SERCA2 siRNA suppressed APN-mediated cardioprotection during I/R. These data demonstrate that S1P is a novel regulator of SERCA2 that activates CaMKII-PLB signaling and mediates APN-induced cardioprotection.

Effects of interventions on adiponectin and adiponectin receptors

Adiponectin secreted from adipose tissue binds to two distinct adiponectin receptors (AdipoR1 and AdipoR2) identified and exerts its anti-diabetic effects in insulin-sensitive organs including liver, skeletal muscle and adipose tissue as well as amelioration of vascular dysfunction in the various vasculatures. A number of experimental and clinical observations have demonstrated that circulating levels of adiponectin are markedly reduced in obesity, type 2 diabetes, hypertension, and coronary artery disease. Therapeutic interventions which can improve the action of adiponectin including elevation of circulating adiponectin concentration or up-regulation and/or activation of its receptors, could provide better understanding of strategies to ameliorate metabolic disorders and vascular disease. The focus of the present review is to summarize accumulating evidence showing the role of interventions such as pharmacological agents, exercise, and calorie restriction in the expression of adiponectin and adiponectin receptors.

Role of adiponectin in metabolic and cardiovascular disease

Under disease conditions including obesity (insulin resistance) and diabetes, dysregulation of adipokines such as tumor necrosis factor (TNF)-α, leptin, resistin, and adiponectin contribute to the development of metabolic and cardiovascular disease. Unlike other adipokines, adiponectin has been shown to be a therapeutic target for metabolic syndrome and cardiovascular disease. Circulating levels of adiponectin are markedly reduced in obese, diabetic, hypertensive, and coronary artery disease patients as well as experimental animal models of insulin resistance and diabetes. Recently, the small molecule adiponectin receptors (AdipoRs) agonist was discovered and suggested that the agonist is a novel therapeutic target for the treatment of type 2 diabetes linked to obesity in an experimental mouse model. This review will focus on signaling pathways involved in adiponectin and its receptors and the role of adiponectin in metabolic and cardiovascular disease including insulin resistance, cardiomyopathy, and cardiovascular dysfunction.

Association between risk factors for vascular dementia and adiponectin

Vascular dementia is caused by various factors, including increased age, diabetes, hypertension, atherosclerosis, and stroke. Adiponectin is an adipokine secreted by adipose tissue. Adiponectin is widely known as a regulating factor related to cardiovascular disease and diabetes. Adiponectin plasma levels decrease with age. Decreased adiponectin increases the risk of cardiovascular disease and diabetes. Adiponectin improves hypertension and atherosclerosis by acting as a vasodilator and antiatherogenic factor. Moreover, adiponectin is involved in cognitive dysfunction via modulation of insulin signal transduction in the brain. Case-control studies demonstrate the association between low adiponectin and increased risk of stroke, hypertension, and diabetes. This review summarizes the recent findings on the association between risk factors for vascular dementia and adiponectin. To emphasize this relationship, we will discuss the importance of research regarding the role of adiponectin in vascular dementia.

A-FABP and its association with atherogenic risk profile and insulin resistance in young overweight and obese women

AIM

We evaluated the association of A-FABP with proatherogenic risk profile and insulin resistance (IR) in young, nondiabetic, overweight/obese women.

MATERIALS & METHODS

Serum A-FABP, high-sensitivity CRP, adiponectin, glucose, insulin, lipids and apolipoproteins were measured in 104 women (aged 20-45 years; BMI ≥25 kg/m(2)) and age-matched healthy controls (n = 76; BMI <25 kg/m(2)). All patients underwent blood pressure and anthropometric measurements.

RESULTS

A-FABP concentration was related to IR, and anthropometric and atherogenic indices. A-FABP was an independent predictor of triglyceride:high-density lipoprotein cholesterol, explaining 42% of its variation in overweight/obese women. At a cutoff level of 16 ng/ml, A-FABP discriminated between controls and overweight/obese (area under curve = 0.96) with high sensitivity and specificity. A-FABP predicted atherogenic risk, with an odds ratio of 11.2 (95% CI: 3.7-34.2), 7.1 (1.9-27.2) and 6.7 (2.6-17.2) for having elevated triglyceride:high-density lipoprotein cholesterol, apoB and CRP, respectively, and IR with an odds ratio 5.6 (1.8-17.2).

CONCLUSION

A-FABP seems to be a valuable predictor of atherogenic risk profile; if elevated it contributes to cardiovascular disease beyond its effect on IR.

High serum C1q-binding adiponectin levels in male patients with acute coronary syndrome

BACKGROUND

The complement system is part of the immune system in acute coronary syndrome (ACS). Adiponectin has anti-atherogenic and anti-inflammatory properties. Adiponectin and C1q form a protein complex in blood, and serum C1q binding adiponectin (C1q-APN) can be measured. We investigated the comparative evaluation of serum C1q-APN levels in males with ACS, stable angina pectoris (SAP) versus controls.

METHODS

The study subjects were 138 Japanese patients who underwent diagnostic coronary angiography. Blood total adiponectin (Total-APN), C1q-APN and C1q were measured by enzyme-linked immunosorbent assays. Patients were divided into three groups according to the clinical condition: ACS (n = 78), SAP (n = 41) or normal coronary (NC, n = 19) groups.

RESULTS

Serum C1q levels were significantly higher in the ACS group (54.9±1.2 μg/mL) than in the NC group (48.0±2.5 μg/mL). Although serum Total-APN levels were significantly lower in the SAP and ACS groups, compared with the NC group (7.0±0.5, 7.2±0.3, 10.6±2.0 μg/mL, respectively), serum C1q-APN levels were significantly higher in the ACS group than in the NC and SAP groups (112.1±4.1, 66.3±4.4, 65.7±2.9 units/mL, respectively).

CONCLUSIONS

Patients with ACS had higher serum C1q-APN levels.

TRIAL REGISTRATION

UMIN000002997.

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

Background:

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

Objectives:

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

Materials and Methods:

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

Results:

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

Conclusions:

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

Adiponectin and the cardiometabolic syndrome: an epidemiological perspective

Adiponectin is an adipocyte-derived plasma protein with cardio-vasculo-protective and anti-diabetic properties. Plasma adiponectin levels are low in patients with the cardiometabolic syndrome (a cluster of multiple risk factors based on visceral fat accumulation). Routine measurement of plasma adiponectin may be useful to encourage life-style changes.

Androgenetic alopecia and risk of coronary artery disease

Background:

Androgenetic alopecia (AGA) or male pattern baldness (MPB) has been found to be associated with the risk of coronary artery disease (CAD). The well-known risk factors are family history of CAD, hypertension, increased body mass index (BMI), central obesity, hyperglycemia, and dyslipidemia. The newer risk factors are serum lipoprotein-a (SL-a), serum homocysteine (SH), and serum adiponectin (SA).

Aim:

Identifying individuals at risk of CAD at an early age might help in preventing CAD and save life. Hence, a comparative study of CAD risk factors was planned in 100 males of AGA between the age of 25 and 40 years with equal number of age- and sex-matched controls.

Materials and Methods:

Patients of AGA grade II or more of Hamilton and Norwood (HN) Scale and controls were examined clinically and advised blood test. The reports were available for fasting blood sugar (FBS), serum total serum cholesterol (SC) in 64 cases, 64 controls; lipoproteins (high, low, very low density, HDL, LDL, VLDL), serum triglycerides (ST) in 63 cases, 63 controls; SL-a in 63 cases, 74 controls; SH in 56 cases, 74 controls; and SA in 62 cases, 74 controls.

Results:

In these cases family history (FH) of AGA and CAD was significantly high. The blood pressure (BP) was also found to be significantly high in the cases. The difference of mean serum HDL, LDL, VLDL, ST, SH, and SL-a in cases and controls were statistically significant and with increasing grade of AGA, the risk factors also increased.

Conclusion:

Patients with AGA appear to be at an increased risk of developing CAD, therefore, clinical evaluation of cases with AGA of grade II and above may be of help in preventing CAD in future.

Relationship of plasma adiponectin levels with acute coronary syndromes and coronary lesion severity in north Indian population

Adiponectin is an adipocyte specific cytokine which, in contrast to other adipokines, has been described to have antiinflammatory, antithrombotic, and anti-atherogenic properties. This study evaluates the association between plasma adiponectin levels with acute coronary syndrome (ACS) and angiographic coronary lesion severity in Indian population. Ninety patients included in the study were divided in two groups in 1 : 1 ratio—patients admitted with a diagnosis of ACS and those without ACS. Adiponectin and other risk markers are measured in forty-five consecutive patients in each group undergoing coronary angiography. Patients without ACS were found to have higher adiponectin (16.47 ± 7.88 μg/mL) levels than patients with ACS (9.03 ± 3.13 μg/mL) (P < 0.001). In multiple regression analysis adjusted for all other risk markers, higher adiponectin levels remain positively associated with a lower risk of ACS (P value > 0.002). The greatest increase in risk for ACS was seen at adiponectin levels ≤12.20 μg/mL in study subjects. The adiponectin levels were inversely related to the angiographic severity of coronary artery stenosis increases (P value > 0.02). The study concluded that higher adiponectin levels are independently associated with lower risk of ACS, and patients with severe angiographic coronary artery disease have lower levels of adiponectin.

Effects of coenzyme Q10 supplementation (300 mg/day) on antioxidation and anti-inflammation in coronary artery disease patients during statins therapy: a randomized, placebo-controlled trial

Background

High oxidative stress and chronic inflammation can contribute to the pathogenesis of coronary artery disease (CAD). Coenzyme Q10 is an endogenous lipid-soluble antioxidant. Statins therapy can reduce the biosynthesis of coenzyme Q10. The purpose of this study was to investigate the effects of a coenzyme Q10 supplement (300 mg/d; 150 mg/b.i.d) on antioxidation and anti-inflammation in patients who have CAD during statins therapy.

Methods

Patients who were identified by cardiac catheterization as having at least 50% stenosis of one major coronary artery and who were treated with statins for at least one month were enrolled in this study. The subjects (n = 51) were randomly assigned to the placebo (n = 24) and coenzyme Q10 groups (Q10-300 group, n = 27). The intervention was administered for 12 weeks. The concentrations of coenzyme Q10, vitamin E, antioxidant enzymes activities (superoxide dismutase, catalase, and glutathione peroxidase), and inflammatory markers [C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6)] were measured in the 42 subjects (placebo, n = 19; Q10-300, n = 23) who completed the study.

Results

The levels of the plasma coenzyme Q10 (P < 0.001) and antioxidant enzymes activities (P < 0.05) were significantly higher after coenzyme Q10 supplementation. The levels of inflammatory markers (TNF-α, P = 0.039) were significantly lower after coenzyme Q10 supplementation. The subjects in the Q10-300 group had significantly higher vitamin E (P = 0.043) and the antioxidant enzymes activities (P < 0.05) than the placebo group at week 12. The level of plasma coenzyme Q10 was significantly positively correlated with vitamin E (P = 0.008) and antioxidant enzymes activities (P < 0.05) and was negatively correlated with TNF-α (P = 0.034) and IL-6 (P = 0.027) after coenzyme Q10 supplementation.

Conclusion

Coenzyme Q10 supplementation at 300 mg/d significantly enhances antioxidant enzymes activities and lowers inflammation in patients who have CAD during statins therapy.

Trial registration

Clinical Trials.gov Identifier: NCT01424761.

The potential contribution of circulating and locally produced leptin to cardiac hypertrophy and failure

Leptin is a 16 kDa peptide that was first identified in 1994 through positional cloning of the mouse obesity gene. Although the primary function of leptin is to act a satiety factor through its actions on the hypothalamus, it is now widely recognized that leptin can exert effects on many other organs through activation of its receptors, which are ubiquitously expressed. Leptin is secreted primarily by white adipocytes, but it is also produced by other tissues including the heart where it can exert effects in an autocrine or paracrine manner. One of these effects involves the induction of cardiomyocyte hypertrophy, which appears to occur via multiple cell signalling mechanisms. As adipocytes are the primary site of leptin production, plasma leptin concentrations are generally positively related with body mass index and the degree of adiposity. However, hyperleptinemia is also associated with cardiovascular disease, including heart failure, in the absence of obesity. Here we review the potential role of leptin in heart disease, particularly pertaining to its potential contribution to myocardial remodelling and heart failure, as well as the underlying mechanisms. We further discuss potential interactions between leptin and another adipokine, adiponectin, and the potential implications of this interaction in terms of fully understanding leptin’s effects.

Atorvastatin treatment modulates the interaction between leptin and adiponectin, and the clinical parameters in patients with type II diabetes

The aim of this study was to examine the effect of atorvastatin treatment on levels of leptin, adiponectin and insulin resistance, and their correlation with clinical parameters, in patients with type II diabetes. Patients with diabetes (n=394) were divided into two groups, comprising 161 patients who received 20 mg/day atorvastatin (statin group), and 233 patients who did not receive statins (statin-free group). The results showed that atorvastatin treatment of patients with diabetes was not associated with changes in leptin, adiponectin, the leptin/adiponectin (L/A) ratio or homeostasis model assessment-insulin resistance (HOMA-IR). However, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and total cholesterol (Tchol) were positively correlated with leptin and L/A ratio in the statin group only (P<0.05). By contrast, high-density lipoprotein cholesterol (HDL-C) showed a significant positive correlation with adiponectin in the statin and statin-free groups (P<0.05). Additionally, a positive correlation was found between HOMA-IR and glycated hemoglobin (HbA1c), and TG, in both groups, whereas Tchol was positively correlated with HOMA-IR in the statin group only (P<0.05). When multivariate analysis was performed with HOMA-IR as the dependent variable, and with adjustment for age, body mass index (BMI) and waist circumference, HbA1c was found to be a significant predictor of HOMA-IR or insulin resistance. In conclusion, atorvastatin treatment may have several effects on the interaction between leptin and adiponectin, and on clinical parameters in patients with type II diabetes.

Serum adiponectin levels predict the risk of coronary heart disease in Japanese patients with type 2 diabetes

AIMS/INTRODUCTION

An inverse association between adiponectin and coronary heart disease (CHD) has been found in Caucasians, but it is uncertain whether this association can be extrapolated to the East Asian population. The present study aimed to investigate whether serum adiponectin levels can predict CHD in Japanese patients with type 2 diabetes as observed in Caucasians.

MATERIALS AND METHODS

This longitudinal study included 504 patients with type 2 diabetes (342 men and 162 women) who were admitted to Sumitomo Hospital between July 2005 and December 2006. We used Cox proportional hazard analysis to estimate the hazard ratio (HR) of CHD associated with serum adiponectin levels at baseline.

RESULTS

During a median follow up of 5.7 years (2177 person-years), 40 participants had new CHD and 10 had recurrent CHD. After multivariate adjustment, the highest compared with the lowest quartile of serum adiponectin levels had a significantly reduced risk of CHD (hazard ratio [HR] 0.35; 95% confidence interval [CI] 0.13-0.94; P = 0.017). The multivariate adjusted HR for the risk of CHD according to a doubling of adiponectin at baseline was 0.61 (95% CI 0.39-0.97; P = 0.037).

CONCLUSIONS

High serum adiponectin levels are significantly associated with a lower risk of CHD in Japanese patients with type 2 diabetes. This association is independent of other well-known CHD risk factors.

Plasma adiponectin: a contributing factor for cardiac changes in visceral obesity-associated hypertension

This study has been designed to evaluate the impact of adiponectin levels on left ventricular geometry and function in visceral obesity-associated hypertension. 94 consecutive subjects, 53 of them were hypertensives and 41 normotensives with age ≤ 65 years, subgrouped according to the presence or absence of visceral obesity, were studied. Total adiponectin levels were measured by a validated competitive radioimmunoassay. Left ventricular telediastolic internal diameter, interventricular septum, posterior wall thickness, total left ventricular mass (LVM) and normalized for height to the 2.7 power (LVM/h(2.7)), relative wall thickness, left ventricular ejection fraction by echocardiography and isovolumic relaxation time, E/A ratio and deceleration time of E velocity, by pulsed-wave Doppler, were calculated. Plasma adiponectin levels were significantly lower in visceral obesity-associated hypertensives than lean hypertensives (p < 0.001) and in lean normotensives (p < 0.001). LVM and LVM/h(2.7) were significantly (p < 0.05) higher in both hypertensive groups, and in visceral obesity-associated normotensives in comparison with lean normotensives. Adiponectin levels correlated inversely with LVM/h(2.7) but only in normotensives (adjusted R squared 0.77, p < 0.0001) and hypertensives (0.67, p < 0.0001) subjects with visceral obesity. Multiple regression analysis indicated that adiponectin levels remain significantly associated (p < 0.001) to LVM/h(2.7) also when adjusted for age, gender, body mass index, waist to hip ratio and mean blood pressure. Our data suggest an important role of adiponectin in increased LVM/h(2.7) in visceral obesity-associated normotensive and hypertensive subjects. In this last group, adiponectin, more than blood pressure, may be able to explain the development of cardiac damage.

Correlation between Plasma Adiponectin Levels and the Presence and Severity of Coronary Artery Disease

BACKGROUND

The existing evidence suggests that plasma adiponectin concentrations can be indicative of the presence and severity of coronary artery disease (CAD). However, the results of the studies conducted hitherto on this subject are inconsistent. We sought to investigate the possible correlation between plasma adiponectin levels and the presence and severity of CAD in patients undergoing non-urgent coronary angiography.

METHODS

In 399 consecutive patients undergoing non-urgent coronary angiography for CAD survey, plasma adiponectin, triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein cholesterol, and fasting blood sugar levels were measured and demographic characteristics such as age, sex, Body Mass Index, diabetes mellitus history, systemic hypertension history, and family history of CAD were collected. According to the angiography results, the patients were divided into two groups of CAD and non-CAD. The severity of coronary atherosclerosis in the CAD group was defined using the Gensini score system.

RESULTS

Average age was 61.4 ± 9.94 years in the CAD group and 57.9 ± 10.75 years in the non-CAD group. Also, 73.7% of the CAD group and 55.4% of the non-CAD group were male. Totally, 278 (69.7%) patients were found to have CAD. Patients without CAD did not have higher mean plasma adiponectin concentrations than did those with CAD (13.38 ± 11.96 vs. 14.95 ± 14.11 mcg/ml; p value = 0. 896). After adjustment for CAD conventional risk factors, plasma adiponectin levels still were not associated with CAD. No association was found between plasma adiponectin levels and the Gensini score. Furthermore, in contrast to the fairly strong correlation previously reported, there was no correlation between adiponectin levels and conventional CAD risk factors.

CONCLUSION

We could not observe any relationship between plasma adiponectin concentrations and the presence or severity of CAD in patients undergoing coronary angiography.

The shared allelic architecture of adiponectin levels and coronary artery disease

OBJECTIVE

A large body of epidemiologic data strongly suggests an association between excess adiposity and coronary artery disease (CAD). Low adiponectin levels, a hormone secreted only from adipocytes, have been associated with an increased risk of CAD in observational studies. However, these associations cannot clarify whether this relationship is causal or due to a shared set of causal factors or even confounding. Genome-wide association studies have identified common variants that influence adiponectin levels, providing valuable tools to examine the genetic relationship between adiponectin and CAD.

METHODS

Using 145 genome wide significant SNPs for adiponectin from the ADIPOGen consortium (n = 49,891), we tested whether adiponectin-decreasing alleles influenced risk of CAD in the CARDIoGRAM consortium (n = 85,274).

RESULTS

In single-SNP analysis, 5 variants among 145 SNPs were associated with increased risk of CAD after correcting for multiple testing (P < 4.4 × 10(-4)). Using a multi-SNP genotypic risk score to test whether adiponectin levels and CAD have a shared genetic etiology, we found that adiponectin-decreasing alleles increased risk of CAD (P = 5.4 × 10(-7)).

CONCLUSION

These findings demonstrate that adiponectin levels and CAD have a shared allelic architecture and provide rationale to undertake a Mendelian randomization studies to understand if this relationship is causal.

High serum C1q-adiponectin/total adiponectin ratio correlates with coronary artery disease in Japanese type 2 diabetics

OBJECTIVE

Adiponectin, an adipocyte-derived protein, has potential antiatherogenic properties. Low levels of serum total-adiponectin (Total-APN) correlate with diabetes and coronary artery disease (CAD). Adiponectin and C1q form a protein complex in blood, and serum C1q-binding adiponectin (C1q-APN) can be measured. We investigated the correlation between C1q-APN and CAD in patients with type 2 diabetes mellitus (T2DM).

METHODS

The study subjects were 107 outpatients with T2DM who underwent evaluation for CAD. Blood C1q, Total-APN, high-molecular weight-adiponectin (HMW-APN) and C1q-APN were measured by enzyme-linked immunosorbent assays.

RESULTS

Serum levels of C1q-APN/Total-APN ratio were higher in patients diagnosed with CAD (10.47±0.59, mean±SEM, n=54) than those without CAD (8.88±0.60, n=53, p=0.0482). Age- and sex-adjusted logistic regression analysis identified serum C1q-APN/Total-APN ratio and hypertension as significant and independent determinants of CAD. A high serum C1q-APN/Total-APN ratio was associated with 3.965-fold increase in CAD prevalence.

CONCLUSIONS

High serum C1q-APN/Total-APN ratio correlates with CAD in T2DM.

Lower ratio of high-molecular-weight adiponectin level to total may be associated with coronary high-risk plaque

Background

Although high-molecular-weight (HMW) adiponectin is believed to protect against atherosclerosis, the association between HMW adiponectin and the composition of coronary plaques is unknown. We evaluated whether the HMW to total adiponectin ratio was associated with the presence of coronary plaque and its composition using multi-slice computed tomography coronary angiography (MSCTCA).

Methods

Serum total and HMW adiponectin levels were measured in 53 consecutive patients (age, 71) with >50% coronary artery stenosis detected by MSCTCA. A low-attenuation coronary plaque was defined as a plaque with a mean CT density <50 Hounsfield units. Multivariate logistic regression analyses were performed to evaluate the predictors of the presence of low-attenuation coronary plaques, which is thought to be high risk, on CT.

Results

Decreased serum levels of total as well as HMW adiponectin were significantly associated with the presence of at least one calcified or non-calcified coronary artery plaque (total adiponectin level: odds ratio 0.76, 95% CI 0.58–0.99, P = 0.048; HMW adiponectin level: odds ratio 0.65, 95% CI 0.42–0.99, P = 0.047). A low ratio of HMW to total adiponectin was significantly associated with the presence of low-attenuation coronary plaques (4.55, 1.94–21.90, P = 0.049). However, neither the total adiponectin nor the HMW adiponectin level was associated with the presence of low-attenuation coronary plaques.

Conclusion

Lower total or HMW adiponectin levels are associated with the presence of calcified and non-calcified coronary plaques, whereas a lower ratio of HMW to total adiponectin associated with the presence of low-attenuation coronary plaques (thought to be high risk). Measurement of total and HMW adiponectin levels and the HMW to total adiponectin ratio may be useful for risk stratification of coronary artery plaques.

Impaired mitochondrial biogenesis due to dysfunctional adiponectin-AMPK-PGC-1α signaling contributing to increased vulnerability in diabetic heart

Impaired mitochondrial biogenesis causes skeletal muscle damage in diabetes. However, whether and how mitochondrial biogenesis is impaired in the diabetic heart remains largely unknown. Whether adiponectin (APN), a potent cardioprotective molecule, regulates cardiac mitochondrial function has also not been previously investigated. In this study, electron microscopy revealed significant mitochondrial disorders in ob/ob cardiomyocytes, including mitochondrial swelling and cristae disorientation and breakage. Moreover, mitochondrial biogenesis of ob/ob cardiomyocytes is significantly impaired, as evidenced by reduced Ppargc-1a/Nrf-1/Tfam mRNA levels, mitochondrial DNA content, ATP content, citrate synthase activity, complexes I/III/V activity, AMPK phosphorylation, and increased PGC-1α acetylation. Since APN is an upstream activator of AMPK and APN plasma levels are significantly reduced in ob/ob mice, we further tested the hypothesis that reduced APN in ob/ob mice is causatively related to mitochondrial biogenesis impairment. One week of APN treatment of ob/ob mice activated AMPK, reduced PGC-1α acetylation, increased mitochondrial biogenesis, and attenuated mitochondrial disorders. In contrast, knocking out APN inhibited AMPK-PGC-1α signaling and impaired both mitochondrial biogenesis and function. The ob/ob mice exhibited lower survival rates and exacerbated myocardial injury after MI, when compared to controls. APN supplementation improved mitochondrial biogenesis and attenuated MI injury, an effect that was almost completely abrogated by the AMPK inhibitor compound C. In high glucose/high fat treated neonatal rat ventricular myocytes, siRNA-mediated knockdown of PGC-1α blocked gAd-enhanced mitochondrial biogenesis and function and attenuated protection against hypoxia/reoxygenation injury. In conclusion, hypoadiponectinemia impaired AMPK-PGC-1α signaling, resulting in dysfunctional mitochondrial biogenesis that constitutes a novel mechanism for rendering diabetic hearts more vulnerable to enhanced MI injury.

Adiponectin, body mass index and hepatic steatosis are independently associated with IGF-I status in obese non-diabetic women

OBJECTIVE

Low IGF-I levels have been associated with obesity, insulin resistance, hepatic steatosis, and were shown to predict cardiovascular mortality. Adiponectin, on the other hand, was proved to have an important protective role against metabolic and cardiovascular diseases. This study investigates the relation between hepatic steatosis, adiponectin and IGF-I levels in a group of non-diabetic obese Romanian women.

DESIGN

This cross-sectional study included 201 obese non-diabetic women, with mean age of 41.1±11.9 years and mean body mass index (BMI) of 44.1±8.3 kg/m(2), consecutively admitted to the Endocrinology Department of a University Hospital to be evaluated as candidates for bariatric surgery. Main measured parameters included total adiponectin (detected by ELISA method), insulin, C reactive protein (CRP), and IGF-I (all by chemiluminescence methods). Insulin sensitivity was assessed using the Quantitative Insulin Sensitivity Check Index (QUICKI). Patients were considered IGF-deficient if IGF-I z score was ≤2 standard deviations from mean for age. Hepatic ultrasound was used to determine the presence of significant steatosis (SS+).

RESULTS

Significant steatosis was observed in 60.7% of our patients and this feature was associated with reduced total adiponectin levels (p<0.001) and lower IGF-I z scores (p<0.001). IGF-I z score negatively correlated with BMI (r=-0.283, p<0.001), alanine aminotransferase (ALT) (r=-0.130, p=0.032), gamma glutamyltransferase (GGT) (r=-0.158, p=0.018) and logarithmic transformed (log) CRP (r=-0.232, p=0.001) and positively correlated with QUICKI (r=0.148, p=0.023) and log adiponectin (r=0.216, p=0.003). The relationship between IGF-I z score and log adiponectin remained significant after adjusting for age, BMI, ALT, QUICKI and log CRP (r=0.183, p=0.012). IGF-I deficiency was present in 33.3% of these obese women. In multivariate logistic analysis, BMI (p<0.001), ALT (p=0.003), log adiponectin (p<0.001) and SS (p=0.043) proved to be independently associated with IGF-I deficiency.

CONCLUSIONS

Adiponectin is significantly correlated with IGF-I z scores and, along with BMI, ALT and significant steatosis, is independently associated with IGF-I deficiency in obese non-diabetic women.

Grape resveratrol increases serum adiponectin and downregulates inflammatory genes in peripheral blood mononuclear cells: a triple-blind, placebo-controlled, one-year clinical trial in patients with stable coronary artery disease

PURPOSE

The grape and wine polyphenol resveratrol exerts cardiovascular benefits but evidence from randomized human clinical trials is very limited. We investigated dose-depending effects of a resveratrol-containing grape supplement on stable patients with coronary artery disease (CAD) treated according to currently accepted guidelines for secondary prevention of cardiovascular disease.

METHODS

In a triple-blind, randomized, placebo-controlled, one-year follow-up, 3-arm pilot clinical trial, 75 stable-CAD patients received 350 mg/day of placebo, resveratrol-containing grape extract (grape phenolics plus 8 mg resveratrol) or conventional grape extract lacking resveratrol during 6 months, and a double dose for the following 6 months. Changes in circulating inflammatory and fibrinolytic biomarkers were analyzed. Moreover, the transcriptional profiling of inflammatory genes in peripheral blood mononuclear cells (PBMCs) was explored using microarrays and functional gene expression analysis.

RESULTS

After 1 year, in contrast to the placebo and conventional grape extract groups, the resveratrol-containing grape extract group showed an increase of the anti-inflammatory serum adiponectin (9.6 %, p = 0.01) and a decrease of the thrombogenic plasminogen activator inhibitor type 1 (PAI-1) (-18.6 %, p = 0.05). In addition, 6 key inflammation-related transcription factors were predicted to be significantly activated or inhibited, with 27 extracellular-space acting genes involved in inflammation, cell migration and T-cell interaction signals presenting downregulation (p < 0.05) in PBMCs. No adverse effects were detected in relation to the study products.

CONCLUSIONS

Chronic daily consumption of a resveratrol-containing grape nutraceutical could exert cardiovascular benefits in stable-CAD patients treated according to current evidence-based standards, by increasing serum adiponectin, preventing PAI-1 increase and inhibiting atherothrombotic signals in PBMCs.

Plasma adiponectin levels in relation to prognosis in patients with angiographic coronary artery disease

OBJECTIVE

The objective was to study the associations between adiponectin levels and cardiovascular adverse clinical outcomes in patients with angiographic coronary artery disease (CAD) within the Han Chinese population in Beijing.

MATERIALS/METHODS

A total of 449 hospitalized patients with angiographic CAD who were Han Chinese in Beijing participated in the study. Plasma adiponectin levels were examined from blood samples using a type of unique enzyme-linked immunosorbent assay that was developed by our laboratory. All of the patients' clinical data, including previously identified cardiovascular risk factors, creatinine clearance and left ventricle ejection fraction, were recorded after admission, and patients were followed up for 19±8 months. The primary end-point was marked by the occurrence of major adverse cardiovascular events (MACE), which included death, targeted vascular revascularization, acute coronary syndrome, heart failure, and transient ischemic attack (TIA) / stroke.

RESULTS

A total of 109 cases of MACE occurred: 15 cases of death, 66 cases of acute coronary syndrome, 4 cases of TIA/stroke, 6 cases of targeted vessel revascularization, and 18 cases of heart failure. Among all the patients, 173 were assigned to the high adiponectin group and 276 were assigned to the low adiponectin group according to their baseline plasma adiponectin levels. The incidence of MACE was significantly higher in the low adiponectin group (P=.037). In a multivariate Cox regression analysis for adiponectin levels, previously documented risk factors, coronary artery stenosis scores, and low adiponectin levels were indicated as independent predictors of MACE in patients with CAD (RR 1.75; 95% CI, 1.066-2.865; P=.027). Further adjustment for hsCRP, Ccr, LVEF, fasting glucose and lipid profile did not attenuate this association (RR=2.36; 95% CI 1.338-4.167; P=.003). The relative risk for low adiponectin levels after additional adjustment for the coronary score was 2.42 (95% CI 1.367-4.279; P=.002). The Kaplan-Meier survival analysis curve suggested that patients with lower adiponectin concentrations had a decreased event-free survival ratio (log-rank χ(2) =4.592, P=.032).

CONCLUSIONS

The results indicate a potential association between plasma adiponectin levels and cardiovascular prognosis in patients with CAD.

Adiponectin profile in Asian patients undergoing coronary revascularization and its association with plaque vulnerability: IDEAS-ADIPO study

Despite potent insulin-sensitizing, anti-inflammatory, and antiatherogenic effects in animal studies, the relationship between serum adiponectin level and coronary artery disease in patients remains unclear. We determined the adiponectin profile in a cohort of multiethnic Asian patients with coronary artery disease, and the association between serum adiponectin level and culprit lesion necrotic core (NC) content. Ninety-four Asian patients (BMI, 25.3 ± 3.7 kg/m(2)) undergoing percutaneous coronary intervention were recruited. The serum adiponectin level was measured (n = 94), and the baseline virtual histology intravascular ultrasound examination was analyzed (n = 88). The median level of adiponectin was 3.7 µg/ml (interquartile range, 2.8-4.5 µg/ml). The serum adiponectin level was below 10 µg/ml in 90 patients (95.7%) and below 6 µg/ml in 80 patients (85.1%). There was a significant association between ethnicity and serum adiponectin level (P = 0.048). The median adiponectin level was highest among the Chinese, followed by the Malay and the Indians. Serum adiponectin levels were positively associated with culprit lesion NC content. A 1-µg/ml increase in log adiponectin was associated with a 3.04% (95% confidence interval: 0.33-5.44) increase in culprit lesion NC content. This association remains significant after adjusting for age, sex, ethnicity, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and procedural indication. We found a low serum level of adiponectin in Asian patients and a significant ethnic effect on serum adiponectin level. Increased serum adiponectin levels were independently associated with increased culprit lesion NC burden, suggesting a role for adiponectin in modulating coronary plaque vulnerability.

Regional evidence of modulation of cardiac adiponectin level in dilated cardiomyopathy: pilot study in a porcine animal model

Background

The role of systemic and myocardial adiponectin (ADN) in dilated cardiomyopathy is still debated. We tested the regulation of both systemic and myocardial ADN and the relationship with AMP-activated protein kinase (AMPK) activity in a swine model of non-ischemic dilated cardiomyopathy.

Methods and results

Cardiac tissue was collected from seven instrumented adult male minipigs by pacing the left ventricular (LV) free wall (180 beats/min, 3 weeks), both from pacing (PS) and opposite sites (OS), and from five controls. Circulating ADN levels were inversely related to global and regional cardiac function. Myocardial ADN in PS was down-regulated compared to control (p < 0.05), yet ADN receptor 1 was significantly up-regulated (p < 0.05). No modifications of AMPK were observed in either region of the failing heart. Similarly, myocardial mRNA levels of PPARγ, PPARα, TNFα, iNOS were unchanged compared to controls.

Conclusions

Paradoxically, circulating ADN did not show any cardioprotective effect, confirming its role as negative prognostic biomarker of heart failure. Myocardial ADN was reduced in PS compared to control in an AMPK-independent fashion, suggesting the occurrence of novel mechanisms by which reduced cardiac ADN levels may regionally mediate the decline of cardiac function.

Relationship of adiponectin and leptin to coronary artery disease, classical cardiovascular risk factors and atherothrombotic biomarkers in the IARS cohort

Adiponectin and leptin link metabolic disorders and coronary artery disease (CAD). We analysed their relationship with CAD, classical risk factors and biomarkers in 287 CAD patients (cases) and 477 unaffected family members (controls) selected from the Indian Atherosclerosis Research Study (IARS). Classical risk factors included diabetes, hypertension, dyslipidaemia and obesity markers. Novel biomarkers were measured according to manufacturer recommendations. Adverse clinical events were recorded through telephonic follow-up. Cases showed lower adiponectin levels (4684.62 ± 190.73 ng/ml) than controls (5768.86 ± 152.87 ng/ml) (p=1.58X10(-5)); Leptin levels were higher in affected males (12.47 ± 1.32 ng/ml) than in male controls (9.53 ± 1.19 ng/ml, p=0.017). Adiponectin 1st quartile showed significant protection against CAD in females when compared to 3rd (odds ratio [OR] 0.39, 0.16-0.92, p=0.032) or 4th (OR 0.32, 0.14-0.72; p=0.006) quartile group. Leptin 3rd quartile showed higher CAD risk in males as compared to 1st quartile group (OR 2.09, 1.09-4.01, p=0.028). Subjects with metabolic syndrome showed low adiponectin and high leptin levels. Adipokines showed opposing association trend with lipids, inflammatory and coagulation markers and strong correlation (r=-0.14 to 0.52) with obesity markers. Cases with recurrent event and controls who developed new cardiac event during follow up showed high adiponectin levels (p<0.05). A model that combined adiponectin, leptin and conventional risk factors yielded the best 'C' index (0.890, 0.067-0.912). CAD patients in the top adiponectin tertile showed relatively poor survival curve as compared to the bottom Adiponectin tertile group. In conclusion, our findings strengthen the reported association between low adiponectin, high leptin, obesity-related metabolic disturbances and incident CAD in Asian Indians.

Obesity and pulmonary arterial hypertension: Is adiponectin the molecular link between these conditions?

Pulmonary arterial hypertension (PAH) is a condition of unknown etiology whose pathological features include increased vascular resistance, perivascular inflammatory cell infiltration and pulmonary arteriolar remodeling. Although risk factors for PAH are poorly defined, recent studies indicate that obesity may be an important risk factor for this condition. The mechanisms leading to this association are largely unknown, but bioactive mediators secreted from adipose tissue have been implicated in this process. One of the most important mediators released from adipose tissue is the adipokine adiponectin. Adiponectin is highly abundant in the circulation of lean healthy individuals, and possesses well-described metabolic and antiinflammatory actions. Levels of adiponectin decrease with increasing body mass, and low levels are directly linked to the development of PAH in mice. Moreover, overexpression of adiponectin has been shown to protect mice from developing PAH in response to inflammation and hypoxia. Based on the findings from these studies, it is suggested that the effects of adiponectin are mediated, in part, through its antiinflammatory and antiproliferative properties. In this review, we discuss the emerging evidence demonstrating a role for adiponectin in lung vascular homeostasis and discuss how deficiency in this adipocyte-derived hormone might explain the recent association between obesity and PAH.

Adiponectin and atherosclerosis risk factors in African hemodialysis patients: a population at low risk for atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (CVD) is the major cause of morbidity and mortality in hemodialysis (HD) patients. Adiponectin (ADPN), a recently discovered collagen-like protein, is secreted exclusively by adipocytes. It has anti-atherogenic properties and reduced serum ADPN levels have been shown to be predictive of cardiovascular events. In this study, we determined the atherosclerotic risk and the significance of ADPN levels in our HD patients and also examined its relationship to other traditional CVD risk factors. A cross-sectional study of 84 patients on maintenance HD (58 Blacks and 26 non-Blacks) and 63 healthy controls matched for age, sex and race (35 Blacks and 28 non-Blacks) was undertaken. Serum ADPN levels and other risk factors, including blood pressure, serum lipid, and C-reactive protein, were studied in HD patients and were compared with the controls. Carotid artery intima-media thickness and plaque occurrence was measured by B-mode ultrasonography while echocardiography was done according to American Society of Echocardiography guidelines. Serum ADPN levels were higher in the HD group compared with the control subjects (22.19 ± 0.98 mg/mL vs. 9.93 ± 0.68 mg/mL; P < 0.001). Higher ADPN levels in HD patients were associated with lower triglyceride levels. ADPN correlated positively (r = 0.49, P < 0.0001) with left ventricular mass index (LVMI) in the total study population. ADPN levels were raised in HD patients and correlated with LVMI, possibly because of the confounding effect of low glomerular filtration rate. ADPN levels were inversely related to risk factors for atherosclerosis and may provide possible targets for therapeutic interventions.

Adiponectin, Non-Esterified Fatty Acids and Antiphospholipid Antibodies in Type II Diabetes Mellitus

The importance of the association of antiphospholipid antibodies (aPL Abs) with the features of type II diabetes mellitus has not yet been elucidated. The aim of this work was to investigate the association of aPL Abs with adiponectin and non-esterified fatty acids (NEFA) in type II diabetes mellitus patients without micro and/or macrovascular complications, and to analyze the differences between the male and female patients with regard to the abovementioned parameters. Male patients with type II diabetes mellitus showed a positive correlation between NEFA concentrations and anti-oxLDL antibodies (r=0.334, p=0.019). A weak, but statistically significant correlation between adiponectin concentrations and the IgM isotype of anti-annexin A5 antibodies was found in type II diabetes mellitus patients (r=0.285, p=0.011). The presence of a positive correlation between NEFA and anti-oxLDL antibodies might be useful in the detection of patients with premature atherosclerosis in type II diabetes mellitus patients without any micro and/or macrovascular complications among type II diabetes mellitus patients.

Fat, fire and muscle--the role of adiponectin in pulmonary vascular inflammation and remodeling

Pulmonary hypertension is a life-threatening condition that results from a heterogeneous group of diseases, many of which demonstrate characteristic pathologic changes of pulmonary vascular inflammation and remodeling. Recent clinical studies indicate obesity to be a risk factor for the development of pulmonary hypertension; however, the mechanisms leading to this association are unknown. Adipocytes secrete multiple bioactive mediators that can influence inflammation and tissue remodeling, suggesting that adipose tissue may directly influence the pathogenesis of pulmonary hypertension. One of these mediators is adiponectin, a protein with a wide range of metabolic, anti-inflammatory, and anti-proliferative activities. Paradoxically, adiponectin is present in high concentration in the serum of lean healthy individuals, but decreases in obesity. Studies suggest that relative adiponectin-deficiency may contribute to the development of inflammatory diseases in obesity, and recent animal studies implicate adiponectin in the pathogenesis of pulmonary hypertension. Most notably, experimental studies show that adiponectin can reduce lung vascular remodeling in response to inflammation and hypoxia. Moreover, mice deficient in adiponectin develop a spontaneous lung vascular phenotype characterized by age-dependent increases in peri-vascular inflammatory cells and elevated pulmonary artery pressures. Emerging evidence indicates adiponectin's effects are mediated through anti-inflammatory and anti-proliferative actions on cells in the lung. This review aims to synthesize the existing data related to adiponectin's effects on the pulmonary vasculature and to discuss how changes in adiponectin levels might contribute to the development of pulmonary hypertension.

Comparison of the efficacy and safety of irbesartan and olmesartan in patients with hypertension (EARTH study)

Fifty-four patients were randomly divided into irbesartan and olmesartan groups. Blood pressure (BP) was significantly decreased in all patients at 12 weeks. In particular, BP in patients who initially received irbesartan showed significant reductions. The equality of variance of BP in the irbesartan group was significantly smaller than that in the olmesartan group at 12 weeks. Blood concentrations of adiponectin were significantly increased in the irbesartan group at 12 weeks. Log [pentraxin-3] in the irbesartan group were significantly decreased. In conclusion, the ability of irbesartan to reduce BP is comparable to that of olmesartan with equivalent safety.

Inflammation and metabolic dysfunction: links to cardiovascular diseases

Abdominal obesity is a major risk factor for cardiovascular disease, and recent studies highlight a key role of adipose tissue dysfunction, inflammation, and aberrant adipokine release in this process. An increased demand for lipid storage results in both hyperplasia and hypertrophy, finally leading to chronic inflammation, hypoxia, and a phenotypic change of the cellular components of adipose tissue, collectively leading to a substantially altered secretory output of adipose tissue. In this review we have assessed the adipo-vascular axis, and an overview of adipokines associated with cardiovascular disease is provided. This resulted in a first list of more than 30 adipokines. A deeper analysis only considered adipokines that have been reported to impact on inflammation and NF-κB activation in the vasculature. Out of these, the most prominent link to cardiovascular disease was found for leptin, TNF-α, adipocyte fatty acid-binding protein, interleukins, and several novel adipokines such as lipocalin-2 and pigment epithelium-derived factor. Future work will need to address the potential role of these molecules as biomarkers and/or drug targets.

Adiponectin and interleukin-6 in inflammation-associated disease

Numerous lines of evidence implicate a role for adipose tissue in the development of a systemic inflammatory state that contributes to metabolic, cardiovascular, and autoimmune disorders. Serum levels of adiponectin, a cytokine that is mainly produced by adipocytes, are paradoxically decreased in individuals with obesity, type 2 diabetes, and cardiovascular disease compared with healthy individuals. Mounting experimental data have revealed that adiponectin exhibits beneficial effects on energy homeostasis and cardiovascular functions that are attributed to its direct modulation of a proinflammatory factor, interleukin-6. However, some recent studies indicate that adiponectin appears to function as an inducer of proinflammatory factors and the elevated adiponectin level aggravates inflammation response in autoimmune disease. In this review, we focus on the action of adiponectin in chronic inflammation-associated metabolic, cardiovascular, and autoimmune disorders. In particular, we discuss the interaction between adiponectin and interleukin-6 in adipocytes and cardiovascular cells.

N-3 Polyunsaturated fatty acid therapy improves endothelial function and affects adiponectin and resistin balance in the first month after myocardial infarction

INTRODUCTION

N-3 Polyunsaturated fatty acids (n-3 PUFA) exert clinical beneficial effects in patients after acute myocardial infarction (AMI). However, their exact mechanisms of action are not well recognized yet. Our aim was to evaluate effects of early introduced n-3 PUFA supplementation on endothelial function and serum adipokine concentrations in patients with AMI.

MATERIAL AND METHODS

Thirty-eight patients with AMI and successful coronary stent implantation were randomized to the study group (PUFA group: n = 19; standard therapy + PUFA 1 g daily) and the control group (control group: n = 19; standard therapy). The study group patients were given n-3 PUFA (Omacor 1 g daily) starting from the 3(rd) day of AMI. Ultrasound vascular indexes (flow-mediated dilatation [FMD], nitroglycerine-mediated dilation [NMD]) and serum concentrations of adiponectin and resistin (ELISA) were evaluated before and after 30 days of pharmacotherapy.

RESULTS

Comparison of the mean delta values (baseline/after 30 days of therapy) between groups revealed significant differences for delta FMD (PUFA 7.6 ±12.4% vs. control -1.7 ±10.5%, p = 0.019) and delta resistin concentrations (PUFA 1.0 ±3.8pg/ml vs. control -1.6 ±2.9pg/ml, p = 0.028). Multiple linear regression analysis for all subjects revealed the n-3 PUFA supplementation (r = 10.933, p = 0.004) and waist circumference (r = -0.467, p = 0.01) as independent factors associated with delta FMD values (R-adjusted 0.29; p = 0.002).

CONCLUSIONS

Early and short-term n-3 PUFA supplementation in AMI with successful primary PCI and optimal pharmacotherapy improves endothelial function. However, increased resistin serum levels observed after 1-month n-3 PUFA supplementation merits further investigations.

Adiponectin in cardiovascular inflammation and obesity

Inflammation is widely known to play a key role in the development and progression of cardiovascular diseases. It is becoming increasingly evident that obesity is linked to many proinflammatory and obesity-associated cardiovascular conditions (e.g., metabolic syndrome, acute coronary syndrome, and congestive heart failure). It has been observed that adipokines play an increasingly large role in systemic and local inflammation. Therefore, adipose tissue may have a more important role than previously thought in the pathogenesis of several disease types. This review explores the recently described role of adiponectin as an immunomodulatory factor and how it intersects with the inflammation associated with both cardiovascular and autoimmune pathologies.

Adipokines as possible new predictors of cardiovascular diseases: a case control study

Background and Aims. The secretion of several adipocytokines, such as adiponectin, retinol-binding protein 4 (RBP4), adipocyte fatty acid binding protein (aFABP), and visfatin, is altered in subjects with abdominal adiposity; these endocrine alterations could contribute to increased cardiovascular risk. The aim of the study was to assess the relationship among adiponectin, RBP4, aFABP, and visfatin, and incident cardiovascular disease. Methods and Results. A case-control study, nested within a prospective cohort, on 2945 subjects enrolled for a diabetes screening program was performed. We studied 18 patients with incident fatal or nonfatal IHD (Ischemic Heart Disease) or CVD (Cerebrovascular Disease), compared with 18 matched control subjects. Circulating adiponectin levels were significantly lower in cases of IHD with respect to controls. Circulating RBP4 levels were significantly increased in CVD and decreased in IHD with respect to controls. Circulating aFABP4 levels were significantly increased in CVD, while no difference was associated with IHD. Circulating visfatin levels were significantly lower in cases of both CVD and IHD with respect to controls, while no difference was associated with CVD. Conclusions. The present study confirms that low adiponectin is associated with increased incidents of IHD, but not CVD, and suggests, for the first time, a major effect of visfatin, aFABP, and RBP4 in the development of cardiovascular disease.

Effects of pravastatin and rosuvastatin on the generation of adiponectin in the visceral adipose tissue in patients with coronary artery disease

Pravastatin increases the plasma adiponectin level. We examined whether this is a statins' class effect or specific to pravastatin. Of 50 patients undergoing cardiac surgery for coronary artery disease (CAD, n = 36) and valvular heart disease (VHD, n = 14), 23 with CAD and serum LDL-cholesterol level >100 mg/dL were randomized to pravastatin at 10 mg/day (PRAVA, n = 12) or rosuvastatin at 2.5 mg/day (ROSUVA, n = 11) for 2 months, and the other 13 with CAD and LDL-cholesterol ≤100 mg/dL were not treated with statin (Non-statin, n = 13). Patients with VHD did not have CAD and were not treated with statin. Blood was sampled at baseline and surgery. Visceral (VIS) and subcutaneous (SC) adipose tissues were harvested during surgery. At baseline, the plasma adiponectin level was low in patients with CAD compared with that of patients with VHD. At surgery, adiponectin level in PRAVA was increased to the level in VHD, whereas those in ROSUVA and Non-statin were unchanged. VIS contents and gene expressions of adiponectin in PRAVA and VHD were similar to each other and were both higher than those in Non-statin and ROSUVA. SC content and gene expression of adiponectin were similar among 4 groups. Protein carbonyl (PC) level, an indicator of oxidative stress, in VIS was lower in PRAVA and VHD than in ROSUVA and Non-statin. There was a negative correlation between the plasma adiponectin and VIS PC levels (r = -0.41, P < 0.05). Thus, pravastatin increases adiponectin generation, whereas rosuvastatin does not.

Association of +45(T/G) and +276(G/T) polymorphisms in the adiponectin gene with coronary artery disease in a population of Iranian patients with type 2 diabetes

The relation of Two single nucleotide polymorphisms (SNPs) at the adiponectin locus (+45T/G and +276G/T) with coronary artery disease (CAD) is controversial. The aim of the present study was to evaluate the genetic influence of the adiponectin gene polymorphisms in the development of CAD among patients with Type 2 diabetes (T2D). The adiponectin genotypes were detected by polymerase chain reaction and restriction analysis (PCR-RFLP) in our patients. Two adiponectin gene (ADIPOQ) SNPs (i.e. SNPs +45T>G and +276G>T) were genotyped in 114 Type 2 diabetic subjects with CAD, and 127 Type 2 diabetic patients without CAD. Demographic and anthropometric data along with plasma biochemistry including lipids, glycemic indices, and adiponectin were collected. There was a significant difference in the distribution of genotypes of +45T/G and +276G/T between CAD and non-CAD individuals (P < 0.05). Based on our results SNP+276G>T is associated with decreased risk of CAD after adjustment for potential confounding factors [adjusted OR = 0.39 (95%CI: 0.22-0.68); P = 0.001]. Similar findings were not observed for the +45T>G SNP. Two haplotypes 45T-276T and 45G-276T were associated with a decreased risk of CAD [adjusted OR = 0.47 (95% CI: 0.32-0.94); P = 0.03 and adjusted OR = 0.33 (95% CI: 0.13-0.83); P = 0.02 respectively]. No significant difference was observed between HOMA-IR, BMI, waist circumference, history of hypertension, HbA1C, and lipid concentrations regarding the two SNPs. In conclusion, these findings suggest that T allele of +276G>T SNP is significantly associated with decreased risk of CAD in T2D Patients. Also Haplotype analysis showed that two haplotypes 45T-276T and 45G-276T were associated with a decreased risk of CAD.

Relationship between Chemerin Levels and Cardiometabolic Parameters and Degree of Coronary Stenosis in Korean Patients with Coronary Artery Disease

BACKGROUND

Chemerin is a novel adipokine that is associated with inflammation and adipogenesis. However, it remains unclear whether chemerin is involved in patients with cardiovascular disease. We investigated whether the serum chemerin levels of Korean patients with coronary artery disease correlated with specific cardiometabolic parameters.

METHODS

In total, 131 patients, all of whom had coronary artery stenosis exceeding 50%, participated in this study. Their serum chemerin levels and cardiometabolic parameters were measured. The serum chemerin levels of two groups of patients were compared; those with one stenotic vessel (n=68) and those with multiple stenotic vessels, including left main coronary artery disease (n=63).

RESULTS

Serum chemerin levels correlated positively with the degree of coronary artery stenosis and fasting glucose, triglyceride, total cholesterol, low density lipoprotein cholesterol, and high sensitive C-reactive protein levels. The group with multiple stenotic vessels, including left main disease, had higher chemerin levels than the group with one stenotic vessel (t=-2.129, P=0.035). Multiple binary logistic regression showed chemerin was not an independent risk factor of multiple vessel disease (odds ratio, 1.018; confidence interval, 0.997 to 1.040; P=0.091).

CONCLUSION

Serum chemerin levels have a significant correlation with several cardiometabolic risk factors and the degree of coronary artery stenosis in Korean patients with coronary artery disease. However, multiple binary logistic regression showed chemerin was not an independent risk factor of multiple vessel disease. Additional investigations are necessary to fully elucidate the role of chemerin in cardiovascular disease.

Elevated resistin opposed to adiponectin or angiogenin plasma levels as a strong, independent predictive factor for the occurrence of major adverse cardiac and cerebrovascular events in patients with stable multivessel coronary artery disease over 1-year follow-up

Background

Adipokines such as adiponectin and resistin, as well as angiogenin, may be associated with inflammation and atherosclerosis. The relationship between their levels and prognosis in high risk patients is, however, still unclear. The aim of this study was to evaluate the prognostic value of these adipokines in patients with stable multivessel coronary artery disease (MCAD).

Material/Methods

The study group comprised 107 MCAD patients (74% males, mean age 63±8 years). Adiponectin, resistin and angiogenin plasma levels were measured at admission and after 1-year follow-up. Primary end point (major adverse cardiac and cerebrovascular events – MACCE) was defined as cardiac death, nonfatal myocardial infarction, stroke, and hospitalization for angina or heart failure over a 1-year period.

Results

After 1-year follow-up, 9 (8%) patients died, all from cardiovascular causes. Primary end point was experienced by 32% of patients. Surgical treatment (CABG) was received by 51% of patients, while 49% were treated medically alone. Total cholesterol concentration levels ≥173 mg/dl were associated with a 7-fold increase (OR 7.3; 95% CI, 1.6–33.0); LDL ≥93.5 mg/dl with a 16-fold increase (OR 16.3; 95% CI, 2.8–93.8), and resistin ≥17.265 ng/ml with a 13-fold increase in MACCE risk (OR 13.5; 95% CI, 2.3–80.3). In multivariate analysis, a medical treatment strategy (p=0.001), a higher CCS class (p=0.004), resistin levels (p=0.003) and a higher Gensini score (p=0.03) were independent predictors of MACCE.

Conclusions

In stable patients with MCAD, elevated plasma resistin (as opposed to adiponectin or angiogenin) is a strong, independent predictive factor for the occurrence of MACCE over 1-year follow-up.