Low adiponectin levels are an independent predictor of mixed and non-calcified coronary atherosclerotic plaques

Epicardial fat volume evaluated with multidetector computed tomography and other risk factors for prevalence of three-vessel coronary lesions

PURPOSE

To retrospectively investigate the epicardial fat volume with multidetector computed tomography (MDCT) and other risk factors for the prevalence of three-vessel coronary lesion.

MATERIALS AND METHODS

MDCT was performed on 424 subjects with or without three-vessel coronary lesion. Blood was tested for triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoprotein A (ApoA), apolipoprotein B (ApoB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipoprotein a, and fasting blood glucose.

RESULTS

Among all the subjects, a significant (P < 0.05) negative linear correlation existed between age and ALT or ALT/AST. The epicardial fat had a significant (P < 0.05) negative linear correlation with HDL and Apo A but a positive correlation with age and ApoB/ApoA. The epicardial fat volume and the fasting blood glucose were significantly (P = 0.001) greater in the patients than in the control group, whereas HDL and Apo A were both significantly (P < 0.0001) smaller in the patients than in the control groups. A significant prediction value (P < 0.05) existed in age increase, male gender, epicardial fat increase, low HDL, high LDL, and elevated fasting blood glucose.

CONCLUSION

Three-vessel coronary lesions are more prevalent in subjects with greater volume of epicardial fat and in male gender.

Exploring the Relationship of Perivascular Adipose Tissue Inflammation and the Development of Vascular Pathologies

Initially thought to only provide mechanical support for the underlying blood vessels, perivascular adipose tissue (PVAT) has now emerged as a regulator of vascular function. A healthy PVAT exerts anticontractile and anti-inflammatory actions on the underlying vasculature via the release of adipocytokines such as adiponectin, nitric oxide, and omentin. However, dysfunctional PVAT produces more proinflammatory adipocytokines such as leptin, resistin, interleukin- (IL-) 6, IL-1β, and tumor necrosis factor-alpha, thus inducing an inflammatory response that contributes to the pathogenesis of vascular diseases. In this review, current knowledge on the role of PVAT inflammation in the development of vascular pathologies such as atherosclerosis and hypertension was discussed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Low Plasma Adiponectin Levels Are Associated With Vulnerable Plaque Features in Patients With Acute Coronary Syndrome: An Optical Coherence Tomography Study

BACKGROUND

Vulnerable plaques are the primary cause of acute coronary syndrome (ACS). The association between in-vivo plaque vulnerability and adiponectin levels in ACS still remains to be determined.

OBJECTIVE

The purpose of this study was to investigate the correlation between adiponectin levels and vulnerable plaque features in ACS patients.

METHODS

We enrolled 107 ACS patients admitted to our institution; 83 with Non-ST elevation ACS (NSTE-ACS) and 24 with ST-elevation myocardial infarction (STEMI). Adiponectin levels were measured in these patients. Coronary angiography and subsequent optical coherence tomography (OCT) analysis of culprit lesions were performed.

RESULTS

Adiponectin level was lower in patients with complex angiographic lesions, compared to those with non-complex lesions (7.13 ± 3.04 vs. 8.94 ± 2.84 μg/ml, P = 0.002). Adiponectin level was lower in patients with plaque rupture (PR), micro-thrombi, and thin cap fibroatheroma (TCFA), compared to those with non-vulnerable features (7.19 ± 2.95 vs 8.79 ± 3.02 μg/ml, P = 0.007 & 7.29 ± 2.97 vs 8.44 ± 3.09 μg/ml, P = 0.04 and 4.76 ± 0.65 vs 9.74 ± 2.35 μg/ml, P < 0.001 μg/ml respectively). There was a significant negative correlation between adiponectin levels and lipid rich plaque extent and maximum lipid arc (r = -0.05, P < 0.001 & r = -0.03, P = 0.03, respectively). However, a significant positive correlation was observed between adiponectin levels and fibrous cap thickness (r = 0.95, P < 0.001).

CONCLUSION

Low adiponectin levels were associated with complex angiographic lesions and vulnerable plaque features in ACS patients, where there was a significant correlation between it and PR, TCFA, and lipid rich plaque.

A three-dimensional quantification of calcified and non-calcified plaques in coronary arteries based on computed tomography coronary angiography images: Comparison with expert's annotations and virtual histology intravascular ultrasound

The detection, quantification and characterization of coronary atherosclerotic plaques has a major effect on the diagnosis and treatment of coronary artery disease (CAD). Different studies have reported and evaluated the noninvasive ability of Computed Tomography Coronary Angiography (CTCA) to identify coronary plaque features. The identification of calcified plaques (CP) and non-calcified plaques (NCP) using CTCA has been extensively studied in cardiovascular research. However, NCP detection remains a challenging problem in CTCA imaging, due to the similar intensity values of NCP compared to the perivascular tissue, which surrounds the vasculature. In this work, we present a novel methodology for the identification of the plaque burden of the coronary artery and the volumetric quantification of CP and NCP utilizing CTCA images and we compare the findings with virtual histology intravascular ultrasound (VH-IVUS) and manual expert's annotations. Bland-Altman analyses were employed to assess the agreement between the presented methodology and VH-IVUS. The assessment of the plaque volume, the lesion length and the plaque area in 18 coronary lesions indicated excellent correlation with VH-IVUS. More specifically, for the CP lesions the correlation of plaque volume, lesion length and plaque area was 0.93, 0.84 and 0.85, respectively, whereas the correlation of plaque volume, lesion length and plaque area for the NCP lesions was 0.92, 0.95 and 0.81, respectively. In addition to this, the segmentation of the lumen, CP and NCP in 1350 CTCA slices indicated that the mean value of DICE coefficient is 0.72, 0.7 and 0.62, whereas the mean HD value is 1.95, 1.74 and 1.95, for the lumen, CP and NCP, respectively.

Inflammation and coronary artery calcification in South Asians: The Mediators of Atherosclerosis in South Asians Living in America (MASALA) study

BACKGROUND AND AIMS

Inflammatory biomarkers and adipocytokines (IBA) may contribute to atherosclerosis by promoting vascular inflammation. The association between IBA and coronary artery calcium (CAC), a marker of subclinical atherosclerosis, is not well defined in South Asians (SA). We hypothesized that IBA (high sensitivity C-reactive protein [hsCRP], tumor necrosis factor alpha [TNF-α], adiponectin, and leptin) were independently associated with and improved discrimination of CAC among SA.

METHODS

We analyzed IBA and CAC among participants in the prospective Mediators of Atherosclerosis in South Asians Living in America (MASALA) study. We used logistic regression models to examine cross-sectional associations of IBA with CAC presence (CAC >0) and severity (CAC >100), and C-statistics to assess the incremental contribution of each IBA to traditional risk factors (TRF) from the AHA/ACC Pooled Cohort Equations (PCE) for discrimination of CAC.

RESULTS

Among 906 participants in the MASALA study, women (n = 420) had significantly higher levels of hsCRP, adiponectin, and leptin but lower levels of TNF-α than men (p < .01 for all). There was no significant association between any of the four IBA and either CAC category in multivariable-adjusted models, respectively. Lastly, none of the four IBA improved discrimination of CAC presence or severity when added to elements of the PCE.

CONCLUSIONS

IBA were not associated with CAC presence or severity in the MASALA population. IBA did not help identify SA at risk of subclinical atherosclerosis, although associations with ASCVD events remain unclear. In SA, CAC may have a distinct pathophysiology independent of inflammation as measured by IBA.

Epicardial adipose tissue density and volume are related to subclinical atherosclerosis, inflammation and major adverse cardiac events in asymptomatic subjects

BACKGROUND

We investigated whether epicardial adipose tissue (EAT) volume and density are related to early atherosclerosis, plaque inflammation and major adverse cardiac events (MACE, cardiac death and myocardial infarction) in asymptomatic subjects.

METHODS

EAT volume and density were quantified from non-contrast cardiac CT in 456 asymptomatic individuals (age 60.3 ± 8.3; 68% with CCS>0) from the prospective EISNER trial. EAT volume and density were examined in relation to coronary calcium score (CCS), inflammatory biomarkers and MACE.

RESULTS

EAT volume was higher and EAT density lower in subjects with coronary calcium compared to subjects without [89 vs 74 cm³, p < 0.001] [-76.9 vs -75.7 HU,p = 0.024]. EAT volume was lowest in individuals with no coronary calcium and was significant higher in subjects with early atherosclerosis (CCS 1-99) [74 vs 87 cm³,p = 0.016] and in subjects with more advanced atherosclerosis (CCS≥100) [89 cm³,p = 0.002]). EAT volume was independently related to serum levels of PAI-1, and MCP-1 and inversely related to adiponectin and HDL-cholesterol (p < 0.05). EAT density was inversely related to PAI-1 and LDL-cholesterol and positively associated to adiponectin, sICAM-1 and HDL-cholesterol (p < 0.05). EAT density was more significantly associated with MACE [(HR 0.8, 95%CI:0.7-0.98), p = 0.029] than EAT volume or CCS.

CONCLUSION

EAT volume was higher and density lower in subjects with coronary calcium compared to subjects with CCS = 0, with similar EAT volume in CCS<100 and CCS≥100. Lower EAT density and increased EAT volume were associated with coronary calcification, serum levels of plaque inflammatory markers and MACE, suggesting that dysfunctional EAT may be linked to early plaque formation and inflammation.

Association between circulating adipocytokine concentrations and microvascular complications in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of controlled cross-sectional studies

BACKGROUND

The adipocytokines leptin and adiponectin have been variously associated with diabetic microvascular complications. No comprehensive clinical data exist examining the association between adipocytokines and the presence of these complications.

METHODS

This is a systematic review of cross-sectional studies comparing circulating adipocytokines in patients with type 2 diabetes mellitus (T2DM), with and without microvascular complications. Studies were retrieved from MEDLINE, EMBASE, Scopus and Cochrane databases. Study quality was evaluated using a modified Newcastle-Ottawa Scale. Meta-analysis was performed using an inverse-variance model, providing standardised mean differences (SMD) and 95% confidence intervals (CI). Heterogeneity was determined by I(2) statistic.

RESULTS

Amongst 554 identified studies, 28 were included in the review. Study quality range was 3.5-9 (maximum 11). Higher leptin levels were associated with microalbuminuria (SMD=0.41; 95% CI=0.14-0.67; n=901; p=0.0003), macroalbuminuria (SMD=0.68; 95% CI=0.30-1.06; n=406; p=0.0004), and neuropathy (SMD=0.26; 95% CI=0.07-0.44; n=609; p=0.008). Higher adiponectin levels were associated with microalbuminuria (SMD=0.55; 95% CI=0.29-0.81, n=274; p<0.001), macroalbuminuria (SMD=1.37; 95% CI=0.78-1.97, n=246; p<0.00001), neuropathy (SMD=0.25; 95% CI=0.14-0.36; n=1516; p<0.00001), and retinopathy (SMD=0.38; 95% CI=0.25-0.51; n=1306; p<0.00001). Meta-regression suggested no influence of body mass index and duration of diabetes on effect size, and a weak trend in terms of age on effect size.

DISCUSSION

Our meta-analysis suggests leptin and adiponectin levels are higher in T2DM patients with microvascular complications. Studies were limited by cross-sectional design. Large prospective analyses are required to validate these findings.

Incremental diagnostic value of epicardial adipose tissue for the detection of functionally relevant coronary artery disease

BACKGROUND AND AIM

To determine the incremental diagnostic value of epicardial adipose tissue (EAT) volume in addition to the coronary artery calcium (CAC) score for detecting hemodynamic significant coronary artery disease (CAD).

METHODS AND RESULTS

122 patients (mean age 61 ± 10 years, 61% male) without a previous cardiac history underwent a non-contrast CT scan for calcium scoring and EAT volume measurements. Subsequently all patients underwent invasive coronary angiography (ICA) in conjunction with fractional flow reserve (FFR) measurements. A stenosis >90% and/or a FFR ≤0.80 were considered significant. Mean EAT volume and CACscore were 128 ± 51 cm(3) and 418 ± 704, respectively. The correlation between EAT volume and the CACscore was poor (r = 0.11, p = 0.24). Male gender (odds ratio [OR] 2.86, p = 0.01), CACscore ([cut-off value 100] OR 3.31, p = 0.003, and EAT volume ([cut-off value 92 cm(3)] OR 4.28, p = 0.01) were associated with flow-limiting disease. The multivariate model revealed that only male gender (OR 2.50, p = 0.045), CAC score (OR 3.60, p = 0.005), and EAT volume (OR 4.95, p = 0.02) were independent predictors of myocardial ischemia. Using the cut-off values of 100 (CAC score) and 92 cm(3) (EAT volume), sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for detecting functionally relevant CAD as indicated by FFR were 71, 57, 77, 50 and 63% and 91, 29, 85, 44 and 52% for the CACscore and EAT volume, respectively. Adding EAT volume to the CAC score and cardiovascular risk factors did not enhance diagnostic performance for the detection of significant CAD (p = 0.57).

CONCLUSION

EAT volume measurements have no diagnostic value beyond calcium scoring and cardiovascular risk factors in the detection of hemodynamic significant CAD.

Imaging of atherosclerotic plaques in obesity: excessive fat accumulation, plaque progression and vulnerability

Obesity is becoming a major health issue in the world due to sedentary lifestyles and increasing intake of Western diets. Obesity is associated with metabolic abnormalities and atherosclerotic cardiovascular diseases. Adipose tissue has been increasingly considered to play a critical role in inducing metabolic disturbances and promoting atherogenesis. Arterial wall imaging permits direct visualization of atheroma burden in various vascular beds. In addition, recent advances in imaging technology help characterize components, microstructures and functional features of atherosclerotic plaques. These imaging modalities have contributed to elucidating factors associated with atherosclerosis in obese patients. Also, it provides opportunities to evaluate the effect of novel therapies on plaques in the setting of obesity. The findings of recent imaging studies and the clinical implications will be reviewed.

Epicardial adipose tissue thickness correlates with the presence and severity of angiographic coronary artery disease in stable patients with chest pain

Objective

Epicardial adipose tissue (EAT) is suggested to correlate with metabolic risk factors and to promote plaque development in the coronary arteries. We sought to determine whether EAT thickness was associated or not with the presence and extent of angiographic coronary artery disease (CAD).

Methods

We measured epicardial fat thickness by computed tomography and assessed the presence and extent of CAD by coronary angiography in participants from the prospective EVASCAN study. The association of EAT thickness with cardiovascular risk factors, coronary artery calcification scoring and angiographic CAD was assessed using multivariate regression analysis.

Results

Of 970 patients (age 60.9 years, 71% male), 75% (n = 731) had CAD. Patients with angiographic CAD had thicker EAT on the left ventricle lateral wall when compared with patients without CAD (2.74±2.4 mm vs. 2.08±2.1 mm; p = 0.0001). The adjusted odds ratio (OR) for a patient with a LVLW EAT value ≥2.8 mm to have CAD was OR = 1.46 [1.03–2.08], p = 0.0326 after adjusting for risk factors. EAT also correlated with the number of diseased vessels (p = 0.0001 for trend). By receiver operating characteristic curve analysis, an EAT value ≥2.8 mm best predicted the presence of>50% diameter coronary artery stenosis, with a sensitivity and specificity of 46.1% and 66.5% respectively (AUC:0.58). Coronary artery calcium scoring had an AUC of 0.76.

Conclusion

Although left ventricle lateral wall EAT thickness correlated with the presence and extent of angiographic CAD, it has a low performance for the diagnosis of CAD.

Association between HMW adiponectin, HMW-total adiponectin ratio and early-onset coronary artery disease in Chinese population

OBJECTIVE

Adiponectin is an adipose-secreting protein that shows atheroprotective property and has inverse relation with coronary artery disease (CAD). High-molecular weight (HMW) adiponectin is reported as the active form of adiponectin. In the present study, we aimed to investigate the association between total adiponectin, HMW adiponectin, HMW-total adiponectin ratio and the severity of coronary atherosclerosis, and to compare their evaluative power for the risk of CAD.

METHODS

Serum levels of total and HMW adiponectin were measured in 382 early-onset CAD (EOCAD) patients and 305 matched controls undergoing coronary angiography by enzyme-linked immunosorbent assay (ELISA). Gensini score was used to evaluate the severity of coronary atherosclerosis.

RESULTS

CAD onset age was positively correlated with HMW adiponectin (r = 0.383, P < 0.001) and HMW-total adiponectin ratio (r = 0.429, P < 0.001) in EOCAD patients. Total and HMW adiponectin and HMW-total adiponectin ratio were all inversely correlated with Gensini score (r = -0.417, r = -0.637, r = -0.578, respectively; all P < 0.001). Multivariate binary logistic regression analysis demonstrated that HMW adiponectin and HMW-total adiponectin ratio were both inversely correlated with the risk of CAD (P < 0.05). ROC analysis indicated that areas under the ROC curves of HMW adiponectin and HMW-total adiponectin ratio were larger than that of total adiponectin (P < 0.05).

CONCLUSIONS

Adiponectin is cardioprotective against coronary atherosclerosis onset in EOCAD patients. HMW adiponectin and HMW-total adiponectin ratio show stronger negative associations with the severity of coronary atherosclerosis than total adiponectin does. HMW adiponectin and HMW-total adiponectin ratio are effective biomarkers for the risk of CAD in Chinese population.

Lower adiponectin is associated with subclinical cardiovascular disease among HIV-infected men

OBJECTIVE

To examine whether altered levels of adipokines, adipose-derived peptides associated with myocardial infarction in the general population, may contribute to subclinical coronary atherosclerosis in HIV-infected persons.

DESIGN

Nested cohort study.

METHODS

We studied HIV-infected (HIV+) and HIV-uninfected (HIV-) men in the Multicenter AIDS Cohort Study with noncontrast computed tomography (CT) to measure coronary artery calcium and regional adiposity; 75% additionally underwent coronary CT angiography to measure plaque composition and stenosis. Adiponectin and leptin levels were assessed. Multiple regression models were used to assess associations between adipokine levels and HIV disease parameters, regional adiposity, and plaque adjusted for age, race, HIV serostatus, and cardiovascular disease (CVD) risk factors.

RESULTS

Significant findings were limited to adiponectin. HIV-positive men (n=493) had lower adiponectin levels than HIV-negative men (n=250) after adjusting for CVD risk factors (P<0.0001), which became nonsignificant after adjustment for abdominal visceral and thigh subcutaneous adipose tissue. Among HIV-positive men, lower adiponectin levels were associated with higher CD4 T-cell counts (P=0.004), longer duration of antiretroviral therapy (P=0.006), and undetectable HIV RNA levels (P=0.04) after adjusting for age, race, and CVD risk factors; only CD4 cell count remained significant after further adjustment for adipose tissue. In both groups, lower adiponectin levels were associated with increased odds of coronary stenosis more than 50% (P<0.007). Lower adiponectin levels were associated with increased extent of plaque in HIV-positive and of mixed plaque in HIV-negative men.

CONCLUSION

Adiponectin levels were lower in HIV-infected men and related to the severity of subclinical atherosclerosis, independent of traditional CVD risk factors.

Circulating concentrations of GLP-1 are associated with coronary atherosclerosis in humans

Background

GLP-1 is an incretine hormone which gets secreted from intestinal L-cells in response to nutritional stimuli leading to pancreatic insulin secretion and suppression of glucagon release. GLP-1 further inhibits gastric motility and reduces appetite which in conjunction improves postprandial glucose metabolism. Additional vasoprotective effects have been described for GLP-1 in experimental models. Despite these vasoprotective actions, associations between endogenous levels of GLP-1 and cardiovascular disease have yet not been investigated in humans which was the aim of the present study.

Methods

GLP-1 serum levels were assessed in a cohort of 303 patients receiving coronary CT-angiography due to typical or atypical chest pain.

Results

GLP-1 was found to be positively associated with total coronary plaque burden in a fully adjusted model containing age, sex, BMI, hypertension, diabetes mellitus, smoking, triglycerides, LDL-C (low density lipoprotein cholesterol), hsCRP (high-sensitive C-reactive protein), and eGFR (estimated glomerular filtration rate) (OR: 2.53 (95% CI: 1.12 – 6.08; p = 0.03).

Conclusion

Circulating GLP-1 was found to be positivity associated with coronary atherosclerosis in humans. The clinical relevance of this observation needs further investigations.

Absolute coronary artery calcium score is the best predictor of non-calcified plaque involvement in patients with low calcium scores (1-100)

OBJECTIVE

We sought to identify the predictors of non-calcified plaque (NCP) burden in patients with low coronary artery calcium (CAC) scores of 1-100.

METHODS

We studied 920 consecutive patients clinically referred for coronary CT angiography (CCTA) with concomitant CAC scoring. The 276 patients with CAC 1-100 were divided into four groups based on the CAC score: CAC = 0, 1-10, 11-50, and 51-100. Univariate and multivariate linear regression analyses were performed for the demographic, risk factor, and CAC score predictors of number of coronary segments with NCP.

RESULTS

Mean age was 55 ± 11 years and 56% were women. Demographics and risk factors failed to identify NCP involvement in univariate models. The lone predictor of NCP burden was the absolute CAC score, which was persistently associated with NCP in multivariable models (CAC 51-100 vs. CAC 1-10, β-coefficient 0.35, p = 0.03).

CONCLUSIONS

Absolute CAC score is the lone robust predictor of NCP burden when CAC is 1-100. Risk within this mild coronary calcification group is likely heterogeneous, driven by the absolute CAC score.

Predictive value of adiponectin in patients with multivessel coronary atherosclerosis detected on computed tomography angiography

AIM

Multislice computed tomography coronary angiography (CTCA) can be used to detect coronary plaques that predict the risk of cardiovascular events. This study aimed to identify the risk factors associated with the extent of coronary plaques detected using CTCA and to determine the value of adiponectin measurement for identifying high-risk patients with multivessel coronary atherosclerosis.

METHODS

The study included 298 patients who underwent CTCA for coronary artery disease (CAD) screening between July 2008 and October 2011. We investigated the relationship between the extent of coronary atherosclerosis in terms of the number of diseased vessels and various risk factors, including the serum adiponectin level.

RESULTS

The adiponectin level was found to be significantly associated with multivessel coronary atherosclerosis in a univariate analysis (p=0.001). A multivariate analysis revealed the adiponectin level to also be significantly associated with multivessel coronary atherosclerosis (p=0.01), independent of other significant risk factors, including an advanced age, male gender, diabetes mellitus (DM) and hypertension (HT). A receiver operating characteristic curve analysis revealed that a combination of these factors significantly predicted multivessel coronary atherosclerosis (area under the curve, 0.73;95% confidence interval, 0.67-0.78). As the number of these factors increased, the proportion of patients with multivessel coronary atherosclerosis increased, while the proportion of patients with normal coronary arteries decreased (p < 0.0001).

CONCLUSIONS

A low adiponectin level combined with an advanced age, male gender, DM, and HT is independently and incrementally associated with multivessel coronary atherosclerosis. The number of factors may predict the extent of coronary atherosclerosis in patients without documented CAD.

AdR1-TG/TALLYHO mice have improved lipid accumulation and insulin sensitivity

BACKGROUND

Overexpression of adiponectin receptor 1 in macrophages can physiologically modulate metabolic activities in vivo by enhancing adiponectin actions in distal metabolically active tissues. To investigate the effects of enhanced adiponectin actions in TALLYHO (TH) diabetic mouse model, we crossed the adiponectin receptor 1 macrophage-specific transgenic mice (AdR1-TG) with the TALLYHO diabetic mice (TH) to examine the changes of lipid accumulation and insulin sensitivity in these mice.

METHODS

AdR1-TG/TH and the control WT/TH mice were fed either normal diet or high fat diet for 28weeks. Whole body weights of these mice were measured and mouse sera were analyzed for the levels of cholesterol, triglyceride, and free fatty acids. Glucose tolerance testing (GTT) and insulin tolerance testing (ITT) in these mice were performed to investigate systemic insulin sensitivity in vivo. Molecular markers for insulin signaling pathway in mouse skeletal muscle tissues, IRS-1 and AKT, were examined. Mouse serum insulin levels were measured and Sirt1 gene expression in mouse pancreatic tissues was also quantified related to the insulin secretion. The Caspase 3 protein levels were analyzed by Western blot methods.

RESULTS

Compared to the control WT/TH mice, AdR1-TG/TH mice showed significantly lower body weights under either normal diet or high fat diet and the mouse serum levels of cholesterol, triglyceride and free fatty acids were significantly decreased in the transgenic crossed mice when compared to those from the control mice. Improved GTT and ITT tests indicating increased systemic insulin sensitivity in the transgenic crossed mice demonstrated the enhanced adiponectin actions on the systemic metabolism in vivo. The increases of insulin secretion and its related gene expression were also detected in the transgenic crossed mice. In contrast, the control mice showed hypertrophy pancreases companying with high apoptosis gene expression. These results suggest that enhanced adiponectin actions by overexpressing adiponectin receptor 1 in macrophages can provide unique interactions with the metabolic tissues/cells, improving lipid accumulation and insulin sensitivity in TALLYHO diabetic mice.

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.

Enhanced adiponectin actions by overexpression of adiponectin receptor 1 in macrophages

OBJECTIVE

Adiponectin is one of several important, metabolically active cytokines secreted from adipose tissue. Epidemiologic studies have associated low circulating levels of this adipokine with multiple metabolic disorders including obesity, insulin resistance, type II diabetes, and cardiovascular disease. To investigate how enhanced adiponectin-mediated changes in metabolism in vivo, we generated transgenic mice which specifically overexpress the gene coding for adiponectin receptor 1 (AdipoR1) in mouse macrophages using the human scavenger receptor A-I gene (SR-AI) enhancer/promoter. We found that macrophage-specific AdipoR1 transgenic mice (AdR1-TG) presented reduced whole body weight, fat accumulation and liver steatosis when these transgenic mice were fed with a high fat diet. Moreover, these macrophage AdR1-TG mice exhibited enhanced whole-body glucose tolerance and insulin sensitivity with reduced proinflammatory cytokines, MCP-1 and TNF-α, both in the serum and in the insulin target metabolic tissues. Additional studies demonstrated that these macrophage AdR1-TG animals exhibited reduced macrophage foam cell formation in the arterial wall when these transgenic mice were crossed with a low-density lipoprotein receptor (Ldlr) deficient mouse model.

CONCLUSIONS

These results suggest that AdipoR1 overexpressed in macrophages can physiologically modulate metabolic activities in vivo by enhancing adiponectin actions in distal metabolically active tissues. The AdipoR1 modified macrophages provide unique interactions with the residented tissues/cells, suggesting a novel role of macrophage adiponectin receptor in improving metabolic disorders in vivo.

Adiponectin: anti-inflammatory and cardioprotective effects

Adipose tissue is an endocrine organ that plays an essential role in regulating several metabolic functions through the secretion of biological mediators called "adipokines". Dysregulation of adipokines plays a crucial role in obesity-related diseases. Adiponectin (APN) is the most abundant adipokine accounting for the 0.01% of total serum protein, and is involved in a wide variety of physiological processes including energy metabolism, inflammation, and vascular physiology. APN plasma levels are reduced in individuals with obesity, type 2 diabetes and coronary artery disease, all traits with low-grade chronic inflammation. It is has been suggested that the absence of APN anti-inflammatory effects may be a contributing factor to this inflammation. APN inhibits the expression of tumor necrosis factor-α-induced endothelial adhesion molecules, macrophage-to-foam cell transformation, tumor necrosis factor-α expression in macrophages and adipose tissue, and smooth muscle cell proliferation. It also has anti-apoptotic and anti-oxidant effects, which play a role in its cardioprotective action. This review will focus on APN as an anti-inflammatory, anti-atherogenic and cardioprotective plasma protein.

Insulin resistance predicts progression of de novo atherosclerotic plaques in patients with coronary heart disease: a one-year follow-up study

BACKGROUND

The aim of our study was to explore and evaluate the relationship between insulin resistance and progression of coronary atherosclerotic plaques. With the great burden coronary heart disease is imposing on individuals, healthcare professionals have already embarked on determining its potential modifiable risk factors in the light of preventive medicine. Insulin resistance has been generally recognized as a novel risk factor based on epidemiological studies; however, few researches have focused on its effect on coronary atherosclerotic plaque progression.

METHODS

From June 7, 2007 to December 30, 2011, 366 patients received their index coronary angiogram and were subsequently found to have coronary atherosclerotic plaques or normal angiograms were consecutively enrolled in the study by the department of cardiology at the Ruijin Hospital, which is affiliated to the Shanghai Jiaotong University School of Medicine. All patients had follow-up angiograms after the 1-year period for evaluating the progression of the coronary lesions. The modified Gensini score was adopted for assessing coronary lesions while the HOMA-IR method was utilized for determining the state of their insulin resistance. Baseline characteristics and laboratory test results were described and the binomial regression analysis was conducted to investigate the relationship between insulin resistance and coronary atherosclerotic plaque progression.

RESULTS

Index and follow-up Gensini scores were similar between the higher insulin lower insulin resistant groups (9.09 ± 14.33 vs 9.44 ± 12.88, p = 0.813 and 17.21 ± 18.46 vs 14.09 ± 14.18, p =0.358). However the Gensini score assessing coronary lesion progression between both visits was significantly elevated in the higher insulin resistant group (8.13 ± 11.83 versus 4.65 ± 7.58, p = 0.019). Multivariate logistic binomial regression analysis revealed that insulin resistance (HOMA-IR > 3.4583) was an independent predictor for coronary arterial plaque progression (OR = 4.969, p = 0.011). We also divided all the participants into a diabetic (n = 136) and a non-diabetic group (n = 230), and HOMA-IR remained an independent predictor for atherosclerosis plaque progression.

CONCLUSIONS

Insulin resistance is an independent predictor of atherosclerosis plaque progression in patients with coronary heart disease in both the diabetic and non-diabetic population.

Endogenous bioactive peptides as potential biomarkers for atherosclerotic coronary heart disease

Cardiovascular disease is the leading cause of death worldwide, with high medical costs and rates of disability. It is therefore important to evaluate the use of cardiovascular biomarkers in the early diagnosis of coronary artery disease (CAD). We have screened a variety of recently identified bioactive peptides candidates in anticipation that they would allow detection of atherosclerotic CAD. Especially, we have focused on novel anti-atherogenic peptides as indicators and negative risk factors for CAD. In vitro, in vivo and clinical studies indicated that human adiponectin, heregulin-β₁, glucagon-like peptide-1 (GLP-1), and salusin-α, peptides of 244, 71, 30, and 28 amino acids, respectively, attenuate the development and progression of atherosclerotic lesions by suppressing macrophage foam cell formation via down-regulation of acyl-coenzyme A: cholesterol acyltransferase-1. Circulating levels of these peptides in the blood are significantly decreased in patients with CAD compared to patients without CAD. Receiver operating characteristic analyses showed that salusin-α is a more useful biomarker, with better sensitivity and specificity, compared with the others for detecting CAD. Therefore, salusin-α, heregulin-β₁, adiponectin, and/or GLP-1, alone or in various combinations, may be useful as biomarkers for atherosclerotic CAD.

Evaluation of serum adipokines in peripheral arterial occlusive disease

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

Adipose tissue mass and location affect circulating adiponectin levels

AIMS/HYPOTHESIS

Plasma levels of adiponectin are inversely associated with body mass. We hypothesised that adipose tissue distribution and body composition influences adiponectin levels.

METHODS

We assessed plasma adiponectin concentrations and dual-energy X-ray absorptiometry (DEXA) measurements of body composition among 2,820 participants from the Dallas Heart Study.

RESULTS

Among both women and men, adiponectin levels were higher in whites than in either Hispanics or African-Americans (for women: median 9.99 μg/ml [25th,75th percentile 7.11, 13.77] vs 7.56 μg/ml [5.05, 9.98] vs 6.39 μg/ml [4.37, 9.41], respectively, p < 0.0001; for men: 6.43 μg/ml [4.66, 9.19] vs 5.55 μg/ml [3.64, 7.50] vs 5.03 μg/ml [3.39, 7.28], p < 0.0001). In univariate analysis, each individual component of body mass was inversely associated with adiponectin. After multivariate analysis, adiponectin levels were found to be positively associated with lower extremity fat, whether expressed in absolute mass (for women: β = 0.055, p < 0.0001; for men: β = 0.061, p < 0.0001), or as a relative proportion (for women: β = 0.035, p < 0.0001; for men: β = 0.034, p < 0.0001). This association was consistent across ethnicities. Conversely, adiponectin was negatively correlated with truncal fat, both in absolute (for women: β = -0.039, p < 0.0001; for men: β = -0.044, p < 0.0001) and relative terms (for women: β = -0.027, p < 0.0001; for men β = -0.033, p < 0.0001). At the extreme of body mass, higher degrees of lower extremity and truncal adiposity were associated with higher levels of adiponectin.

CONCLUSIONS/INTERPRETATION

These data suggest that the location of adipose depots differentially influences circulating adiponectin concentrations-a finding observed across ethnicity and sex. Gross measures of body mass alone do not adequately account for adiponectin levels. This supports a role of adiponectin as a mediator of the positive effects of lower extremity adiposity on improvements in insulin sensitivity.

Adipocytokines and CD34 progenitor cells in Alzheimer's disease

Background

Alzheimer's disease (AD) and atherosclerosis share common vascular risk factors such as arterial hypertension and hypercholesterolemia. Adipocytokines and CD34⁺ progenitor cells are associated with the progression and prognosis of atherosclerotic diseases. Their role in AD is not adequately elucidated.

Methods and Findings

In the present study, we measured in 41 patients with early AD and 37 age- and weight-matched healthy controls blood concentrations of adiponectin and leptin by enzyme linked immunoabsorbent assay and of CD34⁺ progenitor cells using flow cytometry. We found significantly lower plasma levels of leptin in AD patients compared with the controls, whereas plasma levels of adiponectin did not show any significant differences (AD vs. control (mean±SD): leptin:8.9±5.6 ng/mL vs.16.3±15.5 ng/mL;P = 0.038; adiponectin:18.5±18.1 µg/mL vs.16.7±8.9 µg/mL;P = 0.641). In contrast, circulating CD34⁺ cells were significantly upregulated in AD patients (mean absolute cell count±SD:253±51 vs. 203±37; P = 0.02) and showed an inverse correlation with plasma levels of leptin (r = −0.248; P = 0.037).

In logistic regression analysis, decreased leptin concentration (P = 0.021) and increased number of CD34⁺ cells (P = 0.036) were both significantly associated with the presence of AD. According to multifactorial analysis of covariance, leptin serum levels were a significant independent predictor for the number of CD34⁺ cells (P = 0.002).

Conclusions

Our findings suggest that low plasma levels of leptin and increased numbers of CD34⁺ progenitor cells are both associated with AD. In addition, the results of our study provide first evidence that increased leptin plasma levels are associated with a reduced number of CD34⁺ progenitor cells in AD patients. These findings point towards a combined involvement of leptin and CD34⁺ progenitor cells in the pathogenesis of AD. Thus, plasma levels of leptin and circulating CD34⁺ progenitor cells could represent an important molecular link between atherosclerotic diseases and AD. Further studies should clarify the pathophysiological role of both adipocytokines and progenitor cells in AD and possible diagnostic and therapeutic applications.

Pericardial fat amount is an independent risk factor of coronary artery stenosis assessed by multidetector-row computed tomography: the Korean Atherosclerosis Study 2

Pericardial fat surrounding the heart and coronary arteries might aggravate vessel wall inflammation and stimulate the progression of coronary atherosclerosis. However, there has been little comprehensive evaluation of the effects of pericardial fat on coronary artery disease (CAD). We investigated the relationship between pericardial fat volume and the severity of coronary artery stenosis assessed by computed tomography and angiography among patients with suspected CAD. Participants from the cohort of the Korean Atherosclerosis Study 2 (n = 402, mean age of 54 years, 57.0% men) underwent 64-slice multidetector-row computed tomography (MDCT) to assess pericardial fat amount, coronary artery calcium score (CACS), severity of coronary artery stenosis, and plaque characteristics. Patients with atherosclerotic lesion had significantly larger volume of pericardial fat than patients without atherosclerosis (308 ± 96 cm(3) vs. 251 ± 93 cm(3); P < 0.01). In a multivariate regression analysis adjusting for age, gender and BMI, subjects with more pericardial fat had a higher risk for significant (>50%) stenosed coronary vessels (odds ratio (OR) = 1.012; 95% confidence interval (CI) 1.001-1.030; P = 0.017). This association remained after adjusting for hypertension, diabetes, smoking status, and lipid profiles (OR = 1.007; 95% CI 1.001-1.014; P = 0.042). In conclusion, an increased pericardial fat volume was an independent risk factor for stenotic CAD and could be helpful in assessing subclinical CADs.

Coronary Calcification and Hormones

The pathogenesis of coronary artery calcification and its role in atherogenesis has not been completely understood but is a new focus of interest in experimental and clinical research. Various bioactive substances, including hormones, have been implicated in the process of arterial calcification. This review considers the relationship between coronary artery calcification and hormones. These hormones may become therapeutic targets for the prevention of arterial calcification.

Reduced plasma adiponectin levels relative to oxidized low density lipoprotein and nitric oxide in coronary artery disease patients

INTRODUCTION

Adiponectin is a circulating hormone that is produced exclusively by adipocytes and has antiinflammatory and anti-atherogenic properties. The hypothesis that there are differences in adiponectin levels between stable and unstable coronary-artery disease patients remains controversial. Furthermore, the potential relationships between the plasma adiponectin level and the inflammatory and non-inflammatory markers (oxidized low density lipoprotein and nitric oxide) in patients with stable and unstable coronary-artery disease relative to normal subjects have not been assessed.

OBJECTIVES

To assess whether plasma adiponectin levels differ among patients with stable and unstable coronary-artery disease and among control subjects, and to correlate plasma adiponectin level with inflammatory and clinical risk factors (such as oxidized-LDL and nitric oxide) in these patients.

METHODS

This study included 50 control subjects, 50 stable angina patients and 50 unstable angina patients with angiographically documented coronary-artery disease. Plasma adiponectin and oxidized-LDL levels were determined using an enzyme immunoassay. Plasma nitric oxide, high sensitivity C-reactive protein and lipid profile levels were also measured.

RESULTS

Plasma adiponectin levels were lower in the unstable angina patients (4.9 ± 1.30 µg/mL) than in the stable angina patients (6.34 ± 1.0 µg/mL) or in the controls (9.25 ± 1.8 µg/mL); these levels were also significantly lower in stable angina patients versus controls (p<0.001). Plasma adiponectin levels were negatively correlated with oxidized-LDL, high sensitivity C-reactive protein, lipid profile and other clinical risk factors but positively correlated with nitric oxide.

CONCLUSION

Plasma adiponectin levels were found to be lower in both stable and unstable angina patients relative to control subjects, and the correlation between plasma adiponectin and cardiovascular markers is weakened in these patients.

Low Plasma Adiponectin as a Potential Biomarker for Osteonecrosis of the Femoral Head

Objective.

To examine whether plasma adiponectin level is correlated with osteonecrosis of the femoral head (ONFH).

Methods.

Blood adiponectin level in patients with nontraumatic ONFH (n = 120) was compared with a group of healthy subjects (n = 120). Patients with hip osteoarthritis (OA; n = 30) and traumatic ONFH (n = 45) were included as controls. Potential compounding factors, such as plasma low-density lipoprotein (LDL), high-density lipoprotein (HDL), apolipoprotein A1 (apo A1), apolipoprotein B (apo B), total cholesterol (TC), triglycerides (TG), and C-reactive protein (CRP) were also examined.

Results.

Patients with nontraumatic ONFH had significantly lower plasma levels of adiponectin than the healthy controls (7.14 ± 3.53 vs 10.93 ± 3.41 μg/ml, respectively; p < 0.001). Adiponectin level was positively correlated with HDL (r = 0.282, p < 0.001) and age (r = 0.145, p = 0.01), yet negatively correlated with body mass index (r = −0.70, p < 0.001), TG (r = −0.55, p<0.001), LDL/HDL ratio (r = −0.173, p = 0.002), and CRP (r = −0.634, p < 0.001). No correlation was seen with LDL (r = −0.017, p = 0.762). A multiple logistic regression analysis revealed that adiponectin level is an independent predictor of the presence of nontraumatic ONFH (p < 0.001, OR 0.676, 95% CI 0.546 to 0.845).

Conclusion.

Low adiponectin level is significantly associated with the presence of nontraumatic ONFH. This biomarker may be useful in assessing the potential presence of nontraumatic ONFH.

Chronic kidney disease bone and mineral disorder (CKD-MBD) in apolipoprotein E-deficient mice with chronic renal failure

BACKGROUND

Chronic kidney disease (CKD) is associated with disorders of mineral and bone metabolism (MBD) which include renal osteodystrophy and vascular calcifications. This is of clinical concern because the high risk of cardiovascular (CVD) complications observed in uremic patients may be linked with bone disease. In this context, our aim was to characterize the bone lesions in CKD-apolipoprotein E-deficient mice (apoE(-/-)) and analyze their relationships with the vascular calcifications which these animals develop rapidly in this model. With ApoE being also involved in bone metabolism, we compared the effects of CRF on the bone of apoE(-/-) mice to those observed in wild type mice (WT) of the same genetic background, C57/BL6.

METHODS

After CRF creation or sham surgery, 10 week-old female apoE(-/-) and WT mice were randomized to 4 groups (n=10-14/group) and fed with standard diet. Eight weeks later, animals were euthanized. Serum, aorta and femur were sampled. Femurs were imaged with 3-dimensional microtomography (microCT) and processed for bone histomorphometry (BHM). Additional quantitative histology was performed on atherosclerotic and calcified lesions in the aortas of apoE(-/-) mice.

RESULTS

First, apoE(-/-) mice exhibited higher cortical (10%) and trabecular (31%) bone mass than WT. CRF led to a further increase in trabecular BV/TV in WT and in apoE(-/-) mice (10.2% and 77.2%, respectively). We observed a similar increase in osteoid surface and osteoblastic parameters in CRF mice of both genotypes while resorption parameters were less augmented by CRF in apoE(-/-) mice. Finally, based on either BHM or microCT we found positive correlations between the extent of atherosclerotic lesions and bone volume parameters, and between the size of plaque calcification and osteoclast parameters in apoE(-/-) mice.

CONCLUSION

ApoE deficiency is associated with an increase in bone mass and volumetric mineral density in 20 week-old female mice. Bone mass is further increased, whereas bone mineral density is decreased, in response to CRF in association with histological features of osteitis fibrosa. Finally, our findings of correlations between changes in bone and aortic lesions in apoE(-/-) mice, are compatible with the hypothesis of a link between bone and vascular disease and require further study.

The role of adiponectin in the pathogenesis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD. Adiponectin is the most abundant and adipose-specific adipokine. In the liver, adiponectin acts through the activation of 5-AMP-activated protein kinase and peroxisome proliferator-activated receptor-alpha pathways and inhibition of toll-like receptor-4 mediated signalling. There is an evidence that adiponectin decreases hepatic and systematic IR and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and severity of NAFLD, but it remains to be addressed to what extent this is a direct effect or related to the presence of more severe IR. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. Weight loss, through diet, lifestyle changes and/or medications including orlistat, sibutramine, rimonabant or bariatric surgery, increase adiponectin and may improve liver histology. Insulin sensitizers, including pioglitazone and rosiglitazone, and lipid-lowering agents, including statins and fibrates, also upregulate adiponectin and ameliorate liver histology. The wider use of new treatment approaches appears to signal the dawn of a new era in the management of NAFLD. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are systematically analysed.

Visceral Adiposity, Insulin Resistance, and Type 2 Diabetes

The worldwide prevalence of obesity and obesity-related diseases continues to rise. Insulin resistance, the metabolic syndrome, and type 2 diabetes are all associated with obesity. Visceral fat is now recognized to have metabolic, endocrine, and immune functions; increased visceral adiposity enhances the risk of metabolic and cardiovascular disorders. Potential mechanisms of this increased risk may include increased free fatty acid release and alterations in adipokines. Lifestyle interventions resulting in weight loss and loss of visceral fat can have a significant impact on cardiometabolic risk. Bariatric surgery has also been shown to improve insulin resistance, type 2 diabetes, and other comorbidities of obesity. Several medical therapies for type 2 diabetes or obesity also show promise for an impact on visceral adiposity-related comorbidities.

Epicardial adipose tissue and coronary artery plaque characteristics

OBJECTIVE

Epicardial adipose tissue (EAT) has been implicated in the pathogenesis of coronary atherosclerosis. The association of EAT volume with type of coronary artery plaque on computed tomography angiography (CTA) is not known.

METHODS

Coronary artery calcium (CAC) scoring and EAT volume measurement were performed on 214 consecutive patients (mean age 54+/-14 years) referred for coronary CTA. CAC was performed on non-contrast images, while EAT volume, the severity of luminal stenoses, and plaque characterization were assessed using contrast-enhanced CTA images. EAT volume was also indexed to body surface area (EAT-i).

RESULTS

EAT volume correlated with age, height, body mass index (BMI), and CAC score. EAT volume increased significantly with the severity of luminal stenosis (p<0.001), and in patients with no plaques, calcified, mixed, and non-calcified plaques (62+/-33mL, 63+/-22mL, 98+/-47mL, and 99+/-36mL, respectively, p<0.001). The EAT volume was significantly larger in patients with mixed or non-calcified plaques compared to patients with calcified plaques or no plaques (all p<0.01 or smaller). The trend remained significant after adjustment for traditional risk factors for coronary artery disease. In adjusted models EAT was an independent predictor of CAC [exp(B)=3.916, p<0.05], atherosclerotic plaques of any type [exp(B)=4.532, p<0.01], non-calcified plaques [exp(B)=3.849, p<0.01], and obstructive CAD [exp(B)=3.824, p<0.05]. The above results were unchanged after replacing EAT with EAT-i.

CONCLUSION

EAT volume was larger in the presence of obstructive CAD and non-calcified plaques. These data suggest that EAT is associated with the development of coronary atherosclerosis and potentially the most dangerous types of plaques.

MMP-1 serum levels predict coronary atherosclerosis in humans

Background

Myocardial infarction results as a consequence of atherosclerotic plaque rupture, with plaque stability largely depending on the lesion forming extracellular matrix components. Lipid enriched non-calcified lesions are considered more instable and rupture prone than calcified lesions. Matrix metalloproteinases (MMPs) are extracellular matrix degrading enzymes with plaque destabilisating characteristics which have been implicated in atherogenesis. We therefore hypothesised MMP-1 and MMP-9 serum levels to be associated with non-calcified lesions as determined by CT-angiography in patients with coronary artery disease.

Methods

260 patients with typical or atypical chest pain underwent dual-source multi-slice CT-angiography (0.6-mm collimation, 330-ms gantry rotation time) to exclude coronary artery stenosis. Atherosclerotic plaques were classified as calcified, mixed or non-calcified.

Results

In multivariable regession analysis, MMP-1 serum levels were associated with total plaque burden (OR: 1.37 (CI: 1.02-1.85); p < 0.05) in a model adjusted for age, sex, BMI, classical cardiovascular risk factors, hsCRP, adiponectin, pericardial fat volume and medication. Specification of plaque morphology revealed significant association of MMP-1 serum levels with non-calcified plaques (OR: 1.16 (CI: 1.0-1.34); p = 0.05) and calcified plaques (OR: 1.22 (CI: 1,03-1.45); p < 0.05) while association with mixed plaques was lost in the fully adjusted model. No associations were found between MMP9 serum levels and total plaque burden or plaque morphology.

Conclusion

MMP-1 serum levels are associated with total plaque burden but do not allow a specification of plaque morphology.