Adiponectin levels in patients with intracranial atherosclerosis

Associations of Abdominal Visceral Fat Content and Plasma Adiponectin Level With Intracranial Atherosclerotic Stenosis: A Cross-Sectional Study

Background

Abdominal obesity and adipocytokines are closely related to atherosclerosis, and adiponectin level is considered one of the important clinical indicators. This study aimed to analyze the associations of abdominal visceral fat content and adiponectin level with intracranial atherosclerotic stenosis (ICAS).

Methods

A total of 186 patients were enrolled in this study. Patients were distributed into ICAS and non-ICAS by the degree of artery stenosis. Plasma adiponectin levels and the ratio of visceral adipose tissue (VAT) to subcutaneous adipose tissue (SAT) were measured. The related factors of intracranial atherosclerotic stenosis were determined using multivariable logistic regression analysis.

Results

The VAT/SAT ratio (OR, 26.08; 95% CI, 5.92–114.83; p < 0.001) and adiponectin (OR, 0.61; 95% CI, 0.44–0.84; p = 0.002) were found to be the independent predictors of ICAS in a multivariable logistic regression analysis. The prevalence of ICAS increased (T1: 27.4%; T2: 50.0%; T3: 75.8%) as the VAT/SAT ratio tertile increased (p < 0.001). The prevalence of ICAS decreased (T1: 72.6%; T2: 54.8%; T3: 25.8%) as the adiponectin tertile increased (p < 0.001). In ROC curves analysis, VAT/SAT ratio had a sensible accuracy for the prediction of ICAS. The optimal cut-off value of VAT/SAT ratio to predict ICAS in this study was 1.04 (AUC: 0.747; p < 0.001; sensitivity: 67.4%; specificity: 74.7%). The optimal adiponectin cutoff was 3.03 ug/ml (AUC: 0.716; p < 0.001; sensitivity:75.8%; specificity: 61.5%).

Conclusion

Higher VAT/SAT ratio and lower plasma adiponectin levels were closely related to the increased risk of intracranial atherosclerotic stenosis.

Exercise and Stroke

Stroke is a leading cause of mortality and morbidity all around the world. Identification of stroke risk factors and protective lifestyles is necessary for optimizing personalized treatment and reducing mortality. Sedentary lifestyle is a well-known modifiable risk factor in primary and secondary stroke prevention. Also, in recent years, exercise has been described as a neuroprotective and neuroreparative factor. Here we summarized the existing available evidence of the relationship between physical activity and stroke.

Diagnostic Significance of Plasma Levels of Novel Adipokines in Patients With Symptomatic Intra- and Extracranial Atherosclerotic Stenosis

Background: Adipokines have been proven to be associated with atherosclerotic diseases such as ischemic stroke and coronary heart disease. The role of novel adipokines in the development of symptomatic intracranial atherosclerotic stenosis (sICAS) and extracranial atherosclerotic stenosis (sECAS) has not yet been investigated. This study aimed to evaluate the plasma levels of novel adipokines in patients with sICAS and sECAS and their associations with the prognosis of sICAS groups.

Methods: A total of 134 patients with acute ischemic stroke attribute to large-artery atherosclerosis (LAA) and 66 age- and sex-matched controls without atherosclerotic stenosis (NCAS) were included in this study. The LAA group was further sub-classified as sICAS (n = 102) and sECAS (n = 32) according to the location of atherosclerosis. Demographics, clinical parameters, angiographical features and plasma levels of novel adipokines (apelin, visfatin, omentin, RBP-4) were assayed and compared among groups.

Results: LAA patients had significantly lower levels of omentin [39.92 (30.74–52.61) ng/ml vs. 54.42 (34.73–79.91) ng/ml, P < 0.001] and visfatin [11.32 (7.62–16.44) ng/ml vs. 13.01 (9.46–27.54) ng/ml, P < 0.001] than those in the NCAS group. Multiple logistic regression analysis identified that the lowest tertile of omentin was independently associated with LAA (OR, 3.423; 95% CI, 1.267–9.244, when referenced to the third tertile). Levels of omentin, visfatin and RBP-4 showed no significant difference between sICAS and sECAS groups. However, median concentrations of apelin were lower in sECAS [84.94 (46.88–130.41) ng/mL) than in sICAS [118.64 (93.22–145.08) ng/mL, P = 0.002] and NCAS [114.38 (80.56–162.93) ng/mL, P = 0.004]. Logistic regression analysis showed that the lowermost tertile of apelin was independently associated with sECAS (OR, 5.121; 95% CI, 1.597–16.426) when adjusted for risk factors. As for sICAS patients, spearman coefficient analysis showed no significant correlation between these four adipokines and the severity of sICAS or the number of vessels with intracranial stenoses. Patients with severe stroke had lower levels of apelin (P = 0.005), while the other three adipokines showed no such difference. During follow up, no difference was found between these four novel adipokines and short- and long-term outcome of sICAS.

Conclusions: Lower levels of omentin are independent biomarkers of LAA while low apelin plasma levels seem to be risk factors of sECAS.

Blood Biomarkers for Stroke Diagnosis and Management

Biomarkers are objective indicators used to assess normal or pathological processes, evaluate responses to treatment and predict outcomes. Many blood biomarkers already guide decision-making in clinical practice. In stroke, the number of candidate biomarkers is constantly increasing. These biomarkers include proteins, ribonucleic acids, lipids or metabolites. Although biomarkers have the potential to improve the diagnosis and the management of patients with stroke, there is currently no marker that has demonstrated sufficient sensitivity, specificity, rapidity, precision, and cost-effectiveness to be used in the routine management of stroke, thus highlighting the need for additional work. A better standardization of clinical, laboratory and statistical procedures between centers is indispensable to optimize biomarker performance. This review focuses on blood biomarkers that have shown promise for translation into clinical practice and describes some newly reported markers that could add to routine stroke care. Avenues for the discovery of new stroke biomarkers and future research are discussed. The description of the biomarkers is organized according to their expected application in clinical practice: diagnosis, treatment decision, and outcome prediction.

Intracranial atherosclerotic disease

Intracranial atherosclerosis (ICAS) is a progressive pathological process that causes progressive stenosis and cerebral hypoperfusion and is a major cause of stroke occurrence and recurrence around the world. Multiple factors contribute to the development of ICAS. Angiography imaging techniques can improve the diagnosis of and the selection of appropriate treatment regimens for ICAS. Neither aggressive medication nor endovascular interventions can eradicate stroke recurrence in patients with ICAS. Non-pharmacological therapies such as remote ischemic conditioning and hypothermia are emerging. Comprehensive therapy with medication in combination with endovascular intervention and/or non-pharmacological treatment may be a potential strategy for ICAS treatment in the future. We summarized the epidemiology, pathophysiological mechanisms, risk factors, biomarkers, imaging and management of ICAS.

Adipokines in neurovascular diseases

Adipose tissue is now described as an endocrine organ secreting a number of adipokines contributing to the development of inflammation and metabolic imbalance, but also endothelial dysfunction, vascular remodeling, atherosclerosis, and ischemic stroke. Leptin, adiponectin, and resistin are the most studied adipokines which play important roles in the regulation of cardiovascular homeostasis. Leptin and adiponectin mediate both proatherogenic and antiatherogenic responses. Leptin and adiponectin have been linked to the development of coronary heart disease and may be involved in the underlying biological mechanism of ischemic stroke. Resistin, a pro-inflammatory cytokine, is predictive of atherosclerosis and poor clinical outcomes in patients with coronary artery disease and ischemic stroke. The changes in serum levels of novel adipokines apelin, visfatin are also associated with acute ischemic stroke. These adipokines have been proposed as potential prognostic biomarkers of cardiovascular mortality/morbidity and therapeutic targets in patients with cardiometabolic diseases. In this article, we summarize the biologic role of the adipokines and discuss the link between dysfunctional adipose tissue and metabolic/inflammation imbalance, consequently endothelial damage, progression of atherosclerotic disease, and the occurrence of ischemic stroke.

Visceral adiposity index, lipid accumulation product and intracranial atherosclerotic stenosis in middle-aged and elderly Chinese

We investigated the association of the newly established lipid accumulation product (LAP) and visceral adiposity index (VAI) with intracranial atherosclerotic stenosis (ICAS) in middle-aged and elderly Chinese. From June 2012 to January 2013, consecutive patients ≥40 years of age who underwent cerebral vascular imaging for various medical reasons were enrolled in this study. Multivariate logistic regression models were used to evaluate the correlation of VAI and LAP with the risk of ICAS. In total, 845 patients were included in the study. The prevalence of ICAS gradually increased in females and in all patients with advancing tertiles of VAI or LAP. After adjusting for potential risks, both the VAI and LAP were related to ICAS in females [VAI: odds ratio (OR) = 3.25, 95% confidence interval (95%CI) = 1.17–9.03, P = 0.024; LAP: OR = 4.11, 95%CI = 1.39–12.12, P = 0.011; tertiles 3 vs. 1]. The sensitivity, specificity, and positive predictive value (PPV) were 74.7%, 45.5%, and 84.4% for VAI (cut-off: 1.71) and 79.3%, 40.5%, and 84.1% for LAP (cut-off: 23.99). The same relationships in males were not significant. Both VAI and LAP were closely associated with an increased risk of ICAS in middle-aged and elderly Chinese females.

Stroke Caused by Atherosclerosis of the Major Intracranial Arteries

Our goal in this review is to discuss the pathophysiology, diagnosis, and treatment of stroke caused by atherosclerosis of the major intracranial arteries. References for the review were identified by searching PubMed for related studies published from 1955 to June 2016 using search terms intracranial stenosis and intracranial atherosclerosis. Reference sections of published randomized clinical trials and previously published reviews were searched for additional references. Intracranial atherosclerotic disease is a highly prevalent cause of stroke that is associated with a high risk of recurrent stroke. It is more prevalent among blacks, Hispanics, and Asians compared with whites. Diabetes mellitus, hypertension, metabolic syndrome, smoking, hyperlipidemia, and a sedentary lifestyle are the major modifiable risk factors associated with intracranial atherosclerotic disease. Randomized clinical trials comparing aggressive management (dual antiplatelet treatment for 90 days followed by aspirin monotherapy and intensive management of vascular risk factors) with intracranial stenting plus aggressive medical management have shown medical management alone to be safer and more effective for preventing stroke. As such, aggressive medical management has become the standard of care for symptomatic patients with intracranial atherosclerotic disease. Nevertheless, there are subgroups of patients who are still at high risk of stroke despite being treated with aggressive medical management. Future research should aim to establish clinical, serological, and imaging biomarkers to identify high-risk patients, and clinical trials evaluating novel therapies should be focused on these patients.

Cerebrovascular Disease: Consequences of Obesity-Induced Endothelial Dysfunction

Despite the well-known global impact of overweight and obesity in the incidence of cerebrovascular disease, many aspects of this association are still inconsistently defined. In this chapter we aim to present a critical review on the links between obesity and both ischemic and hemorrhagic stroke and discuss its influence on functional outcomes, survival, and current treatments to acute and chronic stroke. The role of cerebrovascular endothelial function and respective modulation is also described as well as its laboratory and clinical assessment. In this context, the major contributing mechanisms underlying obesity-induced cerebral endothelial function (adipokine secretion, insulin resistance, inflammation, and hypertension) are discussed. A special emphasis is given to the participation of adipokines in the pathophysiology of stroke, namely adiponectin, leptin, resistin, apelin, and visfatin.

Location of cerebral atherosclerosis: Why is there a difference between East and West?

Intracranial atherosclerosis is more prevalent in Asian patients, whereas extracranial atherosclerosis is more common in individuals from western countries. The reasons for this discrepancy remain unknown. We reviewed the relevant literature and discussed the currently available information. Although the study population, diagnostic modality, and risk factor definitions differ between studies, hypercholesterolemia is more correlated with extracranial atherosclerosis than intracranial atherosclerosis. The difference in hypercholesterolemia prevalence is one of the main reasons for racial differences. Intracranial arteries contain higher antioxidant level than extracranial arteries and may be more vulnerable to risk factors for antioxidant depletion (e.g., metabolic syndrome and diabetes mellitus). Intracranial arteries may be vulnerable to factors associated with hemodynamic stress (e.g., advanced, salt-retaining hypertension and arterial tortuosity) because of a smaller diameter, thinner media and adventitia, and fewer elastic medial fibers than extracranial arteries. Additionally, non-atherosclerotic arterial diseases (e.g., moyamoya disease) that commonly occur in the intracranial arteries of East Asians may contaminate the reports of intracranial atherosclerosis cases. Genes, including RNF 213 or those associated with high salt sensitivity, may also explain racial differences in atherosclerotic location. To understand racial differences, further well-designed studies on various risk and genetic factors should be performed in patients with cerebral atherosclerosis. Additionally, improvements in diagnostic accuracy via advancements in imaging technologies and increased genetic data will aid in the differentiation of atherosclerosis from non-atherosclerotic intracranial diseases.

The Diagnostic Role of Adiponectin in Pulmonary Embolism

Background and Aims. Pulmonary thromboembolism (PTE) is a frequent disease with difficult diagnosis and high mortality. Misdiagnosis occurs in 2/3 patients and mortality rates reach up to 30%. The aim of our study was to investigate the role of adiponectin used in emergency service in diagnosis of PTE. Materials and Methods. 95 patients with suspected PTE included in the study. Plasma adiponectin and D-dimer levels were measured and chest X-ray and multidetector row computed tomography scan obtained. Diagnosis was supported by vascular filling defect on tomography. Control group consisted of patients with suspected PTE and normal chest computed tomography findings. Results. Mean D-dimer level was 4241.66 ± 1082.98 ng/mL in patients and 2211.21 ± 1765.53 ng/mL in the control group (p ≤ 0.05). Mean adiponectin level was 5.46 ± 4.39 μg/mL in patients and 7.68 ± 4.67 μg/mL in the control group (p ≤ 0.05). Wells and Geneva scores were higher in patients compared to the control group. Conclusions. As a result, we conclude that lower adiponectin levels have an important role in the diagnosis of PTE.

Higher Levels of Cystatin C Are Associated with Extracranial Carotid Artery Steno-Occlusive Disease in Patients with Noncardioembolic Ischemic Stroke

Background

Large artery atherosclerosis is a major cause of ischemic stroke worldwide. Differential biomarker profiles associated with extra- and intracranial atherosclerosis are a topic of considerable interest. Cystatin C (CysC), a marker of renal function, is a risk factor for cardiovascular disease.

Aim

We sought to determine whether CysC levels were associated with extra- and intracranial large artery stenosis (LAS) in patients with acute ischemic stroke.

Methods

We retrospectively analyzed data of acute noncardioembolic ischemic stroke patients who were admitted to our stroke center within 5 days from symptom onset. Serum CysC levels were measured using latex agglutination turbidimetric immunoassay. Extra- and intracranial LAS were defined as ≥50% diameter stenosis or occlusion of the relevant internal carotid artery (ICA) and/or middle cerebral artery (MCA) using carotid echography and volume rendering on magnetic resonance angiography. Multivariate logistic analyses were used to assess the association between CysC levels and LAS after adjustment for potential confounders.

Results

Of 205 patients (mean age 70.2 years), 76 (37.1%) had LAS. The distribution of LAS was 29 extracranial ICA, 34 intracranial ICA/MCA (8 ICA only, 25 MCA only, 1 ICA+MCA) and 13 tandem stenosis (both extracranial ICA and intracranial ICA/MCA). Levels of CysC were higher in patients with extracranial ICA stenosis than in those with intracranial ICA/MCA stenosis (1.23 ± 0.33 vs. 0.97 ± 0.21 mg/l, p < 0.001). In multivariate analysis, the highest CysC tertile (>1.04 mg/l) was significantly associated with extracranial ICA stenosis (adjusted odds ratio [OR] 5.01, 95% confidence interval [CI] 1.51-16.63, p = 0.009) after adjustment for age, sex, diabetes, chronic kidney disease, current smoking, systolic blood pressure, HDL cholesterol, high-sensitivity C-reactive protein (hs-CRP) and premorbid lipid-lowering drugs use. When CysC was considered as a continuous variable, 1 SD increase in CysC was significantly associated with extracranial ICA stenosis (adjusted OR 3.01, 95% CI 1.58-5.72, p = 0.001). However, there were no significant associations between CysC levels and intracranial ICA/MCA stenosis. In addition, CysC levels showed a weak but statistically significant correlation with hs-CRP levels (r = 0.195, p = 0.021). Using receiver operating characteristic curve analysis, CysC value displayed good performance in discriminating extracranial ICA stenosis (c-statistic 0.79, 95% CI 0.69-0.89, p < 0.001).

Conclusions

This preliminary study suggests that higher levels of CysC were independently associated with symptomatic extracranial ICA stenosis, but not with intracranial ICA/MCA stenosis in patients with noncardioembolic stroke. Our findings provide new insights into the link between serum CysC and carotid atherosclerosis.

Brain microangiopathy and macroangiopathy share common risk factors and biomarkers

AIMS

Besides carotid or cardiac embolism, stroke can occur via microangiopathy (small arterial disease [SAD]) and macroangiopathy (intracranial atherosclerotic stroke [ICAS]) of the intracranial vasculature. There have been efforts to identify risk factors specific to microangiopathy and macroangiopathy, including vascular risk factors, and protein and genetic biomarkers. We hypothesized that despite the anatomic and pathophysiological differences between microvessels and macrovessels, microangiopathy and macroangiopathy share common risk factors during disease progression.

METHODS

Among 714 patients with acute infarctions within middle cerebral artery territory, 126 with SAD and 116 with ICAS were included in this study. Subclinical microangiopathy (degree of leukoaraiosis) and macroangiopathy (number of tandem stenosis) was graded in each patient. Inflammatory biomarkers (C-reactive protein, E-selectin, and LpPLA2), endothelial dysfunction (asymmetric dimethylarginine, urinary albumin-to-creatinine ratio, endostatin, and homocysteine), atherogenesis (lipoprotein(a), adiponectin, and resistin), and renal function (creatinine clearance and estimated glomerular filtration rate) were assessed.

RESULTS

Compared with the patients with isolated SAD, those with isolated ICAS were younger, were current smokers, and showed higher apoB levels (p < 0.05 in all cases). However, with the progression of subclinical microangiopathy, asymptomatic macroangiopathy worsened and vice versa. No significant differences in risk factors were observed between advanced SAD and ICAS. Decreased renal function was independently associated with progression of microangiopathy and macroangiopathy. Markers of endothelial dysfunction, but not the other markers, were significantly related to creatinine clearance level.

CONCLUSIONS

Mild to moderate loss of renal function is strongly associated with both intracranial microangiopathy and macroangiopathy. Endothelial dysfunction may be associated with this relationship.

The Intricate Network of Adipokines and Stroke

Cerebrovascular disorders, particularly ischemic stroke, are one of the most common neurological disorders. High rates of overweight and obesity support an interest in the role of adipose tissue and adipose tissue releasing cytokines in inducing associated comorbidities. Adipokines can serve as a key messenger to central energy homeostasis and metabolic homeostasis. They can contribute to the crosstalk between adipose tissue and brain. However recent research has offered ambiguous data on the network of adipose tissue, adipokines, and vascular disorders. In our paper we provide a critical insight into the role of adipokines in evolution of ischemic stroke.

Intracranial atherosclerosis: current understanding and perspectives

The importance of intracranial atherosclerotic disease (ICAD) as a cause of stroke is underscored as compared to that of extracranial carotid stenosis and nonvalvular atrial fibrillation. Recent large clinical trials of ICAD, which evaluated the effectiveness of anticoagulation and stenting to prevent thromboembolism and restore hemodynamic compromise, failed to reduce major vascular events in patients with ICAD. These trials showed the importance of optimal control of risk factors to reduce major vascular events in these patients. Recent advances in risk factors for ICAD are summarized, together with possible reasons for race-ethnic differences in the prevalence of ICAD. In addition, the failure of the major clinical trials of ICAD may be caused by limitations in the understanding of ICAD. Unlike in patients with extracranial carotid stenosis or atrial fibrillation, stroke associated with ICAD occurs in association with various stroke mechanisms such as in situ thrombotic occlusion, artery-to-artery embolism, hemodynamic insufficiency, and branch occlusion. In clinical trials of ICAD, patients with all these types of ICAD were included. However, treatment effects may differ among the different types of ICAD. Treatment strategies might be selected based on clinical features (including the time after onset) and serologic and neuroimaging biomarkers (including diffusion-weighted image pattern and plaque images). Additional clinical trials considering these features are needed.

Atherosclerotic intracranial arterial stenosis: risk factors, diagnosis, and treatment

Intracranial atherosclerosis is one of the most common causes of stroke worldwide and is associated with a high risk of recurrent stroke. New therapeutic approaches to treat this high-risk disease include dual antiplatelet treatment, intensive management of risk factors, and endovascular therapy. Early data from randomised trials indicate that aggressive medical therapy is better than stenting for prevention of recurrent stroke in high-risk patients with atherosclerotic stenosis of a major intracranial artery. Nevertheless, there are subgroups of patients who remain at high risk of stroke despite aggressive medical therapy. Further research is needed to identify these high-risk subgroups and to develop more effective treatments. Non-invasive vascular imaging methods that could be used to identify high-risk patients include fractional flow on magnetic resonance angiography (MRA), quantitative MRA, and high-resolution MRI of the atherosclerotic plaque. Alternative therapies to consider for future clinical trials include angioplasty alone, indirect surgical bypass procedures, ischaemic preconditioning, and new anticoagulants (direct thrombin or Xa inhibitors).

The role of adiponectin in secondary inflammatory reaction in cerebral ischemia

Objective

In this study, we investigate the role of adiponectin in the interaction between leukocytes and endothelium in the secondary inflammatory reaction of cerebral ischemia.

Methods

Adiponectin knock-out mice group (APN-KO) (n = 8) and wild-type mice group (WT) (n = 8) were prepared. Each group was sub-divided into 2 groups by reperfusion time. One-hour middle cerebral artery occlusion and reperfusion were induced using the intraluminal filament technique. At 6 and 12 hours after the occlusion, the mice were placed on a stereotactic frame to perform craniotomy in the left parietal area. After craniotomy, a straight pial venule was selected as a target vessel. With the fluorescence intravital microscope, the number of rolling leukocytes and leukocytes that adhered to endothelium were counted and documented at 6 and 12 hours after the reperfusion.

Results

At 6 and 12 hours after the reperfusion, more rolling leukocyte and leukocyte adhesion were observed in the APN-KO mice than in the WT mice. The difference in leukocyte numbers between the APN-KO and WT mice was found to be statistically significant (p = 0.029) by Mann-Whitney U-test.

Conclusion

We found that adiponectin inhibits the interaction between the endothelium and leukocytes in cerebral ischemia-reperfusion. Therefore adiponectin might prevent the secondary insult caused by the inflammation reaction.

Biomarkers for stroke

Background

Major stroke clinical trials have failed during the past decades. The failures suggest the presence of heterogeneity among stroke patients. Biomarkers refer to indicators found in the blood, other body fluids or tissues that predicts physiologic or disease states, increased disease risk, or pharmacologic responses to a therapeutic intervention. Stroke biomarkers could be used as a guiding tool for more effective personalized therapy.

Main Contents

Three aspects of stroke biomarkers are explored in detail. First, the possible role of biomarkers in patients with stroke is discussed. Second, the limitations of conventional biomarkers (especially protein biomarkers) in the area of stroke research are presented with the reasons. Lastly, various types of biomarkers including traditional and novel genetic, microvesicle, and metabolomics-associated biomarkers are introduced with their advantages and disadvantages. We especially focus on the importance of comprehensive approaches using a variety of stroke biomarkers.

Conclusion

Although biomarkers are not recommended in practice guidelines for use in the diagnosis or treatment of stroke, many efforts have been made to overcome the limitations of biomarkers. The studies reviewed herein suggest that comprehensive analysis of different types of stroke biomarkers will improve the understanding of individual pathophysiologies and further promote the development of screening tools for of high-risk patients, and predicting models of stroke outcome and rational stroke therapy tailored to the characteristics of each case.

Serum adiponectin in relation to race-ethnicity and vascular risk factors in the Northern Manhattan Study

BACKGROUND

Population-based data on serum adiponectin levels, an adipocytokine secreted from adipose tissue, are lacking, particularly across race-ethnic groups. Studies have suggested an inverse association between adiponectin and vascular risk factors, but data are limited and inconsistent. We examined the cross-sectional association between adiponectin, vascular risk factors and race-ethnicity in the population-based Northern Manhattan Study (NOMAS).

METHODS

Blood samples, anthropomorphics, and vascular risk factors were collected at baseline. Multivariable linear regression analysis was conducted with log-transformed adiponectin as the dependent variable.

RESULTS

Adiponectin was measured among 2900 participants (age 69±10 years, body mass index (BMI) 28.0±5.6, 37% male, 21% white, 53% Hispanic, 24% black). The mean adiponectin was 11.4±6.2 μg/mL (median=9.8, range=2.1-53.3). After multivariable adjustment, adiponectin levels were greatest among whites, followed by Hispanics, and lowest among blacks. Lower adiponectin levels were observed in participants with the following characteristics: Male, former smoking, hypertension, diabetes, homeostasis model assessment of insulin resistance (HOMA-IR), metabolic syndrome, moderate alcohol use, elevated waist circumference, BMI, estimated glomerular filtration rate (eGFR), triglycerides, low-density lipoprotein cholesterol (LDL-C), lower high-density lipoprotein cholesterol (HDL-C), and younger age. Obesity was a stronger risk factor for decreased adiponectin among blacks than among whites or Hispanics. The associations for several vascular risk factors, including hypertension, triglycerides, and low HDL-C, with low adiponectin were stronger among individuals who were not obese than among those who were obese.

CONCLUSIONS

Adiponectin levels were lower among blacks and Hispanics and among those with various vascular risk factors, and greater with older age. The association between BMI and adiponectin varied across race-ethnic groups. Investigation of whether differences in body fat distribution may explain race-ethnic differences in adiponectin is needed.

Overexpression of adiponectin promotes focal angiogenesis in the mouse brain following middle cerebral artery occlusion

Recent studies indicate that overexpression of adiponectin (APN) could attenuate ischemic brain injury. However, the mechanism of APN effect remains unclear. In this study, we investigated the cellular mechanisms of APN action during cerebral ischemia. Adult mice (n=120) received an intracerebral injection of adeno-associated viral vector carrying the APN gene (AAV-APN). The mice were subjected to a transient ispilateral middle cerebral artery occlusion (tMCAO) after 7-day AAV-APN gene transfer. Cortical atrophy volume, neurological function, microvessels counts, phospho-AMPK and downstream angiogenic factor vascular endothelial growth factor (VEGF) were examined. Overexpression of APN was observed in the mouse brain following AAV-APN gene transfer. Cortical atrophy volume was attenuated in the AAV-APN-transduced mice compared with the AAV-GFP and saline-treated mice (7.9 ± 0.6%, 19.8 ± 0.3% and 20.3 ± 1.1%, respectively, P<0.05), with significant improvement in neurological function and an increased number of microvessels (199 ± 5 vs 151 ± 4 and 148 ± 4 mm(-2), P<0.01). Furthermore, the expression of phospho-AMPK and VEGF were increased in the AAV-APN-transduced compared with the control mice (P<0.01), whereas inhibiting phospho-AMPK, reducing VEGF expression and attenuating the effect of APN on brain atrophy and angiogenesis (P<0.01). APN overexpression attenuates ischemia-induced brain atrophy and has improvement in neurological function. The consequence is related to promotion of focal angiogenesis. The AMPK signaling pathway has an important role in upregulating angiogenic factor VEGF.

Adipocytokines and ischemic stroke: differential associations between stroke subtypes

OBJECTIVE

Experimental studies have indicated that adipocytokines are associated with vascular diseases with regard to the pathology of atherosclerotic plaque. We hypothesized that the strength of the associations between adipocytokines and stroke would differ between ischemic stroke subtypes.

METHODS

A total of 96 acute ischemic stroke patients (within 5 days from onset) and 48 non-stroke subjects were analyzed in this study. Stroke patients were comprised of 26 strokes due to large artery atherosclerosis (LAA) and 72 non-LAA strokes. Venous blood from all participants was drawn after an overnight fast, and serum levels of leptin, adiponectin and resistin were measured by multiple sandwich immunoassay techniques.

RESULTS

Compared with non-LAA strokes, patients with LAA strokes had lower levels of serum adiponectin (6.4 ± 3.1 vs. 8.5 ± 3.9 μg/mL; P=0.04), and a higher level of leptin-to-adiponectin ratio (L:A ratio; 1.6 ± 1.4 vs. 0.9 ± 0.9; P<0.01). Multinomial logistic regression analyses showed that, although none of the adipocytokines was associated with non-LAA strokes, lower adiponectin (adjusted OR, 0.79 per 1-μg/mL increase; 95% CI, 0.64-0.98), higher leptin (aOR, 1.12 per 1-ng/mL increase; 95% CI, 1.004-1.25) and higher L:A ratio (aOR, 2.93 per 1-quartile increase; 95% CI, 1.39-6.15) showed significant associations with increased odds of having LAA stroke, compared to non-stroke subjects.

CONCLUSION

From our study, we documented that leptin and adiponectin had differential association patterns with ischemic stroke according to the stroke subtype. Careful consideration of the heterogeneity of stroke subtypes would be warranted in studying the utility of biomarkers including adipocytokines.

High level of plasma adiponectin in acute stroke patients is associated with stroke mortality

We examined the association between plasma adiponectin (ADPN) levels and cardiovascular mortality in acute stroke patients. We enrolled 552 consecutive acute stroke patients. Measurements were made at baseline and the patients were followed prospectively. The primary endpoint was cardiovascular (stroke or ischemic heart disease) death and the secondary endpoint was all-cause death. During the median follow-up period of 17 months, 39 patients died, 15 being due to stroke. No patients died of ischemic heart disease. After adjustment for age, sex, presence of hypertension, diabetes mellitus, and hyperlipidemia, the highest tertile of ADPN level (>11.7 μg/ml) was associated with stroke mortality (hazard ratio: 6.55, 95% confidence interval: 1.73-24.8), but not with all-cause mortality (hazard ratio: 1.89, 95% confidence interval: 0.95-3.77). High levels of plasma ADPN can be a predictor of stroke mortality during the 17 months following an episode of acute stroke in patients.

[Intracranial atherosclerosis]

Until recently, intracranial atheromatosis was a probably underdiagnosed clinicopathological entity that was rarely studied in depth. In the last years the advance and expansion in the use of non-invasive diagnostic tools have led intracranial atheromatosis to the front page among the most prevalent causes of stroke worldwide. Important efforts have been accomplished with the aim of identifying markers of poor outcome, which, besides the underlying mechanisms of cerebral ischemia in these patients, are the most important factors on which clinical and therapeutic decisions should be based. To date, the therapeutic armamentarium is scarce and far from optimun, regarding medical and endovascular measures. In this review we address the most important aspects of the natural history and cure treatment of intracranial atheromatosis.

Expression of adipokines in preimplantation rabbit and mice embryos

Recent studies point to a role for adipokines in reproduction. Leptin is involved in embryo metabolism and may participate in embryo-maternal crosstalk. Little is known about potential roles of other adipokines in reproduction. We therefore studied the expression of adiponectin and pathway members during the pre- and periimplantation period in rabbits and mice. Adiponectin protein is localized in glandular epithelium of the rabbit endometrium on day 6 and 8 p.c. and in mouse endometrium on day 3.5 and 5 p.c. Rabbit, but not mice blastocysts express adiponectin mRNA. Adiponectin receptors one and two, adiponectin paralogues and PPARs were found in both species. Both, trophoblast and embryoblast were adiponectin positive. Real time PCR for adipoR1 and adipoR2 in rabbit blastocysts of different gastrulation stages at day 6 p.c. revealed a specific switch in expression: Expression was high in the trophoblast in early stages and in the embryoblast shortly prior to implantation. In conclusion, during the pre- and periimplantation period, members of the adiponectin pathway are expressed in endometrium and blastocysts, with a specific expression pattern in the embryonic disk of the gastrulating rabbit blastocyst, giving support to a role of the adipokine network in blastocyst differentiation and embryo-maternal interactions.