Association of high alpha2-Heremans–Schmid glycoprotein/fetuin concentration in serum and intima-media thickness in patients with atherosclerotic vascular disease and low bone mass

Role of Fetuin-A in the Pathogenesis of Psoriasis and Its Potential Clinical Applications

Fetuin-A is a plasma glycoprotein exhibiting multifaceted physiological and pathological functions. It has been determined to be involved in various essential biological functions, such as regulation of calcium metabolism, osteogenesis, and insulin signaling pathway. It also plays a crucial role in the pathogenesis of several disorders, including psoriasis. Psoriasis is a chronic systemic inflammatory disorder caused by a constellation of environmental, immunogenic, and genetic factors. It has been shown that dysregulation of cytokines mediated immune response is responsible for the development of psoriasis. Several recent publications suggest that dysregulation of fetuin-A correlates with psoriasis disease activities, revealing its putative role in the development of psoriasis. Furthermore, clinical application of fetuin-A as a diagnostic marker, prognostic predictor, and therapeutic target for different clinical conditions is in progress, and some are showing promising outcomes. This review primarily focuses on the current understanding of the role of fetuin-A in the pathogenesis of psoriasis and its potential clinical applications, with a brief highlight of psoriasis epidemiology and burden. The information was gathered systematically from various journals via electronic searches using various search engines: PubMed, Google Scholar, HINARI, and Cochrane Library from inception to 2022. The studies involved were restricted to English language. Conversely, articles written in other languages, studies done on fetuin B, or studies conducted on other dermatological diseases were excluded from the review article.

Serum peptidome: diagnostic window into pathogenic processes following occupational exposure to carbon nanomaterials

BACKGROUND

Growing industrial use of carbon nanotubes and nanofibers (CNT/F) warrants consideration of human health outcomes. CNT/F produces pulmonary, cardiovascular, and other toxic effects in animals along with a significant release of bioactive peptides into the circulation, the augmented serum peptidome. While epidemiology among CNT/F workers reports on few acute symptoms, there remains concern over sub-clinical CNT/F effects that may prime for chronic disease, necessitating sensitive health outcome diagnostic markers for longitudinal follow-up.

METHODS

Here, the serum peptidome was assessed for its biomarker potential in detecting sub-symptomatic pathobiology among CNT/F workers using label-free data-independent mass spectrometry. Studies employed a stratified design between High (> 0.5 µg/m3) and Low (< 0.1 µg/m3) inhalable CNT/F exposures in the industrial setting. Peptide biomarker model building and refinement employed linear regression and partial least squared discriminant analyses. Top-ranked peptides were then sequence identified and evaluated for pathological-relevance.

RESULTS

In total, 41 peptides were found to be highly discriminatory after model building with a strong linear correlation to personal CNT/F exposure. The top-five peptide model offered ideal prediction with high accuracy (Q2 = 0.99916). Unsupervised validation affirmed 43.5% of the serum peptidomic variance was attributable to CNT/F exposure. Peptide sequence identification reveals a predominant association with vascular pathology. ARHGAP21, ADAM15 and PLPP3 peptides suggest heightened cardiovasculature permeability and F13A1, FBN1 and VWDE peptides infer a pro-thrombotic state among High CNT/F workers.

CONCLUSIONS

The serum peptidome affords a diagnostic window into sub-symptomatic pathology among CNT/F exposed workers for longitudinal monitoring of systemic health risks.

Evaluation of the Correlation between the rs4918 Polymorphism of AHSG Gene and Coronary Artery Calcification in Patients with Coronary Artery Disease

Objectives: Fetuin-A is a circulating calcification inhibitor that prevents coronary artery calcification (CAC) by increasing calcium phosphate solubility and inhibiting VSMC differentiation and apoptosis. In this study, we investigated the correlation between rs4918 and CAC in patients with coronary artery disease (CAD). Methods: Forty-two healthy individuals and eighty-one CAD patients were recruited in the present study. The CAC score (CACS) was measured by CT angiography and the genotype analysis of rs4918 single-nucleotide polymorphism SNP was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Results: The CACS was significantly higher in CAD patients compared to healthy individuals (p < 0.001); however, there was no significant difference between the mean CACS in the presence and absence of rs4918 (p = 0.792). The mean calcium score of the left main coronary artery (LMCA) was significantly lower in carriers of the rs4918 allele (p = 0.036). The frequency of rs4918 SNP was almost similar in the control group and CAD patients (p = 0.846). Conclusions: in patients with CAD, we found no significant association between rs4918 SNP and CACS, indicating that carriers of this allele are not at increased risk of developing cardiovascular diseases compared with those without.

Paricalcitol regulatory effect on inflammatory, fibrotic and anticalcificating parameters in renal patiente. Far beyond mineral bone disease regulation

BACKWARD

Cardiovascular events are the major cause of morbidity and mortality in patients with chronic kidney disease (CKD). Inflammation and mineral-bone disorder are pathological conditions that have been associated with an increased cardiovascular risk.

OBJECTIVE

Show paricalcitol regulation overinflammatory, fibrotic and mineral disorder parameters in CKD.

MATERIAL AND METHODS

Prospective Study in 46 CKD stages III-V patients without dialysis patients whith elevated parathormone in which we introduced paricalcitol. We evaluated classic and newest mineral and bone metabolism serum parameters (calcium, phosphorus, parathormone, fibroblast growth factor-23 [FGF-23], Klotho, calcidiol), inflammatory-fibrosis and anticalcifying parameters (interleukin-6 and 10, tumor necrosis factor-a [TNF- α], transforming growth factor-b [TGF-β],bone morphogenic protein-7 [BMP-7] and fetuin-A) for four months.

RESULTS

At the end of study soluble Klotho increased (p=.001), FGF-23 remained stable, calcium and phosphorus levels were not increased, calcidiol increased (p=.010) and PTH decreased (p=.002). Inflammation-fibrosis and calcification parameters showed positive regulation after paricalcitol treatment: interleukin-6 decreased significantly (p=.001) and also TNF-α did (p=.005), on the contrary, interleukin-10 and fetuin-A increased (p=.001 for both). Anti-fibrosis marker BMP-7 increased (p=.001) and TGF-b decreased (p=.001). We did not find significant changes in renal function.

CONCLUSIONS

Paricalcitol treatment might be profitable in regulating inflammatory and anticalcificant parameters, unmodified calcium or phosphorus seric levels and preserving kidney function in renal patients with no dialysis. Our selected parameters could indicate paricalcitol effects in mineral and endothelial disorder related to renal disease.

Association of AHSG gene polymorphisms with serum Fetuin-A levels in individuals with cardiovascular calcification in west of Iran

Fetuin-A (AHSG) is a multifunctional secretory protein and acts as an ectopic valve and artery calcification inhibitor. We assessed the correlation between serum levels of Fetuin-A and both exon 6 (248 C/T) and exon 7 (256 C/G) mutations in patients with coronary artery calcification (CAC), mitral annular calcification (MAC), and aortic valve calcification (AVC). 184 patients and 184 healthy individuals as control group were included. The genetic variants of rs4917 and rs4918 for the AHSG gene were determined by PCR-RFLP and T-ARMS PCR techniques. Fetuin-A levels, fasting blood sugar (FBS), urea, creatinine, calcium phosphorus, and lipid profile were measured. Fetuin-A levels were remarkedly lower in individuals with AVC, MAC, and CAC comparing to the control group (p < 0.001). The CT + TT genotypes and the T allele (AHSG Thr248Met) were associated with the risk of calcification of heart valves and coronary artery by 1.31 and 1.27 times in the patient group, respectively. The frequency of CT genotype and T allele was considerably higher in the patient group comparing to the control group. Patients with T allele (CT + TT) had higher levels of FBS, urea, low-density lipoproteins (LDL)-C, phosphorus, systolic blood pressure (SBP), diastolic blood pressure (DBP) while decreased levels of triglyceride, high-density lipoproteins (HDL)-C, calcium and fetuin-A in comparison to control group. Additionally, there was a positive correlation between serum FBS, urea, creatinine, HDL-C, calcium with fetuin-A, and a negative correlation between phosphorous level, SBP, and DBP with fetuin-A. T allele in rs4917 Single nucleotide polymorphism (SNP) is the risk allele of calcification of heart valves and coronary arteries and fetuin-A levels correlates negatively with the occurrence of the disease.

Clinical implications of fetuin-A

Fetuin-A, also termed alpha2-Heremans-Schmid glycoprotein, is a 46kDa hepatocyte derived protein (hepatokine) and serves multifaceted functions.

The association between fetuin-A and testosterone levels and markers of arterial stiffness in Saudi subjects with type 2 diabetes mellitus

BACKGROUND

Inconsistent results have been described regarding the part of fetuin-A and testosterone in arterial stiffness in type 2 diabetes mellitus (T2DM).

AIM

To look into the links of serum fetuin-A and testosterone levels with brachial-Ankle pulse wave velocity (baPWV), a marker of arteriosclerosis and common carotid intima media thickness (ccIMT), a marker of early atherosclerosis, in diabetic Saudi men patients.

SUBJECTS AND METHODS

One hundred and fifty adult male patients with T2DM and 60 non-diabetic control subjects were enrolled from different Saudi Arabia Taif hospitals. Biochemical analysis, anthropometric measurements, blood pressure, baPWV and ccIMT were investigated.

RESULTS

Stepwise regression in diabetic patients revealed that the most important predictor of ba-PWV was serum fetuin-A followed by serum glucose and the most important predictor of ccIMT was serum fetuin-A followed by serum HDL then serum triglycerides.

CONCLUSIONS

Only fetuin-A levels not testosterone are negatively associated with early markers of atherosclerosis.

Fetuin B links vitamin D deficiency and pediatric obesity: Direct negative regulation by vitamin D

Vitamin D (VD) deficiency (VDD) correlates to obesity, with VD a recognized mediator of metabolic diseases. From a previous proteomic study identifying adiponectin as a link between VDD and pediatric obesity, herein we analysed another protein (SSP2301) increased with VDD. A focused 2D-electrophoretic analysis identified 4 corresponding plasma proteins, with one predicted to be fetuin B (FETUB). FETUB was studied due to its emerging role in metabolic diseases and cytogenetic location (3q27.3) with adiponectin. Results were confirmed in obese children, where plasma FETUB was higher with VDD. A direct effect by 1α,25-(OH)2D3 on hepatocellular FETUB synthesis was observed, with a time and dose dependent reduction. Further, we demonstrated the VD-receptor (VDR) is key, with FETUB "released" with VDR silencing. Finally, VD supplementation (6weeks) to juvenile mice fed a standard diet, reduced plasma FETUB. Only at 22weeks did liver FETUB correspond to plasma FETUB, highlighting the contribution of other VD-responsive tissues. Overall, FETUB is a key protein linking VDD to pediatric obesity. With an emerging role in metabolic diseases, we demonstrate that VD/VDR directly regulate FETUB.

Increased serum levels of fetuin B in patients with coronary artery disease

BACKGROUND

Recent evidence indicates a pivotal role for fetuin B, one of the cystatin superfamily of cysteine protease inhibitors, in the pathogenesis of metabolic diseases. This study investigated whether serum fetuin B levels are associated with the presence of coronary artery disease.

METHODS

Serum fetuin B levels were assessed in 87 patients with coronary artery disease (41 with acute coronary syndromes and 46 with stable angina pectoris) and 87 healthy controls using an enzyme-linked immunosorbent assay. The association of serum fetuin B levels with cardiac risk factors was analyzed.

RESULTS

Serum fetuin B levels were significantly higher in patients with coronary artery disease than those in healthy controls (90.7 ± 32.1 vs. 110.0 ± 32.7 μg/ml, P < 0.001), extremely elevated in group with acute coronary syndromes (115.0 ± 35.2 μg/ml). Pearson correlation analysis showed that serum fetuin B levels were positively associated with the levels of total cholesterol (r = 0.276, P < 0.001), low-density lipoprotein cholesterol (r = 0.363, P < 0.001), and fasting blood glucose (r = 0.159, P < 0.05). In addition, multiple logistic regression analyses revealed that fetuin B was independently associated with the presence of coronary artery disease (OR, 1.019; 95% CI, 1.009 to 1.029; P < 0.001) and acute coronary syndromes (OR, 1.017; 95% CI, 1.006 to 1.028; P < 0.01).

CONCLUSIONS

Our data revealed that high fetuin B levels are associated with the presence of coronary artery disease and acute coronary syndromes, and that fetuin B may serve as a potential biomarker for coronary artery disease.

Serum 25-hydroxyvitamin D is associated with incident peripheral artery disease among white and black adults in the ARIC study cohort

BACKGROUND AND AIMS

Low 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with peripheral artery disease (PAD). Prevalence of low 25(OH)D and PAD differ between whites and blacks. However, these associations have not been studied prospectively or in a population based cohort. We tested the hypothesis that low 25(OH)D is associated with greater risk of incident PAD in white and black adults.

METHODS

25(OH)D was measured in serum collected at ARIC visit 2 (1990-1992). We followed 11,789 ARIC participants free of PAD at visit 2 through 2011 for incident PAD events. 25(OH)D (ng/mL) was categorized as deficient (<20), insufficient (20 to <30) or sufficient (≥30). PAD was defined by an ankle brachial index (ABI) of <0.9 at ARIC visits 3 or 4 or a hospital diagnosis with an ICD-9 code indicating PAD during follow-up. Analysis used multivariable-adjusted Cox proportional hazards regressions.

RESULTS

Over a mean follow-up of 17.1 years, 1250 incident PAD events were identified. 22% of whites and 61% of blacks were 25(OH)D deficient. After adjustment for demographic characteristics, the hazard ratio (95% CI) of PAD in participants with deficient versus sufficient 25(OH)D was 1.49 (1.26, 1.76). Inclusion of BMI, physical activity, and smoking status attenuated the association [1.25 (1.06, 1.48)]. The association between 25(OH)D and PAD was qualitatively stronger in blacks (p for interaction = 0.20).

CONCLUSIONS

Deficient 25(OH)D was associated with increased risk of PAD in black and white participants. Whether treatment of low vitamin D through supplementation or modest sunlight exposure prevents PAD is unknown.

Emerging Human Fetuin A Assays for Biomedical Diagnostics

Human fetuin A (HFA) plays a prominent pathophysiological role in numerous diseases and pathophysiological conditions with considerable biomedical significance; one example is the formation of calciprotein particles in osteoporosis and impaired calcium metabolisms. With impressive advances in in vitro diagnostic assays during the last decade, ELISAs have become a workhorse in routine clinical diagnostics. Recent diagnostic formats involve high-sensitivity immunoassay procedures, surface plasmon resonance, rapid immunoassay chemistries, signal enhancement, and smartphone detection. The current trend is toward fully integrated lab-on-chip platforms with smartphone readouts, enabling health-care practitioners and even patients to monitor pathological changes in biomarker levels. This review provides a critical analysis of advances made in HFA assays along with the challenges and future prospects.

Association between serum fetuin-A level and erectile function

Recent studies have shown that ED is an early symptom of atherosclerosis. Fetuin-A, a glycoprotein secreted by the liver, kidneys and choroid plexus, has been linked to systemic fibrosis and calcification in human and rat studies. Deficiency of this compound may play a role in atherosclerosis and cardiovascular disease progression. The aim of the study was to examine whether serum fetuin-A level is related to erectile function or severity of ED. Sixty ED patients without cardiovascular disease were assigned to one of the three groups (mild, moderate or severe ED) depending on ED severity. Twenty healthy volunteers were included as the control group. The International Index of Erectile Function-5 questionnaire was used to measure erection quality in all four groups. Mean age, body mass index, total testosterone, low- and high-density lipoprotein cholesterol, and triglyceride levels did not significantly differ between the three erectile dysfunction and control groups (P > 0.05). The group with severe ED had a significantly lower mean fetuin-A level than the mild ED and control groups. For both mild and moderate ED groups, the mean serum fetuin-A level was significantly lower in comparison with the control group (P < 0.001). Serum fetuin-A level may be used as a supplemental biochemical parameter in preliminary evaluation of ED.

QCT Volumetric Bone Mineral Density and Vascular and Valvular Calcification: The Framingham Study

There is increasing evidence that bone and vascular calcification share common pathogenesis. Little is known about potential links between bone and valvular calcification. The purpose of this study was to determine the association between spine bone mineral density (BMD) and vascular and valvular calcification. Participants included 1317 participants (689 women, 628 men) in the Framingham Offspring Study (mean age 60 years). Integral, trabecular, and cortical volumetric bone density (vBMD) and arterial and valvular calcification were measured from computed tomography (CT) scans and categorized by sex-specific quartiles (Q4 = high vBMD). Calcification of the coronary arteries (CAC), abdominal aorta (AAC), aortic valve (AVC), and mitral valve (MVC) were quantified using the Agatston Score (AS). Prevalence of any calcium (AS >0) was 69% for CAC, 81% for AAC, 39% for AVC, and 20% for MVC. In women, CAC increased with decreasing quartile of trabecular vBMD: adjusted mean CAC = 2.1 (Q4), 2.2 (Q3), 2.5 (Q2), 2.6 (Q1); trend p = 0.04. However, there was no inverse trend between CAC and trabecular vBMD in men: CAC = 4.3 (Q4), 4.3 (Q3), 4.2 (Q2), 4.3 (Q1); trend p = 0.92. AAC increased with decreasing quartile of trabecular vBMD in both women (AAC = 4.5 [Q4], 4.8 [Q3], 5.4 [Q2], 5.1 [Q1]; trend p = 0.01) and men (AAC = 5.5 [Q4], 5.8 [Q3], 5.9 [Q2], 6.2 [Q1]; trend p = 0.01). We observed no association between trabecular vBMD and AVC or MVC in women or men. Finally, cortical vBMD was unrelated to vascular calcification and valvular calcification in women and men. Women and men with low spine vBMD have greater severity of vascular calcification, particularly at the abdominal aorta. The inverse relation between AAC and spine vBMD in women and men may be attributable to shared etiology and may be an important link on which to focus treatment efforts that can target individuals at high risk of both fracture and cardiovascular events.

Association of Fetuin-A With Incident Fractures in Community-Dwelling Older Adults: The Cardiovascular Health Study

Fetuin-A, a serum protein that regulates calcium mineralization, has been associated with bone mineral density (BMD) in several cross-sectional human studies, suggesting a possible beneficial effect on clinically important measures of bone health. Fetuin-A and incidence of subsequent fracture was assessed in 4714 men and women ≥65 years of age. Proportional hazards models were used to estimate risk of incident hip (hospital discharge ICD-9 codes) and composite fracture (hip, pelvis, humerus, or proximal forearm; hospital discharge ICD-9 codes and Medicare claims data). A total of 576 participants had an incident hip fracture (median follow-up 11.2 years) and 768 had an incident composite fracture (median follow-up 6.9 years). In unadjusted analyses, there was no association between fetuin-A (per SD increase) and risk of hip fracture (hazard ratio [HR], 0.96; 95% CI, 0.88 to 1.05) or composite fracture (HR, 0.99; 95% CI, 0.92 to 1.06). Results were not significantly changed after adjustment for potential confounding variables. Analyses modeling fetuin-A in quartiles or within a subset with available BMD measures also showed no statistically significant association with risk of hip or composite fracture. Though fetuin-A was positively associated with areal BMD in partially adjusted models (total hip: β, 0.013 g/cm(2) ; 95% CI, 0.005 to 0.021; femoral neck: β, 0.011 g/cm(2) ; 95% CI, 0.004 to 0.018; and lumbar spine: β, 0.007 g/cm(2) ; 95% CI, 0.001 to 0.028), these associations were no longer significant after further adjustment for BMI and in final multivariate models. In this large sample of community-dwelling older adults, a small positive association between fetuin-A and areal BMD appeared attributable to confounding variables and we found no evidence of an association between fetuin-A and risk of clinical fracture.

The role of fetuin-A in mineral trafficking and deposition

Calcium and phosphate are the principle ions involved in the deposition of mineral in the human body. Inhibitors of mineralisation are essential for the prevention of ectopic mineral precipitation and deposition. In the past decade, through in vitro, in vivo and clinical observation studies, we have come to appreciate the importance of fetuin-A (Fet-A), a circulating glycoprotein, in preventing ectopic calcium phosphate mineralisation. Moreover, the detection of Fet-A-containing mineral complex, termed calciprotein particles (CPPs), has provided new ways to assess an individual's calcific risk. The pathophysiological significance of CPPs in disease states is yet to be defined, but it provides an exciting avenue to further our understanding of the development of ectopic mineralisation.

Relationship of fibroblast growth factor 23 and fetuin--A to coronary atherosclerosis

BACKGROUND

Serum fibroblast growth factor 23 (FGF-23) and fetuin-A are established predictors of morbidity and mortality due to cardiovascular disease. The objective of the present study is to evaluate the relationship between coronary artery disease (CAD) and serum concentrations of FGF-23 and fetuin-A.

METHODS

A total of 383 subjects who underwent coronary computed tomography angiography (CCTA) were included in the study. CCTA detected CAD in 208 patients; the rest of the patients had no detectable CAD.

RESULTS

Serum FGF-23 and fetuin-A levels were significantly increased in CAD patients compared to non-CAD patients (26.6±21.1pg/mL vs. 17.9±16.1pg/mL, p=0.001 and 826±350mg/L vs. 595±300mg/L, p<0.001, respectively). Serum FGF-23, fetuin-A, low-density lipoprotein (LDL)-cholesterol, and uric acid values were elevated in non-diabetic patients with CAD when compared to those without CAD. FGF-23, and fetuin-A were not significantly different in diabetic patients with CAD when compared to those without CAD. Using multivariate logistic regression analysis, we found that age, hypertension, LDL-Cholesterol, high-density lipoprotein (HDL)-Cholesterol, hs-CRP, uric acid, FGF-23 and fetuin-A levels were independently associated with the presence of CAD.

CONCLUSION

FGF-23 and fetuin-A were positively correlated with coronary atherosclerosis Similar trends were seen among diabetic patients, but this did not reach statistical significance. FGF-23 and fetuin-A could be used as novel risk markers of cardiovascular disease.

The serum protein fetuin-B is involved in the development of acute myocardial infarction

Fetuin-B was one of highly expressed serum proteins in AMI compared with stable angina. This protein affected vascular plaque-stabilizing components in monocytes, macrophages and vascular smooth muscle cells. Fetuin-B may be a possible contributor to AMI.

The relationship of circulating fetuin-a with liver histology and biomarkers of systemic inflammation in nondiabetic subjects with nonalcoholic fatty liver disease

BACKGROUND/AIMS

Fetuin-A, a glycoprotein with anti-inflammatory properties, plays an important role in counter-regulating inflammatory responses. It has also been associated with insulin resistance and metabolic syndrome. We aimed to investigate circulating concentrations of fetuin-A and its possible association with hepatic and systemic inflammation in nondiabetic subjects with nonalcoholic fatty liver disease (NAFLD).

PATIENTS AND METHODS

We included 105 nondiabetic male subjects with NAFLD [nonalcoholic steatohepatitis (NASH, n = 86) and simple steatosis (SS, n = 19)]. Plasma levels of fetuin-A and markers of inflammation [high-sensitive C reactive protein (hsCRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and adiponectin] were measured by enzyme-linked immunosorbent assay method. Insulin sensitivity was determined by homeostasis model assessment of insulin resistance (HOMA-IR) index.

RESULTS

Fetuin-A was negatively correlated with age (r = -0.27, P = 0.006), however there was no association between fetuin-A and body mass index, waist circumference (WC), glucose, insulin, HOMA-IR, lipid parameters, and inflammatory markers. In addition, no significant association was observed between fetuin-A and histological findings including liver fibrosis.

CONCLUSION

This study demonstrated that plasma fetuin-A levels are not correlated with the hepatic histology and systemic markers of inflammation in nondiabetic subjects with NAFLD. Our data also suggested that age is significantly associated with fetuin-A in this clinically relevant condition.

AMP-activated Protein Kinase (AMPK): Does This Master Regulator of Cellular Energy State Distinguish Insulin Sensitive from Insulin Resistant Obesity?

Although a correlation exists between obesity and insulin resistance, roughly 25 % of obese individuals are insulin sensitive. AMP-activated protein kinase (AMPK) is a cellular energy sensor that among its many actions, integrates diverse physiological signals to restore energy balance. In addition, in many situations it also increases insulin sensitivity. In this context, AMPK activity is decreased in very obese individuals undergoing bariatric surgery who are insulin resistant compared to equally obese patients who are insulin sensitive. In this review, we will both explore what distinguishes these individuals, and evaluate the evidence that diminished AMPK is associated with insulin resistance and metabolic syndrome-associated disorders in other circumstances.

[The role of fetuin-A in cardiovascular diseases]

Fetuin-A (also known as α2-Heremans-Schmid glycoprotein) is a multifunctional molecule secreted by the liver. It is a negative acute phase reactant with a debated role in subclinical inflammation. Fetuin-A is an inhibitor of the insulin receptor and its serum level correlates with insulin resistance. The protein has been implicated in adipocyte dysfunction and it is associated with obesity and non-alcoholic fatty liver disease. Although all these properties seem to promote atherosclerosis, the role of fetuin-A in cardiovascular diseases is more complex. As a natural inhibitor of tissue and vascular calcification, fetuin-A also acts as a protective factor in atherosclerosis. The potential role and prognostic value of fetuin-A in arterial calcification and cardiovascular diseases is discussed in this review, along with explanations for seemingly contradicting results in the literature and possible directions for future research.

Circulating fetuin-A and risk of ischemic stroke in women

BACKGROUND

Fetuin-A, a protein secreted primarily by the liver, has been associated with nonalcoholic fatty liver disease and insulin resistance. In a recent study, higher circulating fetuin-A was associated with cardiovascular events, particularly ischemic stroke. However, these data have not been replicated.

METHODS

A nested case control design was used to examine the relationship between fetuin-A and ischemic stroke among female participants of the Nurses' Health Study. Fetuin-A was measured in blood samples collected and stored between 1989 and 1990. A total of 459 incident cases of ischemic stroke were identified and confirmed by medical records according to the National Survey of Stroke criteria between 1990 and 2006 and matched to 459 controls by age, race/ethnicity, date of sample collection, menopausal status, postmenopausal hormone use, and smoking status. The association between fetuin-A and ischemic stroke was modeled using conditional logistic regression.

RESULTS

Circulating fetuin-A was higher in women (P < 0.01) who reported increased body mass index (BMI) of ≥25 kg/m(2), total cholesterol ≥200 mg/dL, high-sensitivity C-reactive protein ≥3 mg/L, and current hormone use at baseline. Significant partial Spearman correlations (P < 0.001), adjusted for matching factors, were found between measured concentrations of fetuin-A and triglycerides (r = 0.20), C-reactive protein (r = 0.14), and BMI (r = 0.15). Fetuin-A quartiles were not significantly associated with increased risk of incident ischemic stroke when adjusted for matching factors (relative risk, 1.03; 95% CI, 0.69-1.54, extreme quartiles); additional adjustment for lifestyle factors or cardiovascular disease risk factors and biomarkers did not alter results.

CONCLUSIONS

In this sample of women, fetuin-A was not significantly associated with risk of ischemic stroke. Further research is needed to explore this association.

The effects of caloric restriction on fetuin-A and cardiovascular risk factors in rats and humans: a randomized controlled trial

OBJECTIVES

The liver-secreted protein fetuin-A is associated with insulin resistance, metabolic syndrome, type 2 diabetes and atherosclerosis. We examined the effect of caloric restriction (CR) on fetuin-A levels and concomitant changes in hepatic steatosis and cardiovascular risk factors in rats and humans.

DESIGN AND SUBJECTS

We performed a randomized, controlled clinical trial to examine circulating fetuin-A levels and cardiovascular risk parameters including visceral fat area (VFA), atherogenic lipid profile, inflammatory markers, adipokines levels and brachial artery endothelial function in 76 overweight women with type 2 diabetes before and after 12 weeks of CR. In addition, the effects of CR on hepatic steatosis and fetuin-A mRNA expression were evaluated in Otuska Long Evans Tokushima Fatty (OLETF) rats, an animal model of obesity and type 2 diabetes.

RESULTS

Circulating fetuin-A levels were significantly decreased after 12 weeks of CR and were accompanied by improvements in VFA, blood pressure, glucose, lipid profiles and liver function. The CR group also showed a significant decrease in apolipoprotein B, leptin and insulin resistance compared to those in the control group, although endothelial function was not different. Multiple regression analysis showed that the changes in fetuin-A levels were independently associated with CR and changes in hsCRP and adiponectin (R² = 0·156). Moreover, CR significantly reduced hepatic steatosis and fetuin-A expression, as well as weight, glucose, total cholesterol and triglyceride levels, in OLETF rats.

CONCLUSION

Caloric restriction significantly reduced the hepatic expression of fetuin-A and its circulating levels and improved several cardiovascular risk factors in obese rats and humans with type 2 diabetes.

Aortic stenosis: a general overview of clinical, pathophysiological and therapeutic aspects

Aortic stenosis is the most prevalent valve pathology and calcific aortic valve disease (CAVD) is its most frequent etiology in developed countries. There is extensive evidence that CAVD represents an active disease process similar to that of atherosclerosis with similar classical cardiovascular risk factors and pathological mechanisms. Given that in the vast majority of situations the only treatment available is valve replacement there is a need to develop pharmacological therapies that retard the disease progression. Lipid-lowering therapies have been the focus of research, however, so far with negative results. Future studies, including animal models, shall provide an opportunity to further evaluate the disease mechanisms of CAVD and to discover potential disease biomarkers and pharmacological interventions that can reduce the need for valve replacement.

Association of AHSG gene polymorphisms with ischemic stroke in a Han Chinese population

Previous studies have shown associations of fetuin-A (alpha2-Heremans-Schmid glycoprotein, AHSG) with various disorders, including insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and atherosclerosis. In this study, genotype and allele frequencies of the rs4918 SNP in the AHSG gene were examined in 380 patients with ischemic stroke and 350 healthy controls from a Northern Han Chinese population via the PCR-RFLP technique. Frequencies of the GG genotype and the G allele in AHSG (rs4918) were significantly higher in patients with ischemic stroke or atherosclerotic cerebral infarction than those in the control group (P < 0.05). Logistic regression analysis demonstrated the significance of rs4918 in these patients, after adjustment for confounding factors (P < 0.05). These findings suggest that rs4918 SNPs of the AHSG gene are associated with a risk for ischemic stroke in a Northern Han Chinese population.

Associations of fetuin-A and osteoprotegerin with arterial stiffness and early atherosclerosis in chronic hemodialysis patients

BACKGROUND

Cardiovascular morbidity and mortality remains excessive in patients with chronic kidney disease. The association of vascular changes with regulators of extraosseous calcification in this patient population is still under investigation. The aim of the present study was to investigate the associations of the calcification inhibitor fetuin-A, and the anti-osteoclastic factor osteoprotegerin (OPG) with vascular pathology in chronic hemodialysis patients.

METHODS

In this cross-sectional study including 81 stable chronic hemodialysis patients, we measured carotid-to-femoral pulse wave velocity (cfPWV) with applanation tonometry, reflecting arterial stiffness, and common carotid intima-media thickness (ccIMT), a surrogate of early atherosclerosis, as well as serum levels of fetuin-A and OPG. Co-morbidities, traditional cardiovascular risk factors, inflammatory markers and mineral-bone disease serology parameters were also recorded.

RESULTS

cfPWV correlated inversely with fetuin-A (r=-0.355, p=0.001) and positively with OPG (r=0.584, p<0.001). In multilinear regression analysis including age, gender, diabetes, cardiovascular disease, hypertension, pulse pressure, LDL, logCRP, both fetuin-A and OPG were independently associated with cfPWV (p=0.024 and p=0.041 respectively). ccIMT was negatively associated with fetuin-A (r=-0.312, p=0.005) and positively with OPG (r=0.521, p<0.0001); however these associations lost statistical significance after adjustment for age.

CONCLUSION

In chronic hemodialysis patients both fetuin-A and OPG levels are independently associated with arterial stiffness but not with early atherosclerotic vascular changes.

Plasma fetuin-A is associated with endothelial dysfunction and subclinical atherosclerosis in subjects with nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD), a hepatic manifestation of metabolic syndrome (MetS) is closely associated with an increased risk of cardiovascular disease. Fetuin-A is associated with MetS and NAFLD. We investigated the relationship of circulating fetuin-A level with markers of endothelial dysfunction and presence of carotid atherosclerosis in subjects with NAFLD.

METHODS

The consecutive 115 patients with NAFLD and age-matched 74 healthy subjects were enrolled. Plasma levels of fetuin-A and markers of endothelial dysfunction [asymmetric dimethyl arginine (ADMA) and adiponectin] were measured by ELISA method. Insulin sensitivity was determined by homeostasis model assessment of insulin resistance (HOMA-IR) index. Carotid artery intima-media thickness (cIMT) was assessed by high-resolution ultrasonography.

RESULTS

Fetuin-A and ADMA were higher and, adiponectin was lower in NAFLD group than the control group (P = 0·004, P < 0·001 and P < 0·001, respectively). In addition, NAFLD group had greater cIMT measurements than the controls (P < 0·001). However, no difference was found for fetuin-A, ADMA, adiponectin and cIMT between two groups when the findings were adjusted according to the glucose, lipids and HOMA-IR index. In correlation analysis, fetuin-A was found to be positively correlated with triglyceride (r = 0·23, P = 0·001), HOMA-IR (r = 0·29, P < 0·001), ADMA (r = 0·24, P = 0·001), cIMT (r = 0·3, P = 0·003) and, negatively correlated with HDL-C (r = -0·17, P = 0·02) and adiponectin (r = -0·19, P = 0·01) levels. Multiple linear regression analysis showed that fetuin-A was independently associated with ADMA and cIMT levels.

CONCLUSION

This study demonstrated for the first time that circulating fetuin-A in NAFLD is independently associated with endothelial dysfunction and subclinical atherosclerosis.

Fetuin-A is inversely associated with coronary artery calcification in community-living persons: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Fetuin-A is a hepatic secretory protein that inhibits arterial calcification in vitro. The association of fetuin-A with coronary arterial calcification (CAC) in the general population is uncertain.

METHODS

Among 2457 community-living individuals without cardiovascular disease (CVD), we measured serum fetuin-A concentrations by ELISA and evaluated the cross-sectional association of fetuin-A with CAC prevalence (any vs none) and severity; on follow-up 3.2 years (median) later, we evaluated the association of fetuin-A with CAC incidence and progression.

RESULTS

The mean age was 62 (SD 10) years, and the mean fetuin-A concentration was 0.48 (0.10) g/L. At baseline, 1200 individuals (49%) had CAC, and 272 individuals developed CAC during follow-up. At baseline, there was a threshold effect at the lowest fetuin-A quartile with CAC prevalence. In models adjusted for demographics, traditional cardiovascular disease (CVD) risk factors and kidney function, the lowest fetuin-A quartile had 7% (95% CI 1%-13%; P = 0.04) greater CAC prevalence compared with quartiles 2-4. Similar associations were observed with CAC severity at baseline, but the association was more linear. Each SD (0.10 g/L) lower fetuin-A was associated with a 12% (95% CI 3%-21%; P = 0.01) greater CAC severity in adjusted models. There was no significant association of fetuin-A with CAC incidence or progression.

CONCLUSIONS

Fetuin-A is inversely associated with CAC severity among community-living individuals without CVD. Whether fetuin-A concentrations are associated with incident CVD event in the general population requires future study.

The associations of fetuin-A with subclinical cardiovascular disease in community-dwelling persons: the Rancho Bernardo Study

OBJECTIVES

The aim of this study was to determine the association of fetuin-A with subclinical cardiovascular disease (CVD) in community-living individuals.

BACKGROUND

Fetuin-A is a hepatic secretory protein that inhibits arterial calcium deposition in vitro. Lower fetuin-A levels are associated with arterial calcification and death in end-stage renal disease populations. The association of fetuin-A with subclinical CVD in the general population is unknown.

METHODS

Among 1,375 community-living individuals without prevalent clinical CVD, we measured plasma fetuin-A concentrations. Peripheral arterial disease (PAD) was defined by ankle brachial index <0.90, coronary artery calcification (CAC) was measured by computed tomography, and common and internal intima-media thickness (cIMT) were measured by carotid ultrasound. PAD was measured concurrent with fetuin-A, and CAC and cIMT were measured 4.6 years (mean) later.

RESULTS

Mean age was 70 ± 11 years, and 64% were women. Fetuin-A levels were inversely associated with CAC severity. When evaluated as CAC categories (0, 1 to 100, 101 to 300, >300) with ordinal logistic regression, each SD higher fetuin-A was associated with 31% lower odds of CAC severity (proportional odds ratio: 0.69; 95% confidence interval: 0.46 to 0.92; p = 0.008) in models adjusted for demographic data, lifestyle factors, traditional CVD risk factors, and kidney function. In contrast, no association of fetuin-A was observed with PAD or high common or internal cIMT in adjusted models.

CONCLUSIONS

Lower fetuin-A levels are independently associated with greater CAC severity but not PAD or cIMT. If confirmed, fetuin-A might mark calcium deposition within the vasculature but not atherosclerosis per se.

Fetuin-A and the cardiovascular system

Fetuin was first isolated from bovine serum in 1944. It is now most commonly known as either fetuin-A or alpha-2-HS-glycoprotein (AHSG), the protein product of Ahsg gene. A prominent feature of this protein is the functional diversity exerted in human physiology and pathophysiology. Fetuin-A plays a role in bone metabolism, metabolic disorders such as insulin resistance and diabetes mellitus (DM), and central nervous system (CNS) disorders such as ischemic stroke (IS) and neurodegenerative diseases. In addition, emerging evidence suggests involvement of fetuin-A in the cardiovascular system. However, there are many discordant findings on the associations between fetuin-A and vascular diseases. In other words, it is unknown whether fetuin-A is an exacerbating or a protective factor in the cardiovascular system. One reason for the seemingly inconsistent behavior is the dual functionality of fetuin-A in vascular diseases where it can act as an atherogenic factor or as a vascular calcification inhibitor. In addition, the existence of confounding factors such as DM and renal dysfunction can veil the primary association between fetuin-A and clinical parameters. Considering these issues, we discuss the role of fetuin-A for atherosclerosis and vascular calcification in this review.

Inside human aortic stenosis: a proteomic analysis of plasma

Valvular aortic stenosis (AS) produces a slowly progressive obstruction in left ventricular outflow track. For this reason, aortic valve replacement is warranted when the valvular stenosis is hemodinamically significant, becoming the most common worldwide cause of aortic valve surgery. Recent epidemiologic studies have revealed an association between degenerative AS and cardiovascular risk factors for atherosclerosis, althought reducing the exposure to such factors and statin therapies both fail to delay or reverse the pathology. Hence, a deeper understanding of the pathophysiology of this disease is required to identify appropriate preventive measures. A proteomic analysis of plasma will permit to know and identify the changes in protein expression induced by AS in this tissue. Using two-dimensional difference gel electrophoresis (2D-DIGE) followed by mass spectrometry (MS), we compared the crude (not pre-fractioned) and pre-fractioned plasma from AS patients and control subjects. We sought to identify plasma proteins whose expression is modified in AS. In addition we investigated if crude plasma presented some alterations in the more abundant proteins since to date, has never been studied before. We also further investigated the link between this disease and atherosclerosis with a view to identifying new potential markers and therapeutic targets.

Serum fetuin-A in metabolic and inflammatory pathways in patients with myocardial infarction

BACKGROUND

Although multifunctional glycoprotein α2HS-glycoprotein/human fetuin-A (AHSG) is involved in atherosclerosis, it is not clear whether high or low concentrations are more important. We studied the correlation of serum AHSG with adiponectin, leptin, resistin, C-reactive protein (CRP) and tumour necrosis factor-α (TNF-α) to see whether its metabolic effects or its involvement in subclinical inflammation are dominant in patients with established coronary disease.

MATERIALS AND METHODS

In this cross-sectional study, AHSG concentration was determined in sera of 171 patients (age: 62 ± 6 years, mean ± SD) with previous myocardial STEMI infarction and normal renal function and 81 age-matched healthy controls by radial immunodiffusion. Results  Patients had increased AHSG levels (673 ± 103 vs. 619 ± 96 mg L(-1), P < 0·001) compared to controls. Obese and diabetic patients had higher AHSG concentration than those with normal BMI or without diabetes but even the latter group had elevated AHSG levels (667 ± 101 mg L(-1), n = 88) compared to controls (P = 0·002). Serum AHSG correlated negatively with adiponectin (r = -0·236, P = 0·006) even after adjusting for BMI (r = -0·177, P = 0·043). AHSG determined adiponectin levels independently from BMI, age and other adipocytokines (P = 0·014). The correlation between leptin and AHSG (r = 0·321, P = 0·021) weakened following adjustment for BMI (r = 0·209, P = 0·072). Serum AHSG did not correlate significantly with CRP, resistin and TNF-α concentrations. BMI and resistin but not AHSG determined TNF-α levels independently.

CONCLUSIONS

AHSG is elevated in sera of patients with previous myocardial infarction. Association with adipokines favours the concept that AHSG is involved in atherosclerosis more likely through metabolic pathways (insulin resistance, obesity and adipocyte dysfunction) than by inflammation in patients with post-myocardial infarction.

Serum level of soluble Hsp70 is associated with vascular calcification

It has been previously reported that serum levels of 70-kDa heat shock protein (Hsp70) are elevated in peripheral artery disease. The aim of the present study was to examine whether increased serum Hsp70 levels are related to the extent of arterial calcification and standard laboratory parameters of patients with peripheral artery disease, as well as to markers of inflammation (C-reactive protein), atherosclerosis (homocysteine), and calcification (fetuin-a). One hundred eighty chronic atherosclerotic patients with significant carotid stenosis and/or lower extremity vascular disease were enrolled in this cross-sectional study. Systemic atherosclerosis and calcification was assessed by ultrasound (carotid intima-media thickness (IMT), presence of calcification at the abdominal aorta, carotid and femoral bifurcations, and aortic and mitral cardiac valves). Standard serum markers of inflammation, diabetes, renal function, ankle-brachial indexes, and traditional risk factors for atherosclerosis were noted. Serum Hsp70 levels were measured with enzyme-linked immunosorbent assay. Standard laboratory parameters (clinical chemistry), C-reactive protein (CRP), and homocysteine levels were determined by an autoanalyzer using the manufacturer's kits. Fetuin-a levels were measured by radial immunodiffusion. Patients' median age was 64 (57-71) years, 69% were men, and 34.5% had diabetes. Serum heat shock protein 70 levels were significantly higher in patients with more severe arterial calcification (p < 0.02) and showed significant positive correlations with serum bilirubin (r = 0.23, p = 0.002) and homocysteine levels (r = 0.18, p = 0.02). Serum Hsp70 did not correlate with body mass index, IMT, CRP, or fetuin-a levels in this cohort. Logistic regression analysis confirmed the association between sHsp70 and calcification score (OR, 2.189; CI, 1.156-4.144, p = 0.016) and this correlation remained significant (OR, 2.264; CI, 1.021-5.020, p = 0.044) after the adjustment for age, sex, eGFR, smoking, CRP, and homocysteine levels. Our data show that serum Hsp70 levels correlate with the severity of atherosclerosis in patients with carotid artery disease and chronic lower limb ischemia. These data support a putative role for plasma Hsp70 in the development of arterial calcification. Nevertheless, further studies are required to investigate the usefulness of circulating Hsp70 level as a marker of atherosclerotic calcification.

Fetuin-A serum levels in patients with aortic aneurysms of Marfan syndrome and atherosclerosis

BACKGROUND

Fetuin-A is a glycoprotein that inhibits extraosseous and vascular calcification. Its serum level is lower in patients with atherosclerosis compared with healthy controls, but its role is unknown in aneurysmal diseases. The aim of our study was to investigate the association of serum fetuin-A levels with aortic aneurysms of different aetiology: Marfan syndrome and atherosclerosis.

MATERIAL AND METHODS

In a single centre cross-sectional observational study, 105 patients (30 with atherosclerotic aortic aneurysm, 15 with Marfan syndrome, 30 with peripheral arterial disease and 30 healthy controls) were examined; sera were analysed for fetuin-A, standard markers of possible inflammation, lipid profile, kidney and hepatic disease and diabetes. Systemic atherosclerosis was assessed by carotid intima-media thickness (IMT) measurement and arterial calcification score of cardiac valves, carotids, aorta and femoral arteries determined by ultrasound.

RESULTS

Serum fetuin-A levels (median and IQR) were significantly lower in the atherosclerotic aneurysm cohort than in patients with Marfan syndrome: 708 μg mL⁻¹ (612-780) and 756 μg mL⁻¹ (708-816), respectively, (P = 0·0428). Fetuin-A levels were 754 μg mL⁻¹ (713-777) in the control group and 654 μg mL⁻¹ (600-756) in patients with peripheral arterial disease. Mean and maximum IMT, ACS values and homocysteine levels were significantly higher in patients with atherosclerosis: P < 0·0001, P < 0·0001, P < 0·0001 and P = 0·0034, respectively. There was no significant difference between aneurysm groups analysing the results of lipid profile and acute-phase markers.

CONCLUSIONS

The significantly lower serum level of fetuin-A in the atherosclerotic aneurysm group supports the protective role of fetuin-A in the evolution of arterial calcification.

Fetuin-A levels are increased in patients with type 2 diabetes and peripheral arterial disease

OBJECTIVE

Low levels of fetuin-A, a systemic calcification inhibitor, are linked to mortality in patients on dialysis. In contrast, elevated fetuin-A is associated with cardiovascular events in non-renal patients. We investigated fetuin-A in patients with type 2 diabetes and peripheral arterial disease (PAD).

RESEARCH DESIGN AND METHODS

We studied fetuin-A in 76 patients with PAD and normal glucose metabolism (NGM-PAD) and in 129 patients with PAD and type 2 diabetes (type 2 diabetes-PAD). Additionally, 40 patients with diabetes without any complications (type 2 diabetes-non-PAD) were examined.

RESULTS

Type 2 diabetes-PAD subjects (399 ± 155 μg/ml) had significantly higher fetuin-A levels than type 2 diabetes-non-PAD subjects (247 ± 42; P < 0.001). In NGM-PAD subjects (376 ± 144), fetuin-A was significantly higher than in type 2 diabetes-non-PAD subjects (P < 0.001). Type 2 diabetes-PAD patients with mediasclerosis had lower fetuin-A than subjects without (P < 0.03). Regression analysis in type 2 diabetes-PAD subjects revealed that glycated A1C (P < 0.001) and mediasclerosis (P = 0.004) were the strongest predictors of fetuin-A. Multivariate regression revealed that a 1-SD increase in fetuin-A was associated with an odds ratio (OR) of 2.1 (95% CI 1.1-3.3; P < 0.001) for the prevalence of PAD and an OR of 1.4 (1.0-1.7, P = 0.039) for the prevalence of myocardial infarction.

CONCLUSIONS

In contrast to previous findings, fetuin-A was higher in type 2 diabetes-PAD patients than in type 2 diabetes-non-PAD patients. In NGM-PAD patients, fetuin-A was also higher than in type 2 diabetes-non-PAD patients. In type 2 diabetes-PAD patients, fetuin-A was inversely associated with mediasclerosis-the calcification process pathognomonic for diabetic PAD. This association persisted in multivariate regression, which is in line with the calcification inhibition in coronary heart or renal disease.

Association of AHSG gene polymorphisms with fetuin-A plasma levels and cardiovascular diseases in the EPIC-Potsdam study

BACKGROUND

Elevated circulating levels of fetuin-A in blood have been associated with increased risk of cardiovascular disease. The goal of our study was to prospectively investigate the potential causal nature of the association between fetuin-A levels and myocardial infarction (MI) and ischemic stroke by applying a Mendelian randomization approach.

METHODS AND RESULTS

Five tagging single-nucleotide polymorphisms (rs2248690, rs2070633, rs2070635, rs4917, and rs6787344) capturing the common genetic variation of the fetuin-A coding gene alpha(2)-Heremans-Schmid glycoprotein (AHSG) were genotyped in a case-cohort comprising 214 MI cases, 154 ischemic stroke cases, and 2152 persons who remained free of cardiovascular disease events in the European Prospective Investigation into Cancer and Nutrition-Potsdam study. One single-nucleotide polymorphism (rs6787344) was discarded because of Hardy-Weinberg disequilibrium. All AHSG tagging single-nucleotide polymorphisms were associated with fetuin-A plasma levels (P<0.0001). AHSG rs4917 C>T showed the strongest association, explaining 21.2% of the phenotypic variance independent of potential confounding factors (+35.5 microg/mL increase per C-allele, P= 2 x 10(-121)). Furthermore, the rs4917 C-allele showed a significant association with MI (adjusted hazard rate ratio [RR] 1.34, 95% CI 1.05 to 1.70, P=0.02). Based on this association, the expected RR for MI corresponding to 1 SD in fetuin-A was 1.54 and, thus, strikingly matches the previously observed association between fetuin-A plasma levels and MI risk (RR 1.59).

CONCLUSIONS

These data provide evidence for the causal nature of the recently reported association between fetuin-A plasma levels and MI risk, thereby suggesting an involvement of fetuin-A in the pathogenesis of cardiovascular disease.

Fetuin-A and CD40 L plasma levels in acute ischemic stroke: differences in relation to TOAST subtype and correlation with clinical and laboratory variables

INTRODUCTION

Accumulating evidence suggests that inflammation plays an important role in the acute phase of ischemic stroke. CD40 L is a well recognized atherosclerotic inflammatory marker, whereas recent evidence suggests a pro-inflammatory role of Fetuin-A. To analyze the role of an inflammatory marker such as CD40 L and of a candidate pro-inflammatory marker such as Fetuin-A in acute stroke we evaluated their serum levels in subjects with acute ischemic stroke and their possible association with other laboratory and clinical variables.

MATERIALS AND METHODS

We enrolled 107 consecutive patients with a diagnosis of acute ischemic stroke admitted to the Internal Medicine Department at the University of Palermo between November 2006 and January 2008, and 102 hospitalized control patients without a diagnosis of acute ischemic stroke.

RESULTS

Patients with acute ischemic stroke in comparison to control subjects without acute ischemic stroke had significantly higher CD40 L levels and Fetuin-A serum levels. No significant differences in plasma CD40 L or Fetuin-A levels among different TOAST groups were detected. At intragroup (intra-TOAST-subtype) correlation analysis, among subjects classified as lacunar, CD40 L plasma levels were positively correlated with LDL-cholesterol and with diabetes, whereas Fetuin-A was significantly (positively) correlated with hypertension and white blood cell count. Among subjects with LAAS subtype, CD40 L levels were positively correlated with triglyceride plasma levels and Fetuin-A, whereas Fetuin-A levels were positively correlated with LDL-cholesterol.

DISCUSSION

Our findings suggest a pro-inflammatory role of Fetuin-A and CD40 L in acute stroke setting. Whether this role should be construed as direct or as a simple expression of a general inflammatory activation will be up to future studies to clarify.

Mechanisms linking osteoporosis with cardiovascular calcification

Cardiovascular calcium deposition is associated with osteoporosis through various potential mechanisms involving molecular regulatory factors at the nanoscale level that govern skeletal bone and cardiovascular tissues. In this article, several possible mechanisms linking cardiovascular calcification and osteoporosis are discussed, including aging, tissue-specific responses to chronic inflammation, flow-limiting atherosclerosis of skeletal end arteries causing ischemic abnormalities in metabolism, shared endogenous regulatory factors that affect the two tissues in a reciprocal manner, and changes in a cysteine protease inhibitor, fetuin. Any or all of these factors and phenomena may contribute to the association.

Extended-release niacin decreases serum fetuin-A concentrations in individuals with metabolic syndrome

BACKGROUND

Fetuin-A, a liver-secreted phosphoprotein and physiological inhibitor of insulin receptor tyrosine kinase, is associated with insulin resistance, metabolic syndrome (MetS), and an increased risk for type 2 diabetes. However, studies on the modulation of circulating levels of fetuin-A are limited. The goal of this study was to determine the effect of niacin administration on serum total- and phosphorylated fetuin-A (phosphofetuin-A) concentrations in individuals with MetS and correlate with changes in serum lipids, insulin sensitivity, and markers of inflammation.

METHODS

Fifteen sedentary, obese, male participants, who met the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria for MetS, were treated with extended-release niacin (Niaspan) for 6 weeks. Blood samples were obtained before and after treatment with niacin.

RESULTS

Serum fetuin-A and phosphofetuin-A concentrations were decreased following niacin administration (p < 0.005). Changes in fetuin-A concentrations were correlated with changes in triglyceride (r = 0.62, p = 0.01) and C-reactive protein (CRP) concentrations (r = 0.58, p < 0.05) after niacin treatment. Changes in high-density lipoproteins (HDL)-cholesterol following niacin intervention were negatively correlated with changes in serum fetuin-A (p < 0.05) and phosphofetuin-A concentrations (p < 0.05). Serum cortisol levels were significantly elevated after niacin administration.

CONCLUSIONS

Niacin treatment lowers serum total- and phosphofetuin-A concentrations in individuals with MetS, and these changes correlate with the beneficial changes in serum lipids. Because niacin is known to induce insulin resistance, these findings suggest that fetuin-A may not be a mediator of niacin-induced insulin resistance but it may blunt the insulin resistance induced by niacin by decreasing its circulating concentrations.