The proteome of perilymph in patients with vestibular schwannoma. A possibility to identify biomarkers for tumor associated hearing loss?

BACKGROUND

Due to the surrounding bone, the human inner ear is relatively inaccessible and difficult to reach for cellular and molecular analyses. However, these types of investigations are needed to better understand the etiology, pathophysiology and progression of several inner ear disorders. Moreover, the fluid from the inner ear cannot be sampled for micro-chemical analyses from healthy individuals in vivo. Therefore, in the present paper, we studied patients with vestibular schwannoma (VS) undergoing trans-labyrinthine surgery (TLS). Our primary aim was to identify perilymph proteins in patients with VS on an individual level. Our second aim was to investigate the proteins identified at a functional level and our final aim was to search for biological markers for tumor-associated hearing loss and tumor diameter.

METHODS AND FINDINGS

Sixteen patients underwent TLS for sporadic VS. Perilymph was aspirated through the round window before opening the labyrinth. One sample was contaminated and excluded resulting in 15 usable samples. Perilymph samples were analyzed with an online tandem LTQ-Orbitrap mass spectrometer. Data were analyzed with MaxQuant software to identify the total number of proteins and to quantify proteins in individual samples. Protein function was analyzed using the PANTHER Overrepresentation tool. Associations between perilymph protein content, clinical parameters, tumor-associated hearing loss and tumor diameter were assessed using Random Forest and Boruta. In total, 314 proteins were identified; 60 in all 15 patients and 130 proteins only once in 15 patients. Ninety-one proteins were detected in at least 12 out of 15 patients. Random Forest followed by Boruta analysis confirmed that alpha-2-HS-glycoprotein (P02765) was an independent variable for tumor-associated hearing loss. In addition, functional analysis showed that numerous processes were significantly increased in the perilymph. The top three enriched biological processes were: 1) secondary metabolic processes; 2) complement activation and 3) cell recognition.

CONCLUSIONS

The proteome of perilymph in patients with vestibular schwannoma has an inter-individual stable section. However, even in a cohort with homogenous disease, the variation between individuals represented the majority of the detected proteins. Alpha-2-HS-glycoprotein, P02765, was shown to be an independent variable for tumor-associated hearing loss, a finding that needs to be verified in other studies. In pathway analysis perilymph had highly enriched functions, particularly in terms of increased immune and metabolic processes.

The hepatokines fetuin-A and fetuin-B are upregulated in the state of hepatic steatosis and may differently impact on glucose homeostasis in humans

The liver is a central regulator of whole body glucose, and lipid homeostasis and hepatokines, like fetuin-A, have been identified as markers and mediators of fatty liver-induced cardiometabolic risk. The closely related protein fetuin-B was shown to be upregulated in the fatty liver and to impact on glucose homeostasis in mice. In the present study we aimed to test the relevance of these findings in humans. In 55 subjects, hepatic mRNA expression of both hepatokines, fetuin-A and fetuin-B, associated positively with liver triglyceride content, whereas only fetuin-A expression associated with the homeostatic model assessment of insulin resistance. In 220 subjects who underwent precise metabolic phenotyping, circulating fetuin-A, but not fetuin-B, associated positively with liver fat content, and negatively with insulin sensitivity, measured during the oral glucose tolerance test (OGTT) and during the euglycemic, hyperinsulinemic clamp. Both circulating fetuin-A and fetuin-B correlated positively with the glucose area under the curve during the OGTT, but after additional adjustment for insulin sensitivity this relationship remained significant only for fetuin-B. In conclusion, despite the fact that the two hepatokines, fetuin-A and fetuin-B, are upregulated in the state of hepatic steatosis in humans, it appears that they differently impact on glucose homeostasis. Our data are in agreement with observations that fetuin-A can alter insulin signaling and that fetuin-B may regulate glucose homeostasis via so far unknown effects, possibly on glucose effectiveness.

The adipokine Chemerin and Fetuin-A Serum Levels in Type 2 Diabetes Mellitus: Relation to Obesity and Inflammatory Markers

Chemerin and fetuin-A are recently discovered as metabolic regulator hormone in obesity and type 2 diabetes mellitus. However, elevated levels of chemerin and fetuin-A have been associated with insulin resistance and systemic inflammation. The present study aimed to investigate the significance of serum chemerin and fetuin-A levels in obese diabetic patients. Also, to determine whether, chemerin and fetuin-A along with markers of inflammation (IL6 and CRP) and obesity-related parameters in T2DM patients. Serum levels of chemerin and fetuin-A were evaluated using ELISA in 71 T2DM patients and 14 apparently healthy controls. Both groups were subdivided into obese and lean. Serum chemerin and fetuin-A levels were significantly higher in T2DM patients compared to controls (P < 0.001, for both) and significantly higher in obese T2DM in comparison to obese control group (P < 0.01 & P < 0.05, respectively). Serum chemerin and fetuin-A levels correlated positively with HbA1c, HOMA-IR, FBG, IL6 and CRP. In obese patients, serum chemerin and fetuin-A levels correlated positively with BMI and waist circumference. In conclusion, the strong association of chemerin and fetuin-A with insulin resistance and some inflammatory markers may provide an interesting link between obesity, inflammation and diabetes mellitus in human.

Serum Fetuin-A levels in obese children with biopsy proven nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Fetuin-A has been proposed as a marker of liver damage in adults with obesity-related NAFLD. The aim of this study was to test serum fetuin-A concentrations in obese children with NAFLD diagnosed either by ultrasonography or by liver biopsy and to determine its applicability as predictive tool in pediatric NAFLD.

METHODS AND RESULTS

Metabolic parameters and fetuin-A levels were investigated in 81 obese children with NAFLD diagnosed by biopsy, 79 obese children with NAFLD defined by liver ultrasonography and 23 lean subjects. Serum fetuin-A correlated significantly with age, waist circumference, systolic blood pressure, fasting insulin and 2-h postload insulin during OGTT, HOMA-IR, ISI, CRP, and apo B levels. Obese children with NAFLD detected by ultrasonography had significantly higher fetuin-A levels compared to those with normal liver. In obese children who underwent liver biopsy, no significant differences were detected in fetuin-A levels between subject with nonalcoholic steatohepatitis and those with simple steatosis. Fetuin-A was not different between obese and lean children.

CONCLUSION

Fetuin-A is not related with the degree of liver damage in obese children with NAFLD and its routine measurement as marker of liver disease severity is therefore not recommended.

The proteome of perilymph in patients with vestibular schwannoma. A possibility to identify biomarkers for tumor associated hearing loss?

BACKGROUND

Due to the surrounding bone, the human inner ear is relatively inaccessible and difficult to reach for cellular and molecular analyses. However, these types of investigations are needed to better understand the etiology, pathophysiology and progression of several inner ear disorders. Moreover, the fluid from the inner ear cannot be sampled for micro-chemical analyses from healthy individuals in vivo. Therefore, in the present paper, we studied patients with vestibular schwannoma (VS) undergoing trans-labyrinthine surgery (TLS). Our primary aim was to identify perilymph proteins in patients with VS on an individual level. Our second aim was to investigate the proteins identified at a functional level and our final aim was to search for biological markers for tumor-associated hearing loss and tumor diameter.

METHODS AND FINDINGS

Sixteen patients underwent TLS for sporadic VS. Perilymph was aspirated through the round window before opening the labyrinth. One sample was contaminated and excluded resulting in 15 usable samples. Perilymph samples were analyzed with an online tandem LTQ-Orbitrap mass spectrometer. Data were analyzed with MaxQuant software to identify the total number of proteins and to quantify proteins in individual samples. Protein function was analyzed using the PANTHER Overrepresentation tool. Associations between perilymph protein content, clinical parameters, tumor-associated hearing loss and tumor diameter were assessed using Random Forest and Boruta. In total, 314 proteins were identified; 60 in all 15 patients and 130 proteins only once in 15 patients. Ninety-one proteins were detected in at least 12 out of 15 patients. Random Forest followed by Boruta analysis confirmed that alpha-2-HS-glycoprotein (P02765) was an independent variable for tumor-associated hearing loss. In addition, functional analysis showed that numerous processes were significantly increased in the perilymph. The top three enriched biological processes were: 1) secondary metabolic processes; 2) complement activation and 3) cell recognition.

CONCLUSIONS

The proteome of perilymph in patients with vestibular schwannoma has an inter-individual stable section. However, even in a cohort with homogenous disease, the variation between individuals represented the majority of the detected proteins. Alpha-2-HS-glycoprotein, P02765, was shown to be an independent variable for tumor-associated hearing loss, a finding that needs to be verified in other studies. In pathway analysis perilymph had highly enriched functions, particularly in terms of increased immune and metabolic processes.

Fetuin-A levels and risk of type 2 diabetes mellitus: a systematic review and meta-analysis

AIMS

Fetuin-A has been linked to insulin resistance and obesity. Its role in the pathogenesis of type 2 diabetes (T2DM) has also been discussed. We aimed to investigate the prospective association of fetuin-A and the risk of T2DM in a systematic review and meta-analysis.

METHODS

A systematic search of studies from the MEDLINE, EMBASE, Pubmed and Web of Science using fetuin-A, diabetes and various synonyms was conducted up to June 5, 2017. Relevant studies were extracted by two reviewers independently. The quality of studies was assessed using Newcastle-Ottawa scales. Overall estimates were pooled using fixed effect with inverse variance meta-analysis. Subgroup analyses by gender, study population, techniques of assessing fetuin-A, diabetes ascertainment methods, follow-up duration and measures of association were conducted.

RESULTS

Seven studies comprising a total of 11,497 individuals and 2176 cases of T2DM were included in the systematic review and meta-analysis. Overall, one SD increment of fetuin-A level was associated with a 23% greater risk of incident T2DM (RR: 1.23, 95% CI 1.16-1.31). No significant heterogeneity or publication bias was found. The association was relatively stable across different subgroups. However, the association seemed only evident in women, but not in men.

CONCLUSIONS

Higher circulating fetuin-A levels were associated with increased risk of T2DM. However, the causality deserved further analysis.

Reduction of side effects of hyperbaric oxygen therapy with thymoquinone treatment in rats

INTRODUCTION

Hyperbaric oxygen (HBO₂) treatment results in elevated production of reactive oxygen species (ROS) that leads to cellular damage. Thymoquinone (TQ) is reported to have anti-inflammatory and antimicrobial activity and may suppress the generation of free radicals. The goal of this study is reduction of side effects of hyperbaric oxygen therapy with thymoquinone treatment.

METHODS

30 female Sprague-Dawley rats were randomly assigned to one of three groups (n = 10 per group). Group 1 represented the control group (no treatment). Group 2 was exposed to 100% oxygen at 2.5 ATA for two sessions of two hours'duration each day for five days. Group 3 was treated identically to Group 2 and was also given thymoquinone once daily at 50 mg/kg/day by oral gavage for five days, after first session of HBO₂.

RESULTS

LOOH and SH levels were significantly elevated in the group receiving HBO₂ treatment relative to the control group rats. Fetuin A is increased during TQ treatment. LOOH and SH levels were significantly decreased in animals treated with TQ.

CONCLUSIONS

Long-term and repeated HBO₂ treatment leads to damage to the lung tissue. In urgent situations or cases of severe hypoxia, repeated HBO₂ sessions may be necessary, and TQ antioxidant agents may be useful for prevention of HBO₂-associated injury. TQ may represent a useful therapeutic option during HBO₂ treatment.

Association of plasma fetuin-a levels with peripheral arterial disease and lower extremity arterial calcification in subjects with type 2 diabetes mellitus

AIMS

Fetuin-A is a hepatic glycoprotein that is involved in insulin resistance and atherosclerosis. Herein we examined the association of plasma fetuin-A levels with peripheral arterial disease (PAD) in patients with type 2 diabetes mellitus (T2DM).

MATERIAL AND METHODS

A total of 71 patients with T2DM and 57 non-diabetic individuals were recruited. Diagnosis of PAD was based on the absence of triphasic waveform at pedal arteries, while ankle-brachial index (ABI) was calculated. Radiographs of both feet and ankles were taken for the assessment of lower extremity arterial calcification (LEAC). Plasma fetuin-A levels were measured using ELISA.

RESULTS

Patients with T2DM had higher fetuin-A levels than non-diabetic participants. Participants with diabetes and PAD had lower fetuin-A levels than non-PAD diabetic patients. In subjects with T2DM fetuin-A levels were associated with ABI. Multivariate analysis demonstrated that in patients with T2DM the odds of PAD increased with long diabetes duration, smoking, presence of arterial hypertension and dyslipidemia, as well as with lower fetuin-A levels. A trend towards higher fetuin-A levels in subjects with less severe LEAC was found.

CONCLUSION

Plasma fetuin-A levels are lower in patients with T2DM and PAD and are associated with PAD, irrespective of traditional cardiovascular risk factors. Moreover, fetuin-A may be involved in arterial calcification.

α2-Heremans-schmid glycoprotein (fetuin A) downregulation and its utility in inflammatory bowel disease

AIM

To investigate the impact of inflammatory bowel disease (IBD) on α2-Heremans-Schmid Glycoprotein (AHSG/fetuin A) and potential associations with disease and patient characteristics.

METHODS

AHSG serum levels were determined in treatment-naïve newly-diagnosed patients, 96 with ulcerative colitis (UC), 84 with Crohn's disease (CD), 62 with diarrhea-predominant or mixed irritable bowel syndrome (IBS, D- and M- types) and 180 healthy controls (HC), by an enzyme linked immunosorbent assay (ELISA). All patients were followed for a minimum period of 3 years at the Gastroenterology Department of the University Hospital of Larissa, Greece. C-reactive protein (CRP), anti-glycan antibodies, anti-Saccharomyces cerevisiae mannan antibodies IgG, anti-mannobioside carbohydrate antibodies IgG, anti-laminariobioside carbohydrate antibodies IgG and anti-chitobioside carbohydrate antibodies IgA were also determined via immunonephelometry and ELISA, respectively.

RESULTS

The mean ± SE of serum AHSG, following adjustment for confounders, was 0.32 ± 0.02 g/L in IBD, 0.32 ± 0.03 g/L in CD and 0.34 ± 0.03 g/L in UC patients, significantly lower than in IBS patients (0.7 ± 0.018 g/L) and HC (0.71 ± 0.02 g/L) (P < 0.0001, in all cases). AHSG levels were comparable between the CD and UC groups. Based on AHSG levels IBD patients could be distinguished from HC with about 90% sensitivity and specificity. Further adjusted analysis verified the inverse association between AHSG and penetrating, as well as stricturing CD (partial correlation coefficient: -0.45 and -0.33, respectively) (P < 0.05). After adjusting for confounding factors, inverse correlations between AHSG and CRP and the need for anti-TNFα therapy or surgery, were found (partial correlation coefficients: -0.31, -0.33, -0.41, respectively, P < 0.05, in all cases). Finally, IBD individuals who were seropositive, for at least one marker, had AHSG levels falling within the two lower quartiles (OR = 2.86, 95%CI: 1.5-5.44, P < 0.001) while those with at least two serological markers positive exhibited AHSG concentrations within the lowest quartile (OR = 5.03, 95%CI: 2.07-12.21, P < 0.001), after adjusting for age, sex and smoking.

CONCLUSION

AHSG can be used to distinguish between IBD and IBS patients or HC while at the same time "predicting" complicated disease behavior, need for therapy escalation and surgery. Moreover, AHSG may offer new insights into the pathogenesis of IBD, since it is involved in key processes.

Fetuin-A and Risk of Diabetes Independent of Liver Fat Content: The Multi-Ethnic Study of Atherosclerosis

Fetuin-A is a hepatic secretory protein and a novel risk factor for diabetes. However, it remains unclear whether the association between high levels of fetuin-A and diabetes can be attributed to nonalcoholic fatty liver disease. We conducted a case-cohort study among 1,957 subcohort members and 455 incident diabetes cases in the Multi-Ethnic Study of Atherosclerosis, a multicenter US study of Caucasian, African-American, Hispanic, and Chinese-American adults aged 45-84 years. Serum fetuin-A and computed tomography-determined liver fat content were measured from samples collected at baseline (2000-2002). In multivariable Cox proportional hazards models with follow-up through 2012, a higher fetuin-A level was associated with a higher risk of diabetes, with a stronger association among women (for top quartile vs. bottom, hazard ratio (HR) = 3.36, 95% confidence interval (CI): 2.08, 5.44) than among men (HR = 1.47, 95% CI: 0.93, 2.35) (P-heterogeneity = 0.001). Adjustment for liver fat content attenuated these associations slightly (women: HR = 2.61, 95% CI: 1.59, 4.26; men: HR = 1.32, 95% CI: 0.84, 2.08). In this study, we observed a particularly strong association of fetuin-A with diabetes risk in women that could not be explained by liver fat.

Investigation of the inflammatory biomarkers of metabolic syndrome in adolescents

BACKGROUND

Metabolic syndrome (MetS) is a chronic and multifactorial syndrome characterized by a low-grade chronic inflammation, and a major risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). In our study, we aimed to investigate the serum levels of high sensitive C-reactive protein (hs-CRP), haptoglobin (Hp), α2-macroglobulin (α2-MG), platelet factor-4 (PF-4), fetuin-A, serum amyloid P (SAP) and α1-acid glycoprotein (AGP) in an adolescent population with MetS.

METHODS

This study was performed in 43 (18 males, 25 females) MetS adolescents between the ages of 13 and 17 years (14.70±1.15) and 43 lean controls were matched for age and sex. The serum levels of Hp, α2-MG, PF-4, fetuin-A, SAP and AGP were measured by using a multi-ELISA technique.

RESULTS

Serum Hp, fetuin-A (p<0.01) and PF-4, hs-CRP, SAP, AGP (p<0.001) values of the MetS subjects were significantly higher than those of the controls. No difference was found in serum α2-MG levels between the MetS and control groups (p=0.184).

CONCLUSIONS

This finding suggests the possibility of using these markers in diagnosis of MetS in adolescents to prevent future complications.

The diagnostic value of serum fucosylated fetuin A in hepatitis B virus-related liver diseases

BACKGROUND

Some changes of glycoproteins have been identified in the serum of patients with different liver diseases, which provided potential glycan biomarkers for diagnosis, prognosis and monitoring of disease progression.

METHODS

We established a lectin-antibody sandwich ELISA method to detect fucosylated fetuin A (fuc-fetuin A) level in serum, in which biotinylated Aleuria aurantia lectin (AAL) was used for specific recognition. Then serum fuc-fetuin A level was detected in 108 healthy controls and 548 hepatitis B virus (HBV)-infected patients, including 232 hepatocellular carcinoma (HCC) patients, 114 liver cirrhosis (LC) patients, 86 liver fibrosis (LF) patients, and 116 asymptomatic HBV carriers, to assess its diagnostic and prognostic value in HBV-related liver diseases.

RESULTS

Serum fetuin A level decreased in LC patients as compared to HCC patients or healthy controls, while it decreased further according to the increasing Child-Pugh grades. The fuc-fetuin A level was in a decreasing order in LC, HCC, LF, HBV-carriers and healthy controls. For distinguishing LC and HCC patients from LF, HBV-carriers and healthy controls, the area under the receiver operating characteristic (ROC) curve is 0.871, with a sensitivity of 0.818 and specificity of 0.819. The survival analysis revealed that higher fuc-fetuin A level was significantly associated with worse recurrence-free survival in HCC patients (p=0.018).

CONCLUSIONS

The results indicated that the serum fuc-fetuin A might serve as a potential glycan biomarker for distinguishing LC and HCC from LF, HBV-carriers and healthy controls. Furthermore, the preoperative fuc-fetuin A level could be a useful prognostic biomarker for HCC patients.

Alterations in serum levels of fetuin A and selenoprotein P in chronic hepatitis C patients with concomitant type 2 diabetes: A case-control study

BACKGROUND

Insulin resistance (IR) and type 2 diabetes mellitus (T2DM) are serious extrahepatic manifestations of chronic hepatitis C virus (HCV) infection. However, the mechanism underlying the IR in chronic HCV is obscure. Hepatokines are group of liver-derived protein, which affect the glucose and lipid metabolism in several tissues. Fetuin A (also known as human α2-HS-glycoprotein) is one of the hepatokines, which was recognized as a natural inhibitor of the insulin receptor tyrosine kinase in liver and skeletal muscle. Additionally, selenoprotein P has emerged as an important hepatokine, which primarily acts as selenium transporter and has been reported to be implicated in glucose homeostasis in human.

OBJECTIVE

The aim of the current case-control study was to investigate the serum levels of both fetuin A and selenoprotein P in chronic hepatitis C patients with or without T2DM and to correlate their levels with other biochemical parameters of insulin resistance.

MAIN FINDINGS

Our results showed that, serum fetuin A levels increased significantly in HCV patients compared with controls (P<0.01) and surplus increase was found in HCV with concomitant T2DM (P>0.001). However, selenoprotein P levels significantly elevated only in patients with both HCV and T2DM (P<0.05) compared with the healthy subjects. Both fetuin A and selenoprotein P were positively correlated with fasting blood glucose. Yet, only fetuin A was significantly correlated to the HOMA-IR (r=0.28; P=0.03).

CONCLUSIONS

These results indicate crucial roles played by fetuin A and selenoprotein P in the IR caused by HCV and that both hepatokines may be targets for the development of therapies to treat or inhibit insulin resistance associated to HCV. However, further studies on large scale should be conducted to confirm our findings.

Diabetes Associated Markers After Bariatric Surgery: Fetuin-A, but Not Matrix Metalloproteinase-7, Is Reduced

BACKGROUND

Recent studies showed that fetuin-A and matrix metalloproteinase-7 (MMP-7) are type 2 diabetes mellitus (T2DM)-associated markers. Bariatric surgery not only reduces body weight but also improves T2DM. This study aimed to investigate the changes of fetuin-A and MMP-7 in obese subjects with and without T2DM after bariatric surgery.

METHODS

We enrolled 130 obese subjects that received bariatric surgery, including 41 Roux-en-Y gastric bypass (RYGB), 67 mini-gastric bypass (MGB), and 22 sleeve gastrectomy (SG) patients. Forty-three patients suffered from T2DM prior to surgery. The fasting serum fetuin-A and MMP-7 levels were measured before and 1 year after surgery.

RESULTS

Only five of 43 patients remained diabetic after surgery. Preoperative T2DM patients had higher fetuin-A and MMP-7 levels than non-T2DM subjects. RYGB, MGB, and SG all decreased the fetuin-A levels 1 year after the operation. The MMP-7 levels were not changed after RYGB, MGB, or SG. In multivariate analyses, the preoperative fetuin-A was significantly related to the diastolic blood pressure (DBP) and glycosylated hemoglobin (HbA1c), while the postoperative fetuin-A was independently related to the waist-to-hip ratio and HbA1c. Moreover, the preoperative MMP-7 level was significantly related to age, DBP, aspartate transaminase, alanine transaminase, and gamma-glutamyl transferase (rGT), while the postoperative MMP-7 level was independently related to age and rGT.

CONCLUSIONS

The fetuin-A and MMP-7 levels are both higher in obese T2DM than non-T2DM subjects. The level of fetuin-A is reduced after RYGB, MGB, and SG, but the level of MMP-7 remains unchanged.

Relation of fetuin A levels with cardiac, subcutaneous lipid accumulation and insulin resistance parameters in Turkish obese children

BACKGROUND

Fetuin A is an inhibitor of insulin action and have been found to be related with subcutaneous lipid accumulation and insulin resistance. The relation of cardiac lipid accumulation, fetuin A and insulin resistance parameters in obese children is not well-known. The aim of the study was to evaluate the relation of serum fetuin A levels with subcutaneous and cardiac lipid accumulation, and insulin resistance parameters in Turkish obese children.

METHODS

Serum fetuin A levels, cardiac and subcutaneous lipid accumulation parameters of 42 obese (10.9±2.3 years, 19 female) and 40 control group subjects (11.2±2.7) were compared. Cardiac lipid accumulation measured by subepicardial adipose tissue thickness. Insulin resistance was assessed using homeostasis model assessment (HOMA-IR) index.

RESULTS

There were significant correlations serum fetuin A levels with BMI-SDS, circumferences of waist, hip and midarm, SATT and HOMA-IR (r=0.362, p=0.018, r=0.728, p=0.001, r=0.662, p=0.0001, r=0.713, p=0.0001, r=0.477, p=0.001, and r=0.330, p=0.038 as, respectively).

CONCLUSIONS

Fetuin A was correlated well with cardiac and subcutaneous lipid accumulation, insulin resistance parameters, which may be related with early pathogenetic mechanisms of metabolic obesity complications in children.

Inflammatory Markers in Obese Adolescents with Type 2 Diabetes and Their Relationship to Hepatokines and Adipokines

OBJECTIVES

To analyze inflammatory markers, adipokines, and hepatokines in obese adolescents with and without type 2 diabetes mellitus (T2DM).

STUDY DESIGN

We studied high sensitivity C-reactive protein (hsCRP), tumor necrosis factor (TNF)-α, interleukin-1β, and interferon-γ, the hepatokines (fetuin-A and fibroblast growth factor [FGF]-21), and the adipokines (adiponectin and leptin) in a cross-sectional study of 74 predominately Caucasian adolescents with T2DM aged 12-18 years and in 74 body mass index (BMI)-, age-, and sex-matched controls.

RESULTS

Adolescents with T2DM had significantly higher concentrations of hsCRP, TNF-α, and interleukin-1β compared with obese controls without T2DM. Interferon-γ was not detectable in obese adolescents with or without T2DM. In multiple linear regression analysis, hsCRP was significantly associated with FGF-21 and BMI, but not with hemoglobin A1c, adiponectin, leptin, fetuin-A, sex, or age. TNF-α was significantly related negatively to leptin, positively to BMI, but not to hemoglobin A1c, adiponectin, fetuin-A, FGF-21 sex, or age in multiple linear regression analysis.

CONCLUSIONS

Increased inflammatory markers are associated with T2DM in adolescents. Because hsCRP was related to FGF-21 and TNF-α was associated with leptin, these findings suggest a link between increased levels of these adipokines and hepatokines and chronic inflammation. Future longitudinal studies in humans are necessary to confirm these hypotheses.

High-Flux Hemodialysis and High-Volume Hemodiafiltration Improve Serum Calcification Propensity

Background

Calciprotein particles (CPPs) may play an important role in the calcification process. The calcification propensity of serum (T₅₀) is highly predictive of all-cause mortality in chronic kidney disease patients. Whether T₅₀ is therapeutically improvable, by high-flux hemodialysis (HD) or hemodiafiltration (HDF), has not been studied yet.

Methods

We designed a cross-sectional single center study, and included stable prevalent in-center dialysis patients on HD or HDF. Patients were divided into two groups based on dialysis modality, were on a thrice-weekly schedule, had a dialysis vintage of > 3 months and vascular access providing a blood flow rate > 300 ml/min. Calcification propensity of serum was measured by the time of transformation from primary to secondary CPP (T₅₀ test), by time-resolved nephelometry.

Results

We included 64 patients, mean convective volume was 21.7L (SD 3.3L). In the pooled analysis, T₅₀ levels increased in both the HD and HDF group with pre- and post-dialysis (mean (SD)) of 244(64) - 301(57) and 253(55) - 304(61) min respectively (P = 0.43(HD vs. HDF)). The mean increase in T₅₀ was 26.29% for HD and 21.97% for HDF patients (P = 0.61 (HD vs. HDF)). The delta values (Δ) of calcium, phosphate and serum albumin were equal in both groups. Baseline T₅₀ was negatively correlated with phosphate, and positively correlated with serum magnesium and fetuin-A. The ΔT₅₀ was mostly influenced by Δ phosphate (r = -0.342; P = 0.002 HD and r = -0.396; P<0.001 HDF) in both groups.

Conclusions

HD and HDF patients present with same baseline T50 calcification propensity values pre-dialysis. Calcification propensity is significantly improved during both HD and HDF sessions without significant differences between both modalities.

Relationship between fetuin-A, bone turnover and inflammatory markers concentrations in serum of maintenance hemodialyzed patients

INTRODUCTION

Fetuin-A plays an important role in bone turnover and vascular calcification.

AIM

The aim of the study was to assess the relationship between serum fetuin-A concentrations, inflammatory and bone turnover markers of patients on maintenance hemodialysis.

MATERIALS AND METHODS

The study was performed in 71 patients (21 women, 40 men) aged 60 ± 12 years on chronic dialysis because of end-stage renal failure for a period of 75 ± 57.2 months. The routine laboratory tests were performed with Modular P analyzer (Roche Diagnostics), serum concentrations of iPTH were measured using Nichols method, hsCRP and IL-6 using nephelometric techniques while fetuin-A, bone-specific alkaline phosphatase (bALP), fully carboxylated osteocalcin (cOC), undercarboxylated osteocalcin (ucOC), and fibroblast growth factor-23 (FGF-23) were measured using commercially available ELISA kits.

RESULTS

Concentrations of fetuin-A were significantly positively correlated with albumin (r=0.37, p=0.003) and negatively associated with patients age (r=26, p=0.04), log (iPTH) (r=0.31, p=0.02), log (CRP) (r=0.31, p=0.02), log (IL-6) (r=0.41, p=0.001), log (ucOC) (r=-0.29, p=0.02), and log (FGF-23) (r=0.27, p=0.04).

CONCLUSIONS

1. Patients on maintenance hemodialysis suffer from severe disturbances of bone turnover. 2. Low serum fetuin-A levels are associated with increase markers of bone turnover and inflammation.

The Successful Treatment of Calciphylaxis with Sodium Thiosulfate and Hyperbaric Oxygen in a Non-dialyzed Patient with Chronic Kidney Disease

We present the case of a non-dialyzed patient with chronic kidney disease and biopsy-proven calciphylaxis who presented with painful cutaneous ulcers on both legs. The skin ulcers drastically improved within 6 months after the initiation of hemodialysis, aggressive wound care, the control of a mineral and bone disorder, and the administration of sodium thiosulfate and hyperbaric oxygen therapy. Notably, the patient's serum levels of C-reactive protein and calciprotein particles decreased and her serum albumin and fetuin-A levels increased in parallel with the alleviation of her calciphylaxis. This case highlights the importance of applying combined medical treatment to calciphylaxis and suggests the possible involvement of calciprotein particles in the pathogenesis of calciphylaxis.

Comparative effects of metformin and pioglitazone on fetuin-A and osteoprotegerin concentrations in patients with newly diagnosed diabetes: A randomized clinical trial

AIMS

Fetuin-A is a circulating glycoprotein capable of inhibiting insulin signaling both in vivo and in vitro and is positively associated with insulin resistance. Osteoprotegerin (OPG) acts as a regulatory molecule with increased levels in the early stages of diabetes and atherosclerosis, and is also associated with insulin resistance. We investigated the effects of pioglitazone and metformin as representative insulin-sensitizing therapies on fetuin-A and OPG levels.

MATERIALS AND METHODS

In a randomized clinical trial setting (NCT02027103), 88 patients with newly diagnosed type 2 diabetes were randomly assigned to pioglitazone (30 mg/day, n=46) or metformin (1000 mg/day, n=42) for 12 weeks. Various anthropometric and metabolic parameters, fetuin-A, OPG, highly sensitive C-reactive protein (hsCRP), and homeostasis model assessment of insulin resistance (HOMA-IR) were measured at baseline and after three months.

RESULTS

The reduction in fasting plasma glucose and haemoglobin A1c levels was comparable in the two arms. Pioglitazone resulted in a significant reduction in both fetuin-A and OPG in men, but only fetuin-A in women. Metformin was only effective in lowering OPG levels in women. When compared, both medications were equally effective with regard to fetuin-A and OPG reduction in women (p=0.413 and 0.359, respectively). In men, pioglitazone more effectively decreased fetuin-A levels in both uni- (p=0.011) and multivariate models (p=0.015) and OPG levels in only uni- (p=0.023) but not the multivariate model (p=0.547).

CONCLUSIONS

Metformin and pioglitazone differentially affect fetuin-A and osteoprotegrin levels in diabetic women and men. The level of change may not necessarily be associated with the amelioration of insulin resistance.

Serum fetuin-A levels and abdominal aortic calcification in healthy men - The STRAMBO study

Vascular calcification results from an imbalance between increased extracellular levels of calcium and phosphate, reduced solubility, and low levels of calcification inhibitors in blood or the vascular wall. Fetuin-A is a major circulating calcification inhibitor. Rodent models of fetuin-A deficit indicate its calcification inhibiting potential. Clinical studies suggest its role as a biomarker in vascular disease. This cross-sectional study was performed in a cohort of 974 men aged ≥ 40 years (average 68 years) consisting of men holding health insurance cover with Mutuelle des Travailleurs de la Région Lyonnaise. Abdominal aortic calcification (AAC) was assessed semi-quantitatively on lateral dual energy X-ray absorptiometry (DXA) spine scans. Serum fetuin-A was measured by an immunoassay. After adjustment for confounders (age, lifestyle, body composition, health status, treatment, glomerular filtration rate [GFR], hormones, and cytokines), prevalence of severe AAC (AAC score>4) decreased with increasing fetuin-A levels (OR=0.68 per SD increase, 95% CI: 0.54-0.84, p<0.001). After adjustment for confounders, low fetuin-A and hypertension were each associated with higher odds of AAC>4. Coexistence of low serum fetuin-A levels and heavy smoking, elevated fibroblast growth factor 23 levels or low serum dickkopf-1 levels were associated with higher odds of AAC>4. Similar results were obtained for 789 men with GFR>60 mL/min/1.73 m(2). Similar results were obtained when severe AAC was defined as AAC score >3 or AAC>5. Thus, lower serum fetuin-A levels are associated with severe AAC, suggesting that poor calcification inhibitory potential contributes to vascular calcification, independently of renal impairment.

Fetuin A as a new marker of inflammation in Hashimoto thyroiditis

AIM

Fetuin-A levels are reported to be low as a negative acute phase reactant in systemical inflammatory situations. Hashimoto thyroiditis is characterized with inflammation. In this study, we hypothesised that the serum fetuin A levels could be found to be low due to inflammation in patients with Hashimoto thyroiditis. For this purpose, serum fetuin A levels in patients with Hashimoto thyroiditis were compared with those in healthy subjects.

METHODS

A total of 85 participants (11 male, 74 female, mean age: 38.60±10.14 years) were included. The patient group consisted of 44 Hashimoto thyroiditis patients with subclinical hypothyroidism (7 male, 37 female) and the control group consisted of 41 healthy subjects (4 male, 37 female). Groups were compared according to their demographic, anthropometric and biochemical data and serum fetuin-A levels. Correlation analysis was used for determining the relation between fetuin A levels and clinical parameters.

RESULTS

Fetuin-A levels of the patient group were found lower than those of the control group (0.58±0.50 g/L versus 1.53±1.60 g/L, P=0.001). Fetuin-A levels were not correlated with clinical parameters such as TSH, C-reactive protein, body mass index, waist circumference, blood pressure, glucose, and lipids.

CONCLUSION

These findings supported the hypothesis that serum fetuin A levels could be found to be low as a negative acute phase reactant in patients with Hashimoto thyroiditis. Fetuin A can be considered as an indicator of inflammation in Hashimoto thyroiditis.

Evaluation of fetuin-A and carotid intima-media thickness in adolescent type 1 diabetic patients

OBJECTIVE

To evaluate fetuin-A level and carotid intima-media thickness (CIMT) in adolescent type 1 diabetics.

PATIENTS AND METHODS

The study included 62 type 1 diabetic patients and 30 healthy volunteers of the same age and sex. Blood sample was taken for assessment of glycosylated hemoglobin (HbA1), lipid profile, and fetuin-A. Urine sample was also taken for assessment of albumin/creatinine ratio. Anthropometric measurements were taken, including weight, height, and waist and hip circumference. CIMT was assessed for all patients and controls.

RESULTS

Serum fetuin-A, Rt., Lt. and both CIMT were significantly higher in diabetics. Fetuin-A had a significant positive correlation with duration of disease, waist and hip circumference, BMI, BMI SDS, waist/height ratio, Rt., Lt. and both CIMT. Stepwise multiple regression analysis revealed that the duration of disease, waist/height ratio, and HDL-c were the factors related to fetuin-A.

CONCLUSION

Adolescent type 1 diabetic patients have high fetuin-A levels and increased CIMT, with the latter representing the development of early atherosclerosis. In this light, adolescents with type 1 diabetes require frequent follow up for early detection of atherosclerosis.

Comparison of pre- and post-levothyroxine high-sensitivity c-reactive protein and fetuin-a levels in subclinical hypothyroidism

OBJECTIVE

The objective of this trial was to determine the levels of inflammatory markers, high-sensitivity C-reactive protein and fetuin-A pre- and post-levothyroxine treatment in cases of subclinical hypothyroidism.

MATERIALS AND METHODS

A total of 32 patients with a diagnosis of subclinical hypothyroidism and a control group of 30 healthy individuals were tested for high-sensitivity C-reactive protein and fetuin-A, followed by the administration of 50 µg of levothyroxine in the patient group for 3 months. During the post-treatment stage, high-sensitivity C-reactive protein and fetuin-A levels in the patient group were re-assessed and compared with pre-treatment values.

RESULTS

Pre-treatment levels of both high-sensitivity C-reactive protein and fetuin-A were observed to be higher in the patient group than in the control group. The decrease in high-sensitivity C-reactive protein levels during the post-treatment stage was not statistically significant. However, the decrease observed in post-treatment fetuin-A levels was found to be statistically significant.

CONCLUSION

The decrease in fetuin-A levels in subclinical hypothyroidism cases indicates that levothyroxine treatment exerts anti-inflammatory and anti-apoptotic effects. Although the decrease in high-sensitivity C-reactive protein levels was statistically non-significant, it is predicted to reach significance with sustained treatment.