Serum visfatin is associated with type 2 diabetes mellitus independent of insulin resistance and obesity

Expression of visfatin in the ovarian follicles of prepubertal and mature gilts and in vitro effect of gonadotropins, insulin, steroids, and prostaglandins on visfatin levels

Recent studies have demonstrated that visfatin participates in the regulation of female reproduction. Due to the lack of data concerning the level of visfatin in the ovarian follicles of pigs, one of the most economically important livestock species, the aim of this study was to investigate the expression and localisation of visfatin and the follicular fluid concentration in the ovarian follicles of prepubertal and mature gilts. We also aimed to examine the in vitro effects of gonadotropins (LH, FSH), insulin, progesterone (P4), oestradiol (E2), prostaglandin E2 (PGE2) and F2α (PGF2α) on visfatin levels. In the present study, we have demonstrated that visfatin expression is dependent on the maturity of the animals and the stage of ovarian follicle development. Visfatin signal was detected in individual follicular compartments from primordial to antral follicles and even in atretic follicles. We have shown that the expression of visfatin in granulosa cells was higher than in theca cells. The level of visfatin is upregulated by LH, FSH, E2, and P4 and downregulated by insulin, while prostaglandins have modulatory effects, dependent on the dose and type of ovarian follicular cells. To summarise, our research has shown that visfatin is widely expressed in the ovarian follicles of prepubertal and mature pigs, and its expression is regulated by gonadotropins, insulin, steroids, and prostaglandins, suggesting that visfatin appears to be an important intra-ovarian factor that could regulate porcine ovarian follicular function.

Extracellular nicotinamide phosphoribosyltransferase: role in disease pathophysiology and as a biomarker

Nicotinamide phosphoribosyltransferase (NAMPT) plays a central role in mammalian cell metabolism by contributing to nicotinamide adenine dinucleotide biosynthesis. However, NAMPT activity is not limited to the intracellular compartment, as once secreted, the protein accomplishes diverse functions in the extracellular space. Extracellular NAMPT (eNAMPT, also called visfatin or pre-B-cell colony enhancing factor) has been shown to possess adipocytokine, pro-inflammatory, and pro-angiogenic activities. Numerous studies have reported the association between elevated levels of circulating eNAMPT and various inflammatory and metabolic disorders such as obesity, diabetes, atherosclerosis, arthritis, inflammatory bowel disease, lung injury and cancer. In this review, we summarize the current state of knowledge on eNAMPT biology, proposed roles in disease pathogenesis, and its potential as a disease biomarker. We also briefly discuss the emerging therapeutic approaches for eNAMPT inhibition.

Assessment of serum and salivary visfatin levels in newly diagnosed patients of type-II DM

Background

Type II diabetes mellitus (T2DM) is a metabolic disorder. It is thought to be an autoinflammatory disease, as inflammatory mediators are associated with the progression of the disease. Visfatin, an adipokine, is linked to insulin resistance.

Aims

We aimed to study serum and salivary visfatin levels, at the time of diagnosis of T2DM, in middle-aged individuals, in the context of other diagnostic parameters like fasting blood sugar (FBS), postprandial blood sugar (PPBS), and glycated haemoglobin A1c (HbA1c).

Materials and Methods

Thirty newly diagnosed T2DM (Group-I, T2DM) patients and 30 healthy nondiabetic individuals (Group-II, health controls [HC]) matched for age and sex were studied. In both the groups, we assessed serum and salivary visfatin levels, and serum high-sensitivity C-reactive protein (hs-CRP) levels. We also compared serum and salivary visfatin levels and serum hs-CRP levels between Group-I and Group-II individuals.

Statistical Analysis

The correlation between the groups was tested using Pearson's correlation. A P- value < 0.001 was considered to be statistically significant. The data was tabulated using software MS Excel and analysed using IBM Statistical Package for the Social Sciences (SPSS) Version 22.0.

Results

A positive correlation with a value of 0.8836 and a P value of 0.001 was noted between serum and salivary visfatin of Group-I.

Conclusion

This is the first study in the Indian scenario to study the serum and salivary visfatin in newly diagnosed T2DM individuals. Serum visfatin and hs-CRP levels increased in T2DM, thus defining the link between visfatin, inflammation and T2DM, but we failed to notice a positive correlation.

Molecular Background and Clinical Implications of Glucose Disorders in Patients with Psoriatic Arthritis

Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease characterized by joint and entheses involvement. This condition is often associated with an increased prevalence of obesity, encompassing more than one-third of all patients. Given the presence of metabolic disorders, it becomes crucial to enhance clinical oversight of metabolic parameters. An early diagnosis of glucose irregularities in PsA allows for the assessment of an effective treatment strategy. The approach proves valuable in preventing the development of insulin resistance (IR) or diabetes mellitus type 2 (DMt2). Similar pathways characterize the pathomechanism of PsA and DMt2, offering an innovative perspective on treatment management. The cytokines and adipokines synthesized in the course of PsA significantly impact the development process of IR and DMt2 in different mechanisms of action. Conversely, glucose disorders influence the activity of PsA and therapy outcomes. Given the chronic inflammatory background shared by PsA, obesity, and DMt2, it is evident that inadequate management of any of the mentioned conditions can exacerbate the others. Thus, when PsA coincides with DMt2, a comprehensive multidimensional approach is necessary. This includes an effective immunosuppressive regimen complemented by appropriate anti-diabetic and insulin therapies. Moreover, often overlooked recommendations concerning overall well-being and lifestyle adjustments hold significance. This manuscript explores the connections and the relationship between the molecular background of PsA and glucose disorders. It provides a detailed exposition of specific therapeutic approaches for both conditions.

Associations between the levels of circulating inflammatory adipokines and the risk of type 2 diabetes in Chinese male individuals: A case-control study

BACKGROUND

Whether the levels of circulating inflammatory adipokines affect the progression of type 2 diabetes (T2D) remains unclear. This study aimed to assess the association between circulating inflammatory adipokine levels and risk of T2D.

METHODS

This case-control study involved 130 individuals consisting of 66 healthy controls (Control group) and 64 patients with T2D (T2D group) in Lishui Municipal Central Hospital from January 2017 to June 2017. Multivariate logistic regression analysis was applied to assess the associations between circulating inflammatory adipokine levels and the risk of T2D.

RESULTS

There were significant differences in the levels of adiponectin (p = 0.013) and visfatin (p < 0.001) between the T2D and Control groups. In contrast, no significant differences in leptin (p = 0.113), TNF-α (p = 0.632), and IL-6 (p = 0.156) levels were found between the groups. Multivariate logistic regression indicated that elevated visfatin level was associated with an increased risk of T2D (OR: 3.543; 95% CI: 1.771-7.088; p < 0.001), while adiponectin (OR: 1.946; 95% CI: 0.925-4.094; p = 0.079), leptin (OR: 3.723; 95% CI: 0.788-17.583; p = 0.097), TNF-α (OR: 1.081; 95% CI: 0.911-1.281; p = 0.373), and IL-6 (OR: 0.878; 95% CI: 0.657-1.173; p = 0.379) were not associated with the risk of T2D.

CONCLUSIONS

This study found elevated visfatin levels are associated with an increased risk of T2D, while adiponectin, leptin, TNF-α, and IL-6 are not. These findings should be further verified by a large-scale prospective study.

Adipose Tissue Secretion Pattern Influences β-Cell Wellness in the Transition from Obesity to Type 2 Diabetes

The dysregulation of the β-cell functional mass, which is a reduction in the number of β-cells and their ability to secure adequate insulin secretion, represents a key mechanistic factor leading to the onset of type 2 diabetes (T2D). Obesity is recognised as a leading cause of β-cell loss and dysfunction and a risk factor for T2D. The natural history of β-cell failure in obesity-induced T2D can be divided into three steps: (1) β-cell compensatory hyperplasia and insulin hypersecretion, (2) insulin secretory dysfunction, and (3) loss of β-cell mass. Adipose tissue (AT) secretes many hormones/cytokines (adipokines) and fatty acids that can directly influence β-cell function and viability. As this secretory pattern is altered in obese and diabetic patients, it is expected that the cross-talk between AT and pancreatic β-cells could drive the maintenance of the β-cell integrity under physiological conditions and contribute to the reduction in the β-cell functional mass in a dysmetabolic state. In the current review, we summarise the evidence of the ability of the AT secretome to influence each step of β-cell failure, and attempt to draw a timeline of the alterations in the adipokine secretion pattern in the transition from obesity to T2D that reflects the progressive deterioration of the β-cell functional mass.

Co‑expressed microRNAs, target genes and pathways related to metabolism, inflammation and endocrine function in individuals at risk for type 2 diabetes

MicroRNAs (miRNAs) may be considered important regulators of risk for type 2 diabetes (T2D). The aim of the present study was to identify novel sets of miRNAs associated with T2D risk, as well as their gene and pathway targets. Circulating miRNAs (n=59) were measured in plasma from participants in a previously completed clinical trial (n=82). An agnostic statistical approach was applied to identify novel sets of miRNAs with optimal co-expression patterns. In silico analyses were used to identify the messenger RNA and biological pathway targets of the miRNAs within each factor. A total of three factors of miRNAs were identified, containing 18, seven and two miRNAs each. Eight biological pathways were revealed to contain genes targeted by the miRNAs in all three factors, 38 pathways contained genes targeted by the miRNAs in two factors, and 55, 18 and two pathways were targeted by the miRNAs in a single factor, respectively (all q<0.05). The pathways containing genes targeted by miRNAs in the largest factor shared a common theme of biological processes related to metabolism and inflammation. By contrast, the pathways containing genes targeted by miRNAs in the second largest factor were related to endocrine function and hormone activity. The present study focused on the pathways uniquely targeted by each factor of miRNAs in order to identify unique mechanisms that may be associated with a subset of individuals. Further exploration of the genes and pathways related to these biological themes may provide insights about the subtypes of T2D and lead to the identification of novel therapeutic targets.

eNAMPT actions through nucleus accumbens NAD+/SIRT1 link increased adiposity with sociability deficits programmed by peripuberty stress

Obesity is frequently associated with impairments in the social domain, and stress at puberty can lead to long-lasting changes in visceral fat deposition and in social behaviors. However, whether stress-induced changes in adipose tissue can affect fat-to-brain signaling, thereby orchestrating behavioral changes, remains unknown. We found that peripubertally stressed male-but not female-mice exhibit concomitant increased adiposity and sociability deficits. We show that reduced levels of the adipokine nicotinamide phosphoribosyltransferase (NAMPT) in fat and its extracellular form eNAMPT in blood contribute to lifelong reductions in sociability induced by peripubertal stress. By using a series of adipose tissue and brain region-specific loss- and gain-of-function approaches, we implicate impaired nicotinamide adenine dinucleotide (NAD+)/SIRT1 pathway in the nucleus accumbens. Impairments in sociability and accumbal neuronal excitability are prevented by normalization of eNAMPT levels or treatment with nicotinamide mononucleotide (NMN), a NAD+-boosting compound. We propose NAD+ boosters to treat social deficits of early life stress origin.

Analysis of an Indian diabetes prevention programme on association of adipokines and a hepatokine with incident diabetes

To study the association and possible predictive role of visfatin, resistin, fetuin-A and chemerin with incident type 2 diabetes (T2DM) among Asian Indians with prediabetes. Their association with insulin resistance, β-cell function, glycaemia and anthropometry were also studied. This is a nested case-control study of a large 2-year prospective prevention trial in persons at high risk of developing T2DM. Baseline HbA1c values between 6.0% (42 mmol/mol) and 6.2% (44 mmol/mol) were chosen for this analysis (n = 144). At follow-up, persons with incident T2DM (HbA1c ≥ 6.5%, 48 mmol/mol) were grouped as cases (n = 72) and those reverted to normoglycaemia, (HbA1c < 5.7% (39 mmol/mol) as controls (n = 72). Insulin resistance showed the strongest association with incident T2DM ((Odds Ratio (OR): 23.22 [95%CI 6.36-84.77]; p < 0.0001). Baseline visfatin (OR: 6.56 [95%CI 2.21-19.5]; p < 0.001) and fetuin-A (OR: 1.01 [95%CI (1.01-1.04)]; p < 0.0001) independently contributed to the conversion of prediabetes to T2DM. The contribution was significantly higher when their elevated levels coexisted (OR: 12.63 [95%CI 3.57-44.63]; p < 0.0001). The area under the curve was 0.77 ± SE 0.4 (95%CI 0.69-0.85) and 0.80 ± SE 0.04 (95%CI 0.73-0.88) for visfatin (median 17.7 ng/ml, sensitivity and specificity: 75%, p < 0.0001) and fetuin-A (mean 236.2 µg/ml, sensitivity: 71%, specificity: 75%, p < 0.0001) respectively. Higher baseline visfatin and fetuin-A concentrations are strongly associated with incident T2DM and are predictive of future diabetes.

eNAMPT Is Localised to Areas of Cartilage Damage in Patients with Hip Osteoarthritis and Promotes Cartilage Catabolism and Inflammation

Obesity increases the risk of hip osteoarthritis (OA). Recent studies have shown that adipokine extracellular nicotinamide phosphoribosyltransferase (eNAMPT or visfatin) induces the production of IL-6 and matrix metalloproteases (MMPs) in chondrocytes, suggesting it may promote articular cartilage degradation. However, neither the functional effects of extracellular visfatin on human articular cartilage tissue, nor its expression in the joint of hip OA patients of varying BMI, have been reported. Hip OA joint tissues were collected from patients undergoing joint replacement surgery. Cartilage explants were stimulated with recombinant human visfatin. Pro-inflammatory cytokines and MMPs were measured by ELISA and Luminex. Localisation of visfatin expression in cartilage tissue was determined by immunohistochemistry. Cartilage matrix degradation was determined by quantifying proteoglycan release. Expression of visfatin was elevated in the synovial tissue of hip OA patients who were obese, and was co-localised with MMP-13 in areas of cartilage damage. Visfatin promoted the degradation of hip OA cartilage proteoglycan and induced the production of pro-inflammatory cytokines (IL-6, MCP-1, CCL20, and CCL4) and MMPs. The elevated expression of visfatin in the obese hip OA joint, and its functional effects on hip cartilage tissue, suggests it plays a central role in the loss of cartilage integrity in obese patients with hip OA.

ANGPTL8/Betatrophin Improves Glucose Tolerance in Older Mice and Metabolomic Analysis Reveals Its Role in Insulin Resistance in HepG2 Cells

BACKGROUND

Insulin resistance is a determining factor in the pathophysiology of type 2 diabetes mellitus (T2DM). Angiopoietin-like protein 8 (ANGPTL8, also known as betatrophin), associated with glucose homeostasis and lipid metabolism, has attracted attention. But its mechanism in glucose metabolism remains unclear. This study aimed to explore the effect of ANGPTL8/betatrophin on glucose tolerance in Kunming (KM) mice of different ages and metabolic profiles in insulin-resistant HepG2 cells. Our study may provide a new perspective of ANGPTL8/betatrophin in insulin resistance from the metabolic changes.

METHODS

Oral glucose tolerance test was performed in KM mice of different ages. Insulin concentration was measured by using a quantitative enzyme-linked immunosorbent assay (ELISA). ANGPTL8/betatrophin knockouts in HepG2 cells were established with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) protein 9 (CRISPR/Cas9) system. Cell counting kit-8 (CCK-8) assay was used to determine cell viability after gene knockout. The effect of ANGPTL8/betatrophin on the metabolomic changes was evaluated in high insulin-induced insulin-resistant HepG2 cells by an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method.

RESULTS

ANGPTL8/betatrophin improved glucose tolerance in older mice not by altering the concentration of insulin. Cell growth was affected in ANGPTL8/betatrophin knockout HepG2. Based on UPLC-MS/MS, compared with wild type insulin-resistant HepG2 cells, we identified 83 differential metabolites in ANGPTL8/betatrophin knockout HepG2 cells after high insulin induction. Among the 14 differential up-regulated metabolites, D-mannose had the highest fold change. In insulin-resistant HepG2 cells, ANGPTL8/betatrophin knockout exerted an effect on the amino acid metabolism, carbohydrate metabolism, metabolism of cofactors and vitamins, lipid metabolism, nucleotide metabolism, and genetic information processing pathway.

CONCLUSION

This study identified the effect of ANGPTL8/betatrophin on glucose tolerance in mice of different ages and metabolic profiles in insulin-resistant HepG2 cells. These findings may contribute to a new understanding of its role in glucose metabolism in the context of insulin resistance.

Evaluation of Serum Biomarkers in Patients with Sarcoidosis: Can Visfatin Be a New Biomarker for Sarcoidosis?

OBJECTIVES

Sarcoidosis is a chronic systemic inflammatory disease that affects multiple organ systems. The role of biomarkers in the diagnosis and prognosis of sarcoidosis is increasing. Interest in the role of adipose tissue-mediated inflammation in the pathogenesis of inflammatory diseases has increased in recent years. Visfatin is a proinflammatory adipocytokine that has been studied for several inflammatory diseases such as diabetes mellitus, obesity, and metabolic syndrome. We aimed to assess serum visfatin levels in sarcoidosis and its relationship with other markers of inflammation such as C-reactive protein (CRP), angiotensin-converting enzyme (ACE) and erythrocyte sedimentation rate (ESR).

MATERIALS AND METHODS

We enrolled 59 patients with sarcoidosis and 21 healthy controls and measured plasma levels of visfatin, along with serum CRP, ESR, and ACE using ELISA (enzyme-linked immunosorbent assay) kits (Blue Gene Biotech, Shanghai, China).

RESULTS

Visfatin levels did not differ significantly between the patients and control subjects (29.9±15.8 ng/mL for patients and 23.93±16.73 ng/mL for controls, p=0.15), and there was no correlation between visfatin and serum CRP, ACE, or ESR in patients with sarcoidosis.

CONCLUSION

Visfatin is recently being discussed as a biomarker for inflammatory diseases in several studies, and results are controversial. In our study, no differences were found in the serum levels of visfatin between patients with sarcoidosis and the control group.

Structure-functional changes in eNAMPT at high concentrations mediate mouse and human beta cell dysfunction in type 2 diabetes

AIMS/HYPOTHESIS

Progressive decline in functional beta cell mass is central to the development of type 2 diabetes. Elevated serum levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT) are associated with beta cell failure in type 2 diabetes and eNAMPT immuno-neutralisation improves glucose tolerance in mouse models of diabetes. Despite this, the effects of eNAMPT on functional beta cell mass are poorly elucidated, with some studies having separately reported beta cell-protective effects of eNAMPT. eNAMPT exists in structurally and functionally distinct monomeric and dimeric forms. Dimerisation is essential for the NAD-biosynthetic capacity of NAMPT. Monomeric eNAMPT does not possess NAD-biosynthetic capacity and may exert distinct NAD-independent effects. This study aimed to fully characterise the structure-functional effects of eNAMPT on pancreatic beta cell functional mass and to relate these to beta cell failure in type 2 diabetes.

METHODS

CD-1 mice and serum from obese humans who were without diabetes, with impaired fasting glucose (IFG) or with type 2 diabetes (from the Body Fat, Surgery and Hormone [BodyFatS&H] study) or with or at risk of developing type 2 diabetes (from the VaSera trial) were used in this study. We generated recombinant wild-type and monomeric eNAMPT to explore the effects of eNAMPT on functional beta cell mass in isolated mouse and human islets. Beta cell function was determined by static and dynamic insulin secretion and intracellular calcium microfluorimetry. NAD-biosynthetic capacity of eNAMPT was assessed by colorimetric and fluorescent assays and by native mass spectrometry. Islet cell number was determined by immunohistochemical staining for insulin, glucagon and somatostatin, with islet apoptosis determined by caspase 3/7 activity. Markers of inflammation and beta cell identity were determined by quantitative reverse transcription PCR. Total, monomeric and dimeric eNAMPT and nicotinamide mononucleotide (NMN) were evaluated by ELISA, western blot and fluorometric assay using serum from non-diabetic, glucose intolerant and type 2 diabetic individuals.

RESULTS

eNAMPT exerts bimodal and concentration- and structure-functional-dependent effects on beta cell functional mass. At low physiological concentrations (~1 ng/ml), as seen in serum from humans without diabetes, eNAMPT enhances beta cell function through NAD-dependent mechanisms, consistent with eNAMPT being present as a dimer. However, as eNAMPT concentrations rise to ~5 ng/ml, as in type 2 diabetes, eNAMPT begins to adopt a monomeric form and mediates beta cell dysfunction, reduced beta cell identity and number, increased alpha cell number and increased apoptosis, through NAD-independent proinflammatory mechanisms.

CONCLUSIONS/INTERPRETATION

We have characterised a novel mechanism of beta cell dysfunction in type 2 diabetes. At low physiological levels, eNAMPT exists in dimer form and maintains beta cell function and identity through NAD-dependent mechanisms. However, as eNAMPT levels rise, as in type 2 diabetes, structure-functional changes occur resulting in marked elevation of monomeric eNAMPT, which induces a diabetic phenotype in pancreatic islets. Strategies to selectively target monomeric eNAMPT could represent promising therapeutic strategies for the treatment of type 2 diabetes.

Serum visfatin levels in patients with axial spondyloarthritis and their relationship to disease activity and spinal radiographic damage: a cross-sectional study

The purpose of this cross-sectional study was to assess the visfatin levels in patients with axial spondyloarthritis (axSpA) and to investigate the association between visfatin, disease activity and radiographic spinal damage. Serum visfatin levels were determined by enzyme-linked immunosorbent assay in 64 patients with axSpA (46 with radiographic axSpA (r-axSpA) and 18 with non-radiographic axSpA (nr-axSpA)) and 61 age-/sex-matched healthy individuals. Patients with r-axSpA were further divided into two subsets based on radiographic spinal damage using modified Stoke Ankylosing Spondylitis Spine Score (mSASSS = 0 and mSASSS ≥ 1). The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was used to assess disease activity. C-reactive protein (CRP) levels and human leukocyte antigen (HLA)-B27 were determined. Visfatin levels were significantly higher in patients with axSpA and in the subgroup of patients with r-axSpA than in healthy individuals (p = 0.010 and p = 0.005, respectively), with no difference between patients with r-axSpA and with nr-axSpA. In general, disease activity was high (mean BASDAI 5.01) and was moderately correlated with visfatin levels (r = 0.585; p = 0.011) in patients with nr-axSpA. Visfatin levels correlated with mSASSS (r = 0.281; p = 0.026) and were significantly higher in axSpA patients with mSASSS ≥ 1 than in those with mSASSS = 0 (p = 0.025). Our study showed that circulating visfatin levels are elevated in axSpA patients, may be associated with disease activity in early phase of the disease and with the degree of radiographic spinal involvement.

The role of adipokines in skeletal muscle inflammation and insulin sensitivity

Background

There is currently an unmet clinical need to develop better pharmacological treatments to improve glucose handling in Type II Diabetes patients with obesity. To this end, determining the effect of obesity-associated adipokines on skeletal muscle insulin sensitivity has emerged as an important area of drug discovery research. This review draws together the data on the functional role of adipokines on skeletal muscle insulin signalling, highlights several understudied novel adipokines and provides a perspective on the direction of future research.

Main body

The adipokines leptin, resistin, visfatin and adiponectin have all been shown to affect skeletal muscle insulin sensitivity by impacting on the activity of components within insulin signalling pathways, affecting GLUT4 translocation and modulating insulin-mediated skeletal muscle glucose uptake. Furthermore, proteomic analysis of the adipose tissue secretome has recently identified several novel adipokines including vaspin, chemerin and pref-1 that are associated with obesity and insulin resistance in humans and functionally impact on insulin signalling pathways. However, predominantly, these functional findings are the result of studies in rodents, with in vitro studies utilising either rat L6 or murine C2C12 myoblasts and/or myotubes. Despite the methodology to isolate and culture human myoblasts and to differentiate them into myotubes being established, the use of human muscle in vitro models for the functional validation of adipokines on skeletal muscle insulin sensitivity is limited.

Conclusion

Understanding the mechanism of action and function of adipokines in mediating insulin sensitivity in skeletal muscle may lead to the development of novel therapeutics for patients with type 2 diabetes. However, to date, studies conducted in human skeletal muscle cells and tissues are limited. Such human in vitro studies should be prioritised in order to reduce the risk of candidate drugs failing in the clinic due to the assumption that rodent skeletal muscle target validation studies will to translate to human.

Genetic associations of the visfatin G-948T polymorphism with obesity-related metabolic traits in an Iranian population

Background:

Obesity is a global public health problem. Visfatin, as an adipocytokine, is coded by a gene known as nicotinamide phosphoribosyltransferase. So far, results were conflicted regarding correlations of visfatin with obesity and metabolic variables. The present study aimed to explore the association between G-948T polymorphism of visfatin gene with obesity and lipid profile in a nationally representative sample of Iranian population.

Materials and Methods:

In this case–control study, we assessed 129 randomly selected patients with obesity and 182 healthy normal weight controls from participants of Isfahan Healthy Heart Program. Genomic DNA was isolated from peripheral blood cells, and high-resolution melt polymerase chain reaction was performed to explore the presence of G-948T polymorphism.

Results:

T carriers “GT + TT” were statistically more frequent in the obese patients than the controls (P = 0.013; odds ratio = 1.9, 95% confidence interval = 1.1–3.1). The serum levels of total cholesterol and low-density lipoprotein cholesterol (LDL-C) were significantly different between T carriers and GG homozygote genotype (P = 0.03 and 0.02, respectively).

Conclusion:

We concluded that visfatin G-948T polymorphism was correlated with obesity, total cholesterol, and LDL-C levels in our population.

An association of serum vistafin level and number of circulating endothelial progenitor cells in type 2 diabetes mellitus patients

BACKGROUND

The decreased number and impaired functions of endothelial progenitor cells (EPCs) may associate with cardiovascular disease (CV) including atherosclerosis. However, the role of vistafin in regulation of angiogenic EPC subset maturation in T2DM patients without known atherosclerosis is still not fully understood.

THE AIM OF THE STUDY

To investigate an association of serum vistafin level and number of circulating EPCs in T2DM patients beyond known CV disease.

METHODS

This case-control observational investigation was evolved 54 subjects with T2DM and 35 healthy volunteers. The flow cytometry was used for predictably distinguishing cell subsets, which depend on expression of CD45, CD34, CD14, Tie-2, and VEGFR2. Biomarkers were measured at baseline of the study.

RESULTS

All T2DM patients were divided depending median of vistafin level (5.88ng/mL) in to two cohorts with low vistafin level (<5.88ng/mL; n=29) and high vistafin level (≥5.88ng/mL; n=25) respectively. Logistic regression analysis has shown that visfatin, hs-CRP, age and BMI were the best variables in the prediction of EPC number labeled as CD14⁺CD309⁺ and CD14⁺CD309⁺Tie²⁺ cells. After adjustment of the model to age and BMI elevated visfatin level remained the best predictor for both CD14⁺CD309⁺ and CD14⁺CD309⁺Tie²⁺ EPCs (OR 0.92, 95% CI: 0.88-0.95; P=0.001 and OR 0.90, 95% CI: 0.87-0.96; P=0.001 respectively).

CONCLUSION

We found that elevated level of vistafin was an independent predictor for declined numerous of non-classical EPCs labeled as CD14⁺CD309⁺ and CD14⁺CD309⁺Tie²⁺, whereas CD34⁺ subsets of EPCs did not associate with vistafin level in T2DM individuals.

Reciprocal changes of serum adispin and visfatin levels in patients with type 2 diabetes after an overnight fast

OBJECTIVE

In order to elucidate the interrelationship of adipokines in glucose hemiostasis, we determined the concentration of visfatin and adipsin in blood samples in patients with type 2 diabetes and age-matched controls after an overnight fast.

SUBJECTS AND METHODS

We enrolled 37 patients with known type 2 diabetes -21 males and 16 females, aged 62.95 ± 15.72 years and 43 controls- 28 males and 15 females, aged 60.79 ± 12.67 years. Blood samples were collected after an overnight fast and routine biochemical parameters such as glucose, cholesterol, HDL, LDL, triglycerides along with Hb1Ac, insulin and c-peptide, in addition to circulating visfatin and adipsin were determined in all samples. Data were considered significant at a level of p < 0.05.

RESULTS

In patients with type 2 diabetes, circulating adipsin levels were decreased and inversely related with glucose levels while circulating visfatin was increased significantly in the fasting state.

CONCLUSION

These results implicate the adipokines adipsin and visfatin as possible participants in the pathogenesis of type 2 diabetes.

Interlinking Periodontitis and Type 2 Diabetes Mellitus by Assessment of Crevicular Visfatin Levels in Health and in Disease Before and After Initial Periodontal Therapy

INTRODUCTION

Visfatin is a new adipocytokine associated with both chronic periodontitis and type 2 diabetes mellitus independently.

AIM

We aimed to estimate and compare the changes in the levels of visfatin in the Gingival Crevicular Fluid (GCF) of healthy subjects and in subjects with periodontitis with or without controlled Type 2 Diabetes Mellitus (T2DM) after administration of non-surgical periodontal therapy.

MATERIALS AND METHODS

Forty two subjects were equally divided into Group 1 (healthy), Group 2 (systemically healthy with chronic periodontitis), Group 3 (subjects with chronic periodontitis having controlled T2DM). Defined clinical parameters were recorded at baseline and at one month follow-up period. Visfatin was assessed using enzyme linked immunosorbent assay. One way ANOVA and Tukey's multiple post hoc procedures were used. Pearson's correlation coefficient was used for correlation.

RESULTS

Significant increase in the visfatin levels was seen with the highest values observed in diabetes with periodontal disease. Visfatin responded to non-surgical periodontal therapy as observed by significant decrease in levels after one month but even at this period diabetics showed the highest levels.

CONCLUSION

Visfatin levels are highest in individuals with both periodontal disease and diabetes even after periodontal therapy. Individuals with T2DM may be at higher risk of developing periodontal disease.

Serum and vitreous levels of visfatin in patients with diabetic retinopathy

Background

Angiogenesis plays an important role in the mechanism of diabetic retinopathy (DR). Visfatin, a recently identified adipokine, is thought to possess an angiogenic effect. The aim of our study was to investigate serum and vitreous levels of visfatin in patients with proliferative diabetic retinopathy (PDR) and non-PDR (NPDR).

Material/Methods

A total of 280 diabetic patients (124 without DR, 56 with NPDR, and 100 with PDR) and 78 control subjects were enrolled in this study. Serum and vitreous levels of visfatin were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Serum and vitreous visfatin levels in PDR patients were significantly elevated compared with those in the other 3 groups. NPDR patients showed elevated vitreous visfatin levels compared with patients without DR. However, no significant differences in serum visfatin levels were found between NPDR patients and patients without DR. In addition, control subjects had significantly lower levels of serum and vitreous visfatin compared with diabetic patients without DR, NPDR patients, and PDR patients.

Conclusions

Serum and vitreous visfatin levels are associated with the presence and severity of DR.

Visfatin and its genetic variants are associated with obesity-related morbidities and cardiometabolic risk in severely obese children

BACKGROUND

Visfatin is an adipokine, associated with obesity and possibly glucose regulation.

OBJECTIVE

The aim of this study was to examine the association of visfatin and its genetic variants with adiposity, cardiometabolic risk factors and obesity-related morbidities in obese children.

METHODS

Anthropometric measurements, dual energy X-ray absorptiometry scan, fasting blood samples and oral glucose tolerance tests were performed for 243 obese children. We screened the visfatin gene of 24 obese subjects and then performed genotyping of identified genetic variants in other 219 obese children through direct DNA sequencing.

RESULTS

Fasting serum visfatin correlated with measures of obesity and liver enzymes and was elevated in obese children with abnormal glucose tolerance and non-alcoholic fatty liver disease. The two upstream single nucleotide polymorphisms, -3187G>A (rs11977021) and -1537C>T (rs61330082), were at complete linkage disequilibrium. The AA genotype of -3187G>A was associated with higher serum visfatin (6.17 ± 0.76 ng mL(-1) vs. 3.92 ± 0.44 ng mL(-1)) and higher triglyceride (1.39 ± 0.08 mmol L(-1) vs. 1.19 ± 0.07 mmol L(-1)) as compared with the GG genotype. There was also a significant linear increase in serum visfatin across GG to GA to AA genotype of -3187G>A, indicating possible additive effect of A allele. The dominant GA + AA genotype model of +21426G>A (rs2302559) was associated with lower serum visfatin (3.83 ± 0.56 ng mL(-1) vs. 5.13 ± 0.34 ng mL(-1)) and lower plasma glucose (4.37 ± 0.08 mmol L(-1) vs. 4.77 ± 0.12 mmol L(-1)) as compared with the GG genotype.

CONCLUSION

Visfatin and its genetic variants were associated with adiposity, obesity-related morbidities and adverse cardiometabolic parameters. This supported our hypothesis that visfatin plays a significant role in the development of obesity-related morbidities and cardiometabolic risk.

Biomarkers in the field of obesity and its related comorbidities

INTRODUCTION

The prevalence of obesity has increased dramatically in the last decades both in children and adults and is now considered a major health problem. It is associated with numerous comorbidities such as hypertension, dyslipidemia, diabetes and subsequent cardiovascular disease (CVD). One of the mechanisms that connect obesity with these comorbidities is the secretion of so-called adipocytokines or adipokines by the adipose tissue itself. Most adipokines with pro-inflammatory properties are overproduced with increasing adiposity, whereas some adipokines with anti-inflammatory or insulin-sensitizing properties, like adiponectin, are decreased. This dysregulation of adipokines production may promote obesity-linked metabolic disorders and CVD. Except adipokines a wide complex network of chemicals balances pro-inflammatory and anti-inflammatory effects.

AREAS COVERED

In this review, we summarize the role of various adipokines and other chemicals associated with obesity and its related cardiometabolic comorbidities, with a special focus on recent evidence showing their potential role as biomarkers whose expression are indicative of obesity and its complications.

EXPERT OPINION

Biomarkers associated with obesity, type 2 diabetes (T2D) and CVD could prove beneficial for early identification, proper treatment and good life assurance. Unfortunately, the complexity of biological pathways interactions is such that further research is necessary before any of these markers could reach an accurate diagnostic value.

Adiponectin, visfatin and regional fat depots in normal weight obese premenopausal women

BACKGROUND

Normal weight obesity (NWO) is defined as percentage body fat (%BF) above 30% or %BF in the upper tertile in normal weight subjects. Using these criteria, we assessed lipid profiles, glucose metabolism parameters, blood pressure and regional fat in 91 premenopausal women with NWO and 54 age-matched healthy controls.

METHODS

We measured total cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides (TG), glucose, insulin, visfatin and adiponectin.%BF, abdominal fat (Android) and hip fat (Gynoid) were measured by dual-energy X-ray absorptiometry. Insulin resistance was evaluated by homoeostasis model assessment (HOMA-IR).

RESULTS

Women with NWO had higher diastolic blood pressure (DBP) (P = 0·003), LDL (P = 0·048), TG (P = 0·004) Android (P = 0·008) and Gynoid (P = 0·007) levels, but lower HDL (P = 0·009) than healthy controls. The NWO women had one (P = 0·041), two (P = 0·007) or three (P = 0·002) metabolic syndrome components more frequently than the controls. Across %BF tertiles, the number of metabolic syndrome components significantly increased (R = 0·21; P = 0·02), as did Gynoid (R = 0·83; P < 0·001) and Android (R = 0·81; P < 0·001) levels. Android (but not Gynoid) level was linearly associated with DBP (R = 0·194; P = 0·019), HDL (R = -0·295; P = 0·0004) and TG (R = 0·183; P = 0·031). Visfatin and adiponectin levels were comparable in both groups. Visfatin was inversely correlated with cholesterol, LDL and HOMA-IR. Adiponectin was inversely correlated with the Android/Gynoid and Android/Total fat ratios.

CONCLUSIONS

Compared with healthy controls, women with NWO had higher DBP, TG, LDL, and regional fat and lower HDL. These findings seem to be associated more with excess Android fat than excess %BF.

Insulin resistance, serum visfatin, and adiponectin levels are associated with metabolic disorders in chronic hepatitis C virus-infected patients

OBJECTIVE

The aim of this study was to determine the serum levels of visfatin, adiponectin, and insulin resistance (IR) in patients with hepatitis C virus (HCV) infection and their relations to the biochemical markers of hepatitis C.

MATERIALS AND METHODS

This study was carried out on 40 HCV-infected patients and 40 sex/age/BMI-matched healthy adults. Lipid profile, liver function tests, IR, serum adiponectin, and visfatin of all patients were examined. Correlations between IR, adiponectin, visfatin, and other variables were analyzed.

RESULTS

The levels of visfatin and adiponectin were significantly lower in HCV patients compared with healthy controls. However, IR of HCV patients were higher than those of healthy controls. IR was significantly correlated to triglycerides, visfatin was closely related to low-density lipoprotein cholesterol, whereas adiponectin was associated with high-density lipoprotein cholesterol. These results suggest that IR, serum visfatin, and adiponectin levels are associated with metabolic disorders in chronic HCV-infected patients.

CONCLUSION

IR, adiponectin, and visfatin were related to several metabolic markers of HCV, suggesting the characteristics of HCV-related metabolic abnormalities.

Common mechanisms of dysfunctional adipose tissue and obesity-related cancers

The relation between cancer and metabolic disorders was recognized several decades ago, but the underlying mechanisms involved in cancer development and progression remain obscure. In the last years, many groups have been studying systemic adipose tissue markers in cancer patients. However, few consistent results were obtained. On the other hand, several studies revealed many aspects of adipose tissue physiology in obesity. Nowadays, it is recognized that excessive lipid uptake in adipocytes leads to hypertrophy and consequently to metabolic dysregulation, hypoxia, inflammation, impaired adipocytokine expression and angiogenesis, insulin resistance and macrophage recruitment. In obese patients, tumours commonly colocalize with excessive adipose tissue accumulation, and most of the features of hypertrophic adipose tissue are observed in cancer patients, namely breast and colon. This review aimed to summarize pathological adipose tissue alterations that may contribute to cancer aetiology and development.

Antihyperlipidaemic and antioxidant effect of the total flavonoids in Selaginella tamariscina (Beauv.) Spring in diabetic mice

Objectives

To investigate the antidiabetic, antihyperlipidaemic and antioxidant activity of total flavonoids in Selaginella tamariscina (Beauv.) Spring (TFST) in a mouse model of diabetes.

Methods

Normal mice, mice fed with a high-fat emulsion diet and streptozotocin (STZ)-induced diabetic mice were treated with TFST for 6 weeks. Serum glucose, insulin and lipid, hepatic steatosis, production of the protein visfatin and antioxidant indices were evaluated.

Key findings

TFST significantly decreased the concentration of fasting blood glucose, total cholesterol, triglycerides and low-density-lipoprotein cholesterol, while it increased the levels of insulin and high-density-lipoprotein cholesterol in diabetic mice. TFST also improved the results of the oral glucose tolerance test to a certain degree. Furthermore, both the free fatty acid levels in the liver and hepatic steatosis were ameliorated by TFST treatment. These changes may be be associated with decreased production of visfatin. Administration of TFST also significantly decreased the levels of malondialdehyde, nitric oxide and inducible nitric oxide synthase and increased the content of glutathione and the activity of superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase in the liver. No change in blood glucose levels were observed in the normal mice treated with TFST.

Conclusions

TFST showed an excellent effect in reducing the high blood glucose level but had no effect on normal blood glucose level. The antidiabetic activity of TFST could be explained by its antioxidant and antihyperlipidaemic activity, which finally elevated the insulin sensitivity of liver.

Serum visfatin levels, adiposity and glucose metabolism in obese adolescents

OBJECTIVE

Visfatin, an adipokine, has insulin-mimetic effects. The main determinants of both the production and the physiologic role of visfatin are still unclear. The aim of this study is to determine the relation of serum visfatin to adiposity and glucose metabolism.

METHODS

40 pubertal adolescents (20 females, 20 males; age range: 9-17 years) with exogenous obesity and 20 age- and sex-matched healthy adolescents (10 females, 10 males) were enrolled in the study. Oral glucose tolerance test (OGTT) was performed in the obese group. Serum glucose, insulin and visfatin levels were analyzed in the fasting state in the controls and at 0, 60 and 120 minutes during the OGTT in the obese group.

RESULTS

The obese group had higher serum visfatin levels than the control group [11.6 (3.3-26) ng/mL vs. 7.5 (3.3-10.5) ng/mL, p<0.001[. Visfatin levels were correlated positively with body mass index, waist/hip ratio, insulin, and homeostasis model assessment for insulin resistance and negatively with glucose/insulin ratio in the combined group (obese subjects plus controls). Visfatin levels were essentially similar in obese subjects with and without insulin resistance (p>0.05). Serum visfatin levels did not change at 60 and 120 minutes of the OGTT compared to the baseline levels (p>0.05).

CONCLUSIONS

Serum visfatin levels are elevated in obese adolescents and do not change with acute changes in glucose metabolism. Visfatin levels are related with adiposity and glucose metabolism parameters. However, the role and contribution of adiposity and glucose metabolism to the circulating visfatin levels in obese patients remain to be explored.

Changes in visfatin levels after oral glucose tolerance test in women with gestational diabetes mellitus

Visfatin levels increased following an oral glucose tolerance test (OGTT) in normal pregnancy, and this increase correlated with metabolic indexes such as blood glucose, blood fat, and insulin resistance. Conversely, visfatin levels in women with gestational diabetes mellitus (GDM) increased to lesser extent than in normal pregnancy, which suggests a disorder in the relationship between visfatin, blood glucose and insulin.

The value of visfatin in the prediction of metabolic syndrome: a multi-factorial analysis

We describe the adipokine concentration in patients with metabolic syndrome, stressing the role of visfatin. A cross-sectional single center study on 70 patients with metabolic syndrome plus 76 controls was performed. Patients with metabolic syndrome had higher visfatin levels compared to controls, following adjustments for age, sex, waist/hip circumference, systolic, and diastolic blood pressure, fasting plasma glucose (FPG), HbA1c, body mass index, and homeostasis model assessment of insulin resistance (HOMA-IR) [(5.39 ± 0.29 vs. 3.88 ± 0.32); F(1, 129) = 10.8, P < 0.01]. A logistic regression analysis revealed that circulating visfatin levels and HbA1c were the top variables for predicating metabolic syndrome. In patients with metabolic syndrome, visfatin did not correlate with any of the measured variables, with the single exception of adiponectin; in patients without metabolic syndrome, circulating visfatin levels were significantly associated with FPG, HbA1c, insulin, HOMA-IR, HDL, and triglyceride. These findings may contribute to our current knowledge about visfatin in metabolic syndrome.

Relationship between adipocytokines and cardiovascular risk factors in patients with type 2 diabetes mellitus

The aim of this study was to explore the relationship between serum profiles of adiponectin, leptin, resistin and visfatin and traditional and non-traditional cardiovascular risk factors in patients with type 2 diabetes mellitus (T2DM). A total of 85 patients with T2DM and 30 non-diabetic controls were enrolled in the study. Levels of adipocytokines (adiponectin, leptin, resistin and visfatin), lipids (total cholesterol, triglycerides), lipoproteins [HDL-cholesterol, LDL-cholesterol, lipoprotein (a)], apolipoproteins (Apo-A1 and Apo-B), non-traditional cardiovascular risk markers [asymmetric dimethylarginine (ADMA), homocysteine] and the inflammatory marker hs-CRP were measured, and anthropometric variables were determined. Serum adiponectin levels were decreased and leptin, resistin and visfatin levels were increased in T2DM patients compared to controls. They were associated with obesity (BMI), insulin resistance (HOMA-IR) and various markers of glucose/lipid profile, inflammation and endothelial dysfunction markers. These results suggest that decreased serum adiponectin and increased leptin, resistin and visfatin levels in T2DM may be novel biochemical risk factors for cardiovascular complications.

The pathophysiology of HIV-/HAART-related metabolic syndrome leading to cardiovascular disorders: the emerging role of adipokines

Individuals infected with human immunodeficiency virus (HIV) frequently demonstrate metabolic syndrome (MS) associated with increased incidence of cardiovascular disorders. Characteristics of HIV infection, such as immunodeficiency, viral load, and duration of the disease, in addition to the highly active antiretroviral therapy (HAART) have been suggested to induce MS in these patients. It is well documented that MS involves a number of traditional cardiovascular risk factors, like glucose, lipids, and arterial blood pressure abnormalities, leading to extensive atherogenic arterial wall changes. Nevertheless, the above traditional cardiovascular risk factors merely explain the exacerbated cardiovascular risk in MS. Nowadays, the adipose-tissue derivatives, known as adipokines, have been suggested to contribute to chronic inflammation and the MS-related cardiovascular disease. In view of a novel understanding on how adipokines affect the pathogenesis of HIV/HAART-related MS and cardiovascular complications, this paper focuses on the interaction of the metabolic pathways and the potential cardiovascular consequences. Based on the current literature, we suggest adipokines to have a role in the pathogenesis of the HIV/HAART-related MS. It is crucial to understand the pathophysiology of the HIV/HAART-related MS and apply therapeutic strategies in order to reduce cardiovascular risk in HIV patients.

Visfatin in overweight/obesity, type 2 diabetes mellitus, insulin resistance, metabolic syndrome and cardiovascular diseases: a meta-analysis and systemic review

There are controversies regarding the association of visfatin with overweight/obesity, type 2 diabetes mellitus, insulin resistance (IR), metabolic syndrome and cardiovascular disease in published articles. A meta-analysis was performed to identify the significance of visfatin in these diseases. We searched for relevant articles in Pubmed, Scopus and SCIE. A total of 1035 articles were surveyed and 46 articles were identified, with 14 reports reporting more than one of our investigated diseases. A total of 13 (n = 644), 19 (n = 2405), 20 (n = 2249), 5 (n = 527) and 5 (n = 851) articles/(participants) were included in each meta-analysis regarding the association of visfatin and overweight/obesity, type 2 diabetes mellitus, insulin resistance, metabolic syndrome and cardiovascular diseases, respectively. Plasma visfatin concentrations were increased in participants diagnosed with overweight/obesity, type 2 diabetes mellitus, metabolic syndrome and cardiovascular diseases, with pooled log odds ratios of 1.164 [95% confidence interval (CI): 0.348 to 1.981, p = 0.005], 1.981 (95% CI: 1.377 to 2.584, p < 0.001), 1.094 (95% CI: 0.678 to 1.511, p < 0.001), and 2.902 (95% CI: 0.924 to 4.879, p < 0.005), respectively. The circulating visfatin level was positively associated with insulin resistance, with a Fisher's z of 0.089 (95% CI: 0.013 to 0.165, p = 0.022). No single study was found to affect the overall result of each analysis by sensitivity testing. No publication bias was found by the Egger test. Our study suggests that the use of visfatin may be promising for predicting obesity, diabetes status, insulin resistance, metabolic syndrome and cardiovascular disease.