Serum visfatin concentrations are positively correlated with serum triacylglycerols and down-regulated by overfeeding in healthy young men

Mitigating diabetes-related complications: Empowering metformin with cholecalciferol and taurine supplementation in type 2 diabetic rats

BACKGROUND

Type 2 diabetes is one of the most prevalent chronic diseases worldwide, significantly impacting patients' quality of life. Current treatment options like metformin (MET) effectively counteract hyperglycemia but fail to alleviate diabetes-associated complications such as retinopathy, neuropathy, nephropathy, hepatopathy, and cardiovascular diseases.

AIM

To propose the supplementation of cholecalciferol (CHO) and taurine (TAU) to enhance MET efficacy in controlling diabetes while minimizing the risk of associated complications.

METHODS

The study involved sixty rats, including ten non-diabetic control rats and fifty experimental rats with type 2 diabetes induced by streptozotocin. The experimental rats were further subdivided into positive control and treatment subgroups. The four treatment groups were randomly allocated to a single MET treatment or MET combined with supplements either CHO, TAU, or both.

RESULTS

Diabetic rats exhibited elevated levels of glucose, insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), glycated hemoglobin%, lipid markers, aspartate aminotransferase, and malondialdehyde, along with reduced levels of antioxidant enzymes (catalase and superoxide dismutase). The administration of CHO and TAU supplements alongside MET in diabetic rats led to a noticeable recovery of islet mass. The antioxidative, anti-inflammatory, and anti-apoptotic properties of the proposed combination therapy significantly ameliorated the aforementioned abnormalities.

CONCLUSION

The supplementation of CHO and TAU with MET showed the potential to significantly improve metabolic parameters and protect against diabetic complications through its antioxidative, anti-inflammatory, and anti-apoptotic effects.

Chia seeds ameliorate cardiac disease risk factors via alleviating oxidative stress and inflammation in rats fed high-fat diet

Obesity upsurges the risk of developing cardiovascular disease, primarily heart failure and coronary heart disease. Chia seeds have a high concentration of dietary fiber and increased concentrations of anti-inflammatoryand antioxidant compounds. They are used for weight loss plus enhancing blood glucose and lipid profile. The current perspective was commenced to examine the protective influence of chia seeds ingestion on cardiovascular disease risk factors in high-fat diet-fed rats. Forty male albino rats (with an initial body weight of 180-200 g) were used in this study. Rats were randomly and equally divided into 4 groups: Group I was the control group and group II was a control group with chia seeds supplementation. Group III was a high-fat diet group (HFD) that received HFD for 10 weeks and group IV was fed on HFD plus chia seeds for 10 weeks. In all groups Echocardiographic measurements were performed, initial and final BMI, serum glucose, AC/TC ratio, lipid profile, insulin (with a computed HOMA-IR), creatinine phosphokinase-muscle/brain (CPK-MB), CRP, and cardiac troponin I (cTnI) and MAP were estimated. Whole heart weight (WHW) was calculated, and then WHW/body weight (BW) ratio was estimated. Eventually, a histopathological picture of cardiac tissues was performed to assess the changes in the structure of the heart under Haematoxylin and Eosin and Crossmon's trichrome stain. Ingestion of a high diet for 10 weeks induced a clear elevation in BMI, AC/ TC, insulin resistance, hyperlipidemia, CRP, CPK-MB, and cTnI in all HFD groups. Moreover, there was a significant increase in MAP, left ventricular end diastolic diameter (LVEDD), and left ventricular end systolic diameter (LVESD). Furthermore, histological cardiac examination showed structural alteration of the normal structure of the heart tissue with an increase in collagen deposition. Also, the Bcl-2 expression in the heart muscle was significantly lower, but Bax expression was significantly higher. Chia seeds ingestion combined with HFD noticeably ameliorated the previously-recorded biochemical biomarkers, hemodynamic and echocardiography measures, and histopathological changes. Outcomes of this report reveal that obesity is a hazard factor for cardiovascular disease and chia seeds could be a good candidate for cardiovascular system protection.

1,25-Dihydroxycholecalciferol down-regulates 3-mercaptopyruvate sulfur transferase and caspase-3 in rat model of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the commonest cause of liver morbidity and mortality and has multiple unclear pathogenic mechanisms. Vitamin D deficiency was associated with increased incidence and severity of NAFLD. Increased hepatic expression of 3-mercaptopyruvate sulfur transferase (MPST) and dysregulated hepatocyte apoptosis were involved in NAFLD pathogenesis. We aimed to explore the protective effect of 1,25-Dihydroxycholecalciferol (1,25-(OH)₂ D3) against development of NAFLD and the possible underlying mechanisms, regarding hepatic MPST and caspase-3 expression. 60 male adult rats were divided into 4 and 12 week fed groups; each was subdivided into control, high-fat diet (HFD), and HFD + VD. Serum levels of lipid profile parameters, liver enzymes, insulin, glucose, C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and hepatic levels of malondialdehyde (MDA), total antioxidant capacity (TAC), and reactive oxygen species (ROS) were measured. BMI and HOMA-IR were calculated, and liver tissues were processed for histopathological and immunohistochemical studies. The present study found that 1,25-(OH)₂ D3 significantly decreased BMI, HOMA-IR, serum levels of glucose, insulin, liver enzymes, lipid profile parameters, CRP, TNF-α, hepatic levels of MDA, ROS, hepatic expression of MPST, TNF-α, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and caspase-3; and significantly increased hepatic TAC in both HFD-fed groups. In conclusion: Administration of 1,25-(OH)₂ D3 with HFD abolished the NAFLD changes associated with HFD in 4-week group, and markedly attenuated the changes in 12-week group. The anti-apoptotic effect via decrement of caspase-3 and MPST expression are novel mechanisms suggested to be implicated in the protective effect of 1,25-(OH)₂ D3.

Extracellular Nicotinamide Phosphoribosyltransferase as a Surrogate Marker of Prominent Malignant Potential in Colonic Polyps: A 2-Year Prospective Study

Background/aims: The implications of extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a cancer metabokine, in colonic polyps remain uncertain. Methods: A 2-year prospective cohort study of patients who underwent colonoscopy was conducted. Biochemical parameters and serum eNAMPT levels were analyzed at baseline and every 24 weeks postpolypectomy. NAMPT-associated single-nucleotide polymorphisms (SNPs), including rs61330082, rs2302559, rs10953502, and rs23058539, were assayed. Results: Of 532 patients, 80 (15%) had prominent malignant potential (PMP) in colonic polyps, including villous adenomas (n = 18, 3.3%), adenomas with high-grade dysplasia (n = 33, 6.2%), and adenocarcinomas (n = 29, 5.5%). Baseline associations were as follows: colonic polyp pathology (p < 0.001), total cholesterol (p = 0.019), and neutrophil-to-lymphocyte ratio (p = 0.023) with eNAMPT levels; and age (p < 0.001), polyp size (p < 0.001), and eNAMPT levels (p < 0.001) with polyp pathology. Higher baseline eNAMPT levels were noted in patients harboring polyps with PMP than in patients without PMP (p < 0.001), and baseline eNAMPT levels significantly predicted PMP (cutoff: >4.238 ng/mL, p < 0.001). Proportions of eNAMPT-positive glandular and stromal cells were higher in polyps with PMP than in polyps without PMP (64.55 ± 11.94 vs. 14.82 ± 11.45%, p = 0.025). eNAMPT levels decreased within 48 weeks postpolypectomy (p = 0.01) and remained stable afterward regardless of PMP until 96 weeks postpolypectomy. However, those with PMP had a higher degree of eNAMPT decline within 24 weeks (p = 0.046). All investigated SNPs were in linkage disequilibrium with each other but were not associated with eNAMPT levels. Conclusion: With a link to inflammation and lipid metabolism, along with its decreasing trend after polypectomy, serum eNAMPT may serve as a surrogate marker of PMP in colonic polyps. In situ probing of the NAMPT-associated pathway holds promise in attenuating PMP, as much of the eNAMPT likely originates from colonic polyps.

Cognitive impairment in obese rat model: role of glial cells

BACKGROUND

Obesity is a worldwide problem. Some studies revealed that it leads to deterioration of the cognitive function, regardless of age.

AIM OF THE STUDY

explore the effect of obesity on cognitive function in a rat model of obesity highlighting the role of glial cells.

MATERIALS AND METHODS

twenty adult male albino rats were assigned to two groups: group I: consumed normal diet, group II: consumed high-fat diet. Body Mass Index (BMI), serum glucose, insulin, HOMA IR and lipid profile were measured. Also, hippocampal expression of Brain derived neurotrophic factor (Bdnf), synapsin, Ionized calcium binding adaptor molecule 1 (Iba), nuclear factor erythroid -related factor 2 (Nrf2), Myelin basic protein (Mbp) were measured by real-time polymerase chain reaction. The Morris Water Maze is a test used to assess spatial learning and memory capacities of rats.

RESULTS

There was a high significant increase in lipid profile, serum glucose, insulin serum levels and HOMA-IR in obese groups with impaired Morris water maze performance compared to control group. There was a significant downregulation in hippocampal Bdnf and synapsin mRNA expression. In addition to decrease in Mbp mRNA expression (P < 0.001). This could be explained by oxidative stress through significant downregulation of Nrf2 mRNA, and inflammation observed in significant upregulation Iba mRNA gene expression in the obese group.

CONCLUSION

Many factors contribute to obesity associated cognitive impairment. In our study, we figured out the crucial roles of glial cells including microglial activation and oligodendrocytes affection with other underlying mechanisms including oxidative stress and hippocampal inflammation.

Association between Tumor Prognosis Marker Visfatin and Proinflammatory Cytokines in Hypertensive Patients

Visfatin has been reported as a risk factor and a potential diagnostic marker in cancer. It is an adipokine, secreted by visceral fat and associated with the pathogenesis of arterial hypertension. We investigated the circulatory levels of visfatin in hypertensive patients with hypertriglyceridemia, which are the risk factors for various cancers and its association with proinflammatory cytokines. A total of 81 (male/female: 33/48) subjects with or without hypertension were enrolled for this study. Group 1 was normotensive, Group 2 hypertensive, and Group 3 with hypertension with hypertriglyceridemia. Data on anthropometric and biochemical data were recorded. Plasma visfatin levels were measured using an ELISA kit. The plasma inflammatory cytokines were estimated using a multiplex bead-based assay. The results revealed that the hypertension with hypertriglyceridemia group has the highest levels of visfatin compared to the hypertension and control groups with a significant difference (p < 0.001). Besides, circulatory visfatin showed the strongest possible correlation with proinflammatory cytokines among hypertensive patients with hypertriglyceridemia. We found a positive correlation between visfatin and diastolic blood pressure as well as high-density lipoproteins. In conclusion, the outcomes of the present study demonstrate that plasma visfatin levels were found to be elevated in hypertensive patients with hypertriglyceridemia and associated with proinflammatory cytokines. Since hypertension has been documented as the most common comorbidity observed in cancer patients, visfatin may be a novel potential therapeutic target for hypertension in cancer patients and survivors.

The biology of human overfeeding: A systematic review

This systematic review has examined more than 300 original papers dealing with the biology of overfeeding. Studies have varied from 1 day to 6 months. Overfeeding produced weight gain in adolescents, adult men and women and in older men. In longer term studies, there was a clear and highly significant relationship between energy ingested and weight gain and fat storage with limited individual differences. There is some evidence for a contribution of a genetic component to this response variability. The response to overfeeding was affected by the baseline state of the groups being compared: those with insulin resistance versus insulin sensitivity; those prone to obesity versus those resistant to obesity; and those with metabolically abnormal obesity versus those with metabolically normal obesity. Dietary components, such as total fat, polyunsaturated fat and carbohydrate influenced the patterns of adipose tissue distribution as did the history of low or normal birth weight. Overfeeding affected the endocrine system with increased circulating concentrations of insulin and triiodothyronine frequently present. Growth hormone, in contrast, was rapidly suppressed. Changes in plasma lipids were influenced by diet, exercise and the magnitude of weight gain. Adipose tissue and skeletal muscle morphology and metabolism are substantially altered by chronic overfeeding.

Circulating visfatin levels in the second and third trimester of pregnancies with gestational diabetes: a systematic review

INTRODUCTION

There are multiple published conflicting associations of the adipocytokine visfatin with gestational diabetes. In this study, we attempted to investigate this relationship via a systematic review of the published literature.

EVIDENCE ACQUISITION

Literature retrieval using PubMed, Google Scholar, Scopus and Hydi databases followed by article selection and data extraction were conducted. Relevant studies published up to June 2018 were included. In total, 29 cohorts that were published in 27 articles were analyzed. Three studies carried out in early pregnancy were excluded. A total of 2365 individuals, with 1069 gestational diabetes (GDM) cases and 1296 controls from studies describing visfatin in the second or third trimester of gestation were included.

EVIDENCE SYNTHESIS

The difference in visfatin levels between women with GDM and the controls in the second and third trimester was measured by weighted mean difference (WMD) and 95% confidence intervals (CI). Heterogeneity was inspected by using both subgroup and meta-regression analysis. Analysis was restricted to studies describing singleton pregnancies. The quality of included studies was assessed by the Newcastle-Ottawa Scale.

CONCLUSIONS

No significant difference in circulating visfatin levels in GDM during the second trimester of pregnancy (WMD -0.30 ng/mL, 95% CI: -2.06, 1.45, SE=0.895, P=0.733) was detected. Meta-analysis of the studies in the third trimester revealed a significant negative effect, that was however driven by only one study. This finding limits the meaningful interpretation of the pooled analysis. Significant heterogeneity was identified between studies, and meta-regression analysis showed that homeostatic model assessment for insulin resistance contributes significantly to heterogeneity. In conclusion, our findings suggest that peripheral blood visfatin concentration cannot be robustly associated with gestational diabetes status in the second and third trimesters of pregnancy.

Evaluation of irisin and visfatin levels in very low birth weight preterm newborns compared to full term newborns-A prospective cohort study

Premature infants represent one of the groups with increased risk for metabolic syndrome. Our study is the first one to evaluate irisin and visfatin levels, associated with the metabolic syndrome, both in blood of preterm and full-term infants, as well as in the breastmilk of their mothers. A total of 72 newborns was enrolled in the study, including 53 very low birth weight preterm infants and a control group of 19 term infants. The levels of irisin and visfatin were determined by a commercial enzyme-linked immunoabsorbent assay both in the baby serum and maternal milk twice, first during the 1^st week of life and then 4 weeks later. Preterm infants had significantly lower serum irisin levels compared to the term infants. Overall, serum irisin level during the 1^st week of life was positively correlated with several anthropometric measurements at birth, as well as during 5^th weeks of age. In contrast, serum visfatin levels during 5^th week of life were negatively correlated with z-scores of birth weight, weight and head circumference during 5^th week of age. We found a strong negative correlation between serum irisin and serum visfatin levels at both analyzed time points. The level of milk visfatin was significantly higher in the mothers of the preterm group during 5^th week of life. In conclusion, our results provide further evidence that irisin and visfatin may play physiologic roles in development of both preterm and full-term newborns during their first month after birth. Observed differences in irisin and visfatin serum and breastmilk concentrations during the earliest stages of life may contribute to development of catch up growth, but also, they might eventually lead to a higher risk for metabolic syndrome in prematurely born children in later years.

Neurogenic obesity and systemic inflammation following spinal cord injury: A review

CONTENT

Spinal Cord Injury (SCI) results in physiological changes that markedly reduces whole-body metabolism, resulting in neurogenic obesity via adipose tissue accumulation. Adipose tissue has been implicated in the release of proinflammatory adipokines that lead to chronic, systemic inflammation, and evidence suggests these adipokines contribute to the pathogeneses of metabolic diseases that often accompany obesity. In this review, we propose the concept of neurogenic obesity through paralysis-induced adiposity as the primary source of systemic inflammation and metabolic dysfunction reported in chronic SCI. We also briefly discuss how exercise in SCI can attenuate the negative consequences of obesity-induced inflammation and its comorbidities.

METHODS

A MEDLINE, PubMed, Google Scholar, and ClinicalKey search was performed using the following search terms: obesity, adiposity, adipose tissue, proinflammatory adipokines, proinflammatory cytokines, metabolic dysfunction, exercise, physical activity, and spinal cord injury. All papers identified were full-text, English language papers. The reference list of identified papers was also searched for additional papers.

RESULTS

Research suggests that obesity in SCI results in a state of chronic, systemic inflammation primarily through proinflammatory adipokines secreted from excess adipose tissue. The reduction of adipose tissue through the use of diet and exercise demonstrates promise to combat neurogenic obesity, inflammation, and cardiometabolic dysfunction in SCI.

CONCLUSION

Proinflammatory adipokines may serve as biomarkers for the development of obesity-related complication in SCI. Mechanistic and interventional studies on neurogenic obesity-induced inflammation in chronic SCI are warranted.

Short-Term Overfeeding with Dairy Cream Does Not Modify Gut Permeability, the Fecal Microbiota, or Glucose Metabolism in Young Healthy Men

Background

High-fat diets (HFDs) have been linked to low-grade inflammation and insulin resistance.

Objective

The main purpose of the present study was to assess whether acute overfeeding with an HFD affects insulin sensitivity, gut barrier function, and fecal microbiota in humans.

Methods

In a prospective intervention study, 24 healthy men [mean ± SD: age 23.0 ± 2.8 y, body mass index (in kg/m2) 23.0 ± 2.1] received an HFD (48% of energy from fat) with an additional 1000 kcal/d (as whipping cream) above their calculated energy expenditure for 7 d. Insulin sensitivity (hyperinsulinemic euglycemic clamp), gut permeability (sugar and polyethylene glycol absorption tests, plasma zonulin), and gut microbiota profiles (high-throughput 16S rRNA gene sequencing) were assessed before and after overfeeding, and 14 d after intervention. Additionally, inflammation markers such as high-sensitivity C-reactive protein, lipopolysaccharide-binding protein, leptin, high-molecular-weight adiponectin, calprotectin, regulated on activation normal, T cell expressed and secreted (RANTES), and monocyte chemoattractant protein-1 were measured in plasma by ELISA. Finally, lipid parameters were analyzed in serum by a laboratory service.

Results

Although participants gained 0.9 ± 0.6 kg (P < 0.001) body weight, overnutrition was not associated with a significant change in insulin sensitivity (M value and glucose disposal). Overfeeding for 7 d resulted in elevated serum total (10.2%), LDL (14.6%) and HDL (14.8%) cholesterol concentrations (P < 0.01). In contrast, fasting plasma triglyceride significantly declined (29.3%) during overfeeding (P < 0.001). In addition, there were no significant changes in inflammatory markers. Urine excretion of 4 sugars and polyethylene glycol, used as a proxy for gut permeability, and plasma concentration of zonulin, a marker of paracellular gut permeability, were unchanged. Moreover, overfeeding was not associated with consistent changes in gut microbiota profiles, but marked alterations were observed in a subgroup of 6 individuals.

Conclusions

Our findings suggest that short-term overfeeding with an HFD does not significantly impair insulin sensitivity and gut permeability in normal-weight healthy men, and that changes in dominant communities of fecal bacteria occur only in certain individuals. The study was registered in the German Clinical Trial Register as DRKS00006211.

Combination of Obestatin and Bone Marrow Mesenchymal Stem Cells Prevents Aggravation of Endocrine Pancreatic Damage in Type II Diabetic Rats

One of the new promising therapies in treatment of diabetes mellitus is mesenchymal stem cells (MSCs) which have an interesting therapeutic potentiality based on their paracrine effect and transdifferentiation potentiality. Also obestatin improves the generation of functional β cells/islet-like cell clusters in vitro, suggesting implications for cell-based replacement therapy in diabetes. So the aim of this study was to evaluate the effect of combination of both MSCs and obestatin on an experimental model of type II diabetes mellitus (T2DM). Sixty male rats were divided into; group I (control group), group II (T2DM group) induced by administration of high fat diet (HFD) and injection of streptozotocin (STZ) in low dose, group III (T2DM treated with MSCs), group IV (T2DM treated with obestatin), group V (T2DM treated with MSCs and obestatin). Fasting blood glucose, C-peptide, insulin and lipid profile were measured. HOMA-IR and HOMA-β were calculated. Pancreatic expression of insulin, glucagon like peptide -1 (GLP-1) and pancreatic duodenal homeobox 1 (Pdx1) mRNA levels were measured. In addition pancreatic histological changes, insulin and Bax were analyzed by immunohistochemical examination of islets of Langerhans. Diabetic rats showed significant increase in HOMA-IR, serum glucose and lipid profile levels with significant decrease in insulin, HOMA-β, GLP-1 and Pdx1 levels. MSCs and obestatin caused significant improvement in all parameters with more significant improvement in combined therapy. The protective effects afforded by MSCs and obestatin may derive from improvement of the metabolic profile, antiapoptosis and by increase in pancreatic GLP-1and Pdx1 gene expression.

Cardiovascular risk of adipokines: a review

Over the last two decades, the understanding of adipose tissue has undergone radical change. The perception has evolved from an inert energy storage tissue to that of an active endocrine organ. Adipose tissue releases a cluster of active molecules named adipokines. The severity of obesity-related diseases does not necessarily correlate with the extent of body fat accumulation but is closely related to body fat distribution, particularly to visceral localization. There is a distinction between the metabolic function of central obesity (visceral abdominal) and peripheral obesity (subcutaneous) in the production of adipokines. Visceral fat accumulation, linked with levels of some adipokines, induces chronic inflammation and metabolic disorders, including glucose intolerance, hyperlipidaemia, and arterial hypertension. Together, these conditions contribute to a diagnosis of metabolic syndrome, directly associated with the onset of cardiovascular disease. If it is well known that adipokines contribute to the inflammatory profile and appetite regulation, this review is novel in synthesising the current state of knowledge of the role of visceral adipose tissue and its secretion of adipokines in cardiovascular risk.

Relations of Serum Visfatin and Resistin Levels with Endometrial Cancer and Factors Associated with its Prognosis

BACKGROUND

The aims of this study were compare the serum visfatin and resistin levels between endometrial cancer (EC) patients and controls and evaluate their power to predict prognosis.

MATERIALS AND METHODS

This prospective study was conducted between March 2013 to June 2014 on the Gynecologic Oncology Department of the University of Selcuk, Konya, Turkey. A total of 42 EC patients and 42 controls were included and assessed for differences in serum visfatin and resistin levels, along with prognostic factors.

RESULTS

Endometrial cancer patients had significantly higher visfatin levels than control s (p: 0.011), associated with deep myometrial invasion (p: 0.019). In contrast the serum level of resistin did not significantly differ between EC patients and controls (p: 0.362). However, high resistin level in EC patients was associated with increase lymph node metastasis (p: 0.009). On logistic regression analysis, we found that serum visfatin elevation was associated with risk of myometrial invasion (OR: 1,091; 95%CI: 1.021- 1.166; p: 0.010) and serum resistin with risk of lymph node metastasis (OR: 1.018; 95%CI: 1.000- 1.035; p: 0.046). For myometrial invasion prediction, a serum visfatin level greater than 26.8 ng/mL demonstrated a sensitivity and specificity of 66.6 % and 96.4%, respectively. For lymph node metastasis prediction, the best cut-off for serum resistin level was 599ng/mL. A serum resistin level greater than this demonstrated a sensitivity and specificity of 87.5% and 77.1%, respectively.

CONCLUSIONS

Our data suggest that serum visfatin is elevated in patients with EC and serum visfatin and resistin levels could be used to predict the risk of advance stage lesions.

Effect of Metformin, Acarbose and Their Combination on the Serum Visfatin Level in Nicotinamide/Streptozocin-Induced Type 2 Diabetic Rats

BACKGROUND

Diabetes mellitus is a chronic metabolic disease with life-threatening complications. Metformin and acarbose are two oral antidiabetic drugs.

OBJECTIVES

This experimental study was designed and carried out at the Arak University of Medical Sciences in Arak, Iran, to investigate the effects of these drugs (both alone and in combination) on glycemic control, lipid profile, and serum visfatin levels in nicotinamide/streptozotocin type 2 diabetic rats.

MATERIALS AND METHODS

Type 2 diabetes was induced in 30 male Wistar rats by the administration of streptozotocin (STZ) (60 mg/kg body weight) intraperitoneally (IP) 15 minutes after the IP administration of nicotinamide (110 mg/kg body weight). After one week, the diabetic rats were randomly divided into four groups. Three diabetic groups were treated with 150 mg/kg/day of metformin, acarbose (40 mg/100 g of diet), or a combination of the two for six weeks, respectively. Biochemical parameters, including fasting blood glucose, glycated hemoglobin, lipid profile, insulin, and visfatin were assessed and compared with those of the control diabetic group.

RESULTS

The data showed metformin, acarbose, and acarbose + metformin downregulated visfatin levels in diabetic rats, but only the reduction in metformin-treated rats was significant (162 ± 21.7, 195.66 ± 6.45 (ng/l), P = 0.001). Fasting blood glucose and glycated hemoglobin decreased significantly in all treated rats, specifically in the treated group that received the two drugs in combination. The serum insulin level was also reduced in all treated groups, and it was significant in the acarbose (P < 0.05) and the combination therapy groups (P < 0.05). The lipid profile improved in all treated groups.

CONCLUSIONS

Compared with acarbose or metformin monotherapy, the addition of acarbose to metformin had superior antihyperglycemia efficacy and provided an efficacious and safe alternative for the treatment of type 2 diabetic rats. Acarbose/metformin reduced the fasting blood glucose and glycated hemoglobin without significant changes in serum visfatin levels.

The comparison of serum vaspin and visfatin concentrations in obese and normal weight women

BACKGROUND AND OBJECTIVES

There is evidence based studies which show that plasma level of visfatin and vaspin in patients with type 2 diabetes mellitus elevate in comparison with healthy people. But there is no consistency in plasma visfatin and vaspin concentration between studies done on obese people. For this reason, the aim of this study is to investigate the serum level concentrations of visfatin and vaspin in obese women compared to normal weight women.

MATERIALS AND METHODS

The participants of this study consist of 43 women aged 20-50, and 43 healthy women with normal weight as a control group. They were matched for age and physical activity. 24h food recall was used to collect dietary information from subjects. Moreover, blood sampling was taken to measure the blood levels of sugar, lipid profile, vaspin and visfatin.

RESULTS

The mean serum level of visfatin was not statistically different between obese and normal weight women. But, the obese women had statistically higher mean serum level of vaspin than normal women (p=0.04). We found no relations between serum levels of vaspin with serum concentration of visfatin. Also, serum levels of these two adipokines were not related to the serum concentrations of fasting glucose, total cholesterol, low-density lipoprotein cholesterol and triglyserides and high-density lipoprotein cholesterol. Also, there was a significant positive relationship between carbohydrate intake and serum visfatin level in women participating to this study (p=0.018, r=0.257).

CONCLUSION

The results of this study demonstrated that the level of serum vaspin was significantly higher in obese women. But there were no differences in serum levels of visfatin in comparison to normal weight women. Meanwhile this study demonstrated a positive relationship between serum levels of visfatin with dietary intake of carbohydrate, but no relationship between serum level of visfatin and vaspin in women participating in this study.

Associations between tissue visfatin/nicotinamide, phosphoribosyltransferase (Nampt), retinol binding protein-4, and vaspin concentrations and insulin resistance in morbidly obese subjects

Visfatin/Nampt, vaspin, and retinol binding protein-4 (RBP-4) play an important role in insulin resistance. The objectives of this study were to measure visfatin/Nampt, vaspin, and RBP-4 concentrations in blood, liver, muscle, subcutaneous, omental, and mesenteric adipose tissues in morbidly obese subjects and investigate their relationship to insulin resistance. Blood and tissue samples were collected from 38 morbidly obese subjects during Roux-en-Y surgery. Insulin resistance biomarkers were measured using standard kits. Visfatin/Nampt, vaspin, and RBP-4 gene expression levels in tissues were measured using real-time PCR. Their protein concentrations in blood and tissues were measured using ELISA kits. Diabetic subjects had significantly higher homeostasis model of assessment-insulin resistance and age and lower blood HDL-cholesterol concentrations than nondiabetic and prediabetic subjects. Diabetic and prediabetic subjects had significantly higher blood concentrations of visfatin/Nampt and vaspin than nondiabetic subjects. Liver RBP-4 concentrations were positively associated with blood glucose concentrations. Blood insulin resistance biomarker levels were positively associated with visfatin/Nampt concentrations in omental adipose tissue and liver, and vaspin concentrations in mesenteric adipose tissue. In conclusion, the correlations of visfatin/Nampt, vaspin, and RBP-4 with insulin resistance are tissue dependent.

Exercise counteracts the effects of short-term overfeeding and reduced physical activity independent of energy imbalance in healthy young men

Physical activity can affect many aspects of metabolism but it is unclear to what extent this relies on manipulation of energy balance. Twenty-six active men age 25 ± 7 years (mean ± SD) were randomly assigned either to consume 50% more energy than normal by over-consuming their habitual diet for 7 days whilst simultaneously restricting their physical activity below 4000 steps day(-1) to induce an energy surplus (SUR group; n = 14) or to the same regimen but with 45 min of daily treadmill running at 70% of maximum oxygen uptake (SUR+EX group; n = 12). Critically, the SUR+EX group received additional dietary energy intake to account for the energy expended by exercise, thus maintaining a matched energy surplus. At baseline and follow-up, fasted blood samples and abdominal subcutaneous adipose tissue biopsies were obtained and oral glucose tolerance tests conducted. Insulinaemic responses to a standard glucose load increased 2-fold from baseline to follow-up in the SUR group (17 ± 16 nmol (120 min) l(-1); P = 0.002) whereas there was no change in the SUR+EX group (1 ± 6 nmol (120 min) l(-1)). Seven of 17 genes within adipose tissue were differentially expressed in the SUR group; expression of SREBP-1c, FAS and GLUT4 was significantly up-regulated and expression of PDK4, IRS2, HSL and visfatin was significantly down-regulated (P ≤ 0.05). The pAMPK/AMPK protein ratio in adipose tissue was significantly down-regulated in the SUR group (P = 0.005). Vigorous-intensity exercise counteracted most of the effects of short-term overfeeding and under-activity at the whole-body level and in adipose tissue, even in the face of a standardised energy surplus.

Short-term overfeeding increases circulating adiponectin independent of obesity status

Background

Adiponectin is an adipose tissue derived hormone which strengthens insulin sensitivity. However, there is little data available regarding the influence of a positive energy challenge (PEC) on circulating adiponectin and the role of obesity status on this response.

Objective

The purpose of this study was to investigate how circulating adiponectin will respond to a short-term PEC and whether or not this response will differ among normal-weight(NW), overweight(OW) and obese(OB).

Design

We examined adiponectin among 64 young men (19-29 yr) before and after a 7-day overfeeding (70% above normal energy requirements). The relationship between adiponectin and obesity related phenotypes including; weight, percent body fat (%BF), percent trunk fat (%TF), percent android fat (%AF), body mass index (BMI), total cholesterol, HDLc, LDLc, glucose, insulin, homeostatic model assessment insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were analyzed before and after overfeeding.

Results

Analysis of variance (ANOVA) and partial correlations were used to compute the effect of overfeeding on adiponectin and its association with adiposity measurements, respectively. Circulating Adiponectin levels significantly increased after the 7-day overfeeding in all three adiposity groups. Moreover, adiponectin at baseline was not significantly different among NW, OW and OB subjects defined by either %BF or BMI. Baseline adiponectin was negatively correlated with weight and BMI for the entire cohort and %TF, glucose, insulin and HOMA-IR in OB. However, after controlling for insulin resistance the correlation of adiponectin with weight, BMI and %TF were nullified.

Conclusion

Our study provides evidence that the protective response of adiponectin is preserved during a PEC regardless of adiposity. Baseline adiponectin level is not directly associated with obesity status and weight gain in response to short-term overfeeding. However, the significant increase of adiponectin in response to overfeeding indicates the physiological potential for adiponectin to attenuate insulin resistance during the development of obesity.

Circulating glucagon-like peptide-1 increases in response to short-term overfeeding in men

BACKGROUND

Glucagon-like Peptide-1 (GLP-1) is an incretin hormone secreted from the gastrointestinal tract that facilitates the glucose-dependent insulin response. Additionally, GLP-1 is thought to be involved in energy homeostasis. Currently little is known about GLP-1's responsiveness to an energy surplus, a fundamental cause of obesity and diabetes. Our objective was to examine the response of serum GLP-1 to short-term (7 day) overfeeding in young men.

METHODS

Seventy-two young men from the Canadian province of Newfoundland were recruited for the study. For 7-days, the subjects consumed 70% more calories than required at baseline.Various measurements including: anthropometrics, body composition, markers of glucose/lipid metabolism and serum total GLP-1, were taken at a fasted state before (day 1) and after (day 8) the challenge. Paired t-test analyses were used to assess the change in variables after the overfeeding period. Additionally, the relationship between serum GLP-1 and the measured variables at baseline and change due to overfeeding were analyzed.

RESULTS

Serum GLP-1 was significantly increased in all groups in response to the 7-day energy surplus, indicating the increase was independent of adiposity status. There was no significant difference in fasting GLP-1 at baseline between the normal weight and overweight/obese groups. At baseline, GLP-1 concentration negatively correlated with HDL-cholesterol and positively correlated with triacylglycerols and markers of insulin resistance in the overweight/obese group. Also GLP-1 was negatively correlated with change in percent gynoid fat in the overweight/obese subjects. Percent change in GLP-1 was negatively associated with percent change in gynoid fat in the normal weight group and positively associated with percent change in cholesterol in the overweight/obese group. Percentage change of circulating triacylglycerols was positively associated with percent change in GLP-1 in both adiposity groups.

CONCLUSION

Our findings showed that GLP-1 serum concentration is not a significant factor in determining obesity status. The increase of GLP-1 in all subjects regardless of obesity status, suggest GLP-1 serves as a protective role, counteracting energy surplus.

Increased plasma visfatin concentration is a marker of an atherogenic metabolic profile

BACKGROUND AND AIMS

Visfatin is associated with atherosclerosis-related diseases. We assessed in non-diabetic individuals the association of plasma visfatin levels with cardiovascular disease (CVD) risk and the atherosclerosis-related metabolic variables.

METHODS AND RESULTS

When study population (n = 179, age 49 ± 11 years) was divided according to visfatin tertiles, the 10-year CVD Framingham risk scores were significantly increased in the top visfatin tertile. We observed a positive association between visfatin tertiles with waist circumference and blood pressure, as well as with total cholesterol and triglyceride levels, but not with apolipoprotein C-III, fibrinogen or pre-beta1 high density lipoprotein (HDL). The percentage of large HDL subclasses was significantly lower and the percentage of small HDL subclasses over the HDL-C concentration was significantly higher in the top visfatin tertile compared with the other tertiles. The atherogenic small dense low density lipoprotein subclasses (sdLDL-C) were significantly increased in the top visfatin tertile compared with the lower tertiles. High sensitivity C-reactive protein (hsCRP) concentration was significantly increased in the top visfatin tertile compared with the lower tertiles. Although age and sex distribution did not differ between visfatin tertiles, the simultaneous adjustment for these parameters attenuated the significance of the differences observed in sdLDL-C and hsCRP levels. Similarly, after adjustment for hsCRP or waist circumference, only triglycerides and blood pressure levels, as well as the distribution of HDL subclasses, remained significantly different between visfatin tertiles.

CONCLUSIONS

Our results support a role for visfatin in the detection of subjects with many metabolic abnormalities, which result in increased CVD risk.

Effects of bariatric surgery on adipokine-induced inflammation and insulin resistance

Over a third of the US population is obese and at high risk for developing type 2 diabetes, insulin resistance, and other metabolic disorders. Obesity is considered a chronic low-grade inflammatory condition that is primarily attributed to expansion and inflammation of adipose tissues. Indeed, adipocytes produce and secrete numerous proinflammatory and anti-inflammatory cytokines known as adipokines. When the balance of these adipokines is shifted toward higher production of proinflammatory factors, local inflammation within adipose tissues and subsequently systemic inflammation occur. These adipokines including leptin, visfatin, resistin, apelin, vaspin, and retinol binding protein-4 can regulate inflammatory responses and contribute to the pathogenesis of diabetes. These effects are mediated by key inflammatory signaling molecules including activated serine kinases such as c-Jun N-terminal kinase and serine kinases inhibitor κB kinase and insulin signaling molecules including insulin receptor substrates, protein kinase B (PKB, also known as Akt), and nuclear factor kappa B. Bariatric surgery can decrease body weight and improve insulin resistance in morbidly obese subjects. However, despite reports suggesting reduced inflammation and weight-independent effects of bariatric surgery on glucose metabolism, mechanisms behind such improvements are not yet well understood. This review article focuses on some of these novel adipokines and discusses their changes after bariatric surgery and their relationship to insulin resistance, fat mass, inflammation, and glucose homeostasis.

Serum acylated ghrelin concentrations in response to short-term overfeeding in normal weight, overweight, and obese men

Background

Ghrelin, an orexigenic gut hormone secreted primarily from the stomach, is involved in energy homeostasis. However, little data is available regarding its response to energy surplus and the development of human obesity.

Objective

The present study investigated the response of circulating acylated ghrelin to a 7-day positive energy challenge.

Design

A total of 68 healthy young men were overfed 70% more calories than required, for 1-week. Subjects were classified based on percent body fat (measured by dual-energy X-ray absorptiometry) as normal weight, overweight, and obese. Serum acylated ghrelin concentration was measured before and after the positive energy challenge. Additionally, the relationship between acylated ghrelin and obesity-related phenotypes including weight, body mass index, percent body fat, cholesterol, HDL-c, LDL-c, glucose, insulin and homeostasis model assessment of insulin resistance and β-cell function at baseline and change due to overfeeding, were assessed.

Results

Contrary to our expectations, serum acylated ghrelin was significantly increased in response to overfeeding and the increase was independent of obesity status. There was no significant difference in fasting acylated ghrelin between normal weight, overweight, and obese men at baseline. Acylated ghrelin was negatively correlated with weight and BMI for normal weight and with BMI in overweight men. Also ghrelin was correlated with change in weight and BMI in overweight (negative relationship) and obese (positive relationship) groups.

Conclusion

Our results showed that circulating acylated ghrelin was increased after a 7-day positive energy challenge regardless of adiposity status. However, acylated ghrelin was correlated with change in weight and BMI in opposing directions, in overweight and obese subjects respectively, thus dependent on obesity status.

Relationship among plasma adipokines, insulin and androgens level as well as biochemical glycemic and lipidemic markers with incidence of PCOS in women with normal BMI

Polycystic ovary syndrome (PCOS) is an endocrine disorder in women. Omentin-1 and vaspin are secretary adipokines that are produced by the visceral adipose tissue. These levels change in obese women with PCOS. The aim of this study is to investigate whether omentin and vaspin levels change in nonobese PCOS subjects. This study is a cross-sectional case control study in which 39 women with PCOS were picked out for this study. The inclusion criteria were based on the Rotterdam 2003 diagnostic criteria. The control group consisted of 39 women with normal pelvic sonographic reports having regular menstruation and showing no signs of infertility. The fasting plasma glucose (FPG), triglyceride (TG), Chol, and high-density lipoprotein cholesterol (HDL-C), insulin, testosterone, omentin and vaspin were measured by the enzymatic methods. The differences within these groups were calculated by the un-paired t-test and the Mann-Whitney test. The results from this study show a significant increase in the amount of insulin, testosterone, homeostasis model assessments for insulin resistance, TG and lower HDL in the patient group. No significant differences were seen in omentin, vaspin, FPG, Cho, low-density lipoprotein, very low-density lipoprotein cholesterol, blood urea nitrogen, Cr and homeostasis model assessments for B cell function levels between groups. Results show that PCOS is not a determinant of decreased omentin and vaspin plasma levels and those high androgen level and insulin resistances are warning signs of PCOS.

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.

Visfatin and its role in obesity development

Visfatin, a product of PBEF gene, is an adipocytokine that harbours strong insulin-mimetic activity and it has been reported previously to associate with obesity. Recent reports also provide evidence that Visfatin has also important intracellular effects as it is homologous with nicotinamide phosphoribosyltransferase (NAMPT). In this review, we summarize the main documented effects of Visfatin on metabolism in humans, with special emphasis put on the pathways associated with obesity.

Assessment of serum visfatin levels in girls with anorexia nervosa

OBJECTIVE

Visfatin (VISF) is a recently described peptide regulating the process of adipocyte differentiation. Only one pilot study of VISF expression in the fat tissue and its circulating concentrations in a small group of patients with anorexia nervosa (AN) have been published, yet.

DESIGN AND PATIENTS

Cross-sectional assessment of VISF serum concentrations in 195 girls aged 11-18·9 years with AN (n = 87), eating disorders not otherwise specified (NOS; n = 17), simple obesity (OB; n = 30), and healthy controls (H; n = 61).

MEASUREMENTS

Blood samples were collected during the fasting state between 7:00 am-8:30 am. VISF serum concentrations were determined using enzyme immunoassay. Comparisons of VISF levels between groups were performed.

RESULTS

Mean serum VISF concentrations in girls with AN and NOS were significantly lower than those in the H and OB groups. Serum VISF concentrations were higher in the OB than in the H groups. When were calculated per body mass index (BMI), VISF concentrations were significantly lower in the AN, NOS, and OB groups than in healthy controls. Among participants with a normal BMI, serum VISF concentrations correlated positively with BMI (r = 0·27; P < 0·05). In the OB group, a significant, negative correlation between BMI and VISF levels (r = -0·38; P = 0·04) was observed.

CONCLUSIONS

Compared with healthy girls, serum VISF concentrations are decreased in girls with AN. Conversely, obese girls have elevated VISF levels. When calculated per BMI (VISF/BMI), the results in AN and OB groups were lower than in healthy participants.

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.

Weight gain following treatment with valproic acid: pathogenetic mechanisms and clinical implications

In the last years, a growing body of literature indicates an association between valproic acid therapy and weight gain. Weight gain during valproate treatment can be observed within the first 3 months of therapy and women seem to be more susceptible than men. The mechanism through which valproic acid may induce a weight gain is still controversial. The scope of this paper is to investigate the possible causal link between treatment and weight gain in epileptic patients. Systematic review of published epidemiological studies has been done in order to evaluate the real extent of this side effect of valproic acid and its clinical implications, such as an increased risk of insulin resistance and other secondary metabolic abnormalities. The knowledge of the potential of valproic acid to cause significant changes in body weight will help in appropriate selection and modification of antiepileptic therapy to minimize the risk for weight abnormalities. Measurements of body weight before initiation of valproic acid therapy should be done as part of the monitoring of patients with epilepsy to detect changes before there are serious adverse consequences; an increase of 2 kg of body weight after 1 month of treatment should imply considerations to change antiepileptic drug therapy.

Serum peptide YY in response to short-term overfeeding in young men

BACKGROUND

Peptide YY (PYY), a gut hormone that inhibits appetite, has been linked to the development of obesity.

OBJECTIVE

This study investigated the nutritional regulation of PYY after 7 d of overfeeding (70% above normal energy requirements) in normal-weight, overweight, and obese men.

DESIGN

Sixty-nine men (aged 19-29 y) participated in the study. We analyzed the relation between fasting serum PYY before and after a 7-d overfeeding challenge in normal-weight, overweight, and obese men. In addition, we analyzed PYY with obesity-related phenotypes including weight, percentage body fat (measured by dual-energy X-ray absorptiometry), body mass index (BMI), total cholesterol, HDL, LDL, glucose, insulin, insulin resistance, and β cell function evaluated by the homeostasis model assessment of insulin resistance (HOMA-IR) and β cell function (HOMA-β) at baseline and in response to the energy surplus.

RESULTS

Fasting serum PYY concentrations at baseline were not significantly different between the normal-weight, overweight, and obese subjects on the basis of dual-energy X-ray absorptiometry or BMI. Although the PYY concentration significantly increased due to overfeeding, no differences were observed between adiposity statuses. In addition, basal PYY was negatively correlated with the changes of total cholesterol, HDL, and LDL in normal weight. In addition, the increase in PYY after overfeeding was positively correlated with HDL cholesterol and glucose in normal-weight subjects.

CONCLUSIONS

Our findings suggest that fasting PYY concentrations are not associated with adiposity status. Moreover, the 7-d overfeeding challenge significantly increased fasting PYY, which is likely a protective response to the positive energy balance.

Compare the effects of different visfatin concentration on cardiovascular risk factors, adiponectin and insulin resistance in patients with T2DM

AIM

The discovery of new adipokine, visfatin can significantly enhance our knowledge of insulin resistance and diabetes mellitus. We explored the relation of visfatin concentrations to cardiovascular risk factors, adiponectin and insulin resistance criteria in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Fifty-eight patients with T2DM were recruited from the out patients clinic of Shariati Hospital. Laboratory and anthropometric measurements include FBG, OGTT, HbA1c, fasting serum visfatin, insulin and adiponectin, HOMA-IR and hsCRP, weight, height, BMI and WHR were performed in all participants. All of the statistical data were analyzed using the SPSS15 software.

RESULTS

The log(10)-transformed (log) plasma visfatin concentration was in significant positive correlation with age (r=0.286, p=0.033). Patients were divided in two groups by median log visfatin (0.85 ng/mL): group I had low values and group II had high values. In group I the log visfatin was in significant positive correlation with age (r=0.436, p=0.018) and in group II log visfatin was in significant negative correlation with FPG and HbA1c (r>0.4, p<0.05).

CONCLUSION

In conclusion high circulating levels of visfatin could be in healthy relations with cardiovascular risk factors, insulin resistance status and adiponectin in diabetic patients.

Circulating visfatin levels in healthy preterm infants are independently associated with high-density lipoprotein cholesterol levels and dietary long-chain polyunsaturated fatty acids

The adipokine visfatin has been proposed to exert insulin-mimicking effects and to play a role in the development of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance and, possibly, for other components of metabolic syndrome. Dietary long-chain polyunsaturated fatty acids (LCPUFAs) during the perinatal period may reduce the risk of metabolic syndrome. The authors' objective was to study the circulating concentrations of visfatin in preterm infants and to examine associations of visfatin with anthropometric measurements, metabolic indices, and dietary LCPUFAs. Serum visfatin concentrations were determined by enzyme-linked immunosorbent assay at mean (SD) 33.8 (11.7) days of life in 60 healthy preterm infants (gestational age, 32.7 [1.9] weeks) randomly assigned to be fed since birth either a formula containing LCPUFA (arachidonic and docosahexaenoic acid) (+LCPUFA group) or the same formula without LCPUFA (-LCPUFA group). Associations of visfatin with anthropometric parameters, serum glucose, insulin, homeostasis model assessment index of insulin resistance, blood lipids, and adiponectin levels were examined. Serum visfatin levels were significantly higher in the +LCPUFA than in the -LCPUFA group (P < .001) and correlated positively with body weight z score (β = 0.31, P = .02), total cholesterol (β = 0.34, P = .01), high-density lipoprotein cholesterol (HDL-C) (β = 0.47, P < .001), and adiponectin levels (β = 0.29, P = .03), but not with indices of insulin sensitivity. In multiple regression analysis, HDL-C and dietary LCPUFAs correlated independently with serum visfatin levels. Circulating visfatin levels in preterm infants are independently associated with HDL-C levels and dietary LCPUFAs. Whether the higher visfatin levels in the +LCPUFA preterm infant group are beneficial for the later health of these infants remains to be determined.

[Visfatin in obese patients, relation with cardiovascular risk factors, a cross sectional study]

BACKGROUND AND OBJECTIVE

Obesity and insulin resistance are associated with cardiovascular risk factors. The aim of the present study was to explore the relation of visfatin with insulin resistance, cardiovascular risk factors and anthropometry in obese patients without comorbidities.

PATIENTS AND METHOD

A population of 270 obese patients was analyzed in a prospective way. In all patients we performed a biochemical analysis (lipid profile, insulin, HOMA and visfatina), and a nutritional evaluation (dietary intake, conventional anthropometry and bioimpedance).

RESULTS

Patients were divided in two groups by median visfatin value (8,32 ng/ml), group I (patients with the low values, average value 7,11 (0,7) ng/ml) and group II (patients with the high values, average value 13,5 (10,1) ng/ml). Patients in the group I had higher weight, body mass index, waist circumference, and waist to hip ratio than patients in group II. Patients in group I had lower LDL-cholesterol and C reactive protein than patients in group II. Correlation analysis showed a positive correlation between visfatin levels and LDL cholesterol (r=0.194; p<0.05) and C reactive protein (r=0.266; p<0.05) and a negative corelation with weight (r=-0.162; p<0.05). In the logistic analysis with age-, sex- and dietary intake- adjusted basal visfatin concentration as a dependent variable, the next variables remained in the model; weight with an odds ratio (OR) 0,97 (IC95% 0,95-0,99), LDL cholesterol 1,012(1,010-1.023) and C reactive protein 1,15 (1.03-1.3).

CONCLUSION

LDL cholesterol and c reactive protein levels are positively correlated with visfatin levels. Weight is negatively correlated with visfatin levels, in an independent way and adjusted by age, sex and dietary intake.

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

OBJECTIVE

The aim of this study was to evaluate the association of serum visfatin, adiponectin and leptin with 2 diabetes mellitus (T2DM) in the context of the role of obesity or insulin resistance, which is not well understood.

METHODS

A total of 76 newly-diagnosed T2DM patients and 76 healthy control subjects, matched for age, body mass index (BMI) and sex ratio, were enrolled. Anthropometric parameters, glycemic and lipid profile, insulin resistance (measured by homeostasis model assessment of insulin resistance index [HOMA-IR]), leptin, adiponectin, and visfatin were assessed.

RESULTS

On the contrary to adiponectin, serum leptin and visfatin levels were higher in T2DM patients compared with controls (10.07 ± 4.5, 15.87 ± 16.4, and 5.49 ± 2.4 vs. 12.22 ± 4.9 μg/ml, 8.5 ± 7.8 ng/ml and 3.58 ± 2.2 ng/ml, respectively, P<0.01). Waist circumference and BMI were correlated with leptin and adiponectin but not with visfatin. Leptin, adiponectin and visfatin all were associated with T2DM following adjusting for obesity measures. After controlling for HOMA-IR, visfatin remained as an independent predictor of T2DM (odds ratio=1.32, P<0.05). In a multiple regression analysis to determine visfatin only triglycerides and fasting glucose remained in the model (P<0.05).

CONCLUSION

Elevation of visfatin in T2DM is independent of obesity and insulin resistance and is mainly determined by fasting glucose and triglycerides.

Visfatin induces sickness responses in the brain

Background/Objective

Visfatin, also known as nicotiamide phosphoribosyltransferase or pre-B cell colony enhancing factor, is a pro-inflammatory cytokine whose serum level is increased in sepsis and cancer as well as in obesity. Here we report a pro-inflammatory role of visfatin in the brain, to mediate sickness responses including anorexia, hyperthermia and hypoactivity.

Methodology

Rats were intracerebroventricularly (ICV) injected with visfatin, and changes in food intake, body weight, body temperature and locomotor activity were monitored. Real-time PCR was applied to determine the expressions of pro-inflammatory cytokines, proopiomelanocortin (POMC) and prostaglandin-synthesizing enzymes in their brain. To determine the roles of cyclooxygenase (COX) and melanocortin in the visfatin action, rats were ICV-injected with visfatin with or without SHU9119, a melanocortin receptor antagonist, or indomethacin, a COX inhibitor, and their sickness behaviors were evaluated.

Principal Findings

Administration of visfatin decreased food intake, body weight and locomotor activity and increased body temperature. Visfatin evoked significant increases in the levels of pro-inflammatory cytokines, prostaglandin-synthesizing enzymes and POMC, an anorexigenic neuropeptide. Indomethacin attenuated the effects of visfatin on hyperthermia and hypoactivity, but not anorexia. Further, SHU9119 blocked visfatin-induced anorexia but did not affect hyperthermia or hypoactivity.

Conclusions

Visfatin induced sickness responses via regulation of COX and the melanocortin pathway in the brain.

Nicotinamide Phosphoribosyltransferase in Human Diseases

Nicotinamide phosphoribosyltransferase (NAMPT) was first reported as a pre-B-cell colony enhancing factor in 1994 with little notice, but it has received increasing attention in recent years due to accumulating evidence indicating that NAMPT is a pleiotropic protein such as a growth factor, a cytokine, an enzyme and a visfatin. Now, NAMPT has been accepted as an official name of this protein. Because of NAMPT's multiple functions in a variety of physiological processes, their dysregulations have been implicated in the pathogenesis of a number of human diseases or conditions such as acute lung injury, aging, atherosclerosis, cancer, diabetes, rheumatoid arthritis and sepsis. This review will cover the current understanding of NAMPT's structure and functions with an emphasis on recent progress of nicotinamide phosphoribosyltransferase's pathological roles in various human diseases and conditions. Future directions on exploring its Terra incognita will be offered in the end.

Effect of postprandial lipemia on plasma concentrations of A-FABP, RBP-4 and visfatin

BACKGROUND AND AIMS

Several studies indicate that changes in the plasma concentrations of adipocyte-fatty acid binding protein (A-FABP), retinol binding protein-4 (RBP-4) and visfatin are associated with chronic states of insulin resistance. Recent studies have shown that postprandial lipemia induces an acute state of insulin resistance. The aim of this study was to investigate the effect of postprandial lipemia on the plasma concentrations of A-FABP, RBP-4 and visfatin.

METHODS AND RESULTS

In a within-subject crossover study, we administered a standardized high-fat meal to 24 healthy subjects (12 males and 12 females). Plasma concentrations of adipocytokines were measured in the morning after an overnight fast and during postprandial lipemia, i.e. 2, 4 and 6 hours after meal ingestion (postprandial experiment). To exclude potential confounding factors affecting the adipocytokine plasma concentrations, a control experiment without meal ingestion was performed over the same time period (postabsorptive control experiment). Comparing plasma concentrations of A-FABP, RBP-4 and visfatin between the postprandial and the postabsorptive control experiments, we found no significant differences. Within either of the two experiments, a decrease of A-FABP was noted reaching, however, statistical significance only in the postprandial experiment, i.e. 2 and 4 hours after meal ingestion.

CONCLUSION

Postprandial lipemia has no significant effect on the plasma concentrations of visfatin, A-FABP or RBP-4 in relation to their postabsorptive plasma profiles. We conclude that prolonged states of insulin resistance are required to affect plasma concentrations of these adipocytokines.

New approach in the interpretation of the adipose tissue

Az elmúlt másfél évtized kutatásai bebizonyították, hogy a zsírszövet aktív endokrin szerv, amely számos hormont választ el. A szerzők a leptin, az adiponektin, a rezisztin, a visfatin és az omentin hormonok működését mutatják be, különös tekintettel az anyagcsere-folyamatokra gyakorolt hatásukra.

The relationship of visfatin/pre-B-cell colony-enhancing factor/nicotinamide phosphoribosyltransferase in adipose tissue with inflammation, insulin resistance, and plasma lipids

Visfatin/pre-B-cell colony-enhancing factor (PBEF)/nicotinamide phosphoribosyltransferase (Nampt) has been proposed as an insulin-mimicking adipocytokine predominantly secreted from visceral adipose tissue (VAT) and correlated with obesity. However, recent evidence challenged this proposal and instead suggested visfatin/PBEF/Nampt as a proinflammatory cytokine. The study aimed to examine whether visfatin/PBEF/Nampt was predominantly expressed in VAT and was correlated with obesity. The relationship of visfatin/PBEF/Nampt gene expression in adipose tissues with proinflammatory gene expression and metabolic phenotypes was also examined. The relative messenger RNA (mRNA) levels of visfatin/PBEF/Nampt, macrophage-specific marker CD68, and proinflammatory genes were measured in paired abdominal VAT and subcutaneous adipose tissues (SAT) and from 53 nondiabetic adults using quantitative real-time polymerase chain reaction. Fasting glucose, insulin, triglyceride, cholesterol, and uric acid levels were measured; and systemic insulin sensitivity was quantified with modified insulin suppression tests. There was no difference in visfatin/PBEF/Nampt mRNA levels between VAT and SAT, and neither was associated with measures of obesity. Visfatin/PBEF/Nampt mRNA levels were strongly correlated with proinflammatory gene expression including CD68 and tumor necrosis factor-alpha gene in both VAT and SAT. The VAT and SAT visfatin/PBEF/Nampt mRNA expressions were positively correlated with steady-state plasma glucose concentrations measured with modified insulin suppression tests, a direct measurement of systemic insulin resistance (r = 0.42, P = .03 and r = 0.44, P = .03, respectively). The VAT visfatin/PBEF/Nampt mRNA expression was also positively correlated with fasting triglyceride (r = 0.42, P = .002) and total cholesterol levels (r = 0.37, P = .009). Visfatin/PBEF/Nampt is not predominantly secreted from VAT and is not correlated with obesity. Our findings suggest that visfatin/PBEF/Nampt is a proinflammatory marker of adipose tissue associated with systemic insulin resistance and hyperlipidemia.

Visfatin is increased in chronic kidney disease patients with poor appetite and correlates negatively with fasting serum amino acids and triglyceride levels

OBJECTIVE

Anorexia is a common complication of chronic kidney disease (CKD), while novel animal and human data suggest a role for visfatin in regulating feeding behavior. We hypothesized that increased visfatin levels in CKD patients may be involved in the regulation of appetite and nutrient homeostasis.

METHODS

This is a cross-sectional study where circulating visfatin levels were analysed in 246 incident CKD stage 5 patients starting dialysis therapy. The associations between visfatin (enzyme-linked immunosorbent assay, ELISA) and anthropometric and biochemical nutritional status, self-reported appetite, fasting serum amino acids (high-performance liquid chromatography) and circulating cytokine levels (ELISAs) were assessed. We also performed genotyping (Pyrosequencing(R)) of two polymorphisms (rs1319501 and rs9770242) in the visfatin gene.

RESULTS

Serum visfatin concentrations were not associated with either body mass index or serum leptin. Across groups with worsening appetite, median visfatin levels were incrementally higher (P < 0.05). With increasing visfatin tertiles, patients proved to be more often anorectic (P < 0.05) and to have incrementally lower serum albumin, cholesterol and triglycerides as well as lower essential and non-essential serum amino acids (P < 0.05 for all). A polymorphism in the visfatin gene was associated with increased circulating visfatin levels and, at the same time, a higher prevalence of poor appetite (P < 0.05 for both).

CONCLUSION

Our study suggests novel links between visfatin and anorexia in CKD patients. Based on recent studies, we speculate that high visfatin in CKD patients may constitute a counter-regulatory response to central visfatin resistance in uremia. Future studies should examine a putative role of visfatin as a regulator of nutrient homeostasis in uremia.

Eicosapentaenoic acid stimulates AMP-activated protein kinase and increases visfatin secretion in cultured murine adipocytes

Visfatin is an adipokine highly expressed in visceral AT (adipose tissue) of humans and rodents, the production of which seems to be dysregulated in excessive fat accumulation and conditions of insulin resistance. EPA (eicosapentaenoic acid), an n-3 PUFA (polyunsaturated fatty acid), has been demonstrated to exert beneficial effects in obesity and insulin resistance conditions, which have been further linked to its reported ability to modulate adipokine production by adipocytes. TNF-alpha (tumour necrosis factor-alpha) is a pro-inflammatory cytokine whose production is increased in obesity and is involved in the development of insulin resistance. Control of adipokine production by some insulin-sensitizing compounds has been associated with the stimulation of AMPK (AMP-activated protein kinase). The aim of the present study was to examine in vitro the effects of EPA on visfatin production and the potential involvement of AMPK both in the absence or presence of TNF-alpha. Treatment with the pro-inflammatory cytokine TNF-alpha (1 ng/ml) did not modify visfatin gene expression and protein secretion in primary cultured rat adipocytes. However, treatment of these primary adipocytes with EPA (200 mumol/l) for 24 h significantly increased visfatin secretion (P<0.001) and mRNA gene expression (P<0.05). Moreover, the stimulatory effect of EPA on visfatin secretion was prevented by treatment with the AMPK inhibitor Compound C, but not with the PI3K (phosphoinositide 3-kinase) inhibitor LY294002. Similar results were observed in 3T3-L1 adipocytes. Moreover, EPA strongly stimulated AMPK phosphorylation alone or in combination with TNF-alpha in 3T3-L1 adipocytes and pre-adipocytes. The results of the present study suggest that the stimulatory action of EPA on visfatin production involves AMPK activation in adipocytes.

Plasma visfatin concentrations after a lifestyle intervention were directly associated with inflammatory markers

BACKGROUND AND AIMS

The biological activity and regulation of the novel adipokine visfatin are still largely unknown. Our aim was to evaluate if visfatin plasma concentrations may be influenced by a lifestyle intervention.

METHODS AND RESULTS

Out of 335 dysmetabolic patients from a population-based cohort, randomized to receive a lifestyle intervention program (intervention group) or family physician usual care (controls), 20 patients per group were randomly selected for plasma visfatin determination. The before-after variation (Delta) in visfatin concentration at 1-year from randomization, and the correlations between (Delta)visfatin and intervention-induced changes in waist circumference, fasting glucose, markers of inflammation, and oxidative stress were evaluated. The intervention group showed a significant improvement in waist circumference, and many metabolic/inflammatory variables, while the controls worsened. Visfatin concentrations slightly decreased in the former and significantly increased in the controls ((Delta)visfatin=-2.4 vs 66.0 ng/ml, p<0.001). In robust regression models, the following variables resulted associated with (Delta)visfatin: (Delta)waist circumference, (Delta)fasting glucose, (Delta)hs-CRP (high-sensitivity C-reactive protein) and (Delta)TNFalpha (tumor necrosis factor-alpha). Significant effects on (Delta)visfatin of (Delta)TNFalpha (beta=16.8; 6.1-25.6; p=0.003) and, modified by group, of (Delta)hs-CRP (beta=29.8; 95% CI 15.4-44.2; p<0.001 and beta=4.2; 2.9-5.5; p<0.001 in the control and intervention group, respectively) were detected. By controlling for (Delta)waist, the effects of (Delta)TNFalpha and of (Delta)hs-CRP on (Delta)visfatin by group did not change, while (Delta)waist was no longer associated. The association between (Delta)visfatin and (Delta)glucose was no longer significant, after adjusting for (Delta)hs-CRP.

CONCLUSION

Visfatin values increased with waist circumference and were associated with variations of inflammatory markers, suggesting participation in inflammatory mechanisms.

Plasma levels of PBEF/Nampt/visfatin are decreased in patients with liver cirrhosis

Liver cirrhosis is a catabolic disease associated with a high incidence of insulin resistance and diabetes mellitus. Pre-B cell colony-enhancing factor/ nicotinamide phosphoribosyltransferase/visfatin has been characterized as a novel adipokine with a potential role in glucose metabolism and nicotinamide dinucleotide (NAD) generation. We studied plasma levels and metabolic relevance of visfatin in 19 patients with cirrhosis and 19 body mass index-, age-, and sex-matched controls. In addition, hepatic mRNA expression was assessed by qPCR in livers of seven patients with cirrhosis and four controls. Circulating visfatin was 78% lower in cirrhotics (P < 0.001) and decreased with worsening of the clinical stage of liver disease. Hepatic visfatin secretion decreased with clinical stage (P < 0.05) and reduced liver function (P = 0.01). Consistent with these data, hepatic visfatin mRNA expression was significantly lower in cirrhotic livers (P < 0.05). Circulating visfatin in cirrhosis was correlated with body cell mass (r = 0.72, P < 0.01) as well as with body fat mass (r = 0.53, P < 0.05) but not with plasma glucose, insulin, the degree of insulin resistance, or whole body glucose oxidation rates. Higher visfatin levels were associated with higher hepatic glucose production (r = 0.53, P < 0.05) and also with a higher arterial ketone body ratio (KBR) (r = 0.48, P < 0.05), an indicator of increased hepatic NAD generation. In conclusion, circulating visfatin levels are significantly decreased in liver cirrhosis, presumably attributable to decreased hepatic expression and production. Plasma visfatin in cirrhosis is not associated with insulin resistance but correlates with hepatic glucose production and the arterial KBR, indicating a potential link between the NAD-generating properties of visfatin and metabolism.

Relation of visfatin to cardiovascular risk factors and adipocytokines in patients with impaired fasting glucose

OBJECTIVE

The discovery of visfatin has great potential to significantly enhance our understanding of impaired fasting glucose and diabetes mellitus. The aim of the present study was to explore the relation of visfatin concentrations to cardiovascular risk factors and serum adipocytokine concentrations in patients with impaired fasting glucose.

METHODS

A sample of 55 patients with impaired fasting glucose was analyzed in a prospective way. All patients with a 2-wk weight-stabilization period before recruitment were enrolled. Weight, blood pressure, basal glucose, lipoprotein(a), C-reactive protein, insulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerols, blood, and adipocytokines (visfatin, leptin, adiponectin, resistin, tumor necrosis factor-α [TNF-α], and interleukin-6) levels were measured. Tetrapolar impedancometry, indirect calorimetry, and prospective serial assessment of nutritional intake with 3-d written food records were performed.

RESULTS

Fourteen men (25.5%) and 41 women (74.5%), with a mean age of 57.3 ± 11.7 y and mean body mass index of 35.8 ± 3.6 kg/m(2), were included. Patients were divided in two groups by median visfatin value (18.2 ng/mL): group I had low values and group II had high values. Patients in group I had greater weight, body mass index, fat mass, fat-free mass, and adiponectin than patients in group II. Patients in group II had higher total cholesterol, low-density lipoprotein cholesterol, resistin, and TNF-α levels than patients in group I. In the multivariate analysis with age- and sex-adjusted basal visfatin concentration as a dependent variable, only TNF-α remained an independent predictor in the model (F = 8.4, P < 0.05), with an inverse correlation. Visfatin concentration decreased 7.33 ng/mL (95% confidence interval 2.10-12.58) for each nanogram per milligram of TNF-α increase.

CONCLUSION

Only TNF-α is related in an independent way to serum visfatin levels.

Changes in the transcriptome of abdominal subcutaneous adipose tissue in response to short-term overfeeding in lean and obese men

BACKGROUND

Obesity is caused by the excessive accumulation of adipose tissue as a result of a chronic energy surplus. Little is known regarding the molecular mechanisms involved in the response to an energy surplus in human adipose tissue at the genomic level.

OBJECTIVE

The objective was to investigate changes in the transcriptome of abdominal subcutaneous adipose tissue after a positive energy challenge induced by overfeeding in both lean and obese subjects to identify novel obesity candidate genes.

DESIGN

A total of 26 men were recruited and classified on the basis of percentage body fat (measured by dual-energy X-ray absorptiometry) as lean (<20%) or obese (>25%) to participate in the baseline comparison. Sixteen men participated in the overfeeding study (8 lean and 8 obese). Adipose tissue biopsy samples were collected from all subjects at the subumbilical region. Global gene expression profiles were determined at baseline and after a 7-d hypercaloric diet at 40% above normal energy requirements by using whole human genome DNA microarrays.

RESULTS

Overfeeding induced differential expression in 45 genes. Six genes displayed a significant interaction effect between adiposity status and overfeeding treatment, including transferrin (TF), stearoyl-CoA desaturase (SCD), transaldolase 1 (TALDO1), cathepsin C (CTSC), insulin receptor substrate 2 (IRS2), and pyruvate dehydrogenase kinase, isozyme 4 (PDK4). Overfeeding resulted in changes in expression of these genes in lean subjects, whereas no significant changes were evident in obese subjects.

CONCLUSIONS

Differential expression of these 6 genes may represent a protective mechanism at the molecular level in lean subjects in response to an energy surplus. These genes represent valuable candidates for downstream studies related to obesity.