scholarly journals Associations between Tissue Visfatin/Nicotinamide, Phosphoribosyltransferase (Nampt), Retinol Binding Protein-4, and Vaspin Concentrations and Insulin Resistance in Morbidly Obese Subjects

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Zeynep Goktas ◽  
Shannon Owens ◽  
Mallory Boylan ◽  
David Syn ◽  
Chwan-Li Shen ◽  
...  

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.

2007 ◽  
Vol 92 (3) ◽  
pp. 1168-1171 ◽  
Author(s):  
Dominik G. Haider ◽  
Karin Schindler ◽  
Gerhard Prager ◽  
Arthur Bohdjalian ◽  
Anton Luger ◽  
...  

Abstract Context: Administration of retinol-binding protein 4 (RBP-4) impairs insulin sensitivity in animals, and elevated serum concentrations have been associated with insulin resistance in humans. Objective: We have studied whether weight loss influences RBP-4. Patients and Methods: Fasting serum concentrations of RBP-4 were measured before and 6 months after gastric banding surgery in 33 morbidly obese patients aged 40 ± 11 yr with a body mass index (BMI) of 46 ± 5 kg/m2. Fourteen healthy subjects aged 29 ± 5 yr with a BMI less than 25 kg/m2 served as controls. To characterize the association of weight loss with central and peripheral appetite regulation, the signaling protein agouti-related protein (AGRP), the orexigenic hormone ghrelin, and its recently identified antagonist obestatin were determined. Results: At baseline, RBP-4 levels were markedly higher in obese than in lean subjects (2.7 ± 0.5 vs. 0.9 ± 0.5 μg/ml; P < 0.001). In contrast, AGRP and obestatin were lower in obese subjects compared with lean controls (all P < 0.001). Six months after gastric banding, BMI was reduced to 40 ± 5 kg/m2, RBP-4 was reduced to 2.0 ± 0.7 μg/ml, AGRP increased from 1.8 ± 1.1 to 3.4 ± 1.1 ng/ml, ghrelin increased from 93 ± 58 to 131 ± 70 pg/ml, and obestatin increased from 131 ± 52 to 173 ± 35 pg/ml (all P < 0.05). Individual changes of RBP-4 were associated with changes of BMI (r = 0.72), the homeostasis model assessment insulin resistance-index (r = 0.53), and total cholesterol (r = 0.42, for all P < 0.05). Conclusion: Reductions in circulating RBP-4 may contribute to improved insulin resistance in morbidly obese subjects after weight loss. This is accompanied by favorable changes in appetite-regulating hormones, which might support the sustained weight loss after obesity surgery.


2008 ◽  
Vol 54 (7) ◽  
pp. 1176-1182 ◽  
Author(s):  
Christina Kanaka-Gantenbein ◽  
Alexandra Margeli ◽  
Panagiota Pervanidou ◽  
Sophia Sakka ◽  
George Mastorakos ◽  
...  

Abstract Background: Although there is much evidence regarding the physiologic and pathogenic roles of the newly described adipokines retinol-binding protein 4 (RBP4) and lipocalin-2 as potential promoters of insulin resistance in obese adults, relatively little information exists regarding their roles in obese children. Methods: We investigated the circulating concentrations of RBP4 and lipocalin-2 in 80 obese girls (ages 9– 15 years) and their relationships with high-sensitivity C-reactive protein (hs-CRP) and the adipokines leptin and adiponectin. We divided participants by their body mass index standard deviation scores (BMI SDSs) into 4 groups of 20 girls each: overweight [mean BMI SDS (SD), 1.8 (0.4)], obese [2.2 (0.4)], morbidly obese [3.6 (0.4)], and lean controls [−0.11 (0.4)]. We measured plasma-soluble RBP4, the RBP4-binding protein transthyretin, lipocalin-2, hs-CRP, leptin, and adiponectin and calculated the homeostatic assessment model (HOMA) index from fasting glucose and insulin concentrations. Results: Unexpectedly, plasma RBP4 and lipocalin-2 concentrations were correlated negatively with BMI SDS values (P = 0.005, and P < 0.03, respectively). These results were different from those of adults and were not correlated with the HOMA index. In contrast, hs-CRP and leptin concentrations were positively correlated with BMI SDS values (P < 0.0001, and P < 0.00001, respectively), as expected, whereas the adiponectin concentration was negatively correlated (P = 0.008). Conclusions: Although the correlations of leptin, adiponectin, and hs-CRP concentrations with BMI in children are similar to those of adults, the correlations of RBP4 and lipocalin-2 with BMI in children are the inverse of those observed in adults. Thus, although systemic inflammation and mild insulin resistance are present in childhood obesity, RBP4 and lipocalin-2 concentrations are not increased in children as they are in obese adults with long-standing severe insulin resistance and type 2 diabetes.


2008 ◽  
Vol 114 (4) ◽  
pp. 275-288 ◽  
Author(s):  
Herbert Tilg ◽  
Alexander R. Moschen

Obesity and obesity-related disorders play an important role in clinical medicine. Adipose tissue, with its soluble mediators called adipocytokines, has emerged as a major endocrine organ. These adipocytokines comprise many mediators such as adiponectin, PBEF (pre-B-cell-enhancing factor)/visfatin, leptin, resistin, retinol-binding protein-4 and others. They play major roles in key aspects of metabolism, such as insulin resistance, fatty acid oxidation, inflammation and immunity. Adiponectin, a prototypic adipocytokine, is of importance in the regulation of insulin resistance, as circulating levels are decreased in obesity and diseases associated with insulin resistance. Besides its major role in regulation of insulin sensitivity, recent evidence suggests potent anti-inflammatory functions for adiponectin. These effects are paralleled by other immune-regulatory properties, such as regulation of endothelial cell function. The in vitro effects of adiponectin have been corroborated by several studies demonstrating potent in vivo anti-inflammatory effects. Many other adipocytokines, such as PBEF/visfatin, leptin, resistin or retinol binding protein-4, are involved in the physiology and pathophysiology of adipocytes, adipose tissue and related diseases. PBEF/visfatin, another recently characterized adipocytokine, has been linked to several inflammatory disease states beyond insulin resistance, such as acute lung injury or inflammatory bowel diseases. It has been recognized for many decades that obesity is accompanied by an increase in cancer and potentially some immune-mediated diseases. Understanding this new exciting world of adipocytokines will be of importance in the development of novel therapies for obesity-associated diseases.


Author(s):  
Vita Silvana ◽  
Andon Hestiantoro ◽  
Muharam Natadisastra ◽  
Kanadi Sumapraja ◽  
Budi Wiweko

Objective: To determine whether visceral adipose tissue or serum RBP-4 were related with the risk increment of insulin resistance in normal BMI PCOS patients. Methods: This was a cross-sectional study conducted in normal body mass index PCOS patients at Yasmin Clinic, RSCM, Jakarta from July 2014 until March 2015. Diagnosis of PCOS was established using Rotterrdam (2003) criteria. Insulin resistance was confirmed by using ratio of HOMA-IR >1.4. Results: Among 40 subjects, 20 subjects (50%) belong insulin resistance group. Serum RBP-4 level was higher in insulin resistance group (p=0.06). After ROC analysis was conducted, area under curve for of serum RBP-4 was 69.9% (CI 95% -3754.77 - (186.60-7696.14, p=0.061)). Cut-off level of serum RBP-4 was 23814.5 ng/mL yielded sensitivity and specificity to a level of 60% and 60%, respectively. After logistic regression were analyzed, visceral adipose tissue demonstrated substantial association with the risk increment of insulin resistance in normal BMI PCOS patients. Conclusions: Visceral adipose tissue demonstrated substantial association with the risk increment of insulin resistance in normal BMI PCOS patients, independent with serum RBP-4 levels. Key words: body mass index, diagnosis, insulin resistance, PCOS, retinol binding protein-4   Abstrak Tujuan: Untuk menentukan apakah jaringan adiposa viseral atau serum RBP-4 berhubungan dengan peningkatan risiko resistensi insulin pada Sindrom Ovarium Polikistik dengan indeks masa tubuh normal. Metode: Studi potong lintang dilakukan pada subjek SOPK dengan IMT normal di Klinik Yasmin, RSCM, Jakarta sejak Juli 2014 sampai dengan Maret 2015. Penegakan diagnosis SOPK dilakukan dengan kriteria Rotterdam (2003). Resistensi insulin dikonfirmasi dengan pemeriksaan rasio HOMA-IR > 1.4 Hasil: Diantara 40 subjek, sebanyak 20 subjek (50%) mengalami resistensi insulin. Kadar serum RBP-4 lebih tinggi pada kelompok resistensi insulin (p=0.06). Setelah dilakukan analisis Receiver Operating Curve (ROC), serum RBP-4 memiliki Area Under the Curve  (AUC) sebesar 69.9% (IK 95% -3754.77 - (186.60-7696.14, p=0,061)). Titik potong kadar serum RBP-4 adalah 23814.5 ng/mL dengan sensitivitas dan spesifisitas masing-masing 60% dan 60%. Setelah dilakukan analisis regresi logistik, jaringan adiposa viseral menunjukan asosiasi yang kuat dengan terjadinya resistensi insulin pada pasien SOPK dengan IMT normal. Kesimpulan: Jaringan adiposa viseral menunjukan asosiasi yang kuat dengan terjadinya resistensi insulin pada SOPK dengan IMT normal, independen terhadap kadar serum RBP-4. Kata kunci: diagnosis, indeks masa tubuh, resistensi insulin, retinol binding protein-4, SOPK


Endocrinology ◽  
2008 ◽  
Vol 149 (3) ◽  
pp. 925-934 ◽  
Author(s):  
Farid F. Chehab

Adipose tissue is unique in that it can undergo significant hypertrophy and atrophy, resulting in wide ranges of obesities and lipodystrophies. At the base of this elasticity is the lipid-filled adipocyte, which can either overfill by storing large amounts of triglycerides or shrink to a tiny cell by depleting its lipids and as such is remarkable in sustaining insults. As a major energy reservoir, the adipocyte may hold considerable calories necessary for survival and reproduction, two functions that are essential for the survival of the species. This review will summarize some of the recent studies that have advanced our understanding of the central and peripheral mechanisms that are initiated by adipocyte-secreted factors such as leptin, adiponectin, resistin, and retinol-binding protein 4. The intersection of obesity and lipodystrophy results in insulin resistance, which may be unlocked by elucidating the roles of these factors in pathways that control insulin sensitivity and glucose uptake.


2009 ◽  
Vol 296 (4) ◽  
pp. E628-E634 ◽  
Author(s):  
Haiya Wu ◽  
Li Wei ◽  
Yuqian Bao ◽  
Junxi Lu ◽  
Ping Huang ◽  
...  

Fenofibrate is a peroxisome proliferator-activated receptor-α (PPARα) activator that has been clinically used to treat dyslipidemia and insulin resistance. To better understand the molecular mechanisms underlying fenofibrate action, we investigated whether fenofibrate affects serum levels of retinol-binding protein-4 (RBP4), an adipocytokine that has recently been shown to link obesity and insulin resistance. Fenofibrate treatment significantly decreased serum RBP4 levels of dyslipidemic patients, which correlated with reduced body weight and increased insulin sensitivity. To elucidate the biochemical mechanisms of fenofibrate action, we investigated the effect of fenofibrate on RBP4 expression in obese rats. Fenofibrate greatly decreased RBP4 mRNA levels in adipose tissue but not in the liver, which correlated with decreased serum RBP4 levels and increased insulin sensitivity in obese rats. Consistent with a direct effect on RBP4 expression, fenofibrate treatment significantly reduced the mRNA expression levels of RPB4 in 3T3-L1 adipocytes. Together, our results demonstrate for the first time that fenofibrate inhibits RPB4 expression in dyslipidemic human subjects and suggest that inhibition of RBP4 expression in adipocytes may provide a mechanism by which fenofibrate improves insulin sensitivity in dyslipidemic patients.


Author(s):  
Noa Noy ◽  
Li Li ◽  
Matthew V. Abola ◽  
Nathan A. Berger

AbstractRetinol binding protein 4 (RBP4) is synthesized in the liver where it binds vitamin A, retinol, and transports it to tissues throughout the body. It has been shown in some studies that the level of circulating RBP4 increases with body mass, and the protein has been implicated as a mediator in the development of insulin resistance and the metabolic disease. Adipose tissue serves as another site of RBP4 synthesis, accounting for its designation as an adipokine. In addition to its function as a transport protein, RBP4 serves as a signaling molecule which, by binding to the membrane receptor STRA6, triggers downstream activation of pro-oncogenic pathways including JAK2/STAT3/5. Taken together, available information suggests the possibility that RBP4 may be a link between obesity and cancer.


2015 ◽  
Vol 35 (2) ◽  
pp. 778-788 ◽  
Author(s):  
Chaoyu Zhu ◽  
Yuanyuan Xiao ◽  
Xiaohua Liu ◽  
Junfeng Han ◽  
Jianmei Zhang ◽  
...  

Background/Aims: Pioglitazone, a peroxisome proliferator-activated receptor γ activator, is clinically used to treat insulin resistance. However, the underlying mechanism of pioglitazone's action remains unclear. We investigated whether, and how, pioglitazone modulates serum level of retinol binding protein 4 (RBP4), an adipocytokine associated with obesity and insulin resistance. Methods: Insulin sensitivity was determined by oral glucose tolerance test, and RBP4 expression was detected by RT-PCR and Western blotting. Results: Pioglitazone treatment significantly decreased serum RBP4 levels in obese rats, which was correlated with reduced body weight and increased insulin sensitivity. Moreover, pioglitazone greatly decreased RBP4 mRNA and protein levels in adipose tissue but not in the liver. Consistently, pioglitazone treatment significantly reduced RBP4 protein expression in 3T3-L1 adipocytes but not in HepG2 cells. Conclusion: These results demonstrate that pioglitazone inhibits the level of serum RPB4 by suppressing RBP4 expression in adipose tissue of obese rats, suggesting that inhibiting RBP4 expression in adipocytes may provide a mechanism by which pioglitazone improves insulin sensitivity in insulin-resistant subjects.


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