Eu3+-Doped Anionic Zinc-Based Organic Framework Ratio Fluorescence Sensing Platform: Supersensitive Visual Identification of Prescription Drugs.

Advanced techniques for both environmental and biological prescription drug monitoring are of ongoing interest. In this work, a fluorescent sensor based on an Eu3+-doped anionic zinc-based metal-organic framework (Eu3+@Zn-MOF) was constructed for rapid visual analysis of the prescription drug molecule demecycline (DEM), achieving both high sensitivity and selectivity. The ligand 2-amino-[1,1'-biphenyl]-4,4'-dicarboxylic acid (bpdc-NH2) not only provides stable cyan fluorescence (467 nm) for the framework through intramolecular charge transfer of bpdc-NH2 infinitesimal disturbanced by Zn2+ but also chelates Eu3+, resulting in red (617 nm) fluorescence. Through the synergy of photoinduced electron transfer and the antenna effect, a bidirectional response to DEM is achieved, enabling concentration quantification. The Eu3+@Zn-MOF platform exhibits a wide linear range (0.25-2.5 µM) to DEM and a detection limit (LOD) of 10.9 nM. Further, we integrated the DEM sensing platform into a paper-based system and utilized a smartphone for the visual detection of DEM in water samples and milk products, demonstrating the potential for large-scale, low-cost utilization of the technology.

Unveiling the Solvent Effect in Plasmon Enhanced Electrochemistry via the Nanoparticle-Impact Technique.

Plasmon-enhanced electrochemistry (PEEC) has been observed to facilitate energy conversion systems by converting light energy to chemical energy. However, comprehensively understanding the PEEC mechanism remains challenging due to the predominant use of ensemble-based methodologies on macroscopic electrodes, which fails to measure electron-transfer kinetics due to constraints from mass transport and the averaging effect. In this study, we have employed nanoparticle impact electrochemistry (NIE), a newly developed electroanalytical technique capable of measuring electrochemical dynamics at a single-nanoparticle level under optimal mass transport conditions, along with microscopic electron-transfer theory for data interpretation. By investigating the plasmon enhanced hydrogen evolution reaction (HER) at individual silver nanoparticles (AgNPs), we have clearly revealed the previously unknown influence of solvent effects within the PEEC mechanism. This finding suggests an additional approach to optimize plasmon-assisted electrocatalysis and electrosynthesis systems.

Sensitive quantification of mercury ions in real water systems based on an aggregation-collision electrochemical detection.

Nanoparticle impact electrochemistry (NIE) is an emerging electroanalytical technique that has been utilized to the sensitive detection of a wide range of biological species. So far, the NIE based trace ion detection is largely unexplored due to the lack of effective signal amplification strategies. We herein develop an NIE-based electrochemical sensing platform that utilizes T-Hg2+-T coordination induced AgNP aggregation to detect Hg2+ in aqueous solution. The proposed aggregation-collision strategy enables highly sensitive and selective detection. A dual-mode analysis based on the change in impact frequency and oxidative charge of the anodic oxidation of the AgNPs in NIE allows for more accurate self-validated quantification. Furthermore, the current NIE-based sensor demonstrates reliable analysis of Hg2+ of real water samples, showing great potential for practical environmental monitoring and point-of-care testing (POCT) applications.

Hedgehog interacting protein as a circulating biomarker in women with obesity: a cross-sectional study and intervention studies.

BACKGROUND: Although a study found a significant increase in serum hedgehog interacting protein (HHIP) concentrations in impaired fasting blood glucose, impaired glucose tolerance and newly diagnosed T2DM patients, the variation in circulating HHIP levels in obese individuals remains unknown. PATIENTS AND METHODS: Gene Set Enrichment Analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were used for differentially expressed genes and signal pathways. The study is comprised of a total of 452 young women, including 248 obese individuals and 204 controls. Circulating HHIP and Adipoq levels were determined with ELISA kits. Euglycemic-hyperinsulinemic clamps (EHC) and oral glucose tolerance test (OGTT) were conducted in every subject. 32 women were given metformin and 49 were given liraglutide treatment for 6 weeks. The study was registered with www.chictr.org.cn (ChiCTR2000032878 and ChiCTR1800019776). RESULTS: Obesity was significantly associated with the cAMP signal pathway, and HHIP was a secreted protein related to cAMP signalling, as determined by KEGG analysis. In this population-based cohort study, we found that the level of circulating HHIP was significantly elevated in obese women, and positively correlated with body mass index and blood glucose, blood lipid, insulin, homeostasis model assessment of insulin resistance, dehydroepiandrostenedione sulphate, and luteinizing hormone, while negatively correlated with M-value and Adipoq. Insulin resistance (IR) and ove™rweight/obesity were associated with the higher HHIP concentration. OGTT and EHC tests revealed that the levels of circulating HHIP were regulated by blood glucose but to a less extent by insulin. After therapy with metformin and liraglutide, circulating HHIP levels were decreased, whereas Adipoq levels increased significantly. CONCLUSIONS: Our findings support HHIP as a potential biomarker for predicting obesity and IR. In addition, drugs targeting HHIP may be a new strategy to treat obesity.

Targeting hepatic serine-arginine protein kinase 2 ameliorates alcohol-associated liver disease by alternative splicing control of lipogenesis.

BACKGROUND AND AIMS: Lipid accumulation induced by alcohol consumption is not only an early pathophysiological response but also a prerequisite for the progression of alcohol-associated liver disease (ALD). Alternative splicing regulates gene expression and protein diversity; dysregulation of this process is implicated in human liver diseases. However, how the alternative splicing regulation of lipid metabolism contributes to the pathogenesis of ALD remains undefined. APPROACH AND RESULTS: Serine-arginine-rich protein kinase 2 (SRPK2), a key kinase controlling alternative splicing, is activated in hepatocytes in response to alcohol, in mice with chronic-plus-binge alcohol feeding, and in patients with ALD. Such induction activates sterol regulatory element-binding protein 1 and promotes lipogenesis in ALD. Overexpression of FGF21 in transgenic mice abolishes alcohol-mediated induction of SRPK2 and its associated steatosis, lipotoxicity, and inflammation; these alcohol-induced pathologies are exacerbated in FGF21 knockout mice. Mechanistically, SRPK2 is required for alcohol-mediated impairment of serine-arginine splicing factor 10, which generates exon 7 inclusion in lipin 1 and triggers concurrent induction of lipogenic regulators-lipin 1ß and sterol regulatory element-binding protein 1. FGF21 suppresses alcohol-induced SRPK2 accumulation through mammalian target of rapamycin complex 1 inhibition-dependent degradation of SRPK2. Silencing SRPK2 rescues alcohol-induced splicing dysregulation and liver injury in FGF21 knockout mice. CONCLUSIONS: These studies reveal that (1) the regulation of alternative splicing by SRPK2 is implicated in lipogenesis in humans with ALD; (2) FGF21 is a key hepatokine that ameliorates ALD pathologies largely by inhibiting SRPK2; and (3) targeting SRPK2 signaling by FGF21 may offer potential therapeutic approaches to combat ALD.

Age-dependent loss of hepatic SIRT1 enhances NLRP3 inflammasome signaling and impairs capacity for liver fibrosis resolution.

Our studies indicate that the longevity factor SIRT1 is implicated in metabolic disease; however, whether and how hepatocyte-specific SIRT1 signaling is involved in liver fibrosis remains undefined. We characterized a functional link of age-mediated defects in SIRT1 to the NLRP3 inflammasome during age-related liver fibrosis. In multiple experimental murine models of liver fibrosis, we compared the development of liver fibrosis in young and old mice, as well as in liver-specific SIRT1 knockout (SIRT1 LKO) mice and wild-type (WT) mice. Liver injury, fibrosis, and inflammation were assessed histologically and quantified by real-time PCR analysis. In a model of hepatotoxin-induced liver fibrosis, old mice displayed more severe and persistent liver fibrosis than young mice during liver injury and after injury cessation, as characterized by inhibition of SIRT1, induction of NLRP3, infiltration of macrophages and neutrophils, activation of hepatic stellate cells (HSCs), and excessive deposition and remodeling of the extracellular matrix. Mechanistically, deletion of SIRT1 in hepatocytes resulted in NLRP3 and IL-1ß induction, pro-inflammatory response, and severe liver fibrosis in young mice, mimicking the ability of aging to impair the resolution of established fibrosis. In an aging mouse model, chronic-plus-binge alcohol feeding-induced liver fibrosis was attenuated by treatment with MCC950, a selective NLRP3 inhibitor. NLRP3 inhibition ameliorated alcoholic liver fibrosis in old mice by repressing inflammation and reducing hepatocyte-derived danger signaling-ASK1 and HMGB1. In conclusion, age-dependent SIRT1 defects lead to NLRP3 activation and inflammation, which in turn impairs the capacity to resolve fibrosis during aging.

Elevated circulating GPHB5 levels in women with insulin resistance and polycystic ovary syndrome: A cross-sectional study and multiple intervention studies.

Objective: GPHB5 has been found to be associated with glucose and lipid metabolism in animal studies. However, the association of GPHB5 with IR and metabolic disorders remains unknown, and there is a lack of research in humans. Our aim in this study was to investigate the relationship between circulating GPHB5 and metabolic disorders in humans. Methods: Bioinformatics analysis was performed to understand the relationship between GPHB5 and metabolic disorders. GPHB5 mRNA expression in mice and rats was determined using RT-qPCR. Circulating GPHB5 concentrations were measured with an ELISA kit. EHC and OGTT were performed in humans. Results: Bioinformatics analysis shows that GPHB5 is associated with metabolic disorders and PCOS. GPHB5 mRNA expression levels in the metabolic-related tissues of HFD-fed mice, db/db and ob/ob mice, and PCOS rats were significantly higher than those of WT mice or rats. In human studies, we find that circulating GPHB5 levels were significantly higher in women with IR and PCOS. GPHB5 levels were positively correlated with age, BMI, WHR, BP, FBG, 2 h-BG, FIns, 2 h-Ins, TC, LDL-C, HbA1c, and FFA, but negatively correlated with adiponectin. Furthermore, GPHB5 was positively correlated with DHEAS and FAI, while negatively correlated with SHBG, FSH, SHBG and FSH. The increased GPHB5 concentration was related to IR and PCOS. After the treatment of metformin, GLP-1RA (Lira), and TZDs, circulating GPHB5 levels were decreased. Conclusions: Our results reveal that circulating GPHB5 could be a biomarker and potential therapeutic target for IR and PCOS in women.

From Nanoparticle Ensembles to Single Nanoparticles: Techniques for the Investigation of Plasmon Enhanced Electrochemistry.

Plasmon enhanced electrochemistry (PEEC), where specific electrochemical reactions are promoted due to the reduced energy barrier of the reaction processes by the light excited "hot carriers" of the plasmonic nanoparticles, has aroused tremendous interest in recent years. A deep understanding of the PEEC process becomes a key issue for facilitating PEEC catalyst design and improving PEEC performance. This concept article begins with a brief discussion of the macroscopic electrochemical method of PEEC study of the plasmonic nanoparticle ensembles. Following that, we highlight two electrochemical techniques that may possess single nanoparticle sensitivity, i. e., scanning electrochemical microscope and nano-impact electrochemistry. The pros and cons of each technique are discussed and an outlook is given. We hope to provide the readers with the current status of PEEC to evoke reflections regarding the reaction mechanisms, performance improvement, and the utilizations to important systems.

Dorzagliatin in drug-naïve patients with type 2 diabetes: a randomized, double-blind, placebo-controlled phase 3 trial.

Improving glucose sensitivity remains an unmet medical need in treating type 2 diabetes (T2D). Dorzagliatin is a dual-acting, orally bioavailable glucokinase activator that enhances glucokinase activity in a glucose-dependent manner, improves glucose-stimulated insulin secretion and demonstrates effects on glycemic control in patients with T2D. We report the findings of a randomized, double-blind, placebo-controlled phase 3 clinical trial to evaluate the efficacy and safety of dorzagliatin in patients with T2D. Eligible drug-naïve patients with T2D (n = 463) were randomly assigned to the dorzagliatin or placebo group at a ratio of 2:1 for 24 weeks of double-blind treatment, followed by 28 weeks of open-label treatment with dorzagliatin for all patients. The primary efficacy endpoint was the change in glycated hemoglobin from baseline to week 24. Safety was assessed throughout the trial. At week 24, the least-squares mean change in glycated hemoglobin from baseline (95% confidence interval) was -1.07% (-1.19%, -0.95%) in the dorzagliatin group and -0.50% (-0.68%, -0.32%) in the placebo group (estimated treatment difference, -0.57%; 95% confidence interval: -0.79%, -0.36%; P < 0.001). The incidence of adverse events was similar between the two groups. There were no severe hypoglycemia events or drug-related serious adverse events in the dorzagliatin group. In summary, dorzagliatin improved glycemic control in drug-naïve patients with T2D and showed a good tolerability and safety profile.

CTRP7 Is a Biomarker Related to Insulin Resistance and Oxidative Stress: Cross-Sectional and Intervention Studies In Vivo and In Vitro.

Objective: CTRP7 is a cytokine that is known to be associated with obesity. However, its relationship with insulin resistance (IR) and metabolic diseases remains unknown. The aim of this study is to investigate the relationship between CTRP7 and IR under in vivo and in vitro conditions. Methods: CTRP7 expression in mice and hepatocytes was determined using RT-qPCR and western blotting. Circulating CTRP7 concentrations were measured with an ELISA kit. EHC, OGTT, lipid-infusion, physical activity, and cold-stimulation experiments were performed in humans and mice. SOD, GSH, and MDA were measured by commercial kits. ROS levels were detected using dichlorofluorescein diacetate. Results: The expression levels of CTRP7 protein in the liver and fat of ob/ob and db/db mice were higher than that of WT mice. Individuals with IGT, T2DM, and obesity had higher circulating CTRP7 levels. CTRP7 levels were associated with HOMA-IR, obesity, and other metabolic parameters. During OGTT, serum CTRP7 levels gradually decreased, while CTRP7 levels significantly increased during EHC in response to hyperinsulinemia in healthy individuals without IR. In addition, lipid infusion-induced IR further increased serum CTRP7 levels in healthy adults. Physical activity increased serum CTRP7 levels in healthy individuals and CTRP7 protein expression in iWAT and skeletal muscle in mice. Under in vitro conditions, the expression of the CTRP7 protein was inhibited in a glucose concentration-dependent manner but was promoted by FFAs and insulin stimulation in hepatocytes. Furthermore, CTRP7 overexpression facilitated oxidative stress and suppressed the phosphorylation of insulin signaling molecules in hepatocytes. Conclusions: Our evidence shows that CTRP7 could be a useful biomarker and potential treatment target in IR and metabolic disorders.

Hepatic lipid accumulation induced by a high-fat diet is regulated by Nrf2 through multiple pathways.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is reportedly involved in hepatic lipid metabolism, but the results are contradictory, and the underlying mechanism remains unclear. Here, we focused on elucidating the effects of Nrf2 on hepatic adipogenesis and on determining the possible underlying mechanism. We established a non-alcoholic fatty liver disease (NAFLD) model in a high-fat diet (HFD)-fed Nrf2 knockout (Nrf2 KO) mice; further, a cell model of lipid accumulation was established using mouse primary hepatocytes (MPHs) treated with free fatty acids (FAs). Using these models, we investigated the relationship between Nrf2 and autophagy and its role in the development of NAFLD. We observed that Nrf2 expression levels were upregulated in patients with NAFLD and diet-induced obese mice. Nrf2 deficiency led to hepatic lipid accumulation in vivo and in vitro, in addition to, promoting lipogenesis mainly by increasing SREBP-1c activity. Moreover, Nrf2 deficiency attenuated autophagic flux and inhibited the fusion of autophagosomes and lysosomes in vivo and in vitro. Decreased autophagy caused reduced lipolysis in the liver. Importantly, chromatin immunoprecipitation-qPCR (ChIP-qPCR) and dual-luciferase assay results proved that Nrf2 bound to the LAMP1 promoter and regulated its transcriptional activity. Accordingly, we report that Nrf2-LAMP1 interaction plays an indispensable role in Nrf2-regulated hepatosteatosis. Our data collectively confirm that Nrf2 deficiency promotes hepatosteatosis by enhancing SREBP-1c activity and attenuating autophagy. Our findings provide a novel multi-pathway effect of Nrf2 on lipid metabolism in the liver. We believe that multi-target intervention of Nrf2 is a novel strategy for the treatment of NAFLD.

Custom-Molded Offloading Footwear Effectively Prevents Recurrence and Amputation, and Lowers Mortality Rates in High-Risk Diabetic Foot Patients: A Multicenter, Prospective Observational Study.

BACKGROUND: Recurrence of high-risk diabetic feet, after wound, healing is a common challenge among diabetic patients. Continuous use of an offloading device significantly prevents recurrence of high-risk diabetic feet, although patient adherence is imperative to ensuring this therapy's clinical efficacy. In this study, we explored clinical outcomes of patients with a high-risk diabetic foot who had been prescribed with custom-molded offloading footwear under different adherence conditions. METHODS: A total of 48 patients (17 females and 31 males) with high-risk diabetic feet, who had been with prescribed offloading footwear in 13 medical centers across 4 cities, were enrolled in the current study. The patients were assigned into either continuous offloading therapy (COT, n = 31) or interrupted offloading therapy (IOT, n = 17) groups, according to their adherence to the therapy. All patients were followed up monthly, and differences in recurrence, amputation, and deaths between the groups were analyzed at 4 months after therapy. RESULTS: Forty-eight patients met our inclusion criteria and were therefore included in the final analysis. Among them, 31 were stratified into the COT group and adhered to offloading therapy throughout the study period, whereas 17 were grouped as IOT and exhibited interrupted adherence to offloading therapy. We found statistically significant differences in recurrence rates (0 vs 38.46%, p < 0.01), amputation (0 vs 11.76%, p < 0.01), and deaths (0% vs 5.88%, p < 0.01) between the groups during follow-up. CONCLUSION: Patients' adherence is imperative to efficacy of custom-molded offloading footwear during treatment of high-risk diabetic foot. Further studies are needed to elucidate the role of improved design of the offloading device and the need for enhanced patient education for improved adherence.

Role of bone morphogenetic protein-9 in the regulation of glucose and lipid metabolism.

Bone morphogenetic protein (BMP)-9 has been reported to regulate energy balance in vivo. However, the mechanisms underlying BMP9-mediated regulation of energy balance remain incompletely understood. Here, we investigated the role of BMP9 in energy metabolism. In the current study, we found that hepatic BMP9 expression was down-regulated in insulin resistance (IR) mice and in patients who are diabetic. In mice fed a high-fat diet (HFD), the overexpression of hepatic BMP9 improved glucose tolerance and IR. The expression of gluconeogenic genes was down-regulated, whereas the level of insulin signaling molecule phosphorylation was increased in the livers of Adenovirus-BMP9-treated mice and glucosamine-treated hepatocytes. Furthermore, BMP9 overexpression ameliorated triglyceride accumulation and inhibited the expression of lipogenic genes in both human hepatocellular carcinoma HepG2 cells treated with a fatty acid mixture as well as the livers of HFD-fed mice. In hepatocytes isolated from sterol regulatory element-binding protein (SREBP)-1c knockout mice, the effects of BMP9 were ablated. Mechanistically, BMP9 inhibited SREBP-1c expression through the inhibition of liver X receptor response element 1 activity in the SREBP-1c promoter. Taken together, our results show that BMP9 is an important regulator of hepatic glucose and lipid metabolism.-Yang, M., Liang, Z., Yang, M., Jia, Y., Yang, G., He, Y., Li, X., Gu, H. F., Zheng, H., Zhu, Z., Li, L. Role of bone morphogenetic protein-9 in the regulation of glucose and lipid metabolism.

Gut ghrelin regulates hepatic glucose production and insulin signaling via a gut-brain-liver pathway.

BACKGROUND: Ghrelin modulates many physiological processes. However, the effects of intestinal ghrelin on hepatic glucose production (HGP) are still unclear. The current study was to explore the roles of intestinal ghrelin on glucose homeostasis and insulin signaling in the liver. METHODS: The system of intraduodenal infusion and intracerebral microinfusion into the nucleus of the solitary tract (NTS) in the normal chow-diet rats and pancreatic-euglycemic clamp procedure (PEC) combined with [3-3H] glucose as a tracer were used to analyze the effect of intestinal ghrelin. Intraduodenal co-infusion of ghrelin, tetracaine and Activated Protein Kinase (AMPK) activator (AICAR), or pharmacologic and molecular inhibitor of N-methyl-D-aspartate receptors within the dorsal vagal complex, or hepatic vagotomy in rats were used to explore the possible mechanism of the effect of intestinal ghrelin on HGP. RESULTS: Our results demonstrated that gut infusion of ghrelin inhibited duodenal AMP-dependent protein kinase (AMPK) signal pathways, increased HGP and expression of gluconeogenic enzymes, and decreased insulin signaling in the liver of the rat. Intraduodenal co-infusion of ghrelin receptor antagonist [D-Lys3]-GHRP-6 and AMPK agonist with ghrelin diminished gut ghrelin-induced increase in HGP and decrease in glucose infusion rate (GIR) and hepatic insulin signaling. The effects of gut ghrelin were also negated by co-infusion with tetracaine, or MK801, an N-methyl-D-aspartate (NMDA) receptor inhibitor, and adenovirus expressing the shRNA of NR1 subunit of NMDA receptors (Ad-shNR1) within the dorsal vagal complex, and hepatic vagotomy in rats. When ghrelin and lipids were co-infused into the duodenum, the roles of gut lipids in increasing the rate of glucose infusion (GIR) and lowering HGP were reversed. CONCLUSIONS: The current study provided evidence that intestinal ghrelin has an effect on HGP and identified a neural glucoregulatory function of gut ghrelin signaling.

Comparative effectiveness of metformin monotherapy in extended release and immediate release formulations for the treatment of type 2 diabetes in treatment-naïve Chinese patients: Analysis of results from the CONSENT trial.

AIMS: Metformin treatment for type 2 diabetes mellitus (T2DM) can be limited by gastrointestinal (GI) adverse events (AEs), resulting in treatment discontinuation. We investigated whether once-daily metformin extended release (XR) is superior in terms of GI tolerability, with non-inferior efficacy, compared with thrice-daily metformin immediate release (IR) in treatment-naïve Chinese patients with T2DM. MATERIALS AND METHODS: This prospective, open-label, randomized, multicentre, phase IV interventional study enrolled Chinese T2DM patients to receive either metformin XR or metformin IR with a 2-week screening period, a 16-week treatment period and a 2-week follow-up period without treatment. Co-primary endpoints were a non-inferiority assessment of metformin XR vs metformin IR in glycated haemoglobin (HbA1c) least squares mean (LSM) change from baseline to week 16 and the superiority of GI tolerability for metformin XR vs metformin IR. RESULTS: Overall, 532 patients were randomized to metformin IR (n = 267) or metformin XR (n = 265). The HbA1c LSM change was -1.61% and -1.58% in each group, respectively (LSM difference, 0.03; 95% confidence interval [CI], -0.10, 0.17). Incidences of drug-related AEs were 26.5% (n = 66) in the metformin IR-only group and 32.2% (n = 85) in the metformin XR-only group, and GI AEs were 23.8% and 22.3% in each group, respectively (difference, -1.52; 95% CI, -8.60, 5.56). The treatment difference met the predefined non-inferiority upper CI margin of 0.4% in HbA1c. CONCLUSIONS: Metformin XR was non-inferior to metformin IR for the LSM change in HbA1c from baseline to week 16 and not superior to metformin IR for overall GI AE incidence during treatment of Chinese T2DM patients.

The natural logarithm of zinc-α2-glycoprotein/HOMA-IR is a better predictor of insulin sensitivity than the product of triglycerides and glucose and the other lipid ratios.

AIM: The euglycemic-hyperinsulinemic clamp (EHC) is not available in most clinical settings and is costly, time consuming and invasive, and requires trained staff. Therefore, an accessible and inexpensive test to identify insulin resistance (IR) is needed. The aim of this study is to assess whether zinc-α2-glycoprotein (ZAG) index [Ln ZAG/homeostasis model assessment of IR (HOMA-IR)] is a better surrogate index for estimating IR or metabolic syndrome (MetS) compared with other surrogate indices. METHODS: We performed a population-based cross-sectional study. Two hundred healthy subjects, 102 polycystic ovary syndrome (PCOS) patients, 97 newly diagnosed type 2 diabetes mellitus (nT2DM) and 84 impaired glucose tolerance (IGT) subjects were enrolled. The EHC was performed to identify IR. Circulating ZAG and adiponectin levels were determined by ELISA. RESULTS: The ZAG index was significantly lower in participants with IR including IGT, nT2DM and PCOS than in those without IR. In addition, subjects with MetS had lower ZAG indices and higher the product of fasting triglycerides and glucose (TyG) indices than those without MetS. The ZAG index showed a significantly stronger association with M values than the other surrogate indices, whereas the TyG index showed a stronger association with MetS. The optimal cutoff value of the ZAG index for detection of IR was 2.97 with a sensitivity of 88% and a specificity of 91%, whereas the optimal cutoff value of TyG index for detection of MetS was 4.90 with a sensitivity of 82% and a specificity of 86%. CONCLUSION: The ZAG index is a better marker than the other surrogate indices for identifying IR, whereas the TyG index has high sensitivity and specificity for identifying MetS.

Effects of sitagliptin on circulating zinc-α2-glycoprotein levels in newly diagnosed type 2 diabetes patients: a randomized trial.

OBJECTIVE: Zinc-α2-glycoprotein (ZAG) has recently been characterized as a potent metabolic regulator. However, the effects of anti-diabetic agents on circulating ZAG levels in humans remain largely unknown. To explore the possible mechanisms by which the dipeptidyl peptidase-IV (DPP-IV) inhibitor improves insulin resistance, we investigated the effect of sitagliptin, a DPP-IV inhibitor, on circulating cytokine levels in newly diagnosed type 2 diabetes (nT2DM) patients. DESIGN AND METHODS: A subset of 141 subjects with nT2DM were assigned to receive placebo (n=47) or sitagliptin (n=94) for 3 months. Before and after treatment, subjects received a 75 g oral glucose tolerance test, euglycemic-hyperinsulinemic clamp (EHC), and measurement of ZAG and adiponectin (ADI) concentrations. RESULTS: Circulating ZAG levels were lower in nT2DM than in control individuals (P<0.01). After 3 months of sitagliptin treatment, HbA1c, fasting plasma glucose, postprandial glucose, 2-h insulin after glucose overload, triglycerides, and homeostasis model assessment of insulin resistance (HOMA-IR) were decreased significantly compared with pre-treatment (P<0.05 or P<0.01), whereas the glucose infusion rate during the stable period of the clamp (M values) during EHC were significantly increased (P<0.01). In addition, circulating ZAG and ADI concentrations were significantly increased along with improved glucose metabolism and insulin sensitivity compared with pre-treatment (both P<0.01) and the change of ZAG (ΔZAG) was positively associated with ΔADI, ΔHOMA-IR, ΔBMI, Δfasting insulin and negatively associated with Δ tumor necrosis factor-α (TNF-α). Furthermore, sitagliptin treatment resulted in significantly lowered plasma TNF-α level (P<0.05). CONCLUSION: A low level of circulating ZAG is associated with insulin resistance and sitagliptin treatment significantly increases circulating ZAG levels. These observations have implications in relation to the mode of action of the DPP-IV inhibitor as an insulin sensitizing agent.