NSAID-Induced Enteropathy Affects Regulation of Hepatic Glucose Production by Decreasing GLP-1 Secretion

Background/Aim: Given their widespread use and their notorious effects on the lining of gut cells, including the enteroendocrine cells, we explored if chronic exposure to non-steroidal anti-inflammatory drugs (NSAIDs) affects metabolic balance in a mouse model of NSAID-induced enteropathy. Method: We administered variable NSAIDs to C57Blk/6J mice through intragastric gavage and measured their energy balance, glucose hemostasis, and GLP-1 levels. We treated them with Exendin-9 and Exendin-4 and ran a euglycemic-hyperinsulinemic clamp. Results: Chronic administration of multiple NSAIDs to C57Blk/6J mice induces ileal ulcerations and weight loss in animals consuming a high-fat diet. Despite losing weight, NSAID-treated mice exhibit no improvement in their glucose tolerance. Furthermore, glucose-stimulated (glucagon-like peptide -1) GLP-1 is significantly attenuated in the NSAID-treated groups. In addition, Exendin-9—a GLP-1 receptor antagonist—worsens glucose tolerance in the control group but not in the NSAID-treated group. Finally, the hyper-insulinemic euglycemic clamp study shows that endogenous glucose production, total glucose disposal, and their associated insulin levels were similar among an ibuprofen-treated group and its control. Exendin-4, a GLP-1 receptor agonist, reduces insulin levels in the ibuprofen group compared to their controls for the same glucose exchange rates. Conclusions: Chronic NSAID use can induce small intestinal ulcerations, which can affect intestinal GLP-1 production, hepatic insulin sensitivity, and consequently, hepatic glucose production.

Differential Effects of Bariatric Surgery on Plasma Levels of ANGPTL3 and ANGPTL4.

Introduction: Angiopoietin-like protein 3 (ANGPTL3) and 4 (ANGPTL4) are regulators of triglycerides storage and utilization. Bariatric surgery (BS) determines profound changes in adipose tissue composition and energy metabolism. We evaluated the impact of BS on plasma levels of ANGPTL3 and ANGPTL4.Method: Twenty-seven morbidly obese subjects with or without type 2 diabetes (T2D) underwent Roux-en-Y gastric bypass (RYGB) and 18 patients with advanced T2D received Biliopancreatic Diversion (BPD). Fasting ANGPTLs levels, insulin sensitivity (evaluated by euglycemic hyperinsulinemic clamp), total bile acids (TBA) and free fatty acids (FFA) were measured at baseline and 1year after surgery.Results: Both surgical procedures resulted in fat mass loss, improved glucose control, and a ~2-fold increase of insulin sensitivity. ANGPTL4 levels decreased significantly with both RYGB (26.6 ± 0.6 to 24.4 ± 0.3 ng/mL, p=0.001) and BPD (27.9 ± 1.5 to 24.0 ± 0.5 ng/mL, p=0.003). In contrast, ANGPTL3 concentrations did not change after RYGB but rose following BPD (225 ± 20 to 300 ± 15 ng/mL, p=0.003). By multiple regression analysis, changes in ANGPTL4 were independently associated with those of blood glucose, p=0.0169) whereas changes in ANGPTL3 after BPD were associated with variations in FFA (p=0.008) and insulin sensitivity (p=0.0427). Discussion: Circulating ANGPTL4 is reduced by BS probably due to the loss of fat mass and improved insulin sensitivity. Conversely, ANGPTL3 levels increased after BPD, presumably because of the metabolic changes induced by the malabsorptive effect of this surgical procedure.

Hepatocyte androgen receptor in females mediates androgen-induced hepatocellular glucose mishandling and systemic insulin resistance

Androgen excess is one of the most common endocrine disorders of reproductive-aged women, affecting up to 20% of this population. Women with elevated androgens often exhibit hyperinsulinemia and insulin resistance. The mechanisms of how elevated androgens affect metabolic function are not clear. Hyperandrogenemia in a dihydrotestosterone (DHT)-treated female mouse model induces whole body insulin resistance possibly through activation of the hepatic androgen receptor (AR). We investigated the role of hepatocyte AR in hyperandrogenemia-induced metabolic dysfunction by using several approaches to delete hepatic AR via animal-, cell-, and clinical-based methodologies. We conditionally disrupted hepatocyte AR in female mice developmentally (LivARKO) or acutely by tail vein injection of an adeno-associated virus with a liver-specific promoter for Cre expression in ARfl/fl mice (adLivARKO). We observed normal metabolic function in littermate female Control (ARfl/fl) and LivARKO (ARfl/fl; Cre+/-) mice. Following chronic DHT treatment, female Control mice treated with DHT (Con-DHT) developed impaired glucose tolerance, pyruvate tolerance, and insulin tolerance, not observed in LivARKO mice treated with DHT (LivARKO-DHT). Further, during an euglycemic hyperinsulinemic clamp, the glucose infusion rate was improved in LivARKO-DHT mice compared to Con-DHT mice. Liver from LivARKO, and primary hepatocytes derived from LivARKO, and adLivARKO mice were protected from DHT-induced insulin resistance and increased gluconeogenesis. These data support a paradigm in which elevated androgens in females disrupt metabolic function via hepatic AR and insulin sensitivity was restored by deletion of hepatic AR.

Insulin Stimulation Reduces Aortic Waveform in Adults with Metabolic Syndrome

Adults with metabolic syndrome (MetS) have increased fasting arterial stiffness and altered central hemodynamics that contribute, partly, to increased cardiovascular disease (CVD) risk. Although insulin affects aortic wave reflections in healthy adults, the effects in individuals with MetS are unclear. We hypothesized that insulin stimulation would reduce measures of pressure waveforms and hemodynamics in people with MetS. Thirty-five adults with obesity (27F; 54.2 ± 6.0 yr; 37.1 ± 4.8 kg/m2) were selected for MetS (ATP III criteria) following an overnight fast. Pulse wave analysis was assessed using applanation tonometry before and after a 2hr euglycemic-hyperinsulinemic clamp (90 mg/dl, 40 mU/m2/min). Deconvolution analysis was used to decompose the aortic waveform (augmentation index corrected to heart rate of 75 bpm (AIx@75); augmentation pressure (AP)) into backward and forward pressure components. Aerobic fitness (VO2max), body composition (DXA), and blood biochemistries were also assessed. Insulin significantly reduced augmentation index (AIx@75, 28.0 ± 9.6 vs. 23.0 ± 9.9 %, P<0.01), augmentation pressure (14.8 ± 6.4 vs. 12.0 ± 5.7 mmHg, P<0.01), pulse pressure amplification (1.26 ± 0.01 vs. 0.03 ± 0.01, P=0.01), and inflammation (hsCRP: P=0.02; MMP-7: P=0.03) compared to fasting. In subgroup analyses to understand HTN influence, there were no insulin stimulation differences on any outcome. VO2max, visceral fat, and blood potassium correlated with fasting AIx@75 (r=-0.39, P=0.02; r=0.41, P=0.03; r=-0.53, P=0.002). Potassium levels were also associated with insulin-mediated reductions in AP (r=0.52, P=0.002). Our results suggest insulin stimulation improves indices of aortic reflection in adults with MetS.

HDL Containing Apolipoprotein C-III is Associated with Insulin Sensitivity: a Multi-Center Cohort Study

Context HDL in humans is composed of a heterogeneous group of particles varying in protein composition as well as biological effects. Objective We investigated the prospective associations between HDL subspecies containing and lacking apoC-III at baseline and insulin sensitivity at year 3. Design, Setting, and Participants A prospective cohort study of 864 healthy volunteers drawn from the RISC study, a multi-center European clinical investigation, whose recruitment initiated in 2002 with a follow-up of 3 years. Main Measures Insulin sensitivity was estimated from an oral glucose tolerance test (OGTT) at baseline and year 3, and by euglycemic-hyperinsulinemic clamp at baseline only. The apolipoprotein concentrations were measured at baseline by a sandwich ELISA-based method. Results The two HDL subspecies demonstrated significantly opposite associations with insulin sensitivity at year 3 (p-heterogeneity=0.004). The highest quintile of HDL containing apoC-III was associated with a 1.2% reduction in insulin sensitivity (p-trend=0.02), while the highest quintile of HDL lacking apoC-III was associated with a 1.3% increase (p-trend=0.01), compared to the lowest quintile. No significant association was observed for total HDL, and VLDL and LDL containing apoC-III. ApoC-III contained in HDL was associated with a decrease in insulin sensitivity even more strongly than plasma total apoC-III. Conclusion Both HDL containing apoC-III and apoC-III in HDL adversely affect the beneficial properties of HDL on insulin response to glucose. Our results support the potential of HDL-associated apoC-III as a promising target for diabetes prevention and treatment.

Evaluation of fasting plasma insulin and proxy measurements to assess insulin sensitivity in horses

Background Proxies are mathematical calculations based on fasting glucose and/or insulin concentrations developed to allow prediction of insulin sensitivity (IS) and β-cell response. These proxies have not been evaluated in horses with insulin dysregulation. The first objective of this study was to evaluate how fasting insulin (FI) and proxies for IS (1/Insulin, reciprocal of the square root of insulin (RISQI) and the quantitative insulin sensitivity check index (QUICKI)) and β-cell response (the modified insulin-to-glucose ratio (MIRG) and the homeostatic model assessment of β-cell function (HOMA-β)) were correlated to measures of IS (M index) using the euglycemic hyperinsulinemic clamp (EHC) in horses with insulin resistance (IR) and normal IS. A second objective was to evaluate the repeatability of FI and proxies in horses based on sampling on consecutive days. The last objective was to investigate the most appropriate cut-off value for the proxies and FI. Results Thirty-four horses were categorized as IR and 26 as IS based on the M index. The proxies and FI had coefficients of variation (CVs) ≤ 25.3 % and very good reliability (intraclass correlation coefficients ≥ 0.89). All proxies and FI were good predictors of the M index (r = 0.76–0.85; P < 0.001). The proxies for IS had a positive linear relationship with the M index whereas proxies for β-cell response and FI had an inverse relationship with the M index. Cut-off values to distinguish horses with IR from horses with normal IS based on the M index were established for all proxies and FI using receiver operating characteristic curves, with sensitivity between 79 % and 91 % and specificity between 85 % and 96 %. The cut-off values to predict IR were < 0.32 (RISQI), < 0.33 (QUICKI) and > 9.5 µIU/mL for FI. Conclusions All proxies and FI provided repeatable estimates of horses’ IS. However, there is no advantage of using proxies instead of FI to estimate IR in the horse. Due to the heteroscedasticity of the data, proxies and FI in general are more suitable for epidemiological studies and larger clinical studies than as a diagnostic tool for measurement of IR in individual horses.

Impaired Suppression of Glucagon in Obese Subjects Parallels Decline in Insulin Sensitivity and Beta-Cell Function

Aim To examine the relationship between plasma glucagon levels and insulin sensitivity and insulin secretion in obese subjects. Methods Suppression of plasma glucagon was examined in 275 obese Hispanic Americans with varying glucose tolerance. All subjects received a 2-hour oral glucose tolerance test (OGTT) and a subset (n = 90) had euglycemic hyperinsulinemic clamp. During OGTT, we quantitated suppression of plasma glucagon concentration, Matsuda index of insulin sensitivity, and insulin secretion/insulin resistance (disposition) index. Plasma glucagon suppression was compared between quartiles of insulin sensitivity and beta-cell function. Results Fasting plasma glucagon levels were similar in obese subjects with normal glucose tolerance (NGT), prediabetes, and type 2 diabetes (T2D), but the fasting glucagon/insulin ratio decreased progressively from NGT to prediabetes to T2D (9.28 ± 0.66 vs 6.84 ± 0.44 vs 5.84 ± 0.43; P &lt; 0.001). Fasting and 2-hour plasma glucagon levels during OGTT progressively increased and correlated positively with severity of insulin resistance (both Matsuda index and euglycemic hyperinsulinemic clamp). The fasting glucagon/insulin ratio declined with worsening insulin sensitivity and beta-cell function, and correlated with whole-body insulin sensitivity (Matsuda index, r = 0.81; P &lt; 0.001) and beta-cell function (r = 0.35; P &lt; 0.001). The glucagon/insulin ratio also correlated and with beta-cell function during OGTT at 60 and 120 minutes (r = −0.47; P &lt; 0.001 and r = −0.32; P &lt; 0.001). Conclusion Insulin-mediated suppression of glucagon secretion in obese subjects is impaired with increasing severity of glucose intolerance and parallels the severity of insulin resistance and beta-cell dysfunction.

Evaluation of biosimilarity of RinGlar® (GEROPHARM LLC, Russia) and Lantus® (Sanofi-Aventis Deutschland GmbH, Germany) using the euglycemic hyperinsulinemic clamp technique in patients with type 1 diabetes: double-blind randomized clinical trial

Background: Prevention of the development of micro-and macrovascular complications in patients with diabetes melli-tus (DM) encouraged the search for insulin analogues that allow imitating, as close as possible, a normal physiological insulin secretion in healthy people. Biosimilars (bioanalogues of reference products) play an important role in the full provision with high-quality insulin medications throughout patients. The program of clinical trials of insulin bioanalogues includes pharmacology studies: pharmacokinetics (PK), pharmacodynamics (PD) and clinical safety research.Aims: To test whether RinGlar® (GEROPHARM LLC, Russia) and Lantus® (Sanofi-Aventis Deutschland GmbH, Germany) have similar PK and PD profiles in a hyperinsulinemic euglycaemic clamp (HEC) setting in patients with type 1 diabetes mellitus. Permission of the Ministry of Health of the Russian Federation No. 150 of 03/03/2016.Materials and methods: The study was conducted in 42 patients with type 1 diabetes aged 18 to 65 years. A doubleblind, randomized, crossover study of comparative PK and PD of drugs was chosen as a study design. The investigational products were injected after achieving a state of euglycemia before the HEC in a single dose of 0.6 U/kg subcutaneously into the subcutaneous fat of the anterior abdominal wall. During the study, regular blood sampling was performed, the amount of insulin glargine in the samples was determined by ELISA. The results are used to calculate the PK parameters and generate the concentration-time curves. The glucose infusion rate was corrected based on the measurement of glycemia. These data are used to calculate the PD parameters.Results: RinGlar® and Lantus® interventions have comparable PK and PD profiles in HEC setting in patients with type 1 diabetes. This is confirmed by the similarity of the main PK/PD parameters, PK/PD curves, and comparable safety. The confidence intervals of the geometric mean ratio were 81.02% - 120.62% for the PK parameter AUCins0-T, and 85.43% - 115.64% for the PD-parameter AUCGIR0_T, which fall within the specified limits of 80% - 125% to establish comparability between drugs.Conclusions: Results of the clinical trial demonstrate the biosimilarity of the products RinGlar® and Lantus®.

Association of the components of metabolic syndrome with the circulating levels of cytokine clusters in young women

Background: The purpose of this study was to investigate the relationship between circulating zinc α 2-glycoprotein (ZAG), Irisin, betatrophin and adiponectin concentrations and metabolic syndrome (MetS) components and to analyze the effects of blood glucose and insulin on these cytokine concentrations in vivo. Methods: A total of 196 young women, including 78 healthy women and 118 women with MetS components, were recruited for this cross-sectional study. An oral glucose tolerance test and euglycemic-hyperinsulinemic clamp (EHC) were performed in healthy subjects and women with MetS components. An enzyme-linked immunosorbent assay kit was used to measure serum ZAG, irisin, betatrophin, and adiponectin levels, and their relationship with the MetS components was analyzed. Results: In women with MetS components, circulating irisin and betatrophin levels were significantly higher than those in the healthy women, but circulating ZAG and adiponectin levels were significantly lower . FBG, WC, and Triglyceride were significantly correlated with the circulating levels of these four cytokines (p < 0.001 or < 0.05). All four cytokines were associated with MetS and its components. In response to increasing insulin levels, circulating ZAG concentrations were markedly increased in both healthy subjects and women with MetS components during the EHC. However, serum irisin, betatrophin, and adiponectin levels in both healthy subjects and women with MetS components were significantly reduced compared with baseline. Conclusion: Serum ZAG, Irisin, betatrophin and adiponectin were associated with MetS and might be biomarkers for screening MetS components.

In utero low-protein-diet-programmed type 2 diabetes in adult offspring is mediated by sex hormones in rats†

Sex steroids regulate insulin sensitivity and glucose metabolism. We had characterized a lean type 2 diabetes (T2D) rat model using gestational low-protein (LP) diet programming. Our objective was to identify if endocrine dysfunction leading to decreased sex hormone levels will precede the development of T2D and if steroid replacement will prevent the onset of the disease. Pregnant rats were fed control or isocaloric LP diet from gestational day 4 until delivery. Normal diet was given to all mothers after delivery and to pups after weaning. LP offspring developed glucose intolerance and insulin resistance at 4 months. We measured sex steroid hormone profiles and expression of key genes involved in steroidogenesis in testis and ovary. Furthermore, one-month old rats were implanted with 90-day slow release T and E2 pellets for males and females, respectively. Glucose tolerance test (GTT) and euglycemic hyperinsulinemic clamp was performed at 4 months. LP-programmed T2D males had low T levels and females had low E2 levels due to dysregulated gene expression during steroidogenesis in gonads. GTT and euglycemic hyperinsulinemic clamp showed that LP males and females were glucose intolerant and insulin resistant; however, steroid supplementation prevented the onset of glucose intolerance and insulin resistance. Rats that developed T2D by LP programming have compromised gonadal steroidogenesis leading to low T and E2 in males and females, respectively. Sex steroid supplementation prevented the onset of glucose intolerance and insulin resistance indicating low sex steroid levels could cause compromised glucose metabolism ultimately leading to T2D.