Hyperinsulinemic-euglycemic Clamp Test Research Articles

Disturbances in dynamics of glucose, insulin and C-peptide in blood after a normalized intake of mixed meal in obesity and type 2 diabetes mellitus

The aim of the study is to investigate the dynamics of venous blood glucose, insulin, and C-peptide in response to intake a meal normalized to body mass in obese patients without and with type 2 diabetes mellitus. Venous blood samples were taken from 7 healthy subjects, 9 obese patients, and 10 obese patients with type 2 diabetes mellitus (mean period of diagnosed diabetes 7 years) before and 30, 60, 90, 120, and 180 min after a mixed meal (6 kcal/kg of body mass); additionally, 9 patients with obesity and type 2 diabetes mellitus and 3 healthy volunteers completed a hyperinsulinemic euglycemic clamp test. In patient groups the energy content of food did not differ, but was 1.8 times higher than in the control. An increase in glucose level one hour after a meal was maximal in patients with type 2 diabetes, but an increase in insulin and C-peptide — in obese patients, that related to impairment of insulin-dependent glucose uptake by tissues and of the rate of insulin secretion (dysfunction of â-cells) in patients. At the same time, an increase in the total area under the curve “C-peptide–time” shows that the maximum secretory response of â-cells is comparable in obese patients without and with type 2 diabetes mellitus. The absolute blood glucose level 90 minutes after a meal was closely correlated with the M-index — the marker of systemic sensitivity to insulin (rs = –0.82, p = 0.002). Our results characterize the features in the regulation of carbohydrate metabolism after intake a mixed meal, normalized to body mass, in people with the varying severity of metabolic disorders, and open up prospects for a wider application of this test in practice.

Surrogate indices of insulin resistance using the Matsuda index as reference in adult men-a computational approach.

Overweight and obesity, high blood pressure, hyperglycemia, hyperlipidemia, and insulin resistance (IR) are strongly associated with non-communicable diseases (NCDs), including type 2 diabetes, cardiovascular disease, stroke, and cancer. Different surrogate indices of IR are derived and validated with the euglycemic-hyperinsulinemic clamp (EHC) test. Thus, using a computational approach to predict IR with Matsuda index as reference, this study aimed to determine the optimal cutoff value and diagnosis accuracy for surrogate indices in non-diabetic young adult men. A cross-sectional descriptive study was carried out with 93 young men (ages 18-31). Serum levels of glucose and insulin were analyzed in the fasting state and during an oral glucose tolerance test (OGTT). Additionally, clinical, biochemical, hormonal, and anthropometric characteristics and body composition (DEXA) were determined. The computational approach to evaluate the IR diagnostic accuracy and cutoff value using difference parameters was examined, as well as other statistical tools to make the output robust. The highest sensitivity and specificity at the optimal cutoff value, respectively, were established for the Homeostasis model assessment of insulin resistance index (HOMA-IR) (0.91; 0.98; 3.40), the Quantitative insulin sensitivity check index (QUICKI) (0.98; 0.96; 0.33), the triglyceride-glucose (TyG)-waist circumference index (TyG-WC) (1.00; 1.00; 427.77), the TyG-body mass index (TyG-BMI) (1.00; 1.00; 132.44), TyG-waist-to-height ratio (TyG-WHtR) (0.98; 1.00; 2.48), waist-to-height ratio (WHtR) (1.00; 1.00; 0.53), waist circumference (WC) (1.00; 1.00; 92.63), body mass index (BMI) (1.00; 1.00; 28.69), total body fat percentage (TFM) (%) (1.00; 1.00; 31.07), android fat (AF) (%) (1.00; 0.98; 40.33), lipid accumulation product (LAP) (0.84; 1.00; 45.49), leptin (0.91; 1.00; 16.08), leptin/adiponectin ratio (LAR) (0.84; 1.00; 1.17), and fasting insulin (0.91; 0.98; 16.01). The computational approach was used to determine the diagnosis accuracy and the optimal cutoff value for IR to be used in preventive healthcare.

Mathematical Models of the Effect of Glucagon on Glycemia in Individuals With Type 2 Diabetes Treated With Dapagliflozin.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels by promoting urinary glucose excretion, but their overall effects on hormonal and metabolic status remain unclear. We here investigated the roles of insulin and glucagon in the regulation of glycemia in individuals treated with an SGLT2 inhibitor using mathematical model analysis. Hyperinsulinemic-euglycemic clamp and oral glucose tolerance tests were performed in 68 individuals with type 2 diabetes treated with the SGLT2 inhibitor dapagliflozin. Data previously obtained from such tests in 120 subjects with various levels of glucose tolerance and not treated with an SGLT2 inhibitor were examined as a control. Mathematical models of the feedback loops connecting glucose and insulin (GI model) or glucose, insulin, and glucagon (GIG model) were generated. Analysis with the GI model revealed that the disposition index/clearance, which is defined as the product of insulin sensitivity and insulin secretion divided by the square of insulin clearance and represents the glucose-handling ability of insulin, was significantly correlated with glycemia in subjects not taking an SGLT2 inhibitor but not in those taking dapagliflozin. Analysis with the GIG model revealed that a metric defined as the product of glucagon sensitivity and glucagon secretion divided by glucagon clearance (designated production index/clearance) was significantly correlated with blood glucose level in subjects treated with dapagliflozin. Treatment with an SGLT2 inhibitor alters the relation between insulin effect and blood glucose concentration, and glucagon effect may account for variation in glycemia among individuals treated with such drugs.

Glucose turnover at whole-body and skeletal muscle level in response to parenteral nutrition in male patients with alcoholic liver cirrhosis

Cirrhosis is associated with insulin resistance and impaired glucose tolerance, which may be caused by impairments at different tissue levels (liver, skeletal muscle, and/or beta cell). Here, glucose kinetics at whole-body and skeletal muscle level in patients with cirrhosis (Child-Pugh A and B) were studied during parenteral nutrition using the isotope dilution technique and arteriovenous balance approach across the leg. As opposed to the euglycemic hyperinsulinemic clamp or glucose tolerance tests applied in previous studies, this approach provides a nutrient composition more similar to a normal meal while circumventing any possible portal-systemic shunting, impaired hepatic uptake and incretin effect. We confirmed the presence of hepatic and peripheral insulin resistance in our patient population. Endogenous glucose production was less suppressed in response to parenteral nutrition. However, glucose uptake in skeletal muscle was increased. Our results suggests that in our study participants with cirrhosis, the hepatic and peripheral insulin resistance is compensated for by increased insulin secretion and thus, increased glucose uptake in muscle. Hereby, glucose homeostasis is maintained.

A Propolis-Derived Small Molecule Tectochrysin Ameliorates Type 2 Diabetes in Mice by Activating Insulin Receptor β.

Propolis has been found to decrease glucose levels and increase insulin sensitivity in type 2 diabetes. However, the active ingredient responsible for these effects and its regulating mechanism are not fully understood. To address this, molecular docking screening is used to screen the effective hypoglycemic ingredient in propolis and found that tectochrysin (TEC) has a high affinity to the insulin receptor (IR), highlighting its potential for glycemic control. In vivo tests show that TEC decreases glucose levels and enhances insulin sensitivity in db/db mice. By hyperinsulinemic euglycemic clamp test, this study further finds that TEC promotes glucose uptake in adipose tissue and skeletal muscle, as well as inhibits hepatic gluconeogenesis. Moreover, it finds that TEC promotes glucose uptake and adipocytes differentiation in 3T3-L1 cells like insulin, suggesting that TEC exerts an insulin mimetic effect. Mechanistically, pharmacology inhibition of IRβ abolishes the effects of TEC on glucose uptake and the phosphorylation of IR. The study further demonstrates that TEC binds to and activates IRβ by targeting its E1077 and M1079. Therefore, this study sheds light on the mechanism underlying propolis' potential for ameliorating type 2 diabetes, offering a natural food-derived compound as a promising therapeutic option.

M-index as a predictor of glycemia normalization in T2D patients early after bariatric surgery

There are several models for predicting remission of type 2 diabetes mellitus (T2D) a year after bariatric surgery — DiaRem, ABSD, IMS, etc. However, these models cannot be used to predict the early normalization of glycemia (within a few months after surgery). These models also do not include the assessment of insulin resistance (IR).AIM. To assess the effect of insulin resistance on the development of remission of T2D after bariatric surgery.METHODS: The study included 42 patients with T2D and severe obesity, who underwent bariatric surgery. Baseline assessment included hyperinsulinemic euglycemic clamp test (with the determination of the M-index (mg/kg/min), and evaluation of HOMA-IR index. Glycemia normalization was determined by self-monitoring (<6.1 mmol/l at fasting state and <7.8 mmol/l 2 hours after meals) as well as by HbA1c (<6.5%, starting 3 months after surgery). We used ROC analysis to determine the possibility of using IR indicators in predicting of the normalization of glycemia after bariatric surgery. The cut off value was determined using the Yuden criterion.RESULTS: All patients were severely insulin resistant. The median M-index before surgery was 1.535 mg/kg/min, the HO-MA-IR index was 10.0. During 1 year after surgery the increasing number of patients reached normal glycemia: 7 (16.7%) patients in 1 month, 22 (52.4%) patients after 3 months, 31 (73.8%) patients after 6 months, 35 (83.3%) patients after 12 months. In ROC analysis the optimal threshold the M-index was 1.876 mg/kg/min.CONCLUSION: The value of the M-index > 1.876 mg/kg/min can be used to predict the glycemia normalization early after bariatric surgery.

376-OR: Chronic Pancreatitis Does Not Induce Specific Alterations in Beta-Cell Function

Chronic pancreatitis (CP) is the most frequent cause of diabetes due to pancreatic diseases, known as type 3c diabetes mellitus (T3cDM). Although the specific alterations of T3cDM are not completely understood, individuals with T3cDM are considered affected by pancreatic endocrine insufficiency and often treated with insulin. To investigate the functional alterations of T3cDM, we evaluated differences in beta-cell function in patients with and without CP, classified according to their glucose tolerance (NGT, IGT, DM). We recruited 50 patients with CP and 96 individuals without CP (NCP). All participants underwent OGTT, hyperglycemic clamp (HC), hyperinsulinemic euglycemic clamp and mixed meal test (MMT) with measurement of GLP-1 and glucagon. Basal insulin secretion rate (ISR), total ISR, rate secretion and β-cell glucose sensitivity (RS and GS) were estimated by mathematical models from OGTT, MMT and HC. Comparing individuals classified into NGT, IGT or DM based on OGTT-derived glucose tolerance, we did not find any difference in beta-cell function derived by OGTT and MMT within the same category (e.g.: NGT-CP vs. NGT-NCP). GLP-1 and glucagon secretion during MMT was not significantly different between CP vs. NCP. Of note, we found that insulin secretion after arginine stimulus in HC, an indirect measure of beta-cell mass, was reduced only in DM-CP vs. DM-NCP (ARG CP 397 (132; 662) pmol/l vs NCP 795 (604; 1134) pmol/l; p= 0.023). No difference was found in insulin sensitivity evaluated as glucose uptake during euglycemic clamp. At equivalent levels of glucose tolerance, patients with CP had similar beta-cell function, GLP-1 and glucagon secretion to individuals without CP. People with T3cDM have less beta-cell mass than patients with DM without CP, but analogous residual beta-cell function, so they could benefit from other therapies apart from insulin. Future studies are warranted to investigate differences in beta-cell function decline between type 2 diabetes mellitus and T3cDM. Disclosure G.Ciccarelli: None. G.Di giuseppe: None. F.Cinti: None. A.Mari: Consultant; Eli Lilly and Company. T.Mezza: None. A.Giaccari: Speaker's Bureau; Abbott, AstraZeneca, Boehringer-Ingelheim, Eli Lilly and Company, Merck Sharp & Dohme Corp., Novo Nordisk, Sanofi.

Vaccarin improves insulin sensitivity and glucose uptake in diet-induced obese mice via activation of GPR120-PI3K/AKT/GLUT4 pathway

Insulin resistance is a risk factor for type 2 diabetes and is often associated with obesity. Vaccarin, a flavonoid found in vaccaria seeds, is commonly used in traditional Chinese medicine for activating blood circulation. Here, we showed that vaccarin ameliorates high-fat diet-induced obesity and insulin resistance in mice by reducing fat accumulation and improving insulin sensitivity in white adipose tissue. Further hyperinsulinemic-euglycemic clamp test revealed enhanced glucose uptake in vaccarin-treated WAT and skeletal muscle, consistent with activated insulin signaling pathway in these tissues. Mechanistically, vaccarin activates adipose tissue GPR120 and subsequently activating the PI3K/AKT/GLUT4 signaling pathway in 3T3-L1 cells. Together, these results reveal an undiscovered function of vaccarin in preventing obesity-related insulin resistance and advocates that vaccarin holds promise for further development as an innovative agent for the prevention of metabolic disorders.

Feсal microbiota transplantation in the format of complex therapy in obesive siblings: clinical case

Obesity and associated metabolic diseases are often accompanied by changes in the gut microbiota leading to metagenome gene diversity decrease. Fecal microbiota transplantation (FMT) is one of the most effective methods for correcting the intestinal microflora. FMT obtained from healthy donors has been proven to be an effective treatment of infections caused by Clostridium difficile. The use of FMT for correction of metabolic disorders is promising, however, data on its application is limited and has contradictory results. In our work, two patients (siblings) presented with obesity grade II and various types of diabetes mellitus (DM): the older brother (44 years old) with diabetes mellitus type 2 (DM 2), a younger brother (39 years old) with diabetes mellitus type 1 (DM 1). Both patients underwent FMT as part of complex antidiabetic therapy. During the course of treatment, a decrease in body weight was noted in both patients (4–5 kg for the first month of observation, then -1–2 kg per month). One year after FMT, a patient with type 2 diabetes showed a decrease in the severity of insulin resistance (IR), measured by the hyperinsulinemic euglycemic clamp test (initial M-index 2.42 mg/kg*min, after 1 year — 3.83 mg/kg* min) as well as the maintenance of satisfactory carbohydrate metabolism compensation against the diminishing the hypoglycemic therapy. In a patient with DM 1, no significant dynamics of carbohydrate exchange indices, including detected glycated hemoglobin (HbA1c), insulin dose and IR were during the observation period. Metagenomic sequencing of stool samples (n = 20) collected from both patients before and within 1 year after FMT showed no significant changes in the taxonomic profile of the microbiota at the level of microbial families. Metabolomic analysis of the composition of feces showed no directed changes in the composition of metabolites after the FMT procedure, the nature of changes within the samples from each patient during the entire study period was random. Thus, FMT had no effect on the course of DM1, but served as a starting point for weight loss and improvement glucose profile in DM2. However, convincing data confirming a causal correlation between FMT and improvement in the course of T2DM have not been obtained.

The sodium\u2013glucose cotransporter 2 inhibitor ipragliflozin improves liver function and insulin resistance in Japanese patients with type 2 diabetes

Sodium–glucose cotransporter 2 inhibitor (SGLT2i) treatment is a therapeutic approach for type 2 diabetes mellitus (T2DM). Some reports have shown that SGLT2i treatment improves insulin resistance; however, few studies have evaluated insulin resistance by the glucose clamp method. Hepatic insulin clearance (HIC) is a new pathophysiological mechanism of T2DM. The effect of SGLT2i treatment on hepatic insulin clearance and insulin resistance is not well known. We investigated the effect of SGLT2i treatment on insulin resistance, insulin secretion, incretin levels, body composition, and hepatic insulin clearance. We conducted a meal tolerance test (MTT) and a hyperinsulinemic-euglycemic clamp test in 9 T2DM patients. Ipragliflozin (50 mg/day) was administered, and the MTT and clamp test were performed after 4 months. We calculated HIC as the postprandial C-peptide AUC-to-insulin AUC ratio. We also measured GLP-1, GIP, and glucagon levels during the MTT. Body weight and HbA1c were decreased, although not significantly, after 4 months of treatment. Postprandial glucose, fasting insulin and postprandial insulin were significantly decreased. Insulin resistance with the glucose clamp was not changed, but the HOMA-IR and insulin sensitivity indices were significantly improved. Incretin and glucagon levels were not changed. Hepatic insulin clearance was significantly increased, but whole-body insulin clearance was not changed. The FIB-4 index and fatty liver index were significantly reduced. The HOMA-beta and insulinogenic indices were not changed, but the C-peptide index was significantly increased. Although the number of patients was small, these results suggested that SGLT2i treatment improved liver function, decreased hepatic insulin resistance, and increased hepatic insulin clearance, despite the small weight reduction.

Single Point Insulin Sensitivity Estimator in Pediatric Non-Alcoholic Fatty Liver Disease.

BackgroundAttenuated insulin-sensitivity (IS) is a central feature of pediatric non-alcoholic fatty liver disease (NAFLD). We recently developed a new index, single point insulin sensitivity estimator (SPISE), based on triglycerides, high-density-lipoprotein and body-mass-index (BMI), and validated by euglycemic-hyperinsulinemic clamp-test (EHCT) in adolescents. This study aims to assess the performance of SPISE as an estimation of hepatic insulin (in-)sensitivity. Our results introduce SPISE as a novel and inexpensive index of hepatic insulin resistance, superior to established indices in children and adolescents with obesity.Materials and MethodsNinety-nine pubertal subjects with obesity (13.5 ± 2.0 years, 59.6% males, overall mean BMI-SDS + 2.8 ± 0.6) were stratified by MRI (magnetic resonance imaging) into a NAFLD (>5% liver-fat-content; male n=41, female n=16) and non-NAFLD (≤5%; male n=18, female n=24) group. Obesity was defined according to WHO criteria (> 2 BMI-SDS). EHCT were used to determine IS in a subgroup (n=17). Receiver-operating-characteristic (ROC)-curve was performed for diagnostic ability of SPISE, HOMA-IR (homeostatic model assessment for insulin resistance), and HIRI (hepatic insulin resistance index), assuming null hypothesis of no difference in area-under-the-curve (AUC) at 0.5.ResultsSPISE was lower in NAFLD (male: 4.8 ± 1.2, female: 4.5 ± 1.1) than in non-NAFLD group (male 6.0 ± 1.6, female 5.6 ± 1.5; P< 0.05 {95% confidence interval [CI]: male NAFLD 4.5, 5.2; male non-NAFLD 5.2, 6.8; female NAFLD 4.0, 5.1, female non-NAFLD 5.0, 6.2}). In males, ROC-AUC was 0.71 for SPISE (P=0.006, 95% CI: 0.54, 0.87), 0.68 for HOMA-IR (P=0.038, 95% CI: 0.48, 0.88), and 0.50 for HIRI (P=0.543, 95% CI: 0.27, 0.74). In females, ROC-AUC was 0.74 for SPISE (P=0.006), 0.59 for HOMA-IR (P=0.214), and 0.68 for HIRI (P=0.072). The optimal cutoff-level for SPISE between NAFLD and non-NAFLD patients was 5.18 overall (Youden-index: 0.35; sensitivity 0.68%, specificity 0.67%).ConclusionSPISE is significantly lower in juvenile patients with obesity-associated NAFLD. Our results suggest that SPISE indicates hepatic IR in pediatric NAFLD patients with sensitivity and specificity superior to established indices of hepatic IR.

NDRG1 Activity in Fat Depots Is Associated With Type 2 Diabetes and Impaired Incretin Profile in Patients With Morbid Obesity.

ObjectiveWe aimed to investigate insulin-, mTOR- and SGK1-dependent signaling basal states in morbidly obese patients’ fat. We analyzed the correlation between the signaling activity, carbohydrate metabolism, and incretin profiles of patients.MethodsThe omental and subcutaneous fat was obtained in patients with obesity. The omental study included 16 patients with normal glucose tolerance (NGT) and 17 patients with type 2 diabetes mellitus (T2DM); the subcutaneous study included 9 NGT patients and 12 T2DM patients. Insulin resistance was evaluated using the hyperinsulinemic euglycemic clamp test and HOMA-IR index. The oral glucose tolerance test (OGTT) for NGT patients and mixed meal tolerance test (MMTT) for T2DM patients were performed. The levels of incretins (GLP-1, GIP, oxyntomodulin) and glucagon were measured during the tests. Signaling was analyzed by Western blotting in adipose tissue biopsies.ResultsWe have shown equal levels of basal phosphorylation of insulin- and mTOR-dependent signaling in omental fat depot in NGT and T2DM obese patients. Nevertheless, pNDRG1-T346 was decreased in omental fat of T2DM patients. Correlation analysis has shown an inverse correlation of pNDRG1-T346 in omental fat and diabetic phenotype (HbA1c, impaired incretin profile (AUC GLP-1, glucagon)). Moreover, pNDRG1-T346 in subcutaneous fat correlated with impaired incretin levels among obese patients (inverse correlation with AUC glucagon and AUC GIP).ConclusionsAccording to results of the present study, we hypothesize that phosphorylation of pNDRG1-T346 can be related to impairment in incretin hormone processing. pNDRG1-T346 in adipose tissue may serve as a marker of diabetes-associated impairments of the systemic incretin profile and insulin sensitivity.

Insulin sensitivity variations in apparently healthy Arab male subjects: correlation with insulin and C peptide

IntroductionDecreased insulin sensitivity occurs early in type 2 diabetes (T2D). T2D is highly prevalent in the Middle East and North Africa regions. This study assessed the variations in insulin sensitivity...

Prognostic factors for the carbohydrate metabolism normalization in patients with type 2 diabetes mellitus and obesity using liraglutide 3.0 mg per day

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are innovative drugs that effectively reduce glycemic levels and overweight in patients with type 2 diabetes mellitus (T2DM). However, the criteria for predicting the hypoglycemic effect of this group of drugs have not been practically defined. To assess the factors contributing to the achievement the glycemia normalization in patients with diabetes mellitus and obesity by adding to antihyperglycemic therapy (AT) a drug from the GLP-1 RA group liraglutide 3.0 mg per day. A single-center, prospective, non-randomized study was provided. The objects of the study were patients with T2DM and obesity (n=22). Liraglutide 3.0 mg per day was added to the current AT of patients. Initially, the parameters of carbohydrate metabolism, hormones of the incretin system on an empty stomach and during the mixed-meal test, insulin resistance using the euglycemic hyperinsulinemic clamp test, and body composition were studied. After 9 months of therapy, all studies were repeated and a search for possible predictors of the carbohydrate metabolism normalization was made. The body mass index of patients decreased from 42.4 [37.7; 45.0] to 35.9 [33.0; 40.9] kg/m2. Fasting blood glucose and glycated hemoglobin levels decreased from 9.02 [7.40; 11.37] mmol/L and 7.85 [7.43; 8.65]% up to 5.90 [5.12; 6.18] mmol/L and 6.40 [5.90; 6.60]%, respectively. 14 (63.6%) patients reached normoglycemia. Insulin resistance according to the clamp test did not change over the study. Basal concentrations of oxyntomodulin, glycentin and the area under the GLP-1, oxyntomodulin, glycentin curve significantly decreased 9 months after liraglutide administration. The prognostic marker of the achievement of normoglycemia during therapy with liraglutide 3.0 mg/day is the level of endogenous GLP-15.5 pmol/L before the appointment of arGPP-1 therapy. The concentration of endogenous GLP-1 before the appointment of liraglutide therapy at a dose of 3.0 mg per day can be used for prediction the drug hypoglycemic effect and achieving normoglycemia possibility.

Gliquidone ameliorates hepatic insulin resistance in streptozotocin-induced diabetic Sur1−/− rats

Gliquidone was suggested to exert hypoglycemic effect through enhancing hepatic insulin sensitivity. However, inadequate in vivo evidences make this statement controversial. The aim of the present study was to clarify the insulin-sensitizer role of gliquidone in liver and muscle, so as to confirm its extra-pancreatic effects in vivo. TALEN technique was used to create Sur1 knockout (Sur1−/−) rats. Diabetic Sur1−/− rat models were established by high-fat diet combined with streptozotocin, and which were randomly divided into three groups: gliquidone, metformin and saline, treated for 8 weeks. Fasting blood glucose (FBG) and body mass were tested each week. IPGTT, IPITT and hyperinsulinemic-euglycemic clamp tests were used to evaluate glucose tolerance and insulin sensitivity, respectively. Key mediators of glucose metabolism in liver and skeletal muscle and the activity of AKT and AMPK in these tissues were further analyzed. We found that gliquidone decreased FBG and increased insulin sensitivity without increasing insulin secretion in diabetic Sur1−/− rats. Further exploration implied that gliquidone mainly increased hepatic glycogen storage and decreased gluconeogenesis, which were accompanied with activation of AKT, but not enhanced muscle GLUT4 expression. However, both these effects were still weaker than that of metformin. These results suggested that gliquidone could exerts an extra-pancreatic hypoglycemic effect by improving insulin sensitivity, which might be largely attributes to its additional insulin sensitizer role in hepatic glucose metabolism.

1287-PUB: SGK1-NDRG1 Signal Axis as a Key Marker Associated with Insulin Resistance and Impaired Incretin Profile in Subcutaneous and Omental Fat Depots among Obese Patients

Objective: We have performed the comparative study of basal state of SGK-dependent signaling among obese patients with/without type 2 diabetes mellitus (T2DM). We have accomplished correlation analysis of glucose metabolism and incretin profile parameters against phosphorylation and expression parameters for SGK1 and its substrate NDRG1. Methods: 36 patients with long (&amp;gt;10 years) and morbid (BMI&amp;gt;35 kg/m2) obesity, 18 of which had normal glucose tolerance (NGT) and 18 had T2DM were enrolled in this study. Hyperinsulinemic-euglycemic clamp test and HOMA-IR were used to evaluate the insulin resistance. Blood samples taken at 0, 30 and 120 min of food load test were used to assess incretin profile, insulin and glucose levels. Biopsies from subcutaneous and omental fat depots were obtained during bariatric surgery for all patients and signaling states were analyzed by western blot. Results: Analysis of SGK signaling for subcutaneous fat has shown single significant intergroup difference: enhancing of pSGK-S422 phosphorylation in T2DM group, but also pNDRG-T346 level has tendency to accumulation in subcutaneous fat of NGT patients. Analysis of SGK signaling for omental fat has shown similar results: in this case accumulation of pNDRG-T346 in NGT patients was statistically significant. Correlation analysis has shown strong direct correlation of pNDRG-T346 level with BMI and AUC for GLP-1 and reverse correlation of pNDRG-T346 with Hb1Ac and AUC for glucagon. For pSGK-S422 we have observed opposite characters of correlations with the similar parameters of carbohydrate metabolism and incretin profile. Conclusions: In present work we have taken more patients and have shown critical relevance and general character of stress-dependent SGK1-NDRG1 signal axis as a marker of insulin resistance for different fat depots. Disclosure I. Stafeev: None. A. V. Vorotnikov: None. Y. V. Parfyonova: None. M. V. Shestakova: None. I. Sklyanik: None. E. Mamontova: None. S. Michurina: None. E. Shestakova: None. K. Yahyaev: None. A. Yurasov: None. E. Ratner: None. M. Menshikov: None. Funding Russian Science Foundation (17-15-01435)

Islet Function and Insulin Sensitivity in Latent Autoimmune Diabetes in Adults Taking Sitagliptin: A Randomized Trial.

ContextThe long-term effects of dipeptidyl peptidase-4 inhibitors on β-cell function and insulin sensitivity in latent autoimmune diabetes in adults (LADA) are unclear.ObjectiveTo investigate the effects of sitagliptin on β-cell function and insulin sensitivity in LADA patients receiving insulin.Design and SettingA randomized controlled trial at the Second Xiangya Hospital.MethodsFifty-one patients with LADA were randomized to sitagliptin + insulin (SITA) group or insulin alone (CONT) group for 24 months.Main Outcome MeasuresFasting C-peptide (FCP), 2-hour postprandial C-peptide (2hCP) during mixed-meal tolerance test, △CP (2hCP – FCP), and updated homeostatic model assessment of β-cell function (HOMA2-B) were determined every 6 months. In 12 subjects, hyperglycemic clamp and hyperinsulinemic euglycemic clamp (HEC) tests were further conducted at 12-month intervals.ResultsDuring the 24-month follow-up, there were no significant changes in β-cell function in the SITA group, whereas the levels of 2hCP and △CP in the CONT group were reduced at 24 months. Meanwhile, the changes in HOMA2-B from baseline were larger in the SITA group than in the CONT group. At 24 months, first-phase insulin secretion was improved in the SITA group by hyperglycemia clamp, which was higher than in the CONT group (P < .001), while glucose metabolized (M), insulin sensitivity index, and M over logarithmical insulin ratio in HEC were increased in the SITA group (all P < .01 vs baseline), which were higher than in the CONT group.ConclusionCompared with insulin intervention alone, sitagliptin plus insulin treatment appeared to maintain β-cell function and improve insulin sensitivity in LADA to some extent.

Association of insulin resistance and non-alcoholic fatty liver disease

BACKGROUND:The number of patients with chronic metabolic disorders such as obesity, type 2 diabetes mellitus (T2D) and non-alcoholic fatty liver disease (NAFLD) is growing at an alarming rate worldwide in both developed and developing countries. In the world, the prevalence of NAFLD is approaching 25%. Among patients with T2D, 70–80% are diagnosed with NAFLD. Insulin resistance (IR) is recognized as one of the main pathogenetic factors in the development of the most common chronic liver disease — NAFLD.AIM:Our search work was aimed at determining the contribution of the degree of IR to the progression of NAFLD; compare the gold standard for the determination of IR (clamp) and the mathematical model (HOMA-IR).METHODS:An observational one-stage open comparative study was conducted on the basis of the case-control principle. The objects of the study were overweight and obese patients who had not previously been diagnosed carbohydrate metabolism disorders, without secondary causes of fat accumulation in the liver. During the examination, clinical and laboratory studies were carried out, IR indices (M-index, HOMA-IR index) were obtained, a diagnosis of carbohydrate metabolism disturbance (or its absence) was made, a liver biopsy was made, morphological and clinical diagnoses were made.RESULTS:The analysis included information about 60 patients, they are divided into 3 groups: without NAFLD (7 people), with steatosis (18 people), with non-alcoholic steatohepatitis (NASH) (35 people), groups are comparable by age, gender, and body mass index (BMI), glycated hemoglobin. When assessing the degree of IR using the hyperinsulinemic euglycemic clamp test, 19 showed a severe degree of IR, 28 had a moderate degree, 8 had a mild degree, and 5 had no IR. In the three studied groups, the median IR corresponded to an average degree and did not significantly differ. When comparing the gold standard for determining IR and the mathematical model (HOMA-IR) in the studied groups, an negative significant correlation was revealed (p = 0,0001).CONCLUSIONS:In the course of our study, no correlation was found between the degree of IR and the severity of NAFLD. This result allows us to think about other pathogenetic factors that affect the progression of NAFLD.

Reduced Muscle Strength Is Associated With Insulin Resistance in Type 2 Diabetes Patients With Osteoarthritis.

ContextType 2 diabetes is associated with a greater risk for musculoskeletal disorders, yet its impact on joint function remains unclear.ObjectiveWe hypothesized that patients with type 2 diabetes and osteoarthritis would exhibit musculoskeletal impairment, which would associate with insulin resistance and distinct microRNA profiles.MethodsParticipants of the German Diabetes Study with type 2 diabetes (T2D, n = 39) or normal glucose tolerance (CON, n = 27), both with (+OA) or without osteoarthritis (-OA) underwent intravenous glucose tolerance and hyperinsulinemic-euglycemic clamp tests. Musculoskeletal function was assessed by isometric knee extension strength (KES), grip strength, range of motion (ROM), and balance skills, while neural function was measured by nerve conductance velocity (NCV). Arthritis-related symptoms were quantified using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, serum arthritis-related microRNA using quantitative polymerase chain reaction.ResultsInsulin sensitivity was lower in T2D+OA vs T2D-OA (4.4 ± 2.0 vs 5.7 ± 3.0 mg* kg–1*min–1) and in CON+OA vs CON-OA (8.1 ± 2.0 vs 12.0 ± 2.6 mg*kg–1,*min–1, both P < .05). In T2D+OA, KES and ROM were 60% and 22% lower than in CON+OA, respectively (both P < .05). Insulin sensitivity correlated positively with KES (r = 0.41, P < .05) among T2D, and negatively with symptom severity in CON and T2D (r = –0.60 and r = –0.46, respectively, P < .05). CON+OA and T2D+OA had inferior balance skills than CON-OA, whereas NCV was comparable in T2D+OA and T2D-OA. Expression of arthritis-related microRNAs was upregulated in T2D compared to CON, but downregulated in CON+OA compared to CON-OA (P < .05), and did not differ between T2D+OA and T2D-OA.ConclusionMusculoskeletal impairment and osteoarthritis-related symptoms are associated with insulin resistance. Type 2 diabetes can mask changes in arthritis-related microRNA profiles.

Hypothalamic BMP9 suppresses glucose production by central PI3K/Akt/mTOR pathway.

Bone morphogenetic proteins (BMPs) are secreted ligands that belong to the transforming growth factor-β (TGF-β) superfamily. BMP7 has been reported to play a role in reversing obesity and regulating appetite in the hypothalamus. Whether BMP9 plays a central role in regulating glucose metabolism and insulin sensitivity remains unclear. Here, we investigated the impact of central BMP9 signaling and possible route of transmission. We performed intracerebroventricular (ICV) surgery and injected adenovirus expressing BMP9 (Ad-BMP9) into the cerebral ventricle of mice. Metabolic analysis, hyperinsulinemic-euglycemic clamp test, and analysis of phosphatidylinositol 3,4,5-trisphosphate (PIP3) formation were then performed. Real-time PCR and Western blotting were performed to detect gene expression and potential pathways involved. We found that hypothalamic BMP9 expression was downregulated in obese and insulin-resistant mice. Overexpression of BMP9 in the mediobasal hypothalamus reduced food intake, body weight, and blood glucose level, and elevated the energy expenditure in high-fat diet (HFD)-fed mice. Importantly, central treatment with BMP9 improved hepatic insulin resistance (IR) and inhibited hepatic glucose production in HFD-fed mice. ICV BMP9-induced increase in hepatic insulin sensitivity and related metabolic effects were blocked by ICV injection of rapamycin, an inhibitor of mammalian target of rapamycin (mTOR) signaling. In addition, ICV BMP9 promoted the ability of insulin to activate the insulin receptor/phosphoinositide 3-kinase (PI3K)/Akt pathway in the hypothalamus. Thus, this study provides insights into the potential mechanism by which central BMP9 ameliorates hepatic glucose metabolism and IR via activating the mTOR/PI3K/Akt pathway in the hypothalamus.