bluuebunny/crossref_metadata_2025 huggingface dataset:
Age-Related Attenuation of Aerobic Exercise Training Adaptation in 24-Week Old Rats
Authors: SCALZO REBECCA L. , EVANS GRAHAME F. , HULL SARA E. , KNAUB LESLIE , WALKER LORI A. , REUSCH JANE E.
Published: June 2018

Studies of age related declines in health and function often focus on the end of the lifespan. However, chronic diseases such as type 2 diabetes (T2D) develop in middle age. The purpose of this study was to determine the effect of aerobic exercise training on vascular and skeletal muscle responses in mature rats. We hypothesized that mature rats would have attenuated adaptations to exercise training. Young (Y; 12-week old; n = 8) and mature (M; 24 week-old; n = 8) male Wistar rats performed 3-weeks of treadmill running (Ex) or remained sedentary (S). After this time period, insulin and glucose were greater in mature compared with young rats (P < 0.03) and were not different with Ex. Mature rats had lower exercise capacity measured by run to fatigue distance (Y-S: 675 ± 172 vs. M-S: 585 ± 22 m; P < 0.001) and a significantly reduced change in exercise capacity in response to exercise training (Y-Ex: 2387 ± 177 vs. M-Ex: 1341 ± 161 m; P < 0.01). Ex vivo aortic function in response to phenylephrine was impaired and aortic mitochondrial respiration was elevated in mature animals (P < 0.01) and neither endpoint responded to exercise training in the mature rats. Skeletal muscle AMPK activation was 81% greater in the Y-Ex compared with Y-S and this response was attenuated (8% greater) in the M-Ex compared with M-S (P = 0.05). Similarly, muscle PGC1α was greater with exercise training in the young rats and this response was abrogated in the mature rats (P = 0.05).

In summary, mature rats develop insulin resistance and have lower exercise capacity and training adaptation. Vasomotion is impaired and skeletal muscle bioenergetic adaptation to Ex is blunted. As exercise is a cornerstone of therapy for T2D, it is crucial to define the interaction between age and exercise adaptation, and to determine whether T2D modulates or accelerates the impact of age. Future studies will focus on understanding the mechanisms of this age related impairment of exercise adaptation for identification of optimal exercise training and/or pharmacological interventions.

Disclosure

R.L. Scalzo: None. G.F. Evans: None. S.E. Hull: None. L. Knaub: None. L.A. Walker: None. J.E. Reusch: Research Support; Self; Merck & Co., Inc.. Board Member; Self; American Diabetes Association. Research Support; Self; AstraZeneca. Other Relationship; Self; Sanofi-Aventis.
Natriuretic Peptide Deficiency Causes Skeletal Muscle Insulin Resistance in Mice
Authors: MORO CEDRIC
Published: June 2018

Cardiac natriuretic peptides (NP) have been shown to control energy homeostasis. Epidemiological studies have shown that low level of plasma NP predict future development of type 2 diabetes (T2D). We have also observed a reduced expression of the biologically active NP receptor GCA of about 50% in metabolic tissues of obese humans and mice. The purpose of this study was to demonstrate that NP deficiency causes T2D in mice. GCA+/- and atrial NP-/- (ANP) mice and their wild type (WT) littermates were studied under normal chow and high fat diet for 12 weeks. GCA+/- and ANP-/- mice exhibit signs of systemic insulin resistance and glucose intolerance when compared to their WT littermates. This metabolic phenotype is accompanied by skeletal muscle insulin resistance and reduced lipid oxidative capacity, without noticeable changes in inflammatory profile of liver and adipose tissues. Interestingly, we observed elevated levels of lipotoxic lipids in skeletal muscle along with reduced mitochondrial mass and respiratory chain complexes. Collectively, these data indicate that ANP/GCA deficiency causes T2D and that ANP contributes to long-term maintenance of insulin sensitivity.

Disclosure

C. Moro: None.
Multiyear Reproducibility of Clamp-Derived Insulin Sensitivity in Free-Living Humans—Association with Incident Prediabetes in the POP-ABC Study
Authors: UMEKWE NKIRU A. , JAMES DEIRDRE J. , DAGOGO-JACK SAMUEL
Published: June 2018

Background: The hyperinsulinemic euglycemic clamp (HEC) is the gold standard measure for insulin sensitivity (Si-clamp). Here, we determined its reproducibility and metabolic implications.

Methods: POP-ABC is a follow-up study of healthy black and white offspring of parents with T2DM for the primary outcome of prediabetes. Assessments included clinical exam, OGTT, anthropometry, and HEC.

Results: 90 adults (44 AA, 46 EA; 62 women, 28 men) who underwent HEC-1 at baseline consented to HEC-2 after 2.3y (range 2-3.5 y) (Table 1). The mean (SD) baseline age was 47.5 ± 8.13y, BMI was 30.4 ± 9.16 kg/m2, FPG was 94.8 ± 7.92 mg/dl and 2-hrPG was 127.4 ± 26.8. HEC-1 and HEC-2 metrics did not differ significantly (Table 1). Si-clamp values from HEC-1 and HEC-2 were strongly correlated (r=0.81, P<0.0001); the change in Si-clamp correlated with change in weight (r= 0.35, P=0.0009), but not age, gender, race, or FPG. After ∼5 y follow-up, 40 subjects progressed (P) to prediabetes and 50 were Nonprogressors (NP). Si-clamp was lower at baseline and 2.3 y later in P vs. NP (P=0.02). The mean change in Si-clamp (-2.5% in NP and -9.5% in P) predicted prediabetes risk (P=0.02).

Conclusion: Insulin sensitivity by HEC is reproducible over multiyear intervals in nondiabetic free-living subjects. Progressors to prediabetes showed ∼4% /y decline in Si-clamp vs. 1%/y in nonprogressors.

Disclosure

N.A. Umekwe: None. D.J. James: None. S. Dagogo-Jack: None.
Febuxostat Improves Insulin Resistance in the Skeletal Muscle In Vitro and In Vivo
Authors: MORIYA CHIHIRO T. , SATOH HIROAKI , WATADA HIROTAKA
Published: June 2018

Hyperuricemia is closely associated with various metabolic disorders such as diabetes, hypertension, dyslipidemia, and cardiovascular diseases. Xanthine oxidoreductase (XOR) is a key enzyme known to catalyze purines to uric acid. Febuxostat is an orally-active, potent, non-purine, selective XOR inhibitor. However, the effect of febuxostat on glucose and insulin metabolism has not been fully elucidated. Therefore, we investigated the effect of febuxostat on insulin sensitivity in male Wistar rats. Insulin sensitivity was evaluated by the hyperinsulinemic-euglycemic glucose clamp studies (at 25 mU/kg/min insulin infusion rate) after an 8-hour fast. Male Wistar rats were 60% high fat diet containing with either febuxostat (∼4 mg/kg/day) or not, for 4 weeks. The glucose infusion rate and insulin-stimulated glucose disposal rate were significantly increased by 12% and 17%, respectively. But hepatic glucose output was no significant change between two groups. Consistent with the clamp data, the insulin-stimulated phosphorylation of Akt and AMPK were significantly increased by 90% and 53%, respectively, only in skeletal muscle of febuxostat treated rats. Next, to investigate whether this effect is direct or indirect, we examined the effect of febuxostat in the differentiated C2C12 cells. The treatment of 10 μM febuxostat for 48 hours significantly increased the phosphorylation of Akt and AMPK by 65% (P=0.017) and 43% (P=0.028) in the differentiated C2C12 cells, respectively. These results suggest that this effect of febuxostat is direct.

In conclusion, these findings indicate the possibility that febuxostat acts directly on the skeletal muscle and improves insulin resistance.

Disclosure

C.T. Moriya: None. H. Satoh: None. H. Watada: Advisory Panel; Self; AstraZeneca. Consultant; Self; Astellas Pharma US, Inc., AstraZeneca, Boehringer Ingelheim GmbH, Daiichi Sankyo Company, Limited, Sumitomo Dainippon Pharma Co., Ltd., Eli Lilly and Company, Kissei Pharmaceutical Co., Ltd., Kowa Pharmaceuticals America, Inc., Kyowa Hakko Kirin Co., Ltd., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novo Nordisk A/S, Novartis AG, Ono Pharmaceutical Co., Ltd., Sanofi, Sanwa Kagaku Kenkyusho Co., Ltd., Takeda Development Center Asia, Pte. Ltd.. Research Support; Self; Abbott, Astellas Pharma US, Inc., AstraZeneca, Bayer AG, Benefit One Health Care Co., Ltd., Boehringer Ingelheim GmbH, Bristol-Myers Squibb Company, Daiichi Sankyo Company, Limited, Sumitomo Dainippon Pharma Co., Ltd., Eli Lilly and Company, Kissei Pharmaceutical Co., Ltd., Kowa Pharmaceuticals America, Inc., Kyowa Hakko Kirin Co., Ltd., Johnson & Johnson Diabetes Institute, LLC., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Mochida Pharmaceutical Co., Ltd., Nitto Boseki Co., Ltd., Novartis AG, Novo Nordisk A/S, Ono Pharmaceutical Co., Ltd., Pfizer Inc., Sanofi, Sanwa Kagaku Kenkyusho Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Development Center Asia, Pte. Ltd., Terumo Medical Corporation.
Deoxysphingolipids—Novel Skeletal Muscle Lipids Related to Insulin Resistance in Humans That Decrease Insulin Sensitivity In Vitro
Authors: ZARINI SIMONA , PERREAULT LEIGH , NEWSOM SEAN A. , KAHN DARCY E. , KEREGE ANNA , HARRISON KATHLEEN A. , BERGMAN BRYAN
Published: June 2018

Accumulation of sphingolipids are thought to promote skeletal muscle insulin resistance. Deoxysphingolipids (dSL) are a novel type of sphingolipid made by condensing palmitate with alanine (deoxydihydroceramide - dDHCer) or glycine (deoxymethylceramide - dMeCer) instead of serine. In plasma, dSL are increased in individuals with type 2 diabetes and cause beta cell dysfunction in vitro. However, their role in skeletal muscle is unknown. We evaluated skeletal muscle dSL content in endurance trained athletes (n=13), lean (n=14), obese (n=12), and type 2 diabetic (n=10) men and women. Muscle dSL content was measured from biopsies using LC/MS/MS, and insulin sensitivity using a hyperinsulinemic-euglycemic clamp. After adjusting for repeated measures, total and C18:0 muscle dDHCer were inversely related to insulin sensitivity (p=0.0008, and p=0.0003, respectively), while dMeCer were below the limit of detection. Total and C18:0 dDHCer were significantly greater in obese and T2D compared to athletes and lean (p<0.004). In primary myotubes, dSL content was increased to determine effects on insulin sensitivity by altering media amino acid content with 5x alanine/glycine (no serine) or 1x alanine/glycine/serine as a control, and replaced every 24 hours for 2 days. Alanine and glycine supplementation increased myotube dDHCer content by 3.6 fold, dMeCer content by 21 fold, and decreased ceramide content by 30% relative to control. Fluorescence lifetime imaging revealed decreased oxidative flux in enhanced dSL conditions. Insulin sensitivity, measured using the percent increase in insulin stimulated glycogen synthesis, decreased from 55±9.1% in control to 4±9% in enhanced dSL conditions. Combined, these data reveal that dSL accumulate in insulin resistant human muscle, and appear to cause insulin resistance in vitro. These data suggest decreasing skeletal muscle deoxysphingolipid content may prevent or treat skeletal muscle insulin resistance.

Disclosure

S. Zarini: None. L. Perreault: Advisory Panel; Self; Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Advisory Panel; Self; Merck & Co., Inc.. Speaker's Bureau; Self; Merck & Co., Inc., AstraZeneca, Janssen Pharmaceuticals, Inc., Boehringer Ingelheim Pharmaceuticals, Inc.. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Advisory Panel; Self; Sanofi. Speaker's Bureau; Self; Sanofi. S.A. Newsom: None. D.E. Kahn: None. A. Kerege: None. K.A. Harrison: None. B. Bergman: Research Support; Self; Eli Lilly and Company. Advisory Panel; Spouse/Partner; Novo Nordisk Inc., Merck & Co., Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company.
Weight Loss and Exercise Decrease Saturation of Intramyocellular Lipid Species in Association with Improvements in Insulin Sensitivity
Authors: STANDLEY ROBERT , COEN PAUL M. , GOODPASTER BRET H.
Published: June 2018

Observational cross-sectional studies have described associations between the saturation status of both phospholipids and diacylglycerol (DAG) with insulin sensitivity (IS) of skeletal muscle. The purpose of this study was to test the hypothesis that diet-induced weight loss and exercise reduce intramyocellular lipid saturation and that this is associated with improved IS. We studied forty subjects who competed a randomized controlled trial (RCT) consisting of 6 months of either Health Education Control (CON: n=13 5M/8F), Diet-induced weight-loss only (DIWL: n=13 5M/8F), or Weight-loss and Exercise (WLEX: n=14 6M/9F). DIWL and WLEX subjects had a goal of 10% weight-loss through calorie restriction. Hyperinsulinemic euglycemic clamps were employed to measure IS, and muscle biopsies were obtained to quantify intramyocellular lipids by mass spectrometry. The DIWL and WLEX groups both lost a significant amount of weight compared to CON (DIWL: -6.4%, WLEX: -11.3%, CON: -2.5%, P<0.05). IS measured as the glucose infusion rate required to maintain euglycemia during the clamp increased in the DIWL and WLEX groups compared to the control group (DIWL: 1.0, WLEX: 2.7, CON: 0.6 mg/FFMkg/min, P<0.05). Total phosphatidylethanolamine (PE), phosphatidylcholine (PC), diacylglycerols (DAG) did not significantly change following intervention (P>0.05). However, there were trends for unsaturated PE and PC species to increase in the WLEX only and saturated DAG and ceramide species to be reduced in both the DIWL and WLEX group. The increase in unsaturation of PE and PC were associated with improvements in IS (PE: P=0.047, r=0.35; PC: P=0.072, r=0.32) and the decrease in saturation of DAG was associated with improvements in IS (P=0.044, r=-0.36).

In conclusion, weight-loss and exercise increase unsaturated PE and PC species, and reduce saturated DAG species, which are related to improved IS within skeletal muscle.

Disclosure

R. Standley: None. P.M. Coen: None. B.H. Goodpaster: None.
Impact of Longitudinal Changes in Metabolic Syndrome Status Over Two Years on 10-Year Incident Type 2 Diabetes Mellitus
Authors: HUH JI HYE , LEE SUJIN
Published: June 2018

Aim: Metabolic syndrome (MetS) is a known predictor of diabetes mellitus (DM), but whether longitudinal changes in MetS status modify the risk for DM remains unclear. We investigated whether temporal changes in MetS status over two years modify the 10-year risk of incident DM.

Methods: A prospective cohort study was conducted in 7,317 adults aged 40-70 years without DM at baseline. Subjects were categorized into four groups based on repeated longitudinal assessment of MetS status over two years: non-MetS, resolved MetS, incident MetS, and persistent MetS. The hazard ratio (HR) of new-onset DM during 10 years was calculated in each group using Cox models.

Results: During the 10-year follow-up, 1,099 (15.0%) developed DM. Compared to the non-MetS group, the fully adjusted hazard ratios for new-onset DM were 1.27 (1.01-1.61) in the resolved MetS group, 1.78 (1.43-2.22) in the incident MetS group, and 1.85 (1.52-2.26) in the persistent MetS group (P for trend <0.001). The risk of DM in subjects with resolved MetS was attenuated compared to those with persistent MetS over two years (P<0.001). The adjusted hazard ratio for 10-year developing DM gradually increased as the number of MetS components increased two years later (Figure 1).

Conclusion: We found that discrete longitudinal changes pattern in MetS status over two years associated with 10-year risk of DM. These findings suggest that monitoring change of MetS status and controlling it may be important for risk prediction of DM.

Disclosure

J. Huh: None. S. Lee: None.
Contribution of Pancreatic Alpha-Cell Function to Insulin Sensitivity and Glucose Variability in Type 1 Diabetes Patients
Authors: TAKAHASHI NOBUYUKI , CHUJO DAISUKE , KAJIO HIROSHI , UEKI KOHJIRO
Published: June 2018

In type 1 diabetes (T1D) patients, relationships between pancreatic alpha cell function and glucose metabolism remain elusive. Therefore, we aimed to reveal the contribution of alpha cell function to insulin sensitivity, hepatic glucose uptake (HGU), and glucose variability, including the dawn phenomenon, in T1D patients. We recruited forty Japanese T1D patients with a median (interquartile range) BMI of 21.0 (19.3-22.7) kg/m2, diabetes duration of 2.6 (0.1-10.3) years, and HbA1c level of 8.2 (7.4-10.3) %. We measured the arginine-stimulated glucagon secretion using RIA and double-sandwich ELISA and subsequently assessed the dawn phenomenon using an artificial pancreas (STG-55®, Nikkiso, Japan) and performed a hyperinsulinemic-euglycemic clamp followed by oral glucose loading to evaluate insulin sensitivity and HGU. Glycemic variability was analyzed with continuous glucose monitoring (CGM). The median areas under the curve of glucagon measured by RIA (AUCglcRIA) and ELISA (AUCglcELISA) were 3.7 (2.6-4.6) × 104 and 1.9 (0.8-4.3) × 103 pg/mL × min, respectively. The glucose infusion rate (GIR) during the euglycemic clamp was inversely correlated with AUCglcRIA and AUCglcELISA (R2 = 0.21 and 0.44, P = 0.033 and 0.038, respectively, adjusted for age, sex, and BMI). In addition, the median GIR was significantly lower in the high glucagon response group than in the low glucagon response group [7.3 (5.1-8.4) vs. 9.2 (7.0-11.7), P = 0.049]. The dawn index (ratio of insulin requirements between 4:00-8:00 and 0:00-04:00) and HGU did not correlate AUCglcRIA and AUCglcELISA. The standard deviation of glucose levels determined by CGM significantly correlated with AUCglcRIA (R2 = 0.28, P = 0.015) but not with AUCglcELISA (R2 = 0.01, P = 0.62). In conslusion, alpha cell function may contribute to insulin sensitivity in T1D, and its relationship with glycemic variability may be affected by the procedure of the glucagon assay used.

Disclosure

N. Takahashi: None. D. Chujo: Research Support; Self; Mitsubishi Tanabe Pharma Corporation, Sanofi K.K., Kyowa Hakko Kirin Co., Ltd.. H. Kajio: None. K. Ueki: Speaker's Bureau; Self; Daiichi Sankyo Company, Limited, Eli Lilly and Company, Boehringer Ingelheim Pharmaceuticals, Inc., MSD K.K., Novo Nordisk Inc., Mitsubishi Tanabe Pharma Corporation, Kyowa Hakko Kirin Co., Ltd., Takeda. Research Support; Self; Takeda, Astellas, Novo Nordisk Inc..
Individual and Combined Glucose-Lowering Effects of Glucagon Receptor Antagonism and Sodium-Glucose Cotransporter 2 Inhibition
Authors: HAEDERSDAL SOFIE , LUND ASGER B. , MAAGENSEN HENRIK , NIELSEN-HANNERUP ELISABETH , HOLST JENS J. , KNOP FILIP K. , VILSBØLL TINA
Published: June 2018

Studies suggest that sodium-glucose cotransporter 2 inhibitors (SGLT2i) induce hyperglucagonemia, which might counteract its glucose-lowering ability in type 2 diabetes. In a randomized, placebo-controlled, double-dummy, double-blinded, cross-over study, 12 middle-aged patients with type 2 diabetes (BMI [mean (SD)]: 30.3 (5.8) kg/m2; HbA1c: 50.3 (10.5) mmol/mol) underwent four 4-hour liquid mixed meal tests preceded by single-dose administration: 1) Placebo, 2) SGLT2i (25 mg empagliflozin), 3) glucagon receptor antagonist (GRA) (300 mg LY2409021), and 4) GRA + SGLT2i. The SGLT2i and GRA individually lowered fasting plasma glucose (FPG) compared to placebo and the combination further decreased FPG. SGLT2i reduced postprandial glucose excursions as assessed by baseline-subtracted area under curve (bsAUC) whereas GRA increased bsAUC compared to placebo (Figure). The paradoxical GRA-induced increment in bsAUC was annulled by a potent SGLT2i-induced reduction of bsAUC during the combination of SGLT2i and GRA (Figure).

In conclusion, SGLT2i and GRA combined reduce FPG beyond their individual capacity in patients with type 2 diabetes, and in the context of GRA, SGLT2i’s beneficial effect on postprandial glucose excursions seems to be potentiated.

Disclosure

S. Haedersdal: None. A.B. Lund: Other Relationship; Self; Novo Nordisk A/S. H. Maagensen: None. E. Nielsen-Hannerup: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. Board Member; Self; Zealand Pharma A/S. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., AstraZeneca. Research Support; Self; Danish Diabetes Academy, Novo Nordisk Foundation. Other Relationship; Self; Antag Therapeutics. Other Relationship; Spouse/Partner; Antag Therapeutics. F.K. Knop: Advisory Panel; Self; AstraZeneca. Consultant; Self; AstraZeneca. Research Support; Self; AstraZeneca. Speaker's Bureau; Self; AstraZeneca. Advisory Panel; Self; Eli Lilly and Company. Speaker's Bureau; Self; Eli Lilly and Company. Advisory Panel; Self; Amgen Inc.. Speaker's Bureau; Self; Merck Sharp & Dohme Corp.. Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Consultant; Self; Amgen Inc.. Advisory Panel; Self; MedImmune, Sanofi. Consultant; Self; Sanofi. Research Support; Self; Sanofi. Speaker's Bureau; Self; Sanofi. T. Vilsbøll: None.
Risk of Breast Cancer According to Glycaemia and HbA1c Concentration—A Meta-analysis of Prospective Studies
Authors: MACACU ALINA , PIZOT CECILE , BOYLE PETER , AUTIER PHILIPPE
Published: June 2018

Some observational studies have suggested that women with diabetes may be at increased risk of breast cancer. Blood levels of fasting glucose (FG) and of glycated hemoglobin (HbA1c) are major diagnostic tools for diabetes. The aim of this study was to investigate the association between HbA1c, FG and breast cancer occurrence. A systematic literature search identified prospective studies which reported a quantitative estimate of the association between HbA1c or FG and breast cancer. Summary relative risks (SRR) of breast cancer, comparing high vs. low levels of HbA1c or FG, were computed using random-effect meta-analysis. Ten studies for HbA1c (116,035 women and 3,095 breast cancer cases) and 13 studies for FG (971,071 women and 14,579 breast cancer cases) were selected. High levels of HbA1c (FG) ranged from >4.5% to >9% (>5 to >7.8 mmol/L), and low level ranged from <4.3% to <6.7% (<4.4 to <6.1 mmol/L). Overall, the SRR of breast cancer was 0.97 (95% CI: 0.76, 1.24) for HbA1c and 1.15 (95% CI: 1.00, 1.33) for FG, with moderate heterogeneity between studies (I²=44% and 45%, respectively). When the analyses were restricted to women with HbA1c <6.5% and FG <7mmol/L, the SRR was 0.97 (95% CI: 0.81, 1.15) for HbA1c (six studies) and 1.15 (95% CI: 1.01, 1.31) for FG (seven studies) without heterogeneity in both analyses (I²=0%). In 3 studies conducted in diabetic women, the SRR for the association between HbA1c levels and breast cancer was 0.95 (95% CI: 0.79, 1.15) with no heterogeneity (I2=0%). No study was found on FG among diabetic women only. No association was found between HbA1c and breast cancer occurrence, while fasting glucose might be associated with a slight increased risk. The lack of clear association suggests that the increased risk of breast cancer observed among diabetic women appears to be driven by factors other than the blood glucose concentration disorders.

Disclosure

A. Macacu: None. C. Pizot: None. P. Boyle: Other Relationship; Self; Sanofi. P. Autier: Other Relationship; Self; Sanofi.
Endo Soc-3-Decrease in AMP Kinase Expression and Activity in Diabetic Patients with Hypogonadism—Increase following Testosterone Supplementation
Authors: DHINDSA SANDEEP , GHANIM HUSAM , BATRA MANAV , CHAUDHURI AJAY , ABUAYSHEH SANAA , DANDONA PARESH
Published: June 2018

AMP kinase is a key enzyme involved with energy regulation, the intake of macronutrients, the uptake of glucose and fatty acids by cells and the metabolic combustion of fatty acids. We hypothesized that in patients with hypogonadism associated with diabetes, its expression and activity are diminished since there is a quantitative and qualitative loss of skeletal muscle function. Twenty-two men with HH and T2DM were compared with 20 eugonadal men with T2DM at baseline. From the HH patients, 12 were treated with testosterone 200mg every 2 weeks injected intramuscularly for 24 weeks, during which their plasma concentrations were maintained in the physiological range. Hyperinsulinemic, euglycemic clamps (HEC) were carried out prior to and after testosterone replacement and fat (abdomen) and muscle (quadriceps) biopsies were carried out prior to and after HEC procedure on each occasion. In the hypogonadal state, the expression and the activity (measured as phoso-T172-AMPK-α) of AMP kinase-α was significantly lower in HH patients than eugonadal diabetics both in adipose tissue and skeletal muscle by 37% and 29%, respectively, for expression and by 22.1% and 28%, respectively for activity. Following testosterone, there was no change in expression but there was a significant increase in AMP kinase activity by 69±31% (from 14.9±2.8 to 22.8±2.2U/ml, p<0.05) in the muscle but not in the adipose tissue. At the end of the treatment and following the hyperinsulinemic euglycemic clamp, there was a significant increase in AMP kinase expression by 41±9% and 46±11% in adipose tissue and muscle, respectively, while there was only a modest increase (NS) in activity in both tissues. Clearly, therefore, testosterone is an important modulator of AMP kinase activity. This effect of testosterone may contribute to the increase in glucose uptake and an improvement in insulin sensitivity since AMP kinase also induces an increase in Akt-2 and GLUT-4 expression.

Disclosure

S. Dhindsa: None. H. Ghanim: None. M. Batra: Speaker's Bureau; Self; Eli Lilly and Company. A. Chaudhuri: Speaker's Bureau; Self; AstraZeneca, Eli Lilly and Company, Boehringer Ingelheim Pharmaceuticals, Inc., Merck & Co., Inc., Novo Nordisk Inc.. S. Abuaysheh: None. P. Dandona: Advisory Panel; Self; AstraZeneca. Consultant; Self; AstraZeneca. Research Support; Self; AstraZeneca.
Gastrin—A Potential Predictor of Glucoregulation in Newly Diagnosed Type 2 Diabetes Patients
Authors: BERKOVIC MAJA CIGROVSKI , MAHECIC DAVORKA HERMAN , BILIC-CURCIC INES
Published: June 2018

Background and Aims: Experimental data demonstrated that activation of GLP-1 and gastrin signaling induces beta cell neogenesis, resulting in a promotion of glucose-induced insulin secretion. In addition, treatment with proton pump inhibitors is associated with greater glycemic control in patients with type 2 diabetes (T2DM), particularly in those on insulin- or GLP-1-based therapy. The aim of this study was to assess gastrin as a potential predictor of beta cell function and glucoregulation in newly diagnosed T2DM patients.

Materials and Methods: In this cross sectional study 190 patients (64 males and 126 females) with new onset T2DM were included. Patients treated with IPPs were excluded. Fasting plasma glucose (FPG), postprandial PG, HbA1c, fasting insulin, pancreatic B cell function (HOMA-B), insulin resistance index (HOMA-IR), fasting c-peptide and gastrin levels were measured at the time of diagnosis.

Results: Baseline HbA1c was 7.53±2.08%, average age of patients was 61.8±10.years and body mass index (BMI) was 31.25±5.73 kg/m2. Parameters of glucoregulation were not significantly correlated with gastrin (all p>0.05), while there was moderate negative correlation with HOMA-B (HbA1c, FPG and PPG; p <0.01 for all) and positive correlation with HOMA-IR (HbA1c, FPG and PPG; p<0.01 for all). Patients with higher baseline measures of glucose regulation had lower HOMA-B and higher HIMA-IR as was expected. There was no association between gastrin and HOMA-B (p>0.05) or HOMA-IR. Furthermore, no association was established between c-peptide, insulin levels and gastrin (p>0.05).

Conclusion: Baseline gastrin levels are not sufficient to have a significant effect on glucoregulation or HOMA-B and HOMA-IR in newly diagnosed T2DM, therefore it could be postulated that further stimulation of gastrin secretion (e.g., with IPPs or GLP-1 based therapy) is needed in order to influence beta cell function and glycemic control.

Disclosure

M. Cigrovski Berkovic: None. D. Herman Mahecic: None. I. Bilic-Curcic: None.
Anti-inflammatory Cholinergic Signals Inhibit Islet Resident Macrophage Responses to ATP in Living Pancreatic Tissue Slices
Authors: WEITZ JONATHAN , DIAZ RAYNER RODRIGUEZ , ALMACA JOANA , MAKHMUTOVA MADINA , CAICEDO ALEJANDRO
Published: June 2018

When stimulated by high glucose concentrations, beta cells release ATP together with insulin. Under these conditions, the ATP concentration in the islet reaches levels that would induce inflammatory responses in other tissues. Yet inflammation does not occur during normal islet physiology. We therefore postulated that there is a local anti-inflammatory circuit that prevents pathological immune responses. Our studies focused on resident macrophages, which are the local immune cells in the pancreatic islet. We recently showed that islet macrophages detect ATP to gauge the level of beta cell activation. We hypothesized that the potentially inflammatory responses to ATP are inhibited in macrophages by cholinergic input from parasympathetic nerves, as reported for other organs. Using immunohistochemistry, we found that most islet resident macrophages were indeed contacted by local cholinergic nerves, with an innervation density that was equivalent to that of beta cells. To study the impact of local cholinergic nerves on resident macrophages, we used living tissue pancreatic slices, where activity of islet cells, nerves, and macrophages can be visualized in a preserved local microenvironment. We determined that Ca2+ responses to ATP were inhibited in islet macrophages by nicotine, an agonist of nicotinic acetylcholine receptors. These results indicate that macrophages receive cholinergic input from parasympathetic nerves. We expect our studies to identify parasympathetic nerves as a source of anti-inflammatory signals that efficiently dampen the potentially pro-inflammatory environment in the islet.

Disclosure

J. Weitz: None. R. Rodriguez Diaz: None. J. Almaca: None. M. Makhmutova: None. A. Caicedo: None.
Association Between Body Fat Mass and Plasma Insulin Level in the Male Patients with Idiopathic Hypogonadotropic Hypogonadism and Normal Glucose Tolerance
Authors: YANG XUBIN , LIN QIONGYAN , HU XILING , XU WEN , DENG HONG R.
Published: June 2018

Male patients with idiopathic hypogonadotropic hypogonadism (IHH) characterized with low serum testosterone(T) might have higher risks of diabetes and coronary heart disease partly due to the high level of plasma insulin. Low serum T might also affect the body fat mass(BFM) in patients with IHH. However, the relationship between BFM and plasma insulin level in IHH patients has not been clearly clarified.

A total of 22 patients who were admitted to our hospital with IHH and normal glucose tolerance(NGT) confirmed by oral glucose tolerance test and 10 healthy subjects as controls were enrolled into our study. Glucose, insulin, serum T levels, HOMA-IR, HOMA-B and percentage of BFM were determined.

When compared with controls subjects, patients with IHH had significantly lower T concentrations(1.80nmol/L vs. 19.82nmol/L, P<0.001), whereas they had significantly higher BFM(31.38% vs.21.11%, P=0.004), fasting insulin level (15.86 mu/L vs. 7.65 mu/L, P=0.018), HOMA-B(293.19 vs. 120.26, P=0.016) and HOMA-IR(3.18 vs. 1.64, P=0.018). Pearson correlation revealed that BFM was correlated with fasting insulin level(r=0.63, P=0.002), HOMA-B(r=0.53, P=0.014) and HOMA-IR(r=0.47, P=0.031). Multiple linear regression revealed BFM was an independent factor of fasting insulin level(B=0.57, 95% CI:0.24∼0.90, P=0.002), HOMA-B(B=0.096, 95% CI:0.01∼0.18, P=0.030) and HOMA-IR(B=17.09, 95% CI:3.81∼30.37, P=0.014).

BFM was an independent factor of plasma insulin level in IHH patients with NGT.

Disclosure

X. Yang: None. Q. Lin: None. X. Hu: None. W. Xu: None. H.R. Deng: None.
Effects of Epinephrine on Atherothrombotic Responses and In Vivo Endothelial Function in Healthy Humans
Authors: MIKELADZE MAIA , HEDRINGTON MAKA , DUMBADZE SOFIO , BRISCOE VANESSA J. , TATE DONNA , THAYER EVAN , DAVIS STEPHEN
Published: June 2018

In this study we have tested the hypothesis that levels of epinephrine simulating those occurring during hypoglycemia of 70, 60, or 50 mg/dl will result in pro-coagulant and pro-atherothrombotic responses and endothelial dysfunction.

32 healthy humans (16M/16F) participated in 4 separate, single blind, randomized, 1-day studies: Placebo (Protoco1 1) and epinephrine infusions of 0.015, 0.03 and 0.06µg/kg/min (Protocols 2-4) respectively. Studies consisted of 2-hour hyperinsulinemic (133±7µU/ml) euglycemic clamps of 92±1mg/dl. 2D Doppler imaging determined flow mediated dilation (FMD) of the brachial artery.

Increases of IL-6, P-selectin, E-selectin, ICAM-1, and VCAM-1 were higher and reductions in FMD and ET-1 greater during all epinephrine infusions compared to Placebo (p<0.05). (Table 1)Table 1. Changes from baseline to final 30 minProtocol 1Protocol 2Protocol3Protocol 4Δ IL-6 (pg/ml)-3.0±1.22.8±2.9*3.6±2.7*8.1±2.9*Δ P-selectin (pg/ml)-13.7±6.51.3±0.8*2.0±2.0*5.6±1.8*Δ ICAM-1 (ng/ml)-18.7±12.324.1±13.3*65.5±36.9*114.3±69.6*Δ ET-1 (pg/ml)-0.2±0.05-0.4±0.05*-0.5±0.12*-0.6±0.09*Δ FMD (mean maximum%)0.8±0.7-2.0±0.5*-2.6±0.6*-3.7±0.7*Δ Epinephrine (pg/ml)18±2299±38*532±41*1011±12*Mean±SEM * p<0.0007-0.compared to Protocol 1

Epinephrine activated pro-coagulant, inflammatory and pro-atherothrombotic mechanisms while impairing endogenous and exogenous nitric oxide mediated endothelial function.

In conclusion, during hyperinsulinemic euglycemia, epinephrine levels simulating those occurring during hypo of only 70mg/dl produced significant inflammatory effects. Increasing doses of epinephrine resulted in greater inflammatory responses and in-vivo endothelial dysfunction (p<0.001). Epinephrine may be an important mechanism responsible for adverse vascular biologic effects during hypo in healthy humans.

Disclosure

M. Mikeladze: None. M. Hedrington: None. S. Dumbadze: None. V.J. Briscoe: None. D. Tate: None. E. Thayer: None. S. Davis: None.
Anorexic Peptide Nesfatin-1 Exerts Vasoprotective Effects in Injured Arteries of Mice
Authors: MORI YUSAKU , SHIMIZU HIROYUKI , KUSHIMA HIDEKI , TERASAKI MICHISHIGE , HIROMURA MUNENORI , KOSHIBU MASAKAZU , KOHASHI KYOKO , HIRANO TSUTOMU
Published: June 2018

Background: Nesfatin-1 (Nes), an anorexic peptide hormone, has recently gained attention as a potential therapeutic target for obesity and its related metabolic abnormalities, including type 2 diabetes. Recently direct cardioprotective effects of Nes have demonstrated; however, its vasopressor effects at very high dose are also reported, which potentially limit its clinical application. Here, we evaluated vascular actions of Nes in vivo and in vitro.

Methods: Male C57BL/6 and nucleobindin-2, a precursor of Nes, transgenic (NUCB-Tg) mice (9 w) were employed. C57BL6 mice were randomly assigned to treatment with vehicle (control) or Nes at the low or high doses (Nes-L, 0.2 mg/kg/d; Nes-H, 2 mg/kg/d). Subsequently, the mice were subjected to femoral artery wire injury to induce arterial remodeling.

Results: In the Nes-H group, food intake was decreased compared to that in the controls by 10% (p<0.05) without affecting blood pressure (BP) and plasma glucose and lipid levels. Furthermore, Nes-H reduced neointimal hyperplasia in injured arteries by 30% (p<0.05). In contrast, Nes-L did not affect any metabolic or vascular parameters including food intake. In NUCB-Tg mice, BP was slightly elevated, but neointimal area was lower than that observed in littermate controls (50% reduction, p<0.05). Additionally, associated reductions in vascular cell proliferation were observed (r=0.46, p<0.05). In in vitro studies using human umbilical vein endothelial cells, Nes treatment (1-100 nmol/L) dose-dependently increased nitric oxide (NO) production and AMP-activated protein kinase (AMPK) phosphorylation by 1.5- to 3-fold (p<0.05). In contrast, Nes treatment did not directly suppress proliferation of human aortic smooth muscle cells.

Conclusions: We demonstrated that Nes at the dose exerting anorexic, but not vasopressor effects, suppresses arterial remodeling in injured arteries of mice, possibly through the activation of AMPK and enhancement of NO production in vascular endothelial cells.

Disclosure

Y. Mori: None. H. Shimizu: Speaker's Bureau; Self; Eli Lilly and Company, MSD K.K., Daiichi Sankyo Company, Limited, Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk Inc.. H. Kushima: None. M. Terasaki: None. M. Hiromura: None. M. Koshibu: None. K. Kohashi: None. T. Hirano: Speaker's Bureau; Self; Novo Nordisk Inc., AstraZeneca.
ILDR2 Alters Hepatic Phospholipid Composition via MBOAT7—Effects on Liver Fat
Authors: WATANABE KAZUHISA , NAKAYAMA KAZUHIRO , YOSHIDA KEN , MILLINGS ELIZABETH J. , LEDUC CHARLES A. , LEIBEL RUDOLPH , IWAMOTO SADAHIKO
Published: June 2018

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes, and increases the risk for liver cirrhosis and cancer. A diabetes susceptibility gene, ILDR2, encodes a transmembrane protein localized to the ER membrane whose primary physiological functions are unclear. We previously purified ILDR2-containing protein complexes using the tandem affinity purification tags and identified MBOAT7, which mediates acyl-chain remodeling of phosphatidylinositols (PIs). The MBOAT7 variant rs641738 T allele is associated with decreased hepatic PI (36:4) and PI (38:3) and an increase in severity of NAFLD. We hypothesized that ILDR2 may influence hepatic Pl composition in NAFLD. We used two mouse models fed a methionine- and choline-deficient (MCD) diet: 1. liver-specific ILDR2 knockout (LKO-ILDR2) using an AAV-Cre/loxP system; and 2. AAV-overexpressing ILDR2 (OX-ILDR2) mice.

In LKO-ILDR2 mice compared to AAV-GFP injected ILDR2 floxed (GFP-flox) mice, liver triglyceride (TG) content was significantly increased by 1.6-fold with a significant 1.2-fold increase in plasma TG. In LKO-ILDR2 mice compared to GFP-flox mice, hepatic PI (38:4) was significantly decreased. The livers of LKO-ILDR2 mice showed significantly increased JNK activation, collagen gene expression, and increased in hydroxyproline, suggesting that ILDR2 depletion leads to inflammation and the development of fibrosis. In OX-ILDR2 mice compared to AAV-GFP injected WT (GFP-WT) mice, hepatic PI and PC species were significantly increased. The liver in OX-ILDR2 mice showed decreased expression of JNK and ER stress-related genes, and hydroxyproline, with a slight (9%) decrease in hepatic TG compared to GFP-WT mice. Thus, ILDR2 overexpression attenuated hepatic inflammation, ER stress, and fibrogenesis.

Manipulation of hepatic ILDR2 expression is associated with changes in PI and PC molecular species in the liver. Patterns of hepatic phosphatidyl fatty acid composition are associated with NAFLD development.

Disclosure

K. Watanabe: None. K. Nakayama: None. K. Yoshida: None. E.J. Millings: None. C.A. LeDuc: None. R. Leibel: None. S. Iwamoto: None.
The Role of a Glucagon-Like Peptide-1 Receptor Agonist in Visceral and Subcutaneous Fat Redistribution
Authors: ZHAO LI , ZHU CHUNFANG , LU MENG , CHEN CHI , CHEN YI , WANG NINGJIAN , LU YINGLI
Published: June 2018

Glucagon-like peptide-1 receptor agonists (GLP-1RA) are an ideal therapy for type 2 diabetes and recently, for obesity. In contrast to visceral fat, subcutaneous fat accumulation appears to be protective against metabolic syndrome. Here, we reported that liraglutide, a GLP-1RA redistributed visceral and subcutaneous fat via the tissue-specific modulation of lipid metabolism and stimulation of subcutaneous white adipose tissue (WAT) browning. We showed that liraglutide decreased visceral fat and relatively increased subcutaneous fat. Lipogenesis was reduced in visceral WAT but elevated in subcutaneous WAT treated with liraglutide. Lipolysis was also attenuated, and fatty acid oxidation was enhanced. The mRNA expression levels of adipose-related genes displayed similar trends. Liraglutide down-regulated the expression levels of lipogenesis- and lipolysis-related genes but up-regulated the expression levels of β-oxidation-related genes in visceral WAT. In subcutaneous WAT, the expression levels of lipogenesis-related genes were up-regulated in both inguinal and cluneal WAT. However, the lipolysis-related gene expressed higher in inguinal WAT but lower in cluneal WAT, while the β-oxidation-related gene expressed lower in inguinal WAT but higher in cluneal WAT after liraglutide treatment. In addition, the uncoupling protein-1 was up-regulated in subcutaneous WAT. Thus, liraglutide potentially redistributes body fat and promotes browning remodeling in subcutaneous WAT to improve metabolic disorders.

Disclosure

L. Zhao: None. C. Zhu: None. M. Lu: None. C. Chen: None. Y. Chen: None. N. Wang: None. Y. Lu: None.
ICA6150349, a Highly Selective Glucagon Agonist, in Combination with Exenatide Significantly Reduces Weight and Glucose in Obese and Diabetic Rats
Authors: PAULIK MARK , TLUSTY TOM , GRIZZLE MARY K. , COPELAND MARCI , WENG SHARON , BLACKWELL WILLIAM C. , SRIVASTAVA VED , WAY JAMES , ROLLER SHANE , ZANE DORIS , HODGE REBECCA , YOUNG ANDREW A. , FELDMAN PAUL L.
Published: June 2018

ICA6150349, a 38-amino acid analog of glucagon, is peptidase resistant and highly selective for the glucagon receptor. ICA6150349 continuously infused SC at 50 mcg/kg/d (ED50) in DIO LE rats reduced weight (21%), fat mass (37%), and food intake (17%) and normalized triglycerides and cholesterol to lean control levels. ICA6150349 (50 mcg/kg/d) in combination with exenatide (10 mcg/kg/d) further reduced weight (38%), fat mass (70%), and food intake (52%) and also normalized glucose and lipids to lean control levels. ICA6150349 continuously infused at 50 mcg/kg/d in ZDF rats increased HbA1c (1.3%), reduced weight (29%), fat mass (42%), and food intake (13%) and normalized triglycerides (66%) and cholesterol (38%) to lean control levels. ICA6150349 (50 mcg/kg/d) in combination with exenatide (10 mcg/kg/d) decreased HbA1c (1.5%), off-setting the increase seen with ICA6150349 monotherapy. The ICA6150349 and exenatide combination reduced weight (19%), fat mass (25%), food intake (29%) cholesterol (27%) and triglycerides (41%). In rodent models of obesity/T2D, ICA6150349 in combination with exenatide can significantly reduce weight, fat mass, glucose and lipids, sometimes normalizing these parameters to lean control levels.

Disclosure

M. Paulik: Employee; Self; Intarcia Therapeutics, Inc.. T. Tlusty: None. M.K. Grizzle: None. M. Copeland: None. S. Weng: None. W.C. Blackwell: Employee; Self; Intarcia Therapeutics, Inc. V. Srivastava: Employee; Self; Intarcia Therapeutics, Inc. J. Way: Employee; Self; Intarcia Therapeutics, Inc. S. Roller: Employee; Self; Intarcia Therapeutics, Inc.. D. Zane: None. R. Hodge: Employee; Self; Intarcia Therapeutics, Inc.. Stock/Shareholder; Self; Intarcia Therapeutics, Inc. A.A. Young: Employee; Self; Intarcia Therapeutics, Inc.. Stock/Shareholder; Self; GlaxoSmithKline plc. P.L. Feldman: Employee; Self; Intarcia Therapeutics, Inc..
Obesity-Associated Family with Sequence Similarity 13 Member A Gene Regulates Adipocyte Differentiation
Authors: TANG JIAZHEN , ZHOU HONGYI , YANG JING , CHEN WEIQIN
Published: June 2018

Obesity and its associated morbidities represent the major and most rapidly expanding health epidemic in the world. Recent genome-wide association studies (GWAS) have identified single nucleotide polymorphism (SNP) variants in Family with Sequence Similarity 13, Member A (FAM13A) gene to be highly associated with waist-hip ratio (WHR) with adjustment for body mass index (BMI) (WHRadjBMI). However, the exact function of this gene in adipose tissue development and obesity remains largely uncharacterized. We for the first time identified Fam13A as an adipose tissue abundant gene whose expression was highly regulated by fasting/refeed and dramatically reduced in epididymal and subcutaneous fat depots in murine models of genetic obesity and diet-induced obesity (DIO). Its expression was enriched in mature adipocytes and significantly upregulated during murine and human adipogenesis potentially through a PPARγ-dependent mechanism. However, FAM13A-/- mice only exhibited a tendency of higher adiposity and maintained normal glucose clearance and insulin resistance. They are also not protected from high fat diet-induced obesity and metabolic perturbation. The dispensable role of FAM13A was further supported by normal adipogenesis in FAM13A-/- Stromal vascular cells (SVCs). Interestingly, overexpression of FAM13A in 3T3-L1 preadipocytes downregulated beta-catenin expression, impaired preadipocyte survival and enhanced its susceptibility to serum starvation-induced apoptosis. Furthermore, FAM13A-overexpressing preadipocytes failed to differentiate into mature adipocytes through interfering early-stage C/EBPα/PPARγ-mediated adipogenesis. These data for the first time reveal new details of an obesity-associated FAM13A gene in mediating beta-catenin action and adipocyte differentiation, providing novel insight into a relationship between FAM13a and adipose biology.

Disclosure

J. Tang: None. H. Zhou: None. J. Yang: None. W. Chen: None.
Self-Assembled Hyaluronic Acid Nanoparticles Ameliorate Adipose Tissue Inflammation and Insulin Resistance in Diet-Induced Obese Mice
Authors: RHO JUN GI , LEE WANGHEE , LEE EUNYOUNG , KIM CHONGTAE , LEE EUN KYUNG , KIM WOOK
Published: June 2018

Self-assembled hyaluronic acid nanoparticles (HA-NPs), consisting of hydrophobic cores surrounded by a hydrophilic HA shell, have been extensively investigated for biomedical and pharmaceutical applications because of their biocompatibility and receptor-binding properties. Here, we report that an empty HA-NP itself not bearing any drug has therapeutic effects on adipose tissue inflammation and insulin resistance. HA-NPs inhibit not only the receptor-mediated internalization of low-molecular-weight (LMW) free HA but also LMW free HA-induced pro-inflammatory gene expression in mouse primary bone marrow-derived macrophages (BMDMs) isolated from wild type mice. Following systemic administration of Cy5.5-labeled HA-NPs, in vivo biodistribution assay and immunofluorescent staining indicate the distribution of HA-NPs and their co-localization with CD44 in adipose tissues including epididymal white adipose tissue (eWAT). However, these effects are largely reduced or rarely observed in BMDMs isolated from CD44-deficient mice. In addition, diet-induced obese (DIO) mice fed a high-fat diet (HFD) show elevated CD44 expression and HA-NP accumulation in eWAT compared to mice on standard diet. Treatment with HA-NPs in HFD-fed DIO mice suppresses macrophage infiltration into adipose tissue and adipose tissue inflammation, leading to improved insulin sensitivity and glycemic control. It is revealed that HA-NP itself can be a therapeutic agent for the treatment of type 2 diabetes.

Disclosure

J. Rho: None. W. Lee: None. E. Lee: None. C. Kim: None. E. Lee: None. W. Kim: None.