Metformin improves in vivo and in vitro B cell function in individuals with obesity and Type-2 Diabetes.
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SUBMITTER: Diaz A
PROVIDER: S-EPMC5560851 | biostudies-other | 2017 May
REPOSITORIES: biostudies-other
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Project description:Reduced coronary flow reserve (CFR), an indicator of coronary microvascular dysfunction, is seen in type 2 diabetes mellitus (T2DM) and predicts cardiac mortality. Since aldosterone plays a key role in vascular injury, the aim of this study was to determine whether mineralocorticoid receptor (MR) blockade improves CFR in individuals with T2DM. Sixty-four men and women with well-controlled diabetes on chronic ACE inhibition (enalapril 20 mg/day) were randomized to add-on therapy of spironolactone 25 mg, hydrochlorothiazide (HCTZ) 12.5 mg, or placebo for 6 months. CFR was assessed by cardiac positron emission tomography at baseline and at the end of treatment. There were significant and similar decreases in systolic blood pressure with spironolactone and HCTZ but not with placebo. CFR improved with treatment in the spironolactone group as compared with the HCTZ group and with the combined HCTZ and placebo groups. The increase in CFR with spironolactone remained significant after controlling for baseline CFR, change in BMI, race, and statin use. Treatment with spironolactone improved coronary microvascular function, raising the possibility that MR blockade could have beneficial effects in preventing cardiovascular disease in patients with T2DM.
| S-EPMC4274801 | biostudies-literature
Project description:BACKGROUND:Deteriorated arterial function and high incidence of cardiovascular events characterise diabetes mellitus. Metformin and recent antidiabetic drugs, SGLT2 inhibitors, reduce cardiovascular events. We explored the possible effects of empagliflozin's effect on top of metformin treatment on endothelial function and arterial stiffness parameters in type 1 diabetes mellitus (T1DM) patients. METHODS:Forty T1DM patients were randomised into three treatment groups: (1) empagliflozin (25 mg daily), (2) metformin (2000 mg daily) and (3) empagliflozin/metformin (25 mg daily and 2000 mg daily, respectively). The fourth group received placebo. Arterial function was assessed at inclusion and after 12 weeks treatment by: endothelial function [brachial artery flow-mediated dilation (FMD), reactive hyperaemia index (RHI)], arterial stiffness [pulse wave velocity (PWV) and common carotid artery stiffness (?-stiffness)]. For statistical analysis one-way analysis of variance with Bonferroni post-test was used. RESULTS:Empagliflozin on top of metformin treatment significantly improved endothelial function as did metformin after 12 weeks of treatment: FMD [2.6-fold (P?<?0.001) vs. 1.8-fold (P?<?0.05)] and RHI [1.4-fold (P?<?0.01) vs. 1.3-fold (P?<?0.05)]. Empagliflozin on top of metformin treatment was superior to metformin in improving arterial stiffness parameters; it significantly improved PWV and ?-stiffness compared to metformin [by 15.8% (P?<?0.01) and by 36.6% (P?<?0.05), respectively]. Metformin alone did not influence arterial stiffness. CONCLUSION:Empagliflozin on top of metformin treatment significantly improved arterial stiffness compared to metformin in T1DM patients. Endothelial function was similarly improved in all treatment groups. Empagliflozin seems to possess a specific capacity to decrease arterial stiffness, which could support its cardioprotective effects observed in large clinical studies. Trial registration Clinical trial registration: NCT03639545.
| S-EPMC6276165 | biostudies-literature
Project description:ContextType 1 diabetes in adolescence is characterized by insulin deficiency and insulin resistance (IR), both thought to increase cardiovascular disease risk. We previously demonstrated that adolescents with type 1 diabetes have adipose, hepatic, and muscle IR, and that metformin lowers daily insulin dose, suggesting improved IR. However, whether metformin improves IR in muscle, hepatic, or adipose tissues in type 1 diabetes was unknown.ObjectiveMeasure peripheral, hepatic, and adipose insulin sensitivity before and after metformin or placebo therapy in youth with obesity with type 1 diabetes.DesignDouble-blind, placebo-controlled clinical trial.SettingMulti-center at eight sites of the T1D Exchange Clinic Network.ParticipantsA subset of 12- to 19-year-olds with type 1 diabetes (inclusion criteria: body mass index ≥85th percentile, HbA1c 7.5% to 9.9%, insulin dosing ≥0.8 U/kg/d) from a larger trial (NCT02045290) were enrolled.InterventionParticipants were randomized to 3 months of metformin (N = 19) or placebo (N = 18) and underwent a three-phase hyperinsulinemic euglycemic clamp with glucose and glycerol isotope tracers to assess tissue-specific IR before and after treatment.Main outcome measuresPeripheral insulin sensitivity, endogenous glucose release, rate of lipolysis.ResultsBetween-group differences in change in insulin sensitivity favored metformin regarding whole-body IR [change in glucose infusion rate 1.3 (0.1, 2.4) mg/kg/min, P = 0.03] and peripheral IR [change in metabolic clearance rate 0.923 (-0.002, 1.867) dL/kg/min, P = 0.05]. Metformin did not impact insulin suppression of endogenous glucose release (P = 0.12). Adipose IR was not assessable with traditional methods in this highly IR population.ConclusionsMetformin appears to improve whole-body and peripheral IR in youth who are overweight/obese with type 1 diabetes.
| S-EPMC6584133 | biostudies-literature
Project description:Purpose:Patients with type 1 diabetes (T1D) are associated with a high risk of multiple complications, so the development of T1D treatment is urgently needed. This study was set out to explore the molecular mechanism of metformin in the treatment of T1D insulin resistance. Patients and Methods:Subcutaneous adipose tissues were collected from 68 T1D patients and 51 healthy controls. Insulin resistance model rats and cells were constructed and treated with metformin respectively. Western blot was used to detect p53 and RAP2A protein levels, and qPCR was utilized to measure p53 and RAP2A mRNA levels. SiRNA and RAP2A siRNA vectors were constructed to observe their effects on insulin resistance model cells. Results:In T1D, p53 was up-regulated, while RAP2A was down-regulated. Metformin could effectively improve insulin resistance and inflammatory response while down-regulating p53 and up-regulating RAP2A. P53 induced insulin resistance and inflammatory response by inhibiting RAP2A and promoted apoptosis. Conclusion:Metformin improves T1D insulin resistance and inflammatory response through p53/RAP2A pathway, and the regulation of p53/RAP2A pathway is conducive to improving the efficacy of metformin in the treatment of insulin resistance.
| S-EPMC7306576 | biostudies-literature
Project description:ContextType 2 diabetes (T2D) has features of disordered lipid and glucose metabolism, due in part to reduced mitochondrial content.ObjectiveOur objective was to investigate effects of different types of exercise on mitochondrial content and substrate oxidation in individuals with T2D (ancillary study of the randomized controlled trial Health Benefits of Aerobic and Resistance Training in Individuals with Type 2 Diabetes, HART-D).InterventionT2D individuals were randomized to aerobic training (AT, n = 12), resistance training (RT, n = 18), combination training (ATRT, n = 12), or nonexercise control (n = 10). Blood draws, peak oxygen consumption tests, dual-energy x-ray absorptiometry scans and muscle biopsies of vastus lateralis were performed before and after 9 months. Ex vivo substrate oxidations ((14)CO2), mitochondrial content, and enzyme activities were measured. Glycated hemoglobin A1c and free fatty acids were also determined.ResultsMitochondrial content increased after RT and ATRT. Octanoate oxidation increased after AT and ATRT, whereas palmitate, pyruvate, and acetate oxidations increased in all exercise groups. Exercise-induced responses in mitochondrial DNA were associated with improvements in peak oxygen consumption, β-hydroxyacyl-coenzyme A dehydrogenase activity, and palmitate oxidation.ConclusionsNine months of AT and RT significantly improved most aspects of skeletal muscle mitochondrial content and substrate oxidation, whereas the combination improved all aspects. These exercise responses were associated with clinical improvements, indicating that long-term training, especially combination, is an effective lifestyle therapy for individuals with T2D by way of improving muscle substrate metabolism.
| S-EPMC3615199 | biostudies-literature
Project description:ObjectiveAcylated ghrelin (AG) is a diabetogenic and orexigenic gastric polypeptide. These properties are not shared by the most abundant circulating form, which is unacylated (UAG). An altered UAG/AG profile together with an impairment of circulating endothelial progenitor cell (EPC) bioavailability were found in diabetes. Based on previous evidence for the beneficial cardiovascular effects of AG and UAG, we investigated their potential to revert diabetes-associated defects.Research design and methodsHealthy human subjects, individuals with type 2 diabetes, and ob/ob mice were AG or UAG infused. EPC mobilization in patients and mice was evaluated, and the underlying molecular mechanisms were investigated in bone marrow stromal cells. Recovered EPCs were also evaluated for the activity of senescence regulatory pathways and for NADPH oxidase activation by knocking down p47(phox) and Rac1. Finally, UAG modulation of human EPC vasculogenic potential was investigated in an in vivo mouse model.ResultsNeither AG nor UAG had any effect in healthy subjects. However, systemic administration of UAG, but not AG, prevented diabetes-induced EPC damage by modulating the NADPH oxidase regulatory protein Rac1 and improved the vasculogenic potential both in individuals with type 2 diabetes and in ob/ob mice. In addition, unlike AG, UAG facilitated the recovery of bone marrow EPC mobilization. Crucial to EPC mobilization by UAG was the rescue of endothelial NO synthase (eNOS) phosphorylation by Akt, as UAG treatment was ineffective in eNOS knockout mice. Consistently, EPCs expressed specific UAG-binding sites, not recognized by AG.ConclusionsThese data provide the rationale for clinical applications of UAG in pathologic settings where AG fails.
| S-EPMC2844809 | biostudies-literature
Project description:BackgroundCardiovascular disease is the leading cause of mortality in type 1 diabetes mellitus (T1DM) and relates strongly to insulin resistance (IR). Lean and obese adolescents with T1DM have marked IR. Metformin improves surrogate markers of IR in T1DM, but its effect on directly measured IR and vascular health in youth with T1DM is unclear. We hypothesized that adolescents with T1DM have impaired vascular function and that metformin improves this IR and vascular dysfunction.MethodsAdolescents with T1DM and control participants underwent magnetic resonance imaging of the ascending (AA) and descending aorta to assess pulse wave velocity, relative area change, and maximal (WSSMAX) and time-averaged (WSSTA) wall shear stress. Participants with T1DM also underwent assessment of carotid intima-media thickness by ultrasound, brachial distensibility by DynaPulse, fat and lean mass by dual-energy x-ray absorptiometry, fasting laboratories after overnight glycemic control, and insulin sensitivity by hyperinsulinemic-euglycemic clamp (glucose infusion rate/insulin). Adolescents with T1DM were randomized 1:1 to 3 months of 2000 mg metformin or placebo daily, after which baseline measures were repeated.ResultsForty-eight adolescents with T1DM who were 12 to 21 years of age (40% body mass index [BMI] ≥90th percentile; 56% female) and 24 nondiabetic control participants of similar age, BMI, and sex distribution were enrolled. Adolescents with T1DM demonstrated impaired aortic health compared with control participants, including elevated AA and descending aorta pulse wave velocity, reduced AA and descending aorta relative area change, and elevated AA and descending aorta WSSMAX and WSSTA. Adolescents with T1DM in the metformin versus placebo group had improved glucose infusion rate/insulin (12.2±3.2 [mg·kg-1·min-1]/μIU/μL versus -2.4±3.6 [mg·kg-1·min-1]/μIU/μL, P=0.005; 18.6±4.8 [mg·lean kg-1·min-1]/μIU/μL versus -3.4±5.6 [mg·lean kg-1·min-1]/μIU/μL, P=0.005) and reduced weight (-0.5±0.5 kg versus 1.6±0.5 kg; P=0.004), BMI (-0.2±0.15 kg/m2 versus 0.4±0.15 kg/m2; P=0.005), and fat mass (-0.7±0.3 kg versus 0.6±0.4 kg; P=0.01). Glucose infusion rate/insulin also improved in normal-weight participants (11.8±4.4 [mg·kg-1·min-1]/μIU/μL versus -4.5±4.4 [mg·kg-1·min-1]/μIU/μL, P=0.02; 17.6±6.7 [mg·lean kg-1·min-1]/μIU/μL versus -7.0±6.7 [mg·lean kg-1·min-1]/μIU/μL, P=0.02). The metformin group had reduced AA WSSMAX (-0.3±0.4 dyne/cm2 versus 1.5±0.5 dyne/cm2; P=0.03), AA pulse wave velocity (-1.1±1.20 m/s versus 4.1±1.6 m/s; P=0.04), and far-wall diastolic carotid intima-media thickness (-0.04±0.01 mm versus -0.00±0.01 mm; P=0.049) versus placebo.ConclusionsAdolescents with T1DM demonstrate IR and impaired vascular health compared with control participants. Metformin improves IR, regardless of baseline BMI, and BMI, weight, fat mass, insulin dose, and aortic and carotid health in adolescents with T1DM. Metformin may hold promise as a cardioprotective intervention in T1DM.Clinical trial registrationURL: https://www.clinicaltrials.gov . Unique identifier: NCT01808690.
| S-EPMC6428045 | biostudies-literature
Project description:Background and objectivesIn ADOPT (A Diabetes Outcomes Prevention Trial), initial monotherapy with rosiglitazone provided more durable glycemic control than metformin or glyburide in patients with recently diagnosed type 2 diabetes. Herein, we examine differences in albumin excretion, renal function (estimated GFR), and BP over 5 years between treatment groups.Design, setting, participants, & measurementsA total of 4351 recently diagnosed, drug-naïve patients with type 2 diabetes were treated and followed for up to 5 years with rosiglitazone, metformin, or glyburide and were examined with periodic assessments of albumin/creatinine ratio (ACR), modification of diet in renal disease (MDRD)-estimated GFR, and BP.ResultsThe ACR rose slowly with metformin. It fell with rosiglitazone and less so with glyburide over the first 2 years, and then rose slowly over time. Estimated GFR (eGFR) with all therapies rose into the high normal range over the first 3 to 4 years, more so with rosiglitazone, and then declined, more so with glyburide. Systolic BP was stable over time, values with rosiglitazone being lower, and diastolic BP declined over time, more so with rosiglitazone than with metformin or glyburide. There was no difference among groups in the incidence of emergent albuminuria (ACR ≥30 mg/g), hypertension, or impaired eGFR (<60 ml/min per 1.73 m(2)).ConclusionsOver a 5-year period, initial monotherapy with rosiglitazone retards the rise of ACR compared with metformin, preserves eGFR compared with glyburide, and lowers BP relative to both comparators.
| S-EPMC3087768 | biostudies-literature
Project description:Type 2 diabetes (T2D) is a chronic, multifactorial, and metabolic disorder accounting for 90% diabetes cases worldwide. Among them, almost half of T2D have hypertension, which is responsible for cardiovascular disease, morbidity, and mortality in these patients. The Chinese herbal medicine (CHM) prescription patterns of hypertension individuals among T2D patients have yet to be characterized. This study, therefore, aimed to determine their prescription patterns and evaluate the CHM effect. A cohort of one million randomly sampled cases from the National Health Insurance Research Database (NHIRD) was used to investigate the overall survival rate of CHM users, and prescription patterns. After matching CHM and non-CHM users for age, gender and date of diagnosis of hypertension, 980 subjects for each group were selected. The CHM users were characterized with slightly longer duration time from diabetes to hypertension, and more cases for hyperlipidaemia. The cumulative survival probabilities were higher in CHM users than in non-CHM users. Among these top 12 herbs, Liu-Wei-Di-Huang-Wan, Jia-Wei-Xiao-Yao-San, Dan-Shen, and Ge-Gen were the most common herbs and inhibited in vitro smooth muscle cell contractility. Our study also provides a CHM comprehensive list that may be useful in future investigation of the safety and efficacy for individuals with hypertension among type 2 diabetes patients.
| S-EPMC4689379 | biostudies-literature
Project description:BACKGROUND:Exercise is recommended as a cornerstone of treatment for type 2 diabetes mellitus (T2DM), however, it is often poorly adopted by patients. Even in the absence of apparent cardiovascular disease, persons with T2DM have an impaired ability to carry out maximal and submaximal exercise and these impairments are correlated with cardiac and endothelial dysfunction. Glucagon-like pepetide-1 (GLP-1) augments endothelial and cardiac function in T2DM. We hypothesized that administration of a GLP-1 agonist (exenatide) would improve exercise capacity in T2DM. METHODS AND RESULTS:Twenty-three participants (64±4years; mean±SE) with uncomplicated T2DM were randomized in a double-blinded manner to receive either 10?g BID of exenatide or matching placebo after baseline measurements. Treatment with exenatide did not improve VO2peak (P=0.1464) or VO2 kinetics (P=0.2775). Diastolic function, assessed via resting lateral E:E', was improved with administration of exenatide compared with placebo (Placebo Pre: 7.6±1.0 vs. Post: 8.4±1.2 vs. Exenatide Pre: 8.1±0.7 vs. Post: 6.7±0.6; P=0.0127). Additionally, arterial stiffness measured by pulse wave velocity, was reduced with exenatide treatment compared with placebo (Placebo Pre: 10.5±0.8 vs. Post: 11.5±1.1s vs. Exenatide Pre: 11.4±1.8 vs. Post: 10.2±1.4s; P=0.0373). Exenatide treatment did not improve endothelial function (P=0.1793). CONCLUSIONS:Administration of exenatide improved cardiac function and reduced arterial stiffness, however, these changes were not accompanied by improved functional exercise capacity. In order to realize the benefits of this drug on exercise capacity, combining exenatide with aerobic exercise training in participants with T2DM may be warranted.
| S-EPMC5787373 | biostudies-literature