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2.
Diabetes Obes Metab ; 26(3): 851-859, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38082473

ABSTRACT

AIM: To assess the efficacy and safety of iGlarLixi in older people (≥65 years) with type 2 diabetes (T2D) advancing or switching from oral agents, a glucagon-like peptide-1 receptor agonist (GLP-1RA), or basal insulin. MATERIALS AND METHODS: The data of participants aged <65 years and ≥65 years from four LixiLan trials (LixiLan-O, LixiLan-G, LixiLan-L, SoliMix) were evaluated over 26 or 30 weeks. RESULTS: Participants aged <65/≥65 years (n = 1039/n = 497) had a mean baseline body mass index of 31.4 and 30.7 kg/m2 and glycated haemoglobin (HbA1c) concentration of 66 mmol/mol (8.2%) and 65 mmol/mol (8.1%), respectively. Least squares mean HbA1c change from baseline to end of treatment (EOT) was -14.32 mmol/mol (-1.31%) (95% confidence interval [CI] -14.97, -13.77 [-1.37%, -1.26%]) for those aged <65 years and -13.66 mmol/mol (-1.25%) (95% CI -14.54, -12.79 [-1.33%, -1.17%]) for those aged ≥65 years. At EOT, achievement of HbA1c targets was similar between the group aged <65 years and the group aged ≥65 years: <53 mmol/mol (<7%) (59.0% and 56.5%, respectively), <59 mmol/mol (<7.5%) (75.5% and 73.0%, respectively) and <64 mmol/mol (<8%) (83.8% and 84.1%, respectively). The incidence and event rate of American Diabetes Association Level 1 hypoglycaemia during the studies were also comparable between the two groups: 26.7% and 28.2% and 1.7 and 2.1 events per patient-year for the group aged <65 years and the group aged ≥65 years, respectively. A clinically relevant reduction in HbA1c (>1% from baseline for HbA1c ≥64 mmol/mol [≥8%] or ≥0.5% from baseline for HbA1c <64 mmol/mol [<8%]) without hypoglycaemia was attained by 50.0% and 47.6% of participants aged <65 years and ≥65 years, respectively. Adverse events were similar between the two age groups. CONCLUSIONS: iGlarLixi is a simple, well-tolerated, once-daily alternative for treatment advancement in older people with T2D that provides significant improvements in glycaemic control without increasing hypoglycaemia risk, thus reducing the treatment burden.


Subject(s)
Diabetes Mellitus, Type 2 , Hypoglycemia , Humans , Aged , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/chemically induced , Hypoglycemic Agents/adverse effects , Insulin Glargine/adverse effects , Glycated Hemoglobin , Blood Glucose , Drug Combinations , Peptides/adverse effects , Randomized Controlled Trials as Topic , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology
3.
Diabetes Obes Metab ; 25(9): 2495-2504, 2023 09.
Article in English | MEDLINE | ID: mdl-37312665

ABSTRACT

AIM: To compare the efficacy and safety of insulin glargine-300 once daily (Gla-300) with insulin degludec/aspart (IDegAsp) once daily in patients with type 2 diabetes (T2D) inadequately controlled on oral anti-diabetic drugs (OADs). MATERIALS AND METHODS: A systematic literature review of randomized controlled trials was followed by an indirect treatment comparison of studies involving insulin naïve adults, inadequately controlled [glycated haemoglobin (HbA1c) ≥7.0%] on OADs, who received Gla-300 or IDegAsp once daily. Outcomes of interest were change in HbA1c, blood glucose, weight and insulin dose, as well as incidence and event rate of hypoglycaemia and other adverse events. RESULTS: Four trials with broadly similar baseline patient characteristics were included in the meta-analyses and indirect treatment comparison. At 24-28 weeks, the indirect comparison of Gla-300 to IDegAsp once daily estimated no statistically significant difference for change in HbA1c (%) from baseline [mean difference of 0.10% (95% CI: -0.20, 0.39; p = .52)]; a statistically significant mean difference of -1.31 kg (95% CI: -1.97, -0.65; p < .05) for change in body weight from baseline; statistically significant odds ratios of 0.62 (95% CI: 0.41, 0.93; p < .05) for incidence of any hypoglycaemia; and 0.47 (95% CI: 0.25, 0.87; p < .05) for incidence of anytime confirmed hypoglycaemia (plasma glucose <3.0-3.1 mmol/L). No significant differences were observed for insulin dose and adverse events. CONCLUSION: In insulin-naïve patients with T2D inadequately controlled on OADs, commencing Gla-300 shows a comparable HbA1c reduction, but with significantly less weight gain and a lower incidence of any and confirmed hypoglycaemia compared with commencing IDegAsp.


Subject(s)
Diabetes Mellitus, Type 2 , Hypoglycemia , Adult , Humans , Insulin/therapeutic use , Insulin Aspart/therapeutic use , Glycated Hemoglobin , Hypoglycemic Agents/adverse effects , Insulin Glargine , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology , Hypoglycemia/prevention & control , Blood Glucose , Insulin, Regular, Human/therapeutic use
5.
Diabetes Obes Metab ; 22(3): 346-354, 2020 03.
Article in English | MEDLINE | ID: mdl-31646724

ABSTRACT

AIM: To further investigate glycaemic control and hypoglycaemia in BRIGHT, focusing on the titration period. MATERIALS AND METHODS: BRIGHT was a multicentre, open-label, randomized, active-controlled, two-arm, parallel-group, 24-week study in insulin-naïve patients with uncontrolled type 2 diabetes initiated on glargine 300 U/mL (Gla-300) (N = 466) or degludec (IDeg-100) (N = 463). Predefined efficacy and safety outcomes were investigated during the initial 12-week titration period. In addition, patients' characteristics and clinical outcomes were assessed descriptively, stratified by confirmed (≤3.9 mmol/L) hypoglycaemia incidence during the initial titration period. RESULTS: At week 12, HbA1c was comparable between Gla-300 (7.32%) and IDeg-100 (7.23%), with similar least squares (LS) mean reductions from baseline (-1.37% and - 1.39%, respectively; LS mean difference of 0.02; 95% confidence interval: -0.08 to 0.12). Patients who experienced hypoglycaemia during the initial titration period had numerically greater HbA1c reductions by week 12 than patients who did not (-1.46% vs. -1.28%), and higher incidence of anytime (24 hours; 73.3% vs. 35.7%) and nocturnal (00:00-06:00 hours; 30.0% vs. 11.9%) hypoglycaemia between weeks 13-24. CONCLUSIONS: The use of Gla-300 resulted in similar glycaemic control as IDeg-100 during the initial 12-week titration period of the BRIGHT study, when less anytime (24 hours) hypoglycaemia with Gla-300 versus IDeg-100 has been reported. Experiencing hypoglycaemia shortly after initiating Gla-300 or IDeg-100 may be associated with hypoglycaemia incidence in the longer term, potentially impacting glycaemic management.


Subject(s)
Diabetes Mellitus, Type 2 , Hypoglycemia , Blood Glucose , Diabetes Mellitus, Type 2/drug therapy , Glycated Hemoglobin/analysis , Glycemic Control , Humans , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology , Hypoglycemia/prevention & control , Hypoglycemic Agents/adverse effects , Insulin , Insulin Glargine/adverse effects , Insulin, Long-Acting
7.
Diabetes Care ; 41(10): 2147-2154, 2018 10.
Article in English | MEDLINE | ID: mdl-30104294

ABSTRACT

OBJECTIVE: To compare insulin glargine 300 units/mL (Gla-300) versus insulin degludec 100 units/mL (IDeg-100) in this first head-to-head randomized controlled trial. RESEARCH DESIGN AND METHODS: BRIGHT (NCT02738151) was a multicenter, open-label, active-controlled, two-arm, parallel-group, 24-week, noninferiority study in insulin-naive patients with uncontrolled type 2 diabetes. Participants were randomized 1:1 to evening dosing with Gla-300 (N = 466) or IDeg-100 (N = 463), titrated to fasting self-monitored plasma glucose of 80-100 mg/dL. The primary end point was HbA1c change from baseline to week 24. Safety end points included incidence and event rates of hypoglycemia. RESULTS: At week 24, HbA1c improved similarly from baseline values of 8.7% (72 mmol/mol) in the Gla-300 group and 8.6% (70 mmol/mol) in the IDeg-100 group to 7.0% (53 mmol/mol)-least squares mean difference -0.05% (95% CI -0.15 to 0.05) (-0.6 mmol/mol [-1.7 to 0.6])-demonstrating noninferiority of Gla-300 versus IDeg-100 (P < 0.0001). Hypoglycemia incidence and event rates over 24 weeks were comparable with both insulins, whereas during the active titration period (0-12 weeks) the incidence and rate of anytime (24-h) confirmed hypoglycemia (≤70 and <54 mg/dL) were lower with Gla-300. Both insulins were properly titrated and exhibited no specific safety concerns. CONCLUSIONS: Gla-300 and IDeg-100 provided similar glycemic control improvements with relatively low hypoglycemia risk. Hypoglycemia incidence and rates were comparable with both insulins during the full study period but lower in favor of Gla-300 during the titration period. The choice between these longer-acting basal insulins may be determined by factors such as access and cost, alongside clinical considerations.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Insulin, Long-Acting/administration & dosage , Aged , Blood Glucose/analysis , Diabetes Mellitus, Type 2/blood , Female , Glycated Hemoglobin/analysis , Humans , Male , Middle Aged
8.
Diabetes Obes Metab ; 20(12): 2860-2868, 2018 12.
Article in English | MEDLINE | ID: mdl-30003642

ABSTRACT

AIM: To investigate the impact of renal function on the safety and efficacy of insulin glargine 300 U/mL (Gla-300) and insulin glargine 100 U/mL (Gla-100). MATERIALS AND METHODS: A meta-analysis was performed using pooled 6-month data from the EDITION 1, 2 and 3 trials (N = 2496). Eligible participants, aged ≥18 years with a diagnosis of type 2 diabetes (T2DM), were randomized to receive once-daily evening injections of Gla-300 or Gla-100. Pooled results were assessed by two renal function subgroups: estimated glomerular filtration rate (eGFR) <60 and ≥60 mL/min/1.73 m2 . RESULTS: The decrease in glycated haemoglobin (HbA1c) after 6 months and the proportion of individuals with T2DM achieving HbA1c targets were similar in the Gla-300 and Gla-100 groups, for both renal function subgroups. There was a reduced risk of nocturnal (12:00-5:59 am) confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemia with Gla-300 in both renal function subgroups (eGFR <60 mL/min/1.73 m2 : relative risk [RR] 0.76 [95% confidence interval {CI} 0.62-0.94] and eGFR ≥60 mL/min/1.73 m2 : RR 0.75 [95% CI 0.67-0.85]). For confirmed (≤70 mg/dL [≤3.9 mmol/L]) or severe hypoglycaemia at any time of day (24 hours) the hypoglycaemia risk was lower with Gla-300 vs Gla-100 in both the lower (RR 0.94 [95% CI 0.86-1.03]) and higher (RR 0.90 [95% CI 0.85-0.95]) eGFR subgroups. CONCLUSIONS: Gla-300 provided similar glycaemic control to Gla-100, while indicating a reduced overall risk of confirmed (≤3.9 and <3.0 mmol/L [≤70 and <54 mg/dL]) or severe hypoglycaemia, with no significant difference between renal function subgroups.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Diabetic Nephropathies/physiopathology , Hypoglycemia/chemically induced , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Aged , Clinical Trials, Phase III as Topic , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , Diabetic Nephropathies/etiology , Female , Glomerular Filtration Rate , Humans , Kidney/physiopathology , Male , Middle Aged , Randomized Controlled Trials as Topic , Treatment Outcome
9.
PLoS One ; 13(7): e0200092, 2018.
Article in English | MEDLINE | ID: mdl-29969485

ABSTRACT

BACKGROUND AND PURPOSE: Most false negative findings in DWI of ischemic stroke are in patients with minor deficits clinically localized to the brainstem. Our goal was to evaluate the benefit of a thin-sliced sagittal DWI in addition to conventional axial DWI at 1.5T for the detection of brainstem infarctions. METHODS: Data of patients with symptoms consistent with acute and subacute brainstem infarction and an MRI examination including standard axial DWI and thin-sliced sagittal DWI were retrospectively analyzed. Patients with the later diagnosis of a TIA, an inflammation or a tumor of the brainstem were excluded from analysis. Diffusion restrictions were identified by two independent raters blinded for the final clinical diagnosis in three separate reading steps: First, only axial DWI, secondly only sagittal DWI, and lastly both DWIs together. Presence and size of DWI-lesions were documented for each plane. Differences between the observers were settled in consensus in a separate joint reading. RESULTS: Of 73 included patients, 46 patients were clinically diagnosed with brainstem infarction. Inter-observer agreement was excellent for the detection of brainstem lesions in axial and sagittal DWI (kappa = 0.94 and 0.97). In 28/46 patients (60.9%) lesions were detected in the axial plane alone, whereas in 6 more patients (73.9%) lesions were detected in the review of both sequences together. All lesions undetectable in the axial plane were smaller than 5 mm in cranio-caudal direction. CONCLUSIONS: Thin-sliced sagittal DWI in addition to axial DWI improves the detection rate of brainstem infarction with little additional expenditure of time.


Subject(s)
Brain Stem Infarctions/diagnostic imaging , Diffusion Magnetic Resonance Imaging/methods , Brain Stem/diagnostic imaging , Humans , Observer Variation , Retrospective Studies , Sensitivity and Specificity
10.
Diabetes Care ; 41(8): 1672-1680, 2018 08.
Article in English | MEDLINE | ID: mdl-29895556

ABSTRACT

OBJECTIVE: SENIOR compared the efficacy and safety of insulin glargine 300 units/mL (Gla-300) with glargine 100 units/mL (Gla-100) in older people (≥65 years old) with type 2 diabetes. RESEARCH DESIGN AND METHODS: SENIOR was an open-label, two-arm, parallel-group, multicenter phase 3b trial designed to enroll ∼20% of participants aged ≥75 years. Participants were randomized 1:1 to Gla-300 or Gla-100, titrated to a fasting self-monitored plasma glucose of 5.0-7.2 mmol/L (90-130 mg/dL). RESULTS: In total, 1,014 participants were randomized (mean age: 71 years). Comparable reductions in HbA1c were observed from baseline to week 26 for Gla-300 (-0.89%) and Gla-100 (-0.91%) in the overall population (least squares mean difference: 0.02% [95% CI -0.092 to 0.129]) and for participants aged ≥75 years (-0.11% [-0.330 to 0.106]). Incidence and rates of confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycemia events were low and similar between both treatment groups, with lower rates of documented symptomatic hypoglycemia with Gla-300. The lower risk of hypoglycemia with Gla-300 versus Gla-100 was more apparent in the subgroup aged ≥75 years versus the overall population. Significantly lower annualized rates of documented symptomatic (≤3.9 mmol/L [≤70 mg/dL]) hypoglycemia were observed (Gla-300: 1.12; Gla-100: 2.71; rate ratio: 0.45 [95% CI 0.25-0.83]). CONCLUSIONS: Efficacy and safety of Gla-300 was demonstrated in older people (≥65 years of age) with type 2 diabetes, with comparable reductions in HbA1c and similarly low or lower risk of documented symptomatic hypoglycemia versus Gla-100. A significant benefit in hypoglycemia reduction was seen in participants aged ≥75 years.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/adverse effects , Insulin Glargine/administration & dosage , Insulin Glargine/adverse effects , Aged , Aged, 80 and over , Aging/blood , Aging/drug effects , Blood Glucose/drug effects , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/epidemiology , Dose-Response Relationship, Drug , Fasting/blood , Female , Glycated Hemoglobin/analysis , Glycated Hemoglobin/drug effects , Humans , Hypoglycemia/blood , Hypoglycemia/epidemiology , Incidence , Male , Treatment Outcome
11.
Diabetes Obes Metab ; 20(3): 541-548, 2018 03.
Article in English | MEDLINE | ID: mdl-28862801

ABSTRACT

AIMS: To investigate the efficacy and safety of insulin glargine 300 U/mL (Gla-300) vs insulin glargine 100 U/mL (Gla-100) over 12 months in a patient-level meta-analysis, using data from the EDITION studies in people with type 2 diabetes (T2DM). METHODS: EDITION 1, 2 and 3 were multicentre, randomized, open-label, 2-arm, parallel-group, treat-to-target phase IIIa studies. Similar study designs and endpoints enabled a meta-analysis to be conducted. RESULTS: Reductions in glycated haemoglobin (HbA1c) were better sustained over 12 months with Gla-300 than with Gla-100 (least squares [LS] mean difference in change from baseline: -0.10 % [95% confidence interval {CI} -0.18 to -0.02] or -1.09 mmol/mol [95% CI -2.01 to -0.20]; P = .0174). Risk of confirmed (≤3.9 mmol/L) or severe hypoglycaemia was 15% lower with Gla-300 vs Gla-100 at night (relative risk 0.85 [95% CI 0.77-0.92]) and 6% lower at any time of day (relative risk 0.94 [95% CI 0.90-0.98]). Rates of hypoglycaemia were 18% lower with Gla-300 vs Gla-100 at night (rate ratio 0.82 [95% CI 0.67-0.99]), but comparable at any time of day. HbA1c <7.0 % without nocturnal hypoglycaemia was achieved by 24% more participants with Gla-300 than with Gla-100 (relative risk 1.24 [95% CI 1.03-1.50]). Severe hypoglycaemia was rare; in both treatment groups the incidence of events at any time of day was ≤3.6%, while rates were ≤0.08 events per participant-year. CONCLUSIONS: In a broad population of people with T2DM over 12 months, use of Gla-300 provided more sustained glycaemic control and significantly lower hypoglycaemia risk at night and at any time of day compared with Gla-100.


Subject(s)
Diabetes Mellitus, Type 2/prevention & control , Hypoglycemic Agents/administration & dosage , Insulin Glargine/administration & dosage , Body Weight/drug effects , Clinical Trials, Phase III as Topic , Diabetes Mellitus, Type 2/blood , Glycated Hemoglobin/metabolism , Humans , Hypoglycemia/chemically induced , Hypoglycemic Agents/adverse effects , Insulin Glargine/adverse effects , Multicenter Studies as Topic , Randomized Controlled Trials as Topic , Treatment Outcome
13.
Proc Natl Acad Sci U S A ; 110(2): 648-53, 2013 Jan 08.
Article in English | MEDLINE | ID: mdl-23267072

ABSTRACT

The coagulation protease activated protein C (aPC) confers cytoprotective effects in various in vitro and in vivo disease models, including diabetic nephropathy. The nephroprotective effect may be related to antioxidant effects of aPC. However, the mechanism through which aPC may convey these antioxidant effects and the functional relevance of these properties remain unknown. Here, we show that endogenous and exogenous aPC prevents glomerular accumulation of oxidative stress markers and of the redox-regulating protein p66(Shc) in experimental diabetic nephropathy. These effects were predominately observed in podocytes. In vitro, aPC inhibited glucose-induced expression of p66(Shc) mRNA and protein in podocytes (via PAR-1 and PAR-3) and various endothelial cell lines, but not in glomerular endothelial cells. Treatment with aPC reversed glucose-induced hypomethylation and hyperacetylation of the p66(Shc) promoter in podocytes. The hyperacetylating agent sodium butyrate abolished the suppressive effect of aPC on p66(Shc) expression both in vitro and in vivo. Moreover, sodium butyrate abolished the beneficial effects of aPC in experimental diabetic nephropathy. Inhibition of p66(Shc) expression and mitochondrial translocation by aPC normalized mitochondrial ROS production and the mitochondrial membrane potential in glucose-treated podocytes. Genetic ablation of p66(Shc) compensated for the loss of protein C activation in vivo, normalizing markers of diabetic nephropathy and oxidative stress. These studies identify a unique mechanism underlying the cytoprotective effect of aPC. Activated PC epigenetically controls expression of the redox-regulating protein p66(Shc), thus linking the extracellular protease aPC to mitochondrial function in diabetic nephropathy.


Subject(s)
Diabetes Mellitus, Experimental/complications , Diabetic Nephropathies/drug therapy , Epigenetic Repression/drug effects , Mitochondria/drug effects , Protein C/pharmacology , Shc Signaling Adaptor Proteins/antagonists & inhibitors , Analysis of Variance , Animals , Butyrates/pharmacology , Chromatin Immunoprecipitation , DNA Methylation/drug effects , DNA Primers/genetics , Diabetic Nephropathies/etiology , Gene Knockdown Techniques , Immunoblotting , Immunohistochemistry , Membrane Potential, Mitochondrial/drug effects , Mice , Mitochondria/metabolism , Podocytes/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Shc Signaling Adaptor Proteins/metabolism , Src Homology 2 Domain-Containing, Transforming Protein 1 , Statistics, Nonparametric , Subcellular Fractions
14.
Regul Pept ; 165(2-3): 158-62, 2010 Dec 10.
Article in English | MEDLINE | ID: mdl-20619299

ABSTRACT

BACKGROUND AND AIMS: In type 2 diabetes mellitus (T2DM) chronic beta-cell stimulation and oligomers of aggregating human islet amyloid polypeptide (h-IAPP) cause beta-cell dysfunction and induce beta-cell apoptosis. Therefore we asked whether beta-cell rest prevents h-IAPP induced beta-cell apoptosis. MATERIALS AND METHODS: We induced beta-cell rest with a beta-cell selective K(ATP)-channel opener (K(ATP)CO) in RIN cells and human islets exposed to h-IAPP versus r-IAPP. Apoptosis was quantified by time-lapse video microscopy (TLVM) in RIN cells and TUNEL staining in human islets. Whole islets were also studied with TLVM over 48h to examine islet architecture. RESULTS: In RIN cells and human islets h-IAPP induced apoptosis (p<0.001 h-IAPP versus r-IAPP). Concomitant incubation with K(ATP)CO inhibited apoptosis (p<0.001). K(ATP)CO also reduced h-IAPP induced expansion of whole islets (disintegration of islet architecture) by ~70% (p<0.05). Thioflavin-binding assays show that K(ATP)CO does not directly inhibit amyloid formation. CONCLUSIONS: Opening of K(ATP)-channels reduces beta-cell vulnerability to apoptosis induced by h-IAPP oligomers. This effect is not due to a direct interaction of K(ATP)CO with h-IAPP, but might be mediated through hyperpolarization of the beta-cell membrane induced by opening of K(ATP)-channels. Induction of beta-cell rest with beta-cell selective K(ATP)-channel openers may provide a strategy to protect beta-cells from h-IAPP induced apoptosis and to prevent beta-cell deficiency in T2DM.


Subject(s)
Insulin-Secreting Cells/drug effects , Islet Amyloid Polypeptide/toxicity , Islets of Langerhans/drug effects , KATP Channels/agonists , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Cyclic S-Oxides/pharmacology , Diabetes Mellitus, Type 2 , Humans , In Vitro Techniques , Insulin-Secreting Cells/metabolism , KATP Channels/metabolism
16.
Biochemistry ; 48(44): 10568-76, 2009 Nov 10.
Article in English | MEDLINE | ID: mdl-19810772

ABSTRACT

Protein misfolding is a central mechanism for the development of neurodegenerative diseases and type 2 diabetes mellitus. The accumulation of misfolded alpha-synuclein protein inclusions in the Lewy bodies of Parkinson's disease is thought to play a key role in pathogenesis and disease progression. Similarly, the misfolding of the beta-cell hormone human islet amyloid polypeptide (h-IAPP) into toxic oligomers plays a central role in the induction of beta-cell apoptosis in the context of type 2 diabetes. In this study, we show that annexin A5 plays a role in interacting with and reducing the toxicity of the amyloidogenic proteins, h-IAPP and alpha-synuclein. We find that annexin A5 is coexpressed in human beta-cells and that exogenous annexin A5 reduces the level of h-IAPP-induced apoptosis in human islets by approximately 50% and in rodent beta-cells by approximately 90%. Experiments with transgenic expression of alpha-synuclein in Caenorhabditis elegans show that annexin A5 reduces alpha-synuclein inclusions in vivo. Using thioflavin T fluorescence, electron microscopy, and electron paramagnetic resonance, we provide evidence that substoichiometric amounts of annexin A5 inhibit h-IAPP and alpha-synuclein misfolding and fibril formation. We conclude that annexin A5 might act as a molecular safeguard against the formation of toxic amyloid aggregates.


Subject(s)
Amyloid/metabolism , Annexin A5/metabolism , Amyloid/toxicity , Animals , Animals, Genetically Modified , Apoptosis , Caenorhabditis elegans , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Electron Spin Resonance Spectroscopy , Humans , Islet Amyloid Polypeptide , Islets of Langerhans/metabolism , Islets of Langerhans/pathology , Microscopy, Confocal , Microscopy, Electron , Protein Folding , alpha-Synuclein/genetics , alpha-Synuclein/metabolism
17.
Front Biosci (Landmark Ed) ; 14(5): 1835-50, 2009 01 01.
Article in English | MEDLINE | ID: mdl-19273167

ABSTRACT

Beta-cell deficiency is a pathophysiologic component of diabetes mellitus and a primary cause of islet dysfunction. Islet dysfunction is a prerequisite for the development of diabetes mellitus since individuals with insulin resistance (e.g. obesity, pregnancy) do not develop hyperglycemia unless beta-cell compensation fails. Therefore, understanding of the biology and mechanisms involved in normal beta-cell adaptation may provide novel therapeutic targets for preservation and/or regeneration of beta-cell mass in diabetes mellitus. Normal adaptation of beta-cell mass occurs by beta-cell replication and/or neogenesis from precursor cells inside the pancreas. However, the relative importance of both processes for successful adaptation is unknown. In type-2 diabetes, the primary defect is increased beta-cell apoptosis. Since replicating beta-cells are more vulnerable to apoptosis, the proapoptotic diabetic milieu limits the regenerative capacity of the islet and directly causes accelerated islet loss. Therapeutic approaches need to address both processes of islet turnover (regeneration and cell loss) in order to be successful. It may be anticipated that such an intervention is also effective early in the course of diabetes or in prediabetic conditions.


Subject(s)
Diabetes Mellitus/physiopathology , Islets of Langerhans/physiology , Regeneration , Adaptation, Physiological , Apoptosis , Humans , Islets of Langerhans/cytology
18.
Eur J Endocrinol ; 160(2): 185-91, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19004984

ABSTRACT

OBJECTIVE: The prevalence of type 2 diabetes mellitus escalates with aging although beta-cell mass, a primary parameter of beta-cell function, is subject to compensatory regulation. So far it is unclear whether the proliferative capacity of pancreatic islets is restricted by senescence. MATERIALS AND METHODS: Human pancreatic tissue from n=20 non-diabetic organ donors with a mean age of 50.2+/-3.5 years (range 7-66 years) and mean body mass index of 25.7+/-0.9 kg/m(2) (17.2-33.1 kg/m(2)) was morphometrically analyzed to determine beta-cell volume, beta-cell replication, beta-cell apoptosis, islet neogenesis, and pancreatic duodenal homeobox-1 (PDX-1) expression. RESULTS: Relative beta-cell volume in human pancreata (mean 2.3+/-0.2%) remains constant with aging (r=0.26, P=ns). Beta-cell replication (r=0.71, P=0.0004) decreases age-dependently, while beta-cell apoptosis does not change significantly (r=0.42, P=0.08). Concomitantly, PDX-1 expression is downregulated with age in human pancreatic tissue (r=0.65, P=0.002). The rate of islet neogenesis is not affected by aging (r=0.13, P=ns). CONCLUSIONS: In non-diabetic humans, aging is linked with impaired islet turnover possibly due to reduced PDX-1 expression. As beta-cell replication is considered to be the main mechanism responsible for beta-cell regeneration, these changes restrict the flexibility of the aging human pancreas to adapt to changing demands for insulin secretion and increase the risk for the development of diabetes mellitus in older subjects.


Subject(s)
Aging/pathology , Diabetes Mellitus, Type 2/pathology , Insulin-Secreting Cells/pathology , Islets of Langerhans/pathology , Adolescent , Adult , Aged , Cell Division/physiology , Cellular Senescence/physiology , Child , Diabetes Mellitus, Type 2/epidemiology , Female , Glucagon/metabolism , Homeodomain Proteins/metabolism , Humans , Insulin/metabolism , Insulin-Secreting Cells/metabolism , Islets of Langerhans/metabolism , Male , Middle Aged , Prevalence , Risk Factors , Tissue Donors , Trans-Activators/metabolism , Young Adult
19.
J Clin Endocrinol Metab ; 93(5): 1758-66, 2008 May.
Article in English | MEDLINE | ID: mdl-18319317

ABSTRACT

CONTEXT: Pancreas grafts can be drained through the iliac vein (systemic drainage) or the portal vein. OBJECTIVE: We hypothesized that normalization of portal insulin in patients with portal pancreas graft drainage stimulates the GH/IGF-I axis and thereby contributes to glucose control. METHODS: We compared patients after combined kidney and pancreas transplantation with portal drainage (n = 7) to patients with systemic drainage of the pancreas graft (n = 8) and nondiabetic controls (n = 8). Overnight fasting sera were analyzed for free and total IGF-I and IGF-binding proteins. Glucose regulatory hormones were examined after an oral glucose tolerance test and GH after stimulation with GHRH. RESULTS: Systemic drainage led to higher basal and stimulated insulin levels than portal drainage (P < 0.05), but increments in response to oral glucose were reduced in both transplanted groups (P < 0.05 vs. controls). However, glucose tolerance was similar in all groups. Circulating free and total IGF-I and IGF-binding protein-3 were similar to control levels in the systemic drainage group but elevated in the portal drainage group (P < 0.05). Consistently, the GH response was reduced in the portal drainage group (P < 0.05 vs. controls) and correlated inversely with free IGF-I (r = -0.63, P < 0.05). CONCLUSION: Portal drainage of pancreatic endocrine secretion in pancreas graft recipients raises IGF-I and lowers GH secretion. These changes might explain that glucose regulation is maintained despite lower peripheral insulin levels, compared with patients with systemic graft drainage and nondiabetic control subjects.


Subject(s)
Diabetes Mellitus, Type 1/surgery , Human Growth Hormone/physiology , Insulin-Like Growth Factor I/physiology , Pancreas Transplantation , Adult , C-Peptide/analysis , Diabetes Mellitus, Type 1/physiopathology , Drainage , Female , Glucagon/blood , Glucose Tolerance Test , Human Growth Hormone/metabolism , Humans , Insulin/blood , Insulin-Like Growth Factor Binding Protein 3/blood , Male , Middle Aged , Portal Vein/physiology
20.
Diabetes Care ; 31(6): 1105-11, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18316392

ABSTRACT

OBJECTIVE: It was reported that the long-acting insulin analogue glargine induces cell proliferation in a human osteosarcoma cell line and therefore might induce or accelerate tumor growth. Induction of cell proliferation would be particularly relevant for insulin treatment of subjects with diabetes and the potential of bearing tumor cells (e.g., a history of a malignant disease). RESEARCH DESIGN AND METHODS: Proliferation, apoptosis, and the expression levels of insulin receptor, IGF-I receptor, and insulin receptor substrate (IRS) 2 were analyzed in human pancreatic cancer cells (Colo-357) after incubation (72 h) with insulin glargine or regular human insulin at 0-100 nmol/l. A total of 125 subjects, after partial or total pancreatectomy due to pancreatic carcinoma, were analyzed over a median follow-up period of 22 months. RESULTS: There was no significant difference between glargine and regular human insulin with respect to regulation of proliferation and apoptosis of Colo-357 cells. The expression levels of insulin receptor, IGF-I receptor, and IRS2 as a downstream molecule of both receptor signaling pathways were not altered at any concentration tested. The insulin receptor was downregulated to a similar degree by glargine and regular human insulin at high insulin concentrations (P < 0.0001 for glargine, P = 0.002 for regular human insulin). The median survival time after pancreatic surgery was 15 months. Survival analysis showed that the time-dependent proportion of patients who survived was identical in patients receiving insulin glargine versus insulin treatment without glargine and control subjects without diabetes after surgery (P = 0.4, three-sample comparison). CONCLUSIONS: Regular human insulin and insulin glargine may be used to treat diabetes in patients with pancreatic cancer.


Subject(s)
Insulin/analogs & derivatives , Pancreatic Neoplasms/pathology , Bone Neoplasms/pathology , Cell Division/drug effects , Cell Line, Tumor , Flow Cytometry , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Insulin Glargine , Insulin, Long-Acting , Osteosarcoma/pathology , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/mortality , Retrospective Studies , Survival Analysis
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