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1.
Br J Dermatol ; 182(2): 477-480, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31077337

RESUMO

Immune checkpoint inhibitors are now the standard of care in the treatment of several types of cancer. Cutaneous immune-related adverse events (irAEs) are usually of low grade and reversible, while endocrine irAEs are generally irreversible and managed with hormone replacement therapy. We report a 47-year-old patient, treated with the anti-programmed cell death (PD)1 antibody pembrolizumab for a metastatic melanoma, who developed severe lipodystrophy after 10 months of treatment, characterized by the loss of subcutaneous fat tissue, central obesity and insulin resistance with a decreased leptin level. Histological analysis of a cutaneous biopsy revealed subcutaneous fat cell destruction associated with oedema, the presence of lipophages, and a CD3+ lymphocytic infiltrate involving the panniculus. This led to the diagnosis of anti-PD-1-induced acquired generalized lipodystrophy, after ruling out differential diagnoses (i.e. genetic and systemic autoimmune diseases). No corticosteroids were introduced considering the high risk of inducing severe metabolic complications, and pembrolizumab was discontinued as complete response of the melanoma was achieved. However, after 12 months of follow-up, lipodystrophy and its severe metabolic complications are still ongoing. What's already known about this topic? Anti-programmed cell death (PD)1 agents are now a standard of care in the treatment of several cancers, including melanoma. Endocrine and cutaneous immune-related adverse events (irAEs) are among the most frequent irAEs (14-30% and 30-40%, respectively) in patients treated with immune checkpoint inhibitors. What does this study add? Acquired generalized lipodystrophy can occur during anti-PD1 therapy and is associated with severe metabolic complications. With the increase in anti-PD1 prescription in several cancer types, clinicians must be aware of the whole range of irAEs that may occur.


Assuntos
Lipodistrofia Generalizada Congênita , Melanoma , Anticorpos Monoclonais Humanizados , Humanos , Inibidores de Checkpoint Imunológico , Melanoma/tratamento farmacológico , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1
2.
Diabet Med ; 34(3): 426-431, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27657549

RESUMO

AIM: It is unclear whether ketosis-prone diabetes is a specific type or a subtype of Type 2 diabetes. We aimed to describe the clinical and metabolic features of ketosis-prone diabetes in a sub-Saharan population. METHODS: We consecutively enrolled and characterized 173 people with non-autoimmune diabetes admitted for hyperglycaemic crisis at the Yaoundé Central Hospital, Cameroon. Blood samples were collected for fasting glucose, HbA1c , lipid profile and C-peptide assays with insulin resistance and secretion estimation by homeostasis model assessment. People were classified as having Type 2 diabetes (n = 124) or ketosis-prone diabetes (n = 49). Ketosis-prone diabetes was sub-classified as new-onset ketotic phase (n = 34) or non-ketotic phase (n = 15). RESULTS: Ketosis-prone diabetes was found in 28.3% of the hyperglycaemic crises. Age at diabetes diagnosis was comparable in Type 2 and ketosis-prone diabetes [48 ± 14 vs 47 ± 11 years; P = 0.13] with a similar sex distribution. Overall BMI was 27.7 ± 13.4 kg/m2 and was ≥ 25 kg/m2 in 55.8% of those taking part, however, 73.5% of those with ketosis-prone diabetes reported weight loss of > 5% at diagnosis. Blood pressure and lipid profile were comparable in both types. Ketosis-prone diabetes in the ketotic phase was characterized by lower insulin secretion and higher serum triglycerides compared with non-ketotic ketosis prone and Type 2 diabetes. Type 2 and ketosis prone diabetes in the non-ketotic phase were comparable in terms of lipid profile, blood pressure, waist-to-hip ratio, BMI and fat mass, insulin secretion and insulin resistance indices. CONCLUSIONS: Ketosis-prone diabetes is likely to be a subtype of Type 2 diabetes with the potential to develop acute insulinopenic episodes.


Assuntos
Diabetes Mellitus Tipo 2/diagnóstico , Cetoacidose Diabética/diagnóstico , Hiperglicemia/prevenção & controle , Resistência à Insulina , Doença Aguda , Adulto , Idoso , Camarões , Terapia Combinada , Estudos Transversais , Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/terapia , Cetoacidose Diabética/etnologia , Cetoacidose Diabética/metabolismo , Cetoacidose Diabética/terapia , Diagnóstico Diferencial , Feminino , Hemoglobinas Glicadas/análise , Hospitais Urbanos , Humanos , Insulina/sangue , Insulina/metabolismo , Resistência à Insulina/etnologia , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Encaminhamento e Consulta
3.
Diabetes Obes Metab ; 16(9): 861-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24641271

RESUMO

AIM: Glucagon-like peptide-1 (GLP-1) receptor agonists improve islet function and delay gastric emptying in patients with type 2 diabetes mellitus (T2DM). This meta-analysis aimed to investigate the effects of the once-daily prandial GLP-1 receptor agonist lixisenatide on postprandial plasma glucose (PPG), glucagon and insulin levels. METHODS: Six randomized, placebo-controlled studies of lixisenatide 20 µg once daily were included in this analysis: lixisenatide as monotherapy (GetGoal-Mono), as add-on to oral antidiabetic drugs (OADs; GetGoal-M, GetGoal-S) or in combination with basal insulin (GetGoal-L, GetGoal-Duo-1 and GetGoal-L-Asia). Change in 2-h PPG and glucose excursion were evaluated across six studies. Change in 2-h glucagon and postprandial insulin were evaluated across two studies. A meta-analysis was performed on least square (LS) mean estimates obtained from analysis of covariance (ANCOVA)-based linear regression. RESULTS: Lixisenatide significantly reduced 2-h PPG from baseline (LS mean difference vs. placebo: -4.9 mmol/l, p < 0.001) and glucose excursion (LS mean difference vs. placebo: -4.5 mmol/l, p < 0.001). As measured in two studies, lixisenatide also reduced postprandial glucagon (LS mean difference vs. placebo: -19.0 ng/l, p < 0.001) and insulin (LS mean difference vs. placebo: -64.8 pmol/l, p < 0.001). There was a stronger correlation between 2-h postprandial glucagon and 2-h PPG with lixisenatide than with placebo. CONCLUSIONS: Lixisenatide significantly reduced 2-h PPG and glucose excursion together with a marked reduction in postprandial glucagon and insulin; thus, lixisenatide appears to have biological effects on blood glucose that are independent of increased insulin secretion. These effects may be, in part, attributed to reduced glucagon secretion.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Peptídeo 1 Semelhante ao Glucagon/agonistas , Glucagon/sangue , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Peptídeos/uso terapêutico , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Esvaziamento Gástrico/efeitos dos fármacos , Glucagon/efeitos dos fármacos , Glucagon/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , Insulina/sangue , Secreção de Insulina , Período Pós-Prandial , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Diabetologia ; 55(7): 2026-31, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22526607

RESUMO

AIMS/HYPOTHESIS: Anti-zinc transporter (ZnT)8 autoantibodies are commonly detected in type 1 diabetic patients. We hypothesised that ZnT8 is also recognised by CD8(+) T cells and aimed to identify HLA-A2 (A*02:01)-restricted epitope targets. METHODS: Candidate epitopes were selected by ZnT8 plasmid DNA immunisation of HLA-A2/DQ8 transgenic mice and tested for T cell recognition in peripheral blood mononuclear cells of type 1 diabetic, type 2 diabetic and healthy participants by IFN-γ enzyme-linked immunospot. RESULTS: White HLA-A2(+) adults (83%) and children (60%) with type 1 diabetes displayed ZnT8-reactive CD8(+) T cells that recognised a single ZnT8(186-194) (VAANIVLTV) epitope. This ZnT8(186-194)-reactive fraction accounted for 50% to 53% of total ZnT8-specific CD8(+) T cells. Another sequence, ZnT8(153-161) (VVTGVLVYL), was recognised in 20% and 25% of type 1 diabetic adults and children, respectively. Both epitopes were type 1 diabetes-specific, being marginally recognised by type 2 diabetic and healthy participants (7-12% for ZnT8(186-194), 0% for ZnT8(153-161)). CONCLUSIONS/INTERPRETATION: ZnT8-reactive CD8(+) T cells are predominantly directed against the ZnT8(186-194) epitope and are detected in a majority of type 1 diabetic patients. The exceptional immunodominance of ZnT8(186-194) may point to common environmental triggers precipitating beta cell autoimmunity.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Proteínas de Transporte de Cátions/imunologia , Diabetes Mellitus Tipo 1/imunologia , Epitopos de Linfócito T/imunologia , Antígeno HLA-A2/imunologia , Adolescente , Adulto , Animais , Autoanticorpos/genética , Linfócitos T CD4-Positivos/imunologia , Proteínas de Transporte de Cátions/genética , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/genética , Mapeamento de Epitopos , Epitopos de Linfócito T/genética , Feminino , Antígeno HLA-A2/genética , Humanos , Lactente , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Transportador 8 de Zinco
5.
Nat Commun ; 13(1): 5089, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042203

RESUMO

Adipose tissue macrophages (ATM) adapt to changes in their energetic microenvironment. Caloric excess, in a range from transient to diet-induced obesity, could result in the transition of ATMs from highly oxidative and protective to highly inflammatory and metabolically deleterious. Here, we demonstrate that Interferon Regulatory Factor 5 (IRF5) is a key regulator of macrophage oxidative capacity in response to caloric excess. ATMs from mice with genetic-deficiency of Irf5 are characterised by increased oxidative respiration and mitochondrial membrane potential. Transient inhibition of IRF5 activity leads to a similar respiratory phenotype as genomic deletion, and is reversible by reconstitution of IRF5 expression. We find that the highly oxidative nature of Irf5-deficient macrophages results from transcriptional de-repression of the mitochondrial matrix component Growth Hormone Inducible Transmembrane Protein (GHITM) gene. The Irf5-deficiency-associated high oxygen consumption could be alleviated by experimental suppression of Ghitm expression. ATMs and monocytes from patients with obesity or with type-2 diabetes retain the reciprocal regulatory relationship between Irf5 and Ghitm. Thus, our study provides insights into the mechanism of how the inflammatory transcription factor IRF5 controls physiological adaptation to diet-induced obesity via regulating mitochondrial architecture in macrophages.


Assuntos
Fatores Reguladores de Interferon , Macrófagos , Tecido Adiposo/metabolismo , Animais , Fatores Reguladores de Interferon/metabolismo , Macrófagos/metabolismo , Camundongos , Monócitos/metabolismo , Obesidade/genética , Obesidade/metabolismo
6.
Diabetes Metab ; 47(2): 101167, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32473964

RESUMO

The outbreak of COVID-19 led to an unprecedented inflow of hospitalised patients with severe acute respiratory syndrome (SARS), requiring high-flow non-invasive oxygenation, if not invasive mechanical ventilation. While the best option in terms of non-invasive systems of oxygen delivery is still a matter of debate, it also remains unclear as to whether or not the optimal in-bed positioning of patients might also help to improve their oxygen saturation levels. On the basis of three representative cases, it is possible to propose the following hypotheses: (i) how patients are positioned has a strong influence on their oxygen saturation levels; (ii) saturation-optimalised positions are patient-specific; (iii) prone positions require ergonomic devices; and (iv) saturation-optimalised positions should aim to place the most affected part(s) of the lung(s) on top. Considered together, these hypotheses have led us to recommend that COVID-19 patients should undergo a specific assessment at admission to determine their saturation-optimalised in-bed position. However, further studies are still needed to assess the benefits of such a strategy on clinical outcomes.


Assuntos
COVID-19/terapia , Pulmão/diagnóstico por imagem , Idoso , COVID-19/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural , Decúbito Ventral , Respiração Artificial , SARS-CoV-2 , Tomografia Computadorizada por Raios X
7.
Diabetologia ; 53(4): 768-78, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20043143

RESUMO

AIMS/HYPOTHESIS: In rodent adipocytes, activated AMP-activated protein kinase reduces the lipolytic rate. As the hypoglycaemic drugs metformin and thiazolidinediones activate this enzyme in rodents, we tested the hypothesis that in addition to their known actions they could have an anti-lipolytic effect in human adipocytes. METHODS: Adipose tissue was obtained from individuals undergoing plastic surgery. Adipocytes were isolated and incubated with lipolytic agents (isoprenaline, atrial natriuretic peptide) and biguanides or thiazolidinediones. Lipolysis was quantified by the glycerol released in the medium. AMP-activated protein kinase activity and phosphorylation state were determined using standard procedures. RESULTS: In human adipocytes, isoprenaline and atrial natriuretic peptide stimulated the lipolytic rate three- to fourfold. Biguanides and thiazolidinediones activated AMP-activated protein kinase and inhibited lipolysis by 30-40%, at least in part by inhibiting hormone-sensitive lipase translocation to the lipid droplet. Inhibition of AMP-activated protein kinase by compound C precluded this inhibitory effect on lipolysis. Stimulation of lipolysis also induced an activation of AMP-activated protein kinase concomitant with a drop in ATP concentration. CONCLUSIONS/INTERPRETATION: We show for the first time in human adipocytes that biguanides and thiazolidinediones activate AMP-activated protein kinase, thus counteracting lipolysis induced by lipolytic agents. In addition, beta-agonist- or ANP-stimulated lipolysis increases AMP-activated protein kinase activity. This is because of an increase in the AMP/ATP ratio, linked to activation of some of the released fatty acids into acyl-CoA. AMP-activated protein kinase activation could represent a physiological means of avoiding a deleterious drain of energy during lipolysis but could be used to restrain pharmacological release of fatty acids.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/metabolismo , Biguanidas/farmacologia , Lipólise/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Proteínas Quinases Ativadas por AMP/genética , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Adenilato Quinase/metabolismo , Adipócitos/efeitos dos fármacos , Adipócitos/enzimologia , Tecido Adiposo/patologia , Agonistas Adrenérgicos beta/farmacologia , Adulto , Substituição de Aminoácidos , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Cirurgia Bariátrica , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ativação Enzimática , Feminino , Humanos , Resistência à Insulina , Sobrepeso/metabolismo , Sobrepeso/cirurgia , Seleção de Pacientes , Ribonucleotídeos/farmacologia , Serina/genética , Treonina/genética
8.
Diabet Med ; 27(3): 318-26, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20536495

RESUMO

AIM: To demonstrate non-inferiority of vildagliptin compared with gliclazide, as an add-on therapy, in patients with Type 2 diabetes inadequately controlled with metformin in a 52-week, randomized, double-blind, active-controlled study. METHODS: Patients receiving a stable dose of metformin (> or = 1500 mg) were randomized (1 : 1) to receive vildagliptin (50 mg twice daily; n = 513) or gliclazide (up to 320 mg/day; n = 494). RESULTS: Non-inferiority of vildagliptin was demonstrated (95% confidence interval -0.11%, 0.20%) with a mean change (se) from baseline glycated haemoglobin (HbA(1c)) (approximately 8.5% in both groups) to a 52-week endpoint of -0.81% (0.06) with vildagliptin and -0.85% (0.06) with gliclazide. Although a similar proportion of patients reached HbA(1c) < 7.0%, the total number of hypoglycaemic events was lower in the vildagliptin group (6 vs. 11 events). Vildagliptin was non-inferior (margin 0.6 mmol/l) to gliclazide in reducing fasting plasma glucose (1.31 vs. 1.52 mmol/l, P = 0.257). The overall incidence of any adverse events was similar in both groups (approximately 61%), but the number of serious adverse events was higher in the gliclazide group (8.7 vs. 6.7%). The number of patients who discontinued as a result of an unsatisfactory effect was higher in the vildagliptin group (n = 22 vs. 13, respectively) compared with gliclazide, but vildagliptin did not induce weight gain. CONCLUSION: In patients with Type 2 diabetes inadequately controlled with metformin, addition of vildagliptin provided similar HbA(1c)-lowering efficacy compared with gliclazide after 52 weeks of treatment. Although both treatments were well tolerated, vildagliptin-treated patients had fewer hypoglycaemic events and did not gain weight.


Assuntos
Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Gliclazida/uso terapêutico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Nitrilas/uso terapêutico , Pirrolidinas/uso terapêutico , Adamantano/administração & dosagem , Adamantano/efeitos adversos , Adamantano/uso terapêutico , Adolescente , Adulto , Idoso , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Gliclazida/administração & dosagem , Gliclazida/efeitos adversos , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Masculino , Metformina/administração & dosagem , Metformina/efeitos adversos , Pessoa de Meia-Idade , Nitrilas/administração & dosagem , Nitrilas/efeitos adversos , Pirrolidinas/administração & dosagem , Pirrolidinas/efeitos adversos , Vildagliptina , Adulto Jovem
9.
Diabetes Metab ; 46(5): 370-376, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31783142

RESUMO

BACKGROUND: Cardiovascular disease is a leading cause of mortality among patients with type 2 diabetes mellitus (T2DM). Numerous patients with T2DM show resistance to aspirin treatment, which may explain the higher rate of major adverse cardiovascular events observed compared with non-diabetes patients, and it has recently been shown that aspirin resistance is mainly related to accelerated platelet turnover with persistent high platelet reactivity (HPR) 24h after last aspirin intake. The mechanism behind HPR is unknown. The aim of this study was to investigate the precise rate and mechanisms associated with HPR in a population of T2DM patients treated with aspirin. METHODS: Included were 116 consecutive stable T2DM patients who had attended our hospital for their yearly check-up. HPR was assessed 24h after aspirin intake using light transmission aggregometry (LTA) with arachidonic acid (AA) and serum thromboxane B2 (TXB2) measurement. Its relationship with diabetes status, insulin resistance, inflammatory markers and coronary artery disease (CAD) severity, using calcium scores, were investigated. RESULTS: Using LTA, HPR was found in 27 (23%) patients. There was no significant difference in mean age, gender ratio or cardiovascular risk factors in patients with or without HPR. HPR was significantly related to duration of diabetes and higher fasting glucose levels (but not consistently with HbA1c), and strongly related to all markers of insulin resistance, especially waist circumference, HOMA-IR, QUICKI and leptin. There was no association between HPR and thrombopoietin or inflammatory markers (IL-6, IL-10, indoleamine 2,3-dioxygenase activity, TNF-α, C-reactive protein), whereas HPR was associated with more severe CAD. Similar results were found with TXB2. CONCLUSION: Our results reveal that 'aspirin resistance' is frequently found in T2DM, and is strongly related to insulin resistance and severity of CAD, but weakly related to HbA1c and not at all to inflammatory parameters. This may help to identify those T2DM patients who might benefit from alternative antiplatelet treatments such as twice-daily aspirin and thienopyridines.


Assuntos
Aspirina/uso terapêutico , Doença da Artéria Coronariana/diagnóstico por imagem , Diabetes Mellitus Tipo 2/sangue , Resistência a Medicamentos , Ativação Plaquetária , Inibidores da Agregação Plaquetária/uso terapêutico , Calcificação Vascular/diagnóstico por imagem , Idoso , Ácido Araquidônico , Proteína C-Reativa/metabolismo , Feminino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/sangue , Inflamação/metabolismo , Resistência à Insulina , Interleucina-10/sangue , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária , Testes de Função Plaquetária , Índice de Gravidade de Doença , Trombopoetina/sangue , Tromboxano B2/sangue , Fator de Necrose Tumoral alfa/sangue
10.
Diabetes Metab ; 35(2): 85-93, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19230736

RESUMO

Mesenchymal stem cells (MSCs) are multipotent non-haematopoietic progenitor cells that are being explored as a promising new treatment for tissue regeneration. Although their immunomodulatory properties are not yet completely understood, their low immunogenic potential together with their effects on immune response make them a promising therapeutic tool for severe refractory autoimmune diseases. Type 1 diabetes is characterized by T cell-mediated autoimmune destruction of pancreatic beta cells. While insulin replacement represents the current therapy for type 1 diabetes, its metabolic control remains difficult, as exogenous insulin cannot exactly mimic the physiology of insulin secretion. Pancreatic or islet transplantation can provide exogenous insulin independence, but is limited by its intrinsic complications and the scarcity of organ donors. In this context, stem cell therapy, based on the generation of insulin-producing cells (IPCs) derived from MSCs, represents an attractive possibility. In this review, we provide a brief characterization of MSC immunomodulatory effects, and present the current experimental evidence for the potential therapeutic efficacy of MSC transplantation in diabetes.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Células Secretoras de Insulina/citologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia , Animais , Diferenciação Celular , Modelos Animais de Doenças , Humanos , Terapia de Imunossupressão , Células Secretoras de Insulina/fisiologia , Células-Tronco Mesenquimais/imunologia
11.
Diabetes Metab ; 35(1): 20-4, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19062325

RESUMO

AIM: Ketosis prone type 2 diabetes (KPD) is an atypical form of diabetes described mainly in people of sub-Saharan African origin. Its pathogenesis is unknown, although we have previously described a high prevalence of glucose-6-phosphate-dehydrogenase (G6PD) deficiency in patients with KPD. However, 50% of these deficient patients lacked the G6PD gene mutation. The isoforms of the transcription factor sterol regulatory element binding protein 1 (SREBP-1) are known to stimulate G6PD gene expression, and some polymorphisms in the SREBP-1 gene (SREBF-1) have been described only in Africans. We investigated one of these, the Arg585Gln polymorphism, in a candidate gene approach for KPD. METHODS: We examined the presence of the Arg585Gln polymorphism in SREBF-1 in 217 consecutive unrelated Africans [73 patients with KPD, 80 with classical type 2 diabetes (T2D) and 64 nondiabetic subjects]. Patients underwent clinical and biochemical evaluations, and were assessed for G6PD activity and insulin secretion (glucagon test). RESULTS: There were no differences in frequency of the Arg585Gln polymorphism and the 585Gln allele among the three groups (allele frequency: KPD: 0.089, T2D: 0.031, nondiabetic group: 0.070; P=0.1). When the 585Gln allele frequency was compared separately between patients with KPD and those with T2D, it was significantly higher in the former (P=0.032). There was no difference between carriers and noncarriers of the 585Gln allele regarding G6PD activity and insulin secretion. CONCLUSION: The results of this exploratory study show that the polymorphism Arg585Gln in SREBF-1 is not associated with the KPD phenotype. Further studies in larger populations are needed to confirm our findings.


Assuntos
Substituição de Aminoácidos , População Negra/genética , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Polimorfismo Genético , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Adulto , Arginina , Peptídeo C/sangue , Estudos Transversais , Feminino , Glutamina , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade
12.
Diabetes Obes Metab ; 10(10): 912-20, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18093211

RESUMO

Ketosis-prone diabetes (KPD) is a phenotypically defined form of diabetes characterized by male predominance and severe insulin deficiency. Neurogenin3 (NGN3) is a proendocrine gene, which is essential for the fate of pancreatic beta cells. Mice lacking ngn3 develop early insulin-deficient diabetes. Thus, we hypothesized that gender and variants in NGN3 could predispose to KPD. We have studied clinical and metabolic parameters according to gender in patients with KPD (n = 152) and common type 2 diabetes (T2DM) (n = 167). We have sequenced NGN3 in KPD patients and screened gene variants in T2DM and controls (n = 232). In KPD, male gender was associated with a more pronounced decrease in beta-cell insulin secretory reserve, assessed by fasting C-peptide [mean (ng/ml) +/- s.d., M: 1.1 +/- 0.6, F: 1.5 +/- 0.9; p = 0.02] and glucagon-stimulated C-peptide [mean (ng/ml) +/- s.d., M: 2.2 +/- 1.1, F: 3.1 +/- 1.7; p = 0.03]. The rare affected females were in an anovulatory state. We found two new variants in the promoter [-3812T/C (af: 2%) and -3642T/C (af: 1%)], two new coding variants [S171T (af: 1%) and A185S (af: 1%)] and the variant already described [S199F (af: 69%)]. These variants were not associated with diabetes. Clinical investigation revealed an association between 199F and hyperglycaemia assessed by glycated haemoglobin [HbA1c (%, +/-s.d.) S199: 12.6 +/- 1.6, S199F: 12.4 +/- 1.4 and 199F: 14.1 +/- 2.2; p = 0.01]. In vitro, the P171T, A185S and S199F variants did not reveal major functional alteration in the activation of NGN3 target genes. In conclusion, male gender, anovulatory state in females and NGN3 variations may influence the pathogenesis of KPD in West Africans. This has therapeutic implications for potential tailored pharmacological intervention in this population.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diabetes Mellitus Tipo 2/etiologia , Cetoacidose Diabética/etiologia , Proteínas do Tecido Nervoso/genética , Regiões Promotoras Genéticas , Fatores Sexuais , Adulto , Anovulação , Biomarcadores/sangue , População Negra/genética , Peptídeo C/análise , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etnologia , Cetoacidose Diabética/sangue , Cetoacidose Diabética/etnologia , Feminino , Expressão Gênica , Genótipo , Glucagon , Humanos , Insulina/metabolismo , Secreção de Insulina , Masculino , Pessoa de Meia-Idade
13.
Diabetes Metab ; 34(6 Pt 2): 664-73, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19195628

RESUMO

The liver plays a pivotal role in energy metabolism. Under the control of hormones, especially insulin, the liver stores or releases glucose as needed by the body's systems. It is also responsible for an important part of non-esterified fatty-acid and aminoacid metabolism. Assessing hepatic insulin resistance is almost always synonymous with measuring hepatic glucose production (HGP) and calculating indices of hepatic insulin resistance. The most frequently used method to this end is the isotope dilution technique using a tracer. Among tracers, stable isotope-labelled glucose molecules are particularly advantageous over radioactive isotope-labelled glucose and are, therefore, the tracers of choice. The tracer is infused either on its own after an overnight fast to evaluate fasting HGP, or with some among the usual insulin-sensitivity tests to assess HGP suppression by insulin and/or glucose. In a fasting state, HGP is easily calculated whereas, during insulin or glucose infusion, some formula are needed to correct for the non-steady-state condition. The hepatic insulin-resistance index is the product of HGP and the corresponding plasma insulin concentration. Although subject to error, the isotope dilution method nevertheless remains an irreplaceable tool for assessing hepatic insulin resistance in clinical research. From a practical point of view, some easily obtainable indices and clinical or biochemical parameters can serve as surrogates or markers of hepatic insulin resistance in clinical practice. Finally, drugs such as metformin or glitazones can improve hepatic insulin resistance, hence their use in hepatic insulin-resistant states such as type 2 diabetes and non-alcoholic fatty liver disease.


Assuntos
Resistência à Insulina/fisiologia , Insulina/fisiologia , Fígado/fisiopatologia , Adulto , Radioisótopos de Carbono , Criança , Deutério , Metabolismo Energético , Ácidos Graxos não Esterificados/metabolismo , Feminino , Glucose/metabolismo , Humanos , Marcação por Isótopo , Fígado/metabolismo , Fígado/patologia , Modelos Biológicos , Gravidez , Técnica de Diluição de Radioisótopos
14.
Diabetes Metab ; 34 Suppl 2: S65-72, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18640588

RESUMO

Incretin hormones are defined as intestinal hormones released in response to nutrient ingestion, which potentiate the glucose-induced insulin response. In humans, the incretin effect is mainly caused by two peptide hormones, glucose-dependent insulin releasing polypeptide (GIP), and glucagon-like peptide-1 (GLP-1). GIP is secreted by K cells from the upper small intestine while GLP-1 is mainly produced in the enteroendocrine L cells located in the distal intestine. Their effect is mediated through their binding with specific receptors, though part of their biological action may also involve neural modulation. GIP and GLP-1 are both rapidly degraded into inactive metabolites by the enzyme dipeptidyl-peptidase-IV (DPP-IV). In addition to its effects on insulin secretion, GLP-1 exerts other significant actions, including stimulation of insulin biosynthesis, inhibition of glucagon secretion, inhibition of gastric emptying and acid secretion, reduction of food intake, and trophic effects on the pancreas. As the insulinotropic action of GLP-1 is preserved in type 2 diabetic patients, this peptide was likely to be developed as a therapeutic agent for this disease.


Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Polipeptídeo Inibidor Gástrico/fisiologia , Peptídeo 1 Semelhante ao Glucagon/fisiologia , Incretinas/fisiologia , Insulina/metabolismo , Animais , Humanos , Incretinas/biossíntese , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/fisiologia , Células Matadoras Naturais/metabolismo , Proglucagon/fisiologia
15.
Diabetes Metab ; 44(1): 45-54, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28259539

RESUMO

AIM: Alteration of functional beta-cell mass in adults can be programmed by adverse events during fetal life. Previously, it was demonstrated that high glucocorticoid (GC) levels during fetal life participate in this programming by inhibition of beta-cell development. More specifically, GC levels stimulate expression of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α), a transcriptional co-regulator of the GC receptor (GR), which per se impairs beta-cell mass and function when overexpressed. As PGC-1α is also a potent inducer of mitochondrial biogenesis, our study aimed to determine how PGC-1α modifies mitochondrial function in beta cells and how it might regulate insulin secretion. METHODS: Beta-cell function was studied in mice overexpressing PGC-1α specifically in beta cells and in MIN6 cells overexpressing PGC-1α in vitro. RESULTS: PGC-1α overexpression in beta cells in vivo leads to a reduced beta-cell mass early in fetal life, whereas PGC-1α overexpression in vitro stimulates mitochondrial biogenesis and respiratory activity without improving ATP production, while increasing oxidative stress and impairing insulin secretion in response to glucose. While oxidative stress with PGC-1α overexpression in beta cells activates AMPK, it has also been revealed that blocking such oxidative stress or AMPK activation restores insulin secretion. CONCLUSION: PGC-1α induces oxidative stress, which disrupts insulin secretion by AMPK activation. Thus, control of oxidative or energetic stress in beta cells may help to restore insulin secretion.


Assuntos
Células Secretoras de Insulina/metabolismo , Estresse Oxidativo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Animais , Insulina/metabolismo , Camundongos , Camundongos Transgênicos , Consumo de Oxigênio/genética
16.
Diabetes Metab ; 33(2): 135-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17320448

RESUMO

AIMS: To facilitate the transition from urine ketones (acetoacetate) to capillary blood ketones (3-beta-hydroxybutyrate), we studied the correlation between these two tests. METHODS: Retrospective study of all patients with blood glucose greater than or equal to 2.5 g/l on arrival in the Emergency Department. We studied the correlation between urine ketones (Clinitek 50, Bayer) and capillary blood ketones (Optium, Abbott). We then compared the relative risks (RR) of ketoacidosis and hospitalization associated with each of these tests. RESULTS: In 33 months, 529 adult patients with both urine and blood testing for ketones were enrolled (ketoacidosis 8%, admission rate 49%). Urine ketones scored as +, ++ and +++ corresponded to median capillary blood ketone levels of 0.5 mmol/l (IQR: 0.1-0.9), 0.7 mmol/l (IQR: 0.2-1.8) and 3 mmol/l (IQR: 1.4-5.2), respectively. RRs of ketoacidosis or hospitalization associated with blood ketones greater than or equal to 3 mmol/l were higher than those associated with +++ urine ketones: 74 (95% confidence interval [CI]: 48-88) and 2.9 (95% CI: 2.5-3) versus 31 (95% CI: 18-45) and 2 (95% CI: 1.7-2.1), respectively. CONCLUSIONS: In hyperglycaemic patients in the Emergency Department, a good correlation was observed between urine ketones and capillary blood ketones for low values, but a poor correlation was observed for high values. Either test can therefore be used to exclude ketosis, but the capillary blood ketones test is more accurate to confirm ketoacidosis.


Assuntos
Ácido 3-Hidroxibutírico/sangue , Acetoacetatos/urina , Hiperglicemia/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hiperglicemia/urina , Cetonas/sangue , Cetonas/urina , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos
17.
Diabetes Metab ; 43(1): 79-82, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27262367

RESUMO

BACKGROUND AND OBJECTIVES: Peripheral tissue resistance to insulin action is a characteristic of type 2 diabetes mellitus (T2DM). It has also been reported that some chronic viral infections can contribute to insulin resistance. Human herpesvirus (HHV)-8 infection has been detected in T2DM patients in previous studies. Our study investigated whether the presence of the virus is associated with insulin resistance in patients with ketosis-prone type 2 diabetes (KPD), as reported with other viruses. RESEARCH DESIGN AND METHODS: A total of 11 insulin-free KPD patients positive (+) and seven patients who were negative (-) for HHV-8 infection were recruited; the latter had KPD that was well controlled (HbA1c=6.2±0.7%). A two-step euglycaemic-hyperinsulinaemic clamp test coupled with deuterated [6,6-2H2]glucose was used to assess insulin sensitivity, non-esterified fatty acid (NEFA) suppression and endogenous glucose production. RESULTS: In KPD patients, whether HHV-8+ or HHV-8-, there were no differences in NEFA release, endogenous glucose production or insulin sensitivity (M value). CONCLUSION: Asymptomatic HHV-8 infection does not appear to be associated with decreased insulin sensitivity in diabetic patients. These results should now be confirmed in a larger sample population.


Assuntos
Diabetes Mellitus Tipo 2 , Cetoacidose Diabética , Infecções por Herpesviridae , Herpesvirus Humano 8 , Resistência à Insulina , Adulto , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/virologia , Cetoacidose Diabética/epidemiologia , Cetoacidose Diabética/virologia , Feminino , Técnica Clamp de Glucose , Infecções por Herpesviridae/complicações , Infecções por Herpesviridae/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade
18.
Diabetes Res Clin Pract ; 116: 26-8, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27321312

RESUMO

We conducted a pilot study to evaluate two therapeutic strategies at the time of insulin initiation in type 2 diabetic patients insufficiently controlled with metformin+insulin-secretagogues (IS, sulfonylureas or glinides). Patients were randomized to remain under the same dual therapy or to receive metformin+DPP4 inhibitors while starting insulin. Similar glycemic control was achieved in both groups. However less hypoglycemia was observed with DPP4 inhibitors despite higher doses of insulin.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Metformina/uso terapêutico , Compostos de Sulfonilureia/uso terapêutico , Adamantano/análogos & derivados , Adamantano/uso terapêutico , Idoso , Glicemia , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas/uso terapêutico , Projetos Piloto , Pirrolidinas/uso terapêutico , Vildagliptina
20.
Diabetes ; 50(8): 1828-33, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11473045

RESUMO

The offspring of Pima Indians with early onset type 2 diabetes are at high risk for developing diabetes at an early age. This risk is greater among those whose mothers were diabetic during pregnancy. To define the metabolic abnormalities predisposing individuals in these high-risk groups to diabetes, we conducted a series of studies to measure insulin secretion and insulin action in healthy adult Pima Indians. In 104 normal glucose-tolerant subjects, acute insulin secretory response (AIR) to a 25-g intravenous glucose challenge correlated with the age at onset of diabetes in the mother (r = 0.23, P = 0.03) and, in multiple regression analyses, the age at onset of diabetes in the father (P = 0.02), after adjusting for maternal age at onset and after allowing for an interaction between these terms. In contrast, insulin action (hyperinsulinemic glucose clamp) did not correlate with the age at onset of diabetes in the parents. To determine whether early onset diabetes in the parents affected insulin secretion in the offspring across a range of glucose concentrations, responses to a stepped glucose infusion were measured in 23 subjects. Insulin secretion rates were lower in individuals whose mothers had developed diabetes before 35 years of age (n = 8) compared with those whose parents remained nondiabetic until at least 49 years of age (n = 15) (average insulin secretory rates: geometric mean [95% CI] 369 [209-652] vs. 571 [418-780] pmol/min, P = 0.007). Finally, the AIR was lower in individuals whose mothers were diabetic during pregnancy (n = 8) than in those whose mothers developed diabetes at an early age but after the birth of the subject (n = 41) (740 [510-1,310] vs. 1,255 [1,045-1,505] pmol/l, P < 0.02). Thus, insulin secretion is lower in normal glucose tolerant offspring of people with early onset type 2 diabetes. This impairment may be worsened by exposure to a diabetic environment in utero.


Assuntos
Diabetes Mellitus Tipo 2/genética , Indígenas Norte-Americanos , Insulina/metabolismo , Gravidez em Diabéticas/genética , Tecido Adiposo/anatomia & histologia , Adulto , Idade de Início , Análise de Variância , Arizona , Glicemia/metabolismo , Constituição Corporal , Peso Corporal , Estudos de Coortes , Feminino , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Secreção de Insulina , Masculino , Pessoa de Meia-Idade , Mães , Núcleo Familiar , Gravidez , Valores de Referência
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