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2.
J Clin Endocrinol Metab ; 108(3): 529-562, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36477488

RESUMO

CONTEXT: Hypoglycemia in people with diabetes is common, especially in those taking medications such as insulin and sulfonylureas (SU) that place them at higher risk. Hypoglycemia is associated with distress in those with diabetes and their families, medication nonadherence, and disruption of life and work, and it leads to costly emergency department visits and hospitalizations, morbidity, and mortality. OBJECTIVE: To review and update the diabetes-specific parts of the 2009 Evaluation and Management of Adult Hypoglycemic Disorders: Endocrine Society Clinical Practice Guideline and to address developing issues surrounding hypoglycemia in both adults and children living with diabetes. The overriding objectives are to reduce and prevent hypoglycemia. METHODS: A multidisciplinary panel of clinician experts, together with a patient representative, and methodologists with expertise in evidence synthesis and guideline development, identified and prioritized 10 clinical questions related to hypoglycemia in people living with diabetes. Systematic reviews were conducted to address all the questions. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make recommendations. RESULTS: The panel agreed on 10 questions specific to hypoglycemia risk and prevention in people with diabetes for which 10 recommendations were made. The guideline includes conditional recommendations for use of real-time continuous glucose monitoring (CGM) and algorithm-driven insulin pumps in people with type 1 diabetes (T1D), use of CGM for outpatients with type 2 diabetes at high risk for hypoglycemia, use of long-acting and rapid-acting insulin analogs, and initiation of and continuation of CGM for select inpatient populations at high risk for hypoglycemia. Strong recommendations were made for structured diabetes education programs for those at high risk for hypoglycemia, use of glucagon preparations that do not require reconstitution vs those that do for managing severe outpatient hypoglycemia for adults and children, use of real-time CGM for individuals with T1D receiving multiple daily injections, and the use of inpatient glycemic management programs leveraging electronic health record data to reduce the risk of hypoglycemia. CONCLUSION: The recommendations are based on the consideration of critical outcomes as well as implementation factors such as feasibility and values and preferences of people with diabetes. These recommendations can be used to inform clinical practice and health care system improvement for this important complication for people living with diabetes.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Hipoglicemia , Adulto , Criança , Humanos , Glicemia , Automonitorização da Glicemia/métodos , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemia/induzido quimicamente , Hipoglicemia/prevenção & controle , Hipoglicemia/tratamento farmacológico , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos
3.
J Clin Endocrinol Metab ; 108(3): 592-603, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36477885

RESUMO

CONTEXT: Interventions targeting hypoglycemia in people with diabetes are important for improving quality of life and reducing morbidity and mortality. OBJECTIVE: To support development of the Endocrine Society Clinical Practice Guideline for management of individuals with diabetes at high risk for hypoglycemia. METHODS: We searched several databases for studies addressing 10 questions provided by a guideline panel from the Endocrine Society. Meta-analysis was conducted when feasible. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess certainty of evidence. RESULTS: We included 149 studies reporting on 43 344 patients. Continuous glucose monitoring (CGM) reduced episodes of severe hypoglycemia in patients with type 1 diabetes (T1D) and reduced the proportion of patients with hypoglycemia (blood glucose [BG] levels <54 mg/dL). There were no data on use of real-time CGM with algorithm-driven insulin pumps vs multiple daily injections with BG testing in people with T1D. CGM in outpatients with type 2 diabetes taking insulin and/or sulfonylureas reduced time spent with BG levels under 70 mg/dL. Initiation of CGM in hospitalized patients at high risk for hypoglycemia reduced episodes of hypoglycemia with BG levels lower than 54 mg/dL and time spent under 54 mg/dL. The proportion of patients with hypoglycemia with BG levels lower than 70 mg/dL and lower than 54 mg/dL detected by CGM was significantly higher than point-of-care BG testing. We found no data evaluating continuation of personal CGM in the hospital. Use of an inpatient computerized glycemic management program utilizing electronic health record data was associated with fewer patients with and episodes of hypoglycemia with BG levels lower than 70 mg/dL and fewer patients with severe hypoglycemia compared with standard care. Long-acting basal insulin analogs were associated with less hypoglycemia. Rapid-acting insulin analogs were associated with reduced severe hypoglycemia, though there were more patients with mild to moderate hypoglycemia. Structured diabetes education programs reduced episodes of severe hypoglycemia and time below 54 mg/dL in outpatients taking insulin. Glucagon formulations not requiring reconstitution were associated with longer times to recovery from hypoglycemia, although the proportion of patients who recovered completely from hypoglycemia was not different between the 2 groups. CONCLUSION: This systematic review summarized the best available evidence about several interventions addressing hypoglycemia in people with diabetes. This evidence base will facilitate development of clinical practice guidelines by the Endocrine Society.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Hipoglicemia , Humanos , Hipoglicemiantes/efeitos adversos , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/tratamento farmacológico , Automonitorização da Glicemia/métodos , Qualidade de Vida , Glicemia/análise , Hipoglicemia/induzido quimicamente , Hipoglicemia/diagnóstico , Hipoglicemia/prevenção & controle , Insulina/efeitos adversos , Insulina de Ação Prolongada
4.
J Clin Endocrinol Metab ; 107(8): 2129-2138, 2022 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-35690966

RESUMO

In an effort to enhance the trustworthiness of its clinical practice guidelines, the Endocrine Society has recently adopted new policies and more rigorous methodologies for its guideline program. In this Clinical Practice Guideline Communication, we describe these recent enhancements-many of which reflect greater adherence to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to guideline development-in addition to the rationale for such changes. Improvements to the Society's guideline development practices include, but are not limited to, enhanced inclusion of nonendocrinologist experts, including patient representatives, on guideline development panels; implementation of a more rigorous conflict/duality of interest policy; a requirement that all formal recommendations must be demonstrably underpinned by systematic evidence review; the explicit use of GRADE Evidence-to-Decision frameworks; greater use and explanation of standardized guideline language; and a more intentional approach to guideline updating. Lastly, we describe some of the experiential differences our guideline readers are most likely to notice.


Assuntos
Medicina Baseada em Evidências , Medicina Baseada em Evidências/métodos , Humanos
5.
J Endocr Soc ; 4(11): bvaa118, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33094208

RESUMO

This study aimed to compare conventional medication management of type 2 diabetes (T2D) to medication management in conjunction with a lifestyle intervention using continuous glucose monitoring to minimize glucose excursions. Thirty adults (63% female; mean age, 53.3 years) who were diagnosed with T2D for less than 11 years (mean, 5.6 years), had glycated A1c (HbA1c) ≥ 7.0% (51 mmol/mol) (mean 8.8%, [73 mmol/mol]), and were not using insulin, were randomly assigned in a 1:2 ratio to routine care (RC) or 4 group sessions of glycemic excursion minimization plus real-time CGM (GEMCGM). Assessments at baseline and 5 months included a physical exam, metabolic and lipid panels, a review of diabetes medications, and psychological questionnaires. For the week following assessments, participants wore a blinded activity monitor and completed 3 days of 24-hour dietary recall. A subgroup also wore a blinded CGM. GEMCGM participants significantly improved HbA1c (from 8.9% to 7.6% [74-60 mmol/mol] compared with 8.8% to 8.7% [73-72 mmol/mol] for RC (P = .03). Additionally, GEMCGM reduced the need for diabetes medication (P = .01), reduced carbohydrate consumption (P = .009), and improved diabetes knowledge (P = .001), quality of life (P = .01) and diabetes distress (P = .02), and trended to more empowerment (P = .05) without increasing dietary fat, lipids, or hypoglycemia. Confirming our prior research, GEMCGM appears to be a safe, effective lifestyle intervention option for adults with suboptimally controlled T2D who do not take insulin.

6.
J Endocr Soc ; 3(10): 1942-1957, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31608313

RESUMO

Faster-acting insulins, new noninsulin drug classes, more flexible insulin-delivery systems, and improved continuous glucose monitoring devices offer unprecedented opportunities to improve postprandial glucose (PPG) management and overall care for adults with insulin-treated diabetes. These developments led the Endocrine Society to convene a working panel of diabetes experts in December 2018 to assess the current state of PPG management, identify innovative ways to improve self-management and quality of life, and align best practices to current and emerging treatment and monitoring options. Drawing on current research and collective clinical experience, we considered the following issues for the ∼200 million adults worldwide with type 1 and insulin-requiring type 2 diabetes: (i) the role of PPG management in reducing the risk of diabetes complications; (ii) barriers preventing effective PPG management; (iii) strategies to reduce PPG excursions and improve patient quality of life; and (iv) education and clinical tools to support endocrinologists in improving PPG management. We concluded that managing PPG to minimize or prevent diabetes-related complications will require elucidating fundamental questions about optimal ways to quantify and clinically assess the metabolic dysregulation and consequences of the abnormal postprandial state in diabetes and recommend research strategies to address these questions. We also identified practical strategies and tools that are already available to reduce barriers to effective PPG management, optimize use of new and emerging clinical tools, and improve patient self-management and quality of life.

7.
Diabetes Ther ; 10(1): 277-281, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30565055

RESUMO

INTRODUCTION: Efforts to lower glycosylated hemoglobin (A1c) in patients with type 2 diabetes (T2D) are intended to reduce the risk of diabetic complications, but A1c is not the only factor contributing to this risk. Consequently, we re-analyzed published data from a broad-spectrum lifestyle intervention that lowered A1c to assess its effectiveness in lowering the overall risk of two complications of T2D, namely, coronary heart disease (CHD) and stroke. METHODS: Data from 37 adults who participated in a randomized clinical trial of a lifestyle intervention intended to reduce postprandial glucose (PPG) were re-analyzed for their pre- and post-treatment risk of CHD and stroke using the T2D-specific UK Prospective Diabetes Study (UKPDS) v2.0 risk algorithm. RESULTS: Compared to participants who received routine care, those using the lifestyle intervention had a significantly greater reduction in 10-year risk for CHD, but not for stroke. CONCLUSION: These secondary analyses suggest that broad-spectrum lifestyle interventions that focus on lowering PPG may lower the risk of future CHD, which could guide future research. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02432391.

8.
Ann Thorac Surg ; 103(2): 526-532, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27570164

RESUMO

BACKGROUND: Hypoglycemia is a known risk of intensive postoperative glucose control in patients undergoing cardiac operations. However, neither the consequences of hypoglycemia relative to hyperglycemia, nor the possible interaction effects, have been well described. We examined the effects of postoperative hypoglycemia, hyperglycemia, and their interaction on short-term morbidity and mortality. METHODS: Single-institution Society of Thoracic Surgeons (STS) database patient records from 2010 to 2014 were merged with clinical data, including blood glucose values measured in the intensive care unit (ICU). Exclusion criteria included fewer than three glucose measurements and absence of an STS predicted risk of morbidity or mortality score. Primary outcomes were operative mortality and composite major morbidity (permanent stroke, renal failure, prolonged ventilation, pneumonia, or myocardial infarction). Secondary outcomes included ICU and postoperative length of stay. Hypoglycemia was defined as below 70 mg/dL, and hyperglycemia as above 180 mg/dL. Simple and multivariable regression models were used to evaluate the outcomes. RESULTS: A total of 2,285 patient records met the selection criteria for analysis. The mean postoperative glucose level was 140.8 ± 18.8 mg/dL. Overall, 21.4% of patients experienced a hypoglycemic episode (n = 488), and 1.05% (n = 24) had a severe hypoglycemic episode (<40 mg/dL). The unadjusted odds ratio (UOR) for operative mortality for patients with any hypoglycemic episode compared with those without was 5.47 (95% confidence interval [CI] 3.14 to 9.54), and the UOR for major morbidity was 4.66 (95% CI 3.55 to 6.11). After adjustment for predicted risk of morbidity or mortality and other significant covariates, the adjusted odds (AOR) of operative mortality were significant for patients with any hypoglycemia (AOR 4.88, 95% CI 2.67 to 8.92) and patients with both events (AOR 8.29, 95% CI 1.83 to 37.5) but not hyperglycemia alone (AOR 1.62, 95% CI 0.56 to 4.69). The AOR of major morbidity for patients with both hypoglycemic and hyperglycemic events was 14.3 (95% CI 6.50 to 31.4). CONCLUSIONS: Postoperative hypoglycemia is associated with both mortality and major morbidity after cardiac operations. The combination of both hyperglycemia and hypoglycemia represents a substantial increase in risk. Although it remains unclear whether hypoglycemia is a cause, an early warning sign, or a result of adverse events, this study suggests that hypoglycemia may be an important event in the postoperative period after cardiac operations.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Causas de Morte , Mortalidade Hospitalar , Hiperglicemia/mortalidade , Hipoglicemia/mortalidade , Fatores Etários , Idoso , Glicemia/análise , Procedimentos Cirúrgicos Cardíacos/métodos , Bases de Dados Factuais , Feminino , Humanos , Hiperglicemia/etiologia , Hiperglicemia/terapia , Hipoglicemia/etiologia , Hipoglicemia/terapia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Avaliação de Resultados em Cuidados de Saúde , Período Pós-Operatório , Estudos Retrospectivos , Medição de Risco , Fatores Sexuais , Taxa de Sobrevida
10.
Diabetes Res Clin Pract ; 111: 28-35, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26556234

RESUMO

AIMS: This preliminary RCT investigated whether an integrated lifestyle modification program that focuses on reducing postprandial blood glucose through replacing high with low glycemic load foods and increasing routine physical activities guided by systematic self-monitoring of blood glucose (GEM) could improve metabolic control of adults with type 2 diabetes mellitus, without compromising other physiological parameters. METHODS: Forty-seven adults (mean age 55.3 years) who were diagnosed with type 2 diabetes mellitus for less than 5 years (mean 2.1 years), had HbA1c ≥ 7% (mean 8.4%) and were not taking blood glucose lowering medications, were randomized to routine care or five 1-h instructional sessions of GEM. Assessments at baseline and 6 months included a physical exam, metabolic and lipid panels, and psychological questionnaires. RESULTS: The GEM intervention led to significant improvements in HbA1c (decreasing from 8.4 to 7.4% [69-57 mmol/mol] compared with 8.3 to 8.3% [68-68 mmol/mol] for routine care; Interaction p<.01) and psychological functioning without compromising other physiological parameters. CONCLUSIONS: Consistent with a patient-centered approach, GEM appears to be an effective lifestyle modification option for adults recently diagnosed with type 2 diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/terapia , Exercício Físico/fisiologia , Carga Glicêmica/fisiologia , Estilo de Vida , Adulto , Idoso , Terapia Comportamental , Glicemia/metabolismo , Automonitorização da Glicemia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Período Pós-Prandial , Autocuidado/métodos , Inquéritos e Questionários
11.
Curr Opin Clin Nutr Metab Care ; 18(4): 407-14, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26049639

RESUMO

PURPOSE OF REVIEW: Autoimmune destruction of the ß cells is considered the key abnormality in type 1 diabetes mellitus and insulin replacement the primary therapeutic strategy. However, a lack of insulin is accompanied by disturbances in glucagon release, which is excessive postprandially, but insufficient during hypoglycaemia. In addition, replacing insulin alone appears insufficient for adequate glucose control. This review focuses on the growing body of evidence that glucagon abnormalities contribute significantly to the pathophysiology of diabetes and on recent efforts to target the glucagon axis as adjunctive therapy to insulin replacement. RECENT FINDINGS: This review discusses recent (since 2013) advances in abnormalities of glucagon regulation and their link to the pathophysiology of diabetes; new mechanisms of glucagon action and regulation; manipulation of glucagon in diabetes treatment; and analytical and systems biology tools to study glucagon regulation. SUMMARY: Recent efforts 'resurrected' glucagon as a key hormone in the pathophysiology of diabetes. New studies target its abnormal regulation and action that is key for improving diabetes treatment. The progress is promising, but major questions remain, including unravelling the mechanism of loss of glucagon counterregulation in type 1 diabetes mellitus and how best to manipulate glucagon to achieve more efficient and safer glycaemic control.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Glucagon/metabolismo , Proteína de Ligação a CREB/genética , Proteína de Ligação a CREB/metabolismo , Células Secretoras de Glucagon/metabolismo , Gluconeogênese , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Humanos , Insulina/uso terapêutico , Células Secretoras de Insulina/metabolismo , Fígado/metabolismo , Fosforilação , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Endocrinol Metab Clin North Am ; 41(1): 57-87, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22575407

RESUMO

Hypoglycemia is the most important and common side effect of insulin therapy. It is also the rate limiting factor in safely achieving excellent glycemic control. A three-fold increased risk of severe hypoglycemia occurs in both type 1 and type 2 diabetes with tight glucose control. This dictates a need to individualize therapy and glycemia goals to minimize this risk. Several ways to reduce hypoglycemia risk are recognized and discussed. They include frequent monitoring of blood sugars with home blood glucose tests and sometimes continuous glucose monitoring (CGM) in order to identify hypoglycemia particularly in hypoglycemia unawareness. Considerations include prompt measured hypoglycemia treatment, attempts to reduce glycemic variability, balancing basal and meal insulin therapy, a pattern therapy approach and use of a physiological mimicry with insulin analogues in a flexible manner. Methods to achieve adequate control while focusing on minimizing the risk of hypoglycemia are delineated in this article.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Glicemia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Humanos , Hipoglicemia/sangue , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico
13.
Front Physiol ; 3: 40, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22403550

RESUMO

Glucagon counterregulation (GCR) protects against hypoglycemia, but is impaired in type 1 diabetes (T1DM). A model-based analysis of in vivo animal data predicts that the GCR defects are linked to basal hyperglucagonemia. To test this hypothesis we studied the relationship between basal glucagon (BasG) and the GCR response to hypoglycemia in 29 hyperinsulinemic clamps in T1DM patients. Glucose levels were stabilized in euglycemia and then steadily lowered to 50 mg/dL. Glucagon was measured before induction of hypoglycemia and at 10 min intervals after glucose reached levels below 70 mg/dL. GCR was assessed by CumG, the cumulative glucagon levels above basal; MaxG, the maximum glucagon response; and RIG, the relative increase in glucagon over basal. Analysis of the results was performed with our mathematical model of GCR. The model describes interactions between islet peptides and glucose, reproduces the normal GCR axis and its impairment in diabetes. It was used to identify a control mechanism consistent with the observed link between BasG and GCR. Analysis of the clinical data showed that higher BasG was associated with lower GCR response. In particular, CumG and RIG correlated negatively with BasG (r = -0.46, p = 0.012 and r = -0.74, p < 0.0001 respectively) and MaxG increased linearly with BasG at a rate less than unity (p < 0.001). Consistent with these results was a model of GCR in which the secretion of glucagon has two components. The first is under (auto) feedback control and drives a pulsatile GCR and the second is feedback independent (basal secretion) and its increase suppresses the GCR. Our simulations showed that this model explains the observed relationships between BasG and GCR during a three-fold simulated increase in BasG. Our findings support the hypothesis that basal hyperglucagonemia contributes to the GCR impairment in T1DM and show that the predictive power of our GCR animal model applies to human pathophysiology in T1DM.

15.
J Diabetes Sci Technol ; 4(6): 1345-56, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21129329

RESUMO

This review analyzes an interdisciplinary approach to the pancreatic endocrine network-like relationships that control glucagon secretion and glucagon counterregulation (GCR). Using in silico studies, we show that a pancreatic feedback network that brings together several explicit interactions between islet peptides and blood glucose reproduces the normal GCR axis and explains its impairment in diabetes. An α-cell auto-feedback loop drives glucagon pulsatility and mediates triggering of GCR by hypoglycemia by a rapid switch-off of ß-cell signals. The auto-feedback explains the enhancement of defective GCR in ß-cell deficiency by a switch-off of signals in the pancreas that suppress α cells. Our models also predict that reduced ß-cell activity decreases and delays the GCR. A key application of our models is the in silico simulation and testing of possible scenarios to repair defective GCR in ß-cell deficiency. In particular, we predict that partial suppression of hyperglucagonemia may repair the impaired GCR. We also outline how the models can be extended and tested using human data to become a part of a larger construct including the regulation of the hepatic glucose output by the pancreas, circulating glucose, and incretins. In conclusion, a model of the normal GCR control mechanisms and their dysregulation in insulin-deficient diabetes is proposed and partially validated. The model components are clinically measurable, which permits its application to the study of the abnormalities of the human endocrine pancreas and their role in the progression of many diseases, including diabetes, metabolic syndrome, polycystic ovary syndrome, and others. It may also be used to examine therapeutic responses.


Assuntos
Glicemia/metabolismo , Células Secretoras de Glucagon/metabolismo , Glucagon/metabolismo , Modelos Biológicos , Biologia de Sistemas , Animais , Simulação por Computador , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatologia , Retroalimentação Fisiológica , Humanos , Hipoglicemia/metabolismo , Hipoglicemia/fisiopatologia , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Fígado/metabolismo , Reprodutibilidade dos Testes
16.
Curr Diab Rep ; 10(2): 116-23, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20425570

RESUMO

Diabetic patients are at increased risk for developing cardiovascular disease, and they constitute a large proportion of the global cardiovascular disease burden. Although multiple drugs exist for treating the hyperglycemia associated with diabetes, few have been shown to reduce cardiovascular risk. Great hope surrounded the arrival of the thiazolidinediones-drugs that favorably affect insulin sensitivity, inflammation, and some aspects of lipid profiles in diabetic patients. However, the cardiovascular effects of these agents are varied, and studies have suggested that they may be associated with increases in ischemic heart disease and heart failure, as well as with an increased risk for bone fracture. The following article provides a summary of important studies that have been published regarding the safety profiles of these agents. Findings from two recently published trials, RECORD and BARI 2D, are emphasized in this paper.


Assuntos
Tiazolidinedionas/efeitos adversos , Ensaios Clínicos como Assunto , Fraturas Ósseas/induzido quimicamente , Insuficiência Cardíaca/induzido quimicamente , Humanos , Fatores de Risco
18.
Methods Enzymol ; 467: 547-581, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19897107

RESUMO

Glucagon counterregulation (GCR) is a key protection against hypoglycemia compromised in insulinopenic diabetes by an unknown mechanism. In this work, we present an interdisciplinary approach to the analysis of the GCR control mechanisms. Our results indicate that a pancreatic network which unifies a few explicit interactions between the major islet peptides and blood glucose (BG) can replicate the normal GCR axis and explain its impairment in diabetes. A key and novel component of this network is an alpha-cell auto-feedback, which drives glucagon pulsatility and mediates triggering of pulsatile GCR by hypoglycemia via a switch-off of the beta-cell suppression of the alpha-cells. We have performed simulations based on our models of the endocrine pancreas which explain the in vivo GCR response to hypoglycemia of the normal pancreas and the enhancement of defective pulsatile GCR in beta-cell deficiency by switch-off of intrapancreatic alpha-cell suppressing signals. The models also predicted that reduced insulin secretion decreases and delays the GCR. In conclusion, based on experimental data we have developed and validated a model of the normal GCR control mechanisms and their dysregulation in insulin deficient diabetes. One advantage of this construct is that all model components are clinically measurable, thereby permitting its transfer, validation, and application to the study of the GCR abnormalities of the human endocrine pancreas in vivo.


Assuntos
Diabetes Mellitus Experimental , Glucagon/metabolismo , Modelos Biológicos , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Retroalimentação Fisiológica , Células Secretoras de Glucagon/metabolismo , Glucose/metabolismo , Humanos , Hipoglicemia/sangue , Insulina/deficiência , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Modelos Teóricos , Ratos , Reprodutibilidade dos Testes , Transdução de Sinais/fisiologia , Células Secretoras de Somatostatina/metabolismo
19.
20.
J Diabetes Sci Technol ; 3(1): 3-11, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19756168

RESUMO

Hemoglobin A1c (HbA1c), a long-term, integrated average of tissue exposure to hyperglycemia, is the best reflection of average glucose concentrations and the best proven predictor of microvascular complications of diabetes mellitus. However, HbA1c fails to capture glycemic variability and the risks associated with extremes of hypoglycemia and hyperglycemia. These risks are the primary barrier to achieving the level of average glucose control that will minimize both the microvascular and the long-term macrovascular complications of type 1 diabetes. High blood glucose levels largely due to prandial excursions produce oxidative and inflammatory stress with potential acceleration of preexisting atherosclerosis and increased cardiovascular risk. Moreover, some temporal aspects of glycemic variation, including the rates of rise and fall of glucose, are associated with adverse cognitive and mood symptoms in those with diabetes. Methods to quantify the risk of glycemic extremes, both high and low, and the variability including its temporal aspects are now more precise than ever. These important endpoints should be included for use in clinical trials as useful metrics and recognized by regulatory agencies, which has not been the case in the past. Precise evaluation of glycemic variability and its attendant risks are essential in the design of optimal therapies; for these reasons, inclusion of these metrics and the pulsatile hormone patterns in mathematical models may be essential. For the clinician, the incursion of mathematical models that simulate normal and pathophysiological mechanisms of glycemic control is a reality and should be also gradually incorporated into clinical practice.


Assuntos
Glicemia/análise , Diabetes Mellitus/sangue , Modelos Teóricos , Humanos
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