RESUMO
The authors' perspective is described regarding modifications made in their clinic to glucose challenge protocols and mathematical models in order to estimate insulin secretion, insulin sensitivity and glucose effectiveness in patients living with Insulin-Requiring Diabetes and patients who received Pancreatic Islet Transplants to treat Type I diabetes (T1D) with Impaired Awareness of Hypoglycemia. The evolutions are described of protocols and models for use in T1D, and Insulin-Requiring Type 2 Diabetes (T2D) that were the basis for studies in the Islet Recipients. In each group, the need for modifications, and how the protocols and models were adapted is discussed. How the ongoing application of the adaptations is clarifying the Islet pathophysiology in the Islet Transplant Recipients is outlined.
Assuntos
Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas , Modelos Biológicos , Transplantados , Humanos , Resistência à Insulina , Secreção de InsulinaAssuntos
Diabetes Mellitus Tipo 1/cirurgia , Ácidos Graxos não Esterificados/sangue , Teste de Tolerância a Glucose , Transplante das Ilhotas Pancreáticas , Fígado/metabolismo , Biomarcadores/sangue , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Imunossupressores/efeitos adversos , Insulina/sangue , Cinética , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Resultado do TratamentoAssuntos
Diabetes Mellitus Tipo 1/cirurgia , Insulina/metabolismo , Transplante das Ilhotas Pancreáticas/fisiologia , Conscientização , Peptídeo C/sangue , Feminino , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/epidemiologia , Secreção de Insulina , Pessoa de Meia-Idade , Monitorização Fisiológica/métodos , Transplante Homólogo , Resultado do TratamentoRESUMO
BACKGROUND: Glucose effectiveness (S(g)) is an important component in glucose tolerance. Values of S(g) using "open loop" glucose kinetic computer programs are usually higher compared to closed loop method (CLM) programs that incorporate insulin secretion modeling. We aimed to test whether these differences are caused by (1) inclusion of insulin secretion modeling or (2) the method of representing plasma insulin values in the first few minutes of the frequently sampled intravenous glucose tolerance test (FSIGT). METHODS: FSIGTs without insulin supplementation were performed in six healthy volunteers, and the Bergman minimal model was fitted to the data using the simulation and modeling program SAAM. RESULTS: The CLM, which represents the insulin data in the first few minutes by a best-fit curve extrapolated to the y-axis, yielded a significantly lower S(g) than the approach similar to the computer program MINMOD, where the first few minutes of insulin data are represented by a line joining the basal to the peak values (1.55 +/- 0.28 vs. 1.97 +/- 0.27 [SE] x 10(-2)/min, P < 0.05). This second analysis was then repeated while forcing the program to represent the insulin data after the insulin peak in the same way as in the CLM, obtaining an almost identical result for S(g) (1.99 +/- 0.29). Insulin sensitivity was not significantly affected. CONCLUSIONS: The higher S(g) estimates are caused by the method of representing the first few minutes of insulin data rather than by the incorporation of insulin secretion modeling. It is, therefore, important to know how the early insulin data are represented when comparing results from different computer modeling programs.
