Navegando por Palavras-chave "Insulin sensitivity"
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- ItemSomente MetadadadosAcute exercise reverses TRB3 expression in the skeletal muscle and ameliorates whole body insulin sensitivity in diabetic mice(Wiley-Blackwell, 2010-01-01) Matos, Agberto Corrêa de; Ropelle, Eduardo Rochete; Pauli, José Rodrigo [UNIFESP]; Frederico, Marisa Jadna Silva; Pinho, Ricardo Aurino de; Velloso, Lício Augusto; Souza, Claudio Teodoro de; Univ Cruzeiro Sul; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Univ So Santa CatarinaAim:TRB3 became of major interest in diabetes research when it was shown to interact with and inhibit the activity of Akt. Conversely, physical exercise has been linked to improved glucose homeostasis. Thus, the current study was designed to investigate the effects of acute exercise on TRB3 expression and whole body insulin sensitivity in obese diabetic mice.Methods:Male leptin-deficient (ob/ob) mice swam for two 3-h-long bouts, separated by a 45-min rest period. After the second bout of exercise, food was withdrawn 6 h before antibody analysis. Eight hours after the exercise protocol, the mice were submitted to an insulin tolerance test (ITT). Gastrocnemius muscle samples were evaluated for insulin receptor (IR) and IRS-1 tyrosine phosphorylation, Akt serine phosphorylation, TRB3/Akt association and membrane GLUT4 expression.Results:Western blot analysis showed that TRB3 expression was reduced in the gastrocnemius of leptin-deficient (ob/ob) mice submitted to exercise when compared with respective ob/ob mice at rest. in parallel, there was an increase in the insulin-signalling pathway in skeletal muscle from leptin-deficient mice after exercise. Furthermore, the GLUT4 membrane expression was increased in the muscle after the exercise protocol. Finally, a single session of exercise improved the glucose disappearance (K(ITT)) rate in ob/ob mice.Conclusion:Our results demonstrate that acute exercise reverses TRB3 expression and insulin signalling restoration in muscle. Thus, these results provide new insights into the mechanism by which physical activity ameliorates whole body insulin sensitivity in type 2 diabetes.
- ItemSomente MetadadadosChildren recovered from malnutrition exhibit normal insulin production and sensitivity(Cambridge Univ Press, 2008-02-01) Martins, Vinícius José Baccin [UNIFESP]; Martins, Paula Andrea [UNIFESP]; Neves, Janaina das [UNIFESP]; Sawaya, Ana Lydia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Protein-energy malnutrition promotes adaptive hormonal changes that result in stunting. A previous study showed that stunted children had increased insulin sensitivity and diminished pancreatic P-cell function. the objectives of the present study were to analyse the glucose, insulin, homeostasis model assessment of insulin sensitivity (HOMA-S) and homeostasis model assessment of pancreatic P-cell function (HOMA-B) levels after nutritional recovery. the recovered group (n 62) consisted of malnourished children after treatment at a nutrition rehabilitation centre. At the beginning of treatment their age was 2.41 (SD 1.28) and 2.31 (SD 1.08) years, weight-for-age Z score -2.09 (SD 0.94) and -2.05 (SD 0.55) and height-for-age Z score - 1.85 (SD 1.11) and - 1.56 (SD 0.90), for boys and girls respectively. the control group consisted of well-nourished children without treatment (n 26). After treatment, boys of the recovered group gained 1.29 (SD 1.06) Z scores of height-for-age and 1.14 (SD 0-99) Z scores of weight-for-age, and girls, 1.12 (SD 0.91) and 1.21 (SD 0-74) Z scores respectively. No differences were found between control and recovered groups in insulin levels for boys (P=0.704) and girls (P=0.408), HOMA-B for boys (P=0.451) and girls (P=0.330), and HOMA-S (P=0.765) for boys and girls (P=0-456) respectively. the present study shows that the changes observed previously in glucose metabolism and insulin were reverted in children who received adequate treatment at nutritional rehabilitation centres and showed linear catch-up.
- ItemSomente MetadadadosEffects of extended regimens of the contraceptive vaginal ring on carbohydrate metabolism(Elsevier B.V., 2012-03-01) Guazzelli, Cristina A. F. [UNIFESP]; Barreiros, Fernando A. [UNIFESP]; Torloni, Maria R. [UNIFESP]; Barbieri, Marcia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background: There are few publications on the metabolic effects of extended regimens of the contraceptive vaginal ring. the aim of this study was to assess changes in fasting plasma glucose levels and insulin concentration of women using the contraceptive vaginal ring continuously over a 1-year period.Study Design: This prospective cohort enrolled 75 women (ages 18-37 years) who used a contraceptive vaginal ring releasing 120 mcg of etonogestrel and 15 mcg of ethinyl estradiol daily continuously for 84 days, followed by a 7-day ring-free interval, during I year. Fasting glucose and insulin levels were measured, and homeostatic model assessment was calculated at baseline and every 3 months during the 1-year study period. the repeated-measures analysis of variance test was used to analyze differences in the results of these exams over time.Results: None of the 75 participants had results outside the normal range in any of the assessments. There were no pregnancies during the 1-year period, and a total of 62 participants completed the study. There were no significant changes in mean fasting glucose levels (79.3 and 78.9 mg/dL at baseline and after 12 months, respectively), mean fasting insulin concentration (9.6 and 10.1 mu U/mL) or mean homeostatic model assessment results (1.88% and 1.97%).Conclusion: Fasting plasma glucose concentration, insulin levels and homeostatic model assessment values of women using the vaginal ring on an extended regimen did not change significantly over a 1-year period. (c) 2012 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosFamily History of Diabetes as a New Determinant of Insulin Sensitivity and Secretion in Patients Who Have Undergone a Simultaneous Pancreas-Kidney Transplant(Baskent Univ, 2010-03-01) Rangel, Erika Bevilaqua [UNIFESP]; Melaragno, Cláudio Santiago [UNIFESP]; Neves, Maria Deolinda F. [UNIFESP]; Dib, Sergio Atala [UNIFESP]; Gonzalez, Adriano Miziara [UNIFESP]; Linhares, Marcelo Moura [UNIFESP]; Pacheco-Silva, Alvaro [UNIFESP]; Sá, João Roberto de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objectives: We used homeostasis model assessment to investigate insulin sensitivity and secretion after a simultaneous pancreas-kidney transplant or kidney transplant alone. In that model, fasting plasma glucose and C-peptide levels are used to evaluate insulin sensitivity and beta-cell function.Materials and Methods: Factors (eg, age, sex, race, delayed kidney allograft function) were correlated with homeostasis model assessment of beta-cell function and homeostasis model assessment of insulin sensitivity values after simultaneous pancreas-kidney transplant (n=89) or kidney transplant alone (n=68), and the results were compared with those in healthy subjects (n=49).Results: Homeostasis model assessment of beta-cell function values were similar in patients who underwent kidney transplant alone or a simultaneous pancreas-kidney transplant, and were higher than homeostasis model assessment of beta-cell function values in healthy subjects. The homeostasis model assessment of insulin sensitivity showed intermediate values for patients who underwent a simultaneous pancreas-kidney transplant and correlated with prednisone dosages (in those who underwent kidney transplant alone) and tacrolimus levels (in patients who underwent a simultaneous pancreas-kidney transplant). Homeostasis model assessment of beta-cell function values correlated with prednisone dosages in both groups and with tacrolimus levels in only those who underwent a simultaneous pancreas-kidney transplant. The body mass index of subjects who underwent kidney transplant alone correlated with both homeostasis model assessment of beta-cell function results and homeostasis model assessment of insulin sensitivity results. A family history of diabetes in subjects who underwent a simultaneous pancreas-kidney transplant correlated with homeostasis model assessment of beta-cell function results and homeostasis model assessment of insulin sensitivity results.Conclusions: Immunosuppressive regimen and body mass index were linked with reduced insulin sensitivity after kidney transplant. A family history of diabetes was linked with higher values of insulin secretion and lower insulin sensitivity in patients who underwent a simultaneous pancreas-kidney transplant.
- ItemAcesso aberto (Open Access)Non-obese adult onset diabetes with oral hypoglycemic agent failure: islet cell autoantibodies or reversible beta cell refractoriness?(Associação Brasileira de Divulgação Científica, 2003-10-01) Sá, João Roberto [UNIFESP]; Silva, Reinaldo Correia [UNIFESP]; Nasri, Fabio [UNIFESP]; Aguade, Luiz Carlos Muria [UNIFESP]; Velloso, Lício Augusto [UNIFESP]; Chacra, Antonio Roberto [UNIFESP]; Dib, Sergio Atala [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Pancreatic ß cell function and insulin sensitivity, analyzed by the homeostasis model assessment, before and after 24 weeks of insulin therapy were studied and correlated with the presence of autoantibodies against ß cells (islet cell and anti-glutamic acid decarboxylase antibodies), in a group of 18 Brazilian lean adult non-insulin-dependent diabetes mellitus (NIDDM) patients with oral hypoglycemic agent failure (OHAF). Median fasting plasma glucose before and after insulin treatment was 19.1 and 8.5 mmol/l, respectively (P < 0.001); median HbA1c was 11.7% before vs 7.2% after insulin treatment (P < 0.001). Forty-four percent of the patients were positive (Ab+) to at least one autoantibody. Fasting C-peptide levels were lower in Ab+ than Ab- patients, both before (Ab+: 0.16 ± 0.09 vs Ab-: 0.41 ± 0.35 nmol/l, P < 0.003) and after insulin treatment (Ab+: 0.22 ± 0.13 vs Ab-: 0.44 ± 0.24 nmol/l, P < 0.03). Improvement of Hß was seen in Ab- (median before: 7.3 vs after insulin therapy: 33.4%, P = 0.003) but not in Ab+ patients (median before: 6.6 vs after insulin therapy: 20.9%). These results show that the OHAF observed in the 18 NIDDM patients studied was due mainly to two major causes: autoantibodies and ß cell desensitization. Autoantibodies against ß cells could account for 44% of OHAF, but Ab- patients may still present ß cell function recovery, mainly after a period of ß cell rest with insulin therapy. However, the effects of ß cell function recovery on the restoration of the response to oral hypoglycemic agents need to be determined.
- ItemAcesso aberto (Open Access)Relação da homocisteinemia com a sensibilidade à insulina e com fatores de risco cardiovascular em um grupo indígena brasileiro(Sociedade Brasileira de Endocrinologia e Metabologia, 2002-06-01) Tavares, Edelweiss Fonseca [UNIFESP]; Vieira Filho, João Paulo Botelho [UNIFESP]; Andriolo, Adagmar [UNIFESP]; Franco, Laercio Joel [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Hyperhomocysteinemia is an independent cardiovascular risk factor. There are controversies about a possible relation between homocysteine and insulin resistance/sensitivity. To test the relation between homocysteinemia and insulin sensitivity, serum total homocysteine concentrations (HPLC) were measured in samples from ninety Parkatêjê Indians (90% of the adult population, without admixture). Insulin sensitivity (%S) was estimated by HOMA. A diabetic woman was excluded from the analysis involving glycaemia, insulin, proinsulin, HbA1c and %S. Hyperhomocysteinemia and fasting hyperinsulinemia were found in 26.7% and 25.8% of Indians, respectively. Log-transformed (ln) homocysteine was positively correlated with systolic (r= 0.22) and diastolic (r= 0.21) blood pressure, triglycerides (r= 0.39) and uric acid (r= 0.40), after adjustment for age and sex, but not with insulin, proinsulin and ln %S. Ln homocysteine was similar among the quartiles of %S and between the subjects with and without fasting hyperinsulinemia. Insulin, proinsulin and ln %S were similar between the subjects with and without hyperhomocisteinemia. Correlations between variables related to cardiovascular risk were observed, but not between these variables and insulin or ln %S. Perhaps this finding could be a peculiar characteristic of this group. In conclusion, the variations in serum homocysteine levels were not related to insulin, proinsulin and %S among the Parkatêjê.