Direct comparison among oral hypoglycemic agents and their association with insulin resistance evaluated by euglycemic hyperinsulinemic clamp: the 60's study. Chitosan improves insulin sensitivity as determined by the euglycemic-hyperinsulinemic clamp technique in obese subjects. Longitudinal changes in insulin release and insulin resistance in nonobese pregnant women. How good a marker is insulin level for insulin resistance? Exercise training augments the peripheral insulin-sensitizing effects of pioglitazone in HIV-infected adults with insulin resistance and central adiposity. Vildagliptin added to metformin on β-cell function after a euglycemic hyperinsulinemic and hyperglycemic clamp in type 2 diabetes patients. Effect of Oral L-Carnitine Administration on Insulin Sensitivity and Lipid Profile in Type 2 Diabetes Mellitus Patients
The aim of the study was to compare the long-term effect of 4 antidiabetic treatment protocol s on insulin resistance evaluated by euglycemic hyperinsulinemic clamp in type 2 diabetes mellitus patients . Two hundred seventy-one type 2 diabetes mellitus patients with poor glycemic control and who were overweight were enrolled in this study . Patients were r and omized and titrated to take pioglitazone , metformin , pioglitazone + metformin , or glimepiride + metformin for 15 months . They underwent a euglycemic hyperinsulinemic clamp at baseline , after 3 months , and after 15 months . Anthropometric and metabolic measurements were assessed at baseline , after 3 months , and after 15 months . There was a decrease in glycated hemoglobin in all groups , but glycated hemoglobin value was lower in the group treated with pioglitazone + metformin compared with the groups treated with metformin alone and with pioglitazone alone . There was a decrease in fasting plasma glucose and postpr and ial plasma glucose values in all groups , but values obtained with pioglitazone + metformin were lower compared with values in the groups treated with metformin alone and with pioglitazone alone . Fasting plasma insulin and postpr and ial plasma insulin values were higher in the group treated with glimepiride + metformin compared with the other groups . After 15 months , glucose infusion rate and total glucose requirement values observed in the groups treated with pioglitazone alone and with pioglitazone + metformin were higher compared with the values in the group treated with metformin alone and with glimepiride + metformin ; furthermore , values obtained in the group treated with pioglitazone + metformin were higher than the value obtained with pioglitazone alone . Pioglitazone-metformin-based therapeutic control is associated with the most quantitatively relevant improvement in insulin resistance-related parameters , whereas the sulfonylurea-metformin-including protocol has less relevant effects In accordance with obesity is associated with insulin resistance and dyslipidemia and chitosan decrease weight and lipids , but its effect on insulin sensitivity is unknown . Our hypothesis for the research was that chitosan improves insulin sensitivity estimated with the euglycemic-hyperinsulinemic clamp technique in obesity . We undertook this study with the objective to determine the effect of chitosan on insulin sensitivity using the euglycemic-hyperinsulinemic clamp technique in obese patients during a 3-month period . A r and omized , double-blind clinical trial was carried out in 12 obese adults without diabetes mellitus . During a 3-month period , 6 patients received chitosan ( 750 mg , 3 times per day ) 30 minutes before meals , and the other 6 subjects received placebo .  Serum glucose , total cholesterol , high-density lipoprotein cholesterol , and triglycerides ( TG ) were measured . Insulin sensitivity was estimated with the euglycemic-hyperinsulinemic clamp technique before and after the intervention . Insulin sensitivity increased significantly with the administration of chitosan ( 2.4 + /- 1.4 vs 3.6 + /- 1.4 mg kg(-1 ) min(-1 ) ; P = .043 ) . In addition , there was a decrease in weight ( 90.7 + /- 14.2 vs 84.7 + /- 13.7 kg ; P = .027 ) , body mass index ( 34.3 + /- 2.7 vs 31.6 + /- 2.2 kg/m(2 ) ; P = .028 ) , waist circumference ( 106 + /- 12 vs 99 + /- 9 cm ; P = .028 ) and TG ( 2.4 + /- 0.9 vs 1.6 + /- 0.9 mmol/L ; P = .028 ) in the chitosan group . In conclusion , 3-month administration of chitosan increased insulin sensitivity  in obese patients and demonstrated a decrease in weight , body mass index , waist circumference , and TG To assess the longitudinal changes in insulin release and insulin sensitivity in nonobese normal women during gestation , six women were evaluated with oral glucose tolerance testing , body composition analysis , intravenous glucose tolerance tests , and the hyperinsulinemic-euglycemic clamp before conception , at 12 to 14 weeks , and at 34 to 36 weeks ' gestation . There was a significant increase in the insulin/glucose ratio ( p = 0.028 ) during the oral glucose tolerance test during gestation . There was also a significant 3.0- to 3.5-fold increase throughout gestation in first-phase ( p = 0.001 ) and second-phase ( p = 0.0001 ) insulin release during the intravenous glucose tolerance test . Peripheral insulin sensitivity was estimated as the glucose infusion rate ( in milligrams per kilogram fat-free mass per minute ) during the hyperinsulinemic-euglycemic clamp . There was a significant ( p = 0.0003 ) 56 % decrease in insulin sensitivity through 36 weeks ' gestation . These results are the first to prospect ively evaluate the longitudinal changes in maternal carbohydrate metabolism from the time before conception through late gestation with newer methods such as the hyperinsulinemic-euglycemic clamp Epidemiologic studies have correlated fasting and postload insulin levels with the risk of coronary heart disease , assuming that insulin levels are reliable markers of insulin resistance . However , this assumption has not been systematic ally studied . The author measured insulin response to an oral glucose load and quantitated insulin resistance using the euglycemic hyperinsulinemic clamp technique to evaluate the correlation between insulin level and the degree of insulin resistance in individuals with varying degrees of glucose tolerance . Subjects were r and omly selected from previous population studies done in 1987 - 1989 at the Department of Medicine of the University of Kuopio in east Finl and . Altogether , 50 subjects with normal glucose tolerance , 28 with impaired glucose tolerance , and 54 with non-insulin-dependent diabetes mellitus were studied . Correlations of insulin resistance ( whole-body glucose uptake in clamp studies ) with fasting or postload insulin levels were remarkably consistent , ranging from -0.58 to -0.74 ( p < 0.01 ) in subjects with normoglycemia . In contrast , corresponding correlations were substantially weaker in subjects with impaired glucose tolerance and non-insulin-dependent diabetes . Among these subjects , only the fasting insulin level correlated significantly with insulin resistance ( -0.47 , p < 0.05 and -0.48 , p < 0.01 , respectively ) . The authors conclude that in population studies , only the fasting insulin level should be used as a marker of insulin resistance , particularly in subjects with abnormal glucose tolerance The prevalence and incidence of insulin resistance and type 2 diabetes mellitus ( DM ) are higher in people treated for human immunodeficiency virus-1 ( HIV ) infection than in the general population . Identifying safe and effective interventions is a high priority . We evaluated whether the peroxisome proliferator-activated receptor-γ agonist pioglitazone with exercise training improves central and peripheral insulin sensitivity more than pioglitazone alone in HIV-infected adults with insulin resistance and central adiposity . Forty-four HIV-infected adults with baseline insulin resistance and central adiposity were r and omly assigned to 4 mo of pioglitazone ( 30 mg/day ) with or without supervised , progressive aerobic , and resistance exercise training ( 1.5 - 2 h/day , 3 days/wk ) . The hyperinsulinemic euglycemic clamp was used to evaluate alterations in central and peripheral insulin sensitivity . Thirty-nine participants completed the study . Hepatic insulin sensitivity improved similarly in both groups . Exercise training augmented the beneficial effects of pioglitazone on peripheral insulin sensitivity . Greater improvements in peripheral insulin sensitivity were associated with reductions in total body and limb adipose content rather than increases in limb adiposity or pioglitazone-induced increases in adiponectin concentration . We conclude that supplementing pioglitazone with increased physical activity improved insulin sensitivity more effectively than pioglitazone alone in HIV-infected adults with insulin resistance and central adiposity . Pioglitazone alone did not significantly increase limb adipose content . Potential cardiovascular benefits of these interventions in HIV need investigation BACKGROUND This study evaluated the effect of vildagliptin + metformin on glycemic control and β-cell function in type 2 diabetes patients . SUBJECTS AND METHODS One hundred seventy-one type 2 diabetes patients , naive to antidiabetes therapy and with poor glycemic control , were instructed to take metformin for 8±2 months up to a mean dosage of 2,500±500 mg/day ; then they were r and omly assigned to add vildaglipin 50 mg twice a day or placebo for 12 months . We evaluated at 3 , 6 , 9 , and 12 months : body mass index , glycemic control , fasting plasma insulin , homeostasis model assessment insulin resistance index ( HOMA-IR ) , homeostasis model assessment β-cell function index ( HOMA-β ) , fasting plasma proinsulin , proinsulin/fasting plasma insulin ratio , C-peptide , glucagon , adiponectin , and high-sensitivity C-reactive protein . Before and at 12 months after the addition of vildagliptin , patients underwent a combined euglycemic hyperinsulinemic and hyperglycemic clamp , with subsequent arginine stimulation , to assess insulin sensitivity and insulin secretion . RESULTS After 12 months of treatment , vildagliptin + metformin gave a better decrease of body weight , glycemic control , HOMA-IR , and glucagon and a better increase of HOMA-β compared with placebo + metformin . Regarding the measures of β-cell function , treatment-induced changes in M-value , first- and second-phase C-peptide response to glucose , and C-peptide response to arginine were significantly higher in the vildagliptin + metformin group compared with the placebo + metformin group . CONCLUSION The addition of vildagliptin to metformin gave a better improvement of glycemic control , insulin resistance , and β-cell function  compared with metformin alone Aim : It was the aim of this study to evaluate the effect of oral L-carnitine administration on insulin sensitivity and lipid profile in subjects with type 2 diabetes mellitus . Subjects and Methods : A r and omized , double-blind , placebo-controlled clinical trial was carried out in 12 subjects with type 2 diabetes . Six subjects received L-carnitine 1 g orally 3 times a day before meals for a period of 4 weeks . Six other individuals took a placebo for the same period of time , as the control group . Before and after the intervention , insulin sensitivity and the lipid profile were estimated . To assess insulin sensitivity , the euglycemic-hyperinsulinemic clamp technique was performed . Wilcoxon ’s signed rank and the Mann-Whitney U test were used for the statistical analyses . Results : There were no significant differences in basal clinical characteristics between the 2 groups . Insulin sensitivity and the basal lipid profile were similar . There were no significant changes in either group after the intervention in insulin sensitivity ( 3.2 ± 1.2 vs. 4.5 ± 1.7 mg/kg/min , p = 0.115 , and 3.5 ± 0.6 vs. 3.5 ± 0.4 mg/kg/min , p = 0.917 , for the placebo and L-carnitine groups , respectively ) and in lipid profile . Conclusion : L-Carnitine orally administered for a period of 4 weeks did not modify insulin sensitivity or the lipid profile
Insulin mediated inhibition of lipolysis was decreased in patients , reflected by increased non-esterified fatty acid levels .
Insulin resistance is a prominent feature of patients with type 1 diabetes mellitus and involves hepatic , peripheral and adipose tissues
OBJECTIVE The aim of this study was to perform a systematic review and meta- analysis on insulin resistance in adult patients with type 1 diabetes mellitus compared to healthy controls , assessed by hyperinsulinemic euglycemic clamp studies .