Effects of elevated and exercise-reduced muscle glycogen levels on insulin sensitivity

1985 ◽  
Vol 59 (1) ◽  
pp. 154-159 ◽  
Author(s):  
J. L. Ivy ◽  
B. A. Frishberg ◽  
S. W. Farrell ◽  
W. J. Miller ◽  
W. M. Sherman
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Muscle Glycogen ◽  
Insulin Response ◽  
Tolerance Test ◽  
Exhaustive Exercise ◽  
Oral Glucose ◽  
Mixed Diet ◽  
Exercise Induced

The effects of an exercise-induced muscle glycogen reduction and an elevated muscle glycogen concentration on glucose tolerance and the insulin response to an oral glucose tolerance test (GTT) were examined. GTTs were administered to seven male subjects after 3 days on a mixed diet (C), after exhaustive exercise and 1 day on a high-fat protein diet (L-FP), after exhaustive exercise and 1 day on a mixed diet (L-M), and after exhaustive exercise and 3 days on a high-carbohydrate diet (H-CHO). The L-M treatment resulted in a significant reduction in muscle glycogen (C, 79.6 +/- 4.2 mmol/kg wet wt vs. L-M, 53.9 +/- 1.2 mmol/kg wet wt) and a 31.7% reduction in the insulin-glucose (IG) index, a measure of insulin sensitivity in vivo. Muscle glycogen was also significantly reduced by the L-FP treatment (49.1 +/- 2.4 mmol/kg wet wt), but there was no change in the IG index. Preventing a decrease in the IG index during the L-FP treatment may have been a result of elevated free fatty acids (67%) and ketones (552%) prior to the GTT. Muscle glycogen was significantly increased by the H-CHO treatment (124.8 +/- 11.1 mmol/kg wet wt); however, the IG index was not different from that of the C treatment. The results suggest that an exercise-induced reduction in muscle glycogen can improve insulin sensitivity in vivo but that this effect is diet dependent.

Oral glucose tolerance test and insulin sensitivity in low insulin responders

1983 ◽  
Vol 104 (1) ◽  
pp. 77-84 ◽  
Author(s):  
A. Wajngot ◽  
R. Luft ◽  
S. Efendić
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Fasting Blood Glucose ◽  
Insulin Response ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Infusion Test ◽  
Glucose Infusion Test ◽  
Low Insulin Response

Abstract. Oral and iv glucose tolerance, insulin response to iv and oral glucose load as well as insulin sensitivity were evaluated in 58 'low insulin responders'. They were selected from a group of 226 healthy subjects with normal fasting blood glucose and normal iv glucose tolerance test on the basis of a low insulin response during a standardized glucose infusion test (GIT). The insulin response to GIT was analysed by parameter identification in a mathematical model (parameter KI). Insulin sensitivity was also measured by computer analysis of GIT (parameter KG) and, in a limited group of subjects, by a somatostatin infusion test. Thirty-three low insulin responders had normal OGTT, whereas 5 demonstrated borderline-1, 16 borderline-2, and 4 decreased OGTT. The first group of subjects demonstrated normal or enhanced insulin sensitivity. Borderline and decreased OGTT, in most instances, was accompanied by decreased insulin sensitivity, implying that a subgroup of low insulin responders exhibited signs of both impaired insulin response to glucose and insulin resistance. Since these defects characterize manifest type-2 diabetes, these subjects possibly may run a high risk to develop this type of diabetes. On the other hand, low insulin response in combination with increased insulin sensitivity may reflect adaptation of the secretory capacity of B-cells to the need of insulin.

Adding fat calories to meals after exercise does not alter glucose tolerance

2004 ◽  
Vol 97 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Amanda K. Fox ◽  
Amy E. Kaufman ◽  
Jeffrey F. Horowitz
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Muscle Glycogen ◽  
Composite Index ◽  
Tolerance Test ◽  
Peak Oxygen Uptake ◽  
Oral Glucose ◽  
High Fat ◽  
Low Fat ◽  
The Hours

A single session of exercise increases insulin sensitivity for hours and even days, and dietary carbohydrate ingested after exercise alters the magnitude and duration of this effect. Although increasing systemic fatty acid availability is associated with insulin resistance, it is uncertain whether increasing dietary fat availability after exercise alters the exercise-induced increase in insulin sensitivity. The purpose of this study was to determine whether adding fat calories to meals after exercise alters glucose tolerance the next day. Seven healthy men cycled 90 min at 66 ± 2% peak oxygen uptake followed by a maximum of five high-intensity intervals. During the hours after exercise, subjects ingested three meals containing either low-fat (5% energy from fat) or high-fat (45% energy from fat) foods (Low-Fat and High-Fat groups, respectively). Each diet contained the same amount of carbohydrate and protein. An oral glucose tolerance test was performed the next morning. Muscle glycogen and intramuscular triglyceride (IMTG) concentrations were measured in muscle biopsy samples obtained immediately before exercise and the next morning. The day after exercise, muscle glycogen concentration was identical in High-Fat and Low-Fat (393 ± 70 and 379 ± 38 mmol/kg dry wt). At the same time, IMTG concentration was ∼20% greater during High-Fat compared with Low-Fat (42.5 ± 3.4 and 36.3 ± 3.3 mmol/kg dry wt; P < 0.05). Despite the addition of ∼165 g of fat to meals after exercise (∼1,500 kcal) and a resultant elevation in IMTG concentration, glucose tolerance was identical in High-Fat and Low-Fat (composite index: 8.7 ± 1.0 and 8.4 ± 1.0). In summary, as long as meals ingested in the hours after exercise contain the same carbohydrate content, the addition of ∼1,500 kcal from fat to these meals did not alter muscle glycogen resynthesis or glucose tolerance the next day.

Insulin Secretion and Glucose Tolerance after Islet Transplantation in Rats with Noninsulin-Dependent Diabetes Induced by Neonatal Streptozotocin

1997 ◽  
Vol 6 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Maria-Angeles Tormo ◽  
Trinidad Leon-Quinto ◽  
Catherine Saulnier ◽  
Danielle Bailbe ◽  
Patricia Serradas ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Insulin Release ◽  
Insulin Response ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Β Cells ◽  
Basal Plasma

The present study was designed to identify in a model of noninsulin-dependent diabetes induced by neonatal streptozotocin (n0-STZ), the long-term consequences of an islet graft upon 1) glucose handling of the recipient and, 2) glucose response of the residual β cells in the recipient pancreas. We have examined, 4 and 8 wk after islet implantation under the kidney capsule of syngeneic diabetic n0-STZ rats, their tolerance to glucose administered in vivo, together with their insulin release in response to glucose in vivo (oral glucose tolerance test) as well as in vitro (perfused pancreas). The results in the islet-grafted n0-STZ rats, were compared to those obtained in nongrafted nondiabetic rats and nongrafted n0-STZ rats. Our study shows that transplanting a limited number (900) of adult islets under the kidney capsule reverses to normal, many parameters of the noninsulin-dependent diabetic state in the n0-STZ rat model: these include body weight, basal plasma glucose in both the nonfasted and postabsorptive states, and basal plasma insulin in the postabsorptive state. Furthermore, tolerance to oral glucose administration was greatly improved in the transplanted rats and it was correlated with restoration of a manifest glucose-induced insulin secretion in vivo as evaluated (ΔI) during an oral glucose tolerance test. Our data clearly show that the insulin response to glucose from the endogenous pancreas of n0-STZ diabetic rat was not really improved by long-term (8 wk) basal normoglycemia. More precisely, we were able to detect a slight but significant improvement of the early phase of insulin release in vitro in response to glucose; however, the overall insulin response remained 15 times lower than the normal one with no reapparance of the late phase of insulin release. After cessation of glucose stimulation in vivo, off-response of insulin, which is also a landmark of the impaired insulin release by the β cells of n0-STZ rats, was still detectable in the perfused pancreas of the transplanted n0-STZ rats. Finally, because the reactivity to glucose of the endogenous residual β cells was not regained, the insulin released in vivo during the oral glucose test in the graft-bearing n0-STZ rats can be attributed mainly to functioning of the grafted islets population. Copyright © 1997 Elsevier Science Inc.

scholarly journals An Anthocyanin-Rich Mixed-Berry Intervention May Improve Insulin Sensitivity in a Randomized Trial of Overweight and Obese Adults

Nutrients ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2876 ◽  
Author(s):  
Patrick M. Solverson ◽  
Theresa R. Henderson ◽  
Hawi Debelo ◽  
Mario G. Ferruzzi ◽  
David J. Baer ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Serum Insulin ◽  
Statistical Significance ◽  
Insulin Response ◽  
Tolerance Test ◽  
Serum Glucose ◽  
Oral Glucose ◽  
Improve Insulin Sensitivity

Evidence supports the beneficial effects of berries on glucoregulation, possibly related to flavonoid content, fiber content, or both. The purpose of this study was to assess the potential of mixed berries to improve insulin sensitivity and to identify the potential role of flavonoids and fiber. In a randomized cross-over trial with four treatment periods, overweight/obese men and women were fed a controlled 45% fat diet for one week prior to a meal-based glucose tolerance test. The same base diet was provided during each feeding period with the addition of one of four treatments: whole mixed berries, sugar matched mixed berry juice, sugar matched gelatin, and sugar/fiber matched gelatin. Subjects then completed a meal-based oral glucose tolerance test. Serum glucose, insulin and non-esterified fatty acids were not different between individual treatments. However, in a secondary analysis, the combined berry preparations resulted in a lower serum insulin area under the curve (difference of 0.15 ± 0.066 ln pmol min/mL, mean ± SE, p = 0.0228), compared to the combined gelatin treatments, while the difference for serum glucose did not quite meet statistical significance (difference of 0.17 ± 0.093 ln mg·min/dL, mean ± SE, p = 0.0738). These results suggest the potential for mixed berry preparations to improve post-prandial insulin response.

scholarly journals Antidepressant Effects on Insulin Sensitivity and Proinflammatory Cytokines in the Depressed Males

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Yi-Chyan Chen ◽  
Wei-Win Lin ◽  
Yu-Jung Chen ◽  
Wei-Chung Mao ◽  
Yi-Jen Hung
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Rating Scale ◽  
Glucose Tolerance Test ◽  
Antidepressant Treatment ◽  
Insulin Response ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Intravenous Glucose ◽  
Testing Procedures

Growing evidence suggests that mood disorder is associated with insulin resistance and inflammation. Thus the effects of antidepressants on insulin sensitivity and proinflammatory responses will be a crucial issue for depression treatment. In this study, we enrolled 43 non-diabetic young depressed males and adapted standard testing procedures to assess glucose metabolism during 4-week hospitalization. Before and after the 4-week antidepressant treatment, participants underwent oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FSIGT). Insulin sensitivity (SI), glucose effectiveness (SG), acute insulin response, and disposition index (DI) were estimated using the minimal model method. The plasma levels of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α), and adiponectin were measured. The Hamilton depression rating scale (HAM-D) total scores were reduced significantly during the course of treatment. There were no significant changes in the parameters ofSI,SG, and DI. Compared to drug naïve status, the level of plasma IL-6 was significantly elevated (0.77to1.30 pg/ml;P=.001) after antidepressant therapy. However, the concentrations of CRP, TNF-α, and adiponectin showed no differences during the course of treatment. The results suggest that antidepressants may promote stimulatory effect on the IL-6 production in the early stage of antidepressant treatment.

scholarly journals First-phase insulin response (FPIR) to intravenous glucose tolerance test (IVGTT), insulin sensitivity and long-term follow-up in ?- transfusion-dependent thalassemia (TDT) normoglycemic patients with reduced insulin secretion to oral glucose tolerance t

2021 ◽  
Vol 13 (1) ◽  
pp. e2021021
Author(s):  
Vincenzo De Sanctis
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Oral Glucose ◽  
Sensitivity Index ◽  
Intravenous Glucose

Summary. Objective: To  study the function of the endocrine pancreas in transfusion-dependent ?-thalassemia (?-TDT) patients with normal oral glucose tolerance test (OGTT) and hypoinsulinemia. Patients and methods: Seven ?-TDT patients  (mean age 22.4 ± 4.2 years) with normal glucose tolerance test (NGT) and poor insulin response (hypoinsulinemia) to OGTT,  not associated with ?-cell autoimmunity, were referred for a second opinion to an Italian Centre, part of the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescence Medicine (ICET-A). In this pilot study,  the first-phase insulin response (FPIR), expressed as the sum of 1 and  3 minutes insulin, of ?-TDT patients to intravenous glucose tolerance test (IVGTT), was tested. Moreover, the long-term natural history was followed prospectively using an annual OGTT, with the aim of detecting any abnormality of glucose metabolism. Results: The FPIR value  was between the 1st and 3rd percentile in two patients and between the 3rd and 10th percentile in  five. After 43 ± 26 months (range 11 - 80 months) of follow-up, 2 patients developed impaired glucose tolerance (IGT), 3 both IGT and impaired fasting glucose (IFG) and two overt diabetes mellitus (DM). Interestingly, the patients who developed DM had, at baseline the lowest value of insulinogenic index (IGI, 0.08 and 0.25), defined as the ratio of the increment of plasma insulin to plasma glucose during the first 30 minutes after OGTT. Moreover, a significant correlation was found between the IGI at baseline and at follow-up in the patients who developed IGT with or without IFG (R= 0.927; P: 0.023). A significant reduction of Matsuda insulin sensitivity index (ISIM) and Insulin Secretion-Sensitivity Index-2 (ISSI-2) was documented in the study cohort at diagnosis of IFG, IGT and DM. There was a significant inverse correlation between ISSI-2 and area under the curve of plasma glucose (AUC-PG). Conclusions: These data demonstrated, for the first time, a progressive deterioration in glucose homeostasis in ?-TDT subjects with NGT and hypoinsulinemia.  Thus, we consider that variations of insulin sensitivity could possibly have an impact on glucose tolerance in adult patients with TDT. Further investigations should focus on factors that might positively influence insulin sensitivity, including nutrition, drugs and physical activity.  

scholarly journals Beneficial Effect of Diazoxide in Obese Hyperinsulinemic Adults1

1998 ◽  
Vol 83 (6) ◽  
pp. 1911-1915 ◽  
Author(s):  
Ramin Alemzadeh ◽  
Gina Langley ◽  
Lori Upchurch ◽  
Pam Smith ◽  
Alfred E. Slonim
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Body Fat ◽  
Therapeutic Potential ◽  
Controlled Trial ◽  
Insulin Response ◽  
Tolerance Test ◽  
Fat Free Mass ◽  
Zucker Rats ◽  
Significant Difference

Hyperinsulinemia, insulin resistance, and increased adipose tissue are hallmarks of the obesity state in both humans and experimental animals. The role of hyperinsulinemia as a possible preceding event in the development of obesity has been proposed. We previously demonstrated that administration of diazoxide (DZ), an inhibitor of insulin secretion, to obese hyperinsulinemic Zucker rats resulted in less weight gain, enhanced insulin sensitivity, and improved glucose tolerance. Assuming that hyperinsulinemia plays a major role in the development of human obesity, then its reversal should have therapeutic potential. To test this hypothesis, we conducted a randomized placebo-controlled trial in 24 hyperinsulinemic adults [body mass index (BMI) &gt; 30 kg/m2]. All subjects were placed on a low-calorie (1260 for females and 1570 for males) Optifast (Sandoz, Minneapolis, MN) diet. After an initial 1-week lead-in period, 12 subjects (mean ± se for age and BMI, 31 ± 1 and 40 ± 2, respectively) received DZ (2 mg/kg BW·day; maximum, 200 mg/day, divided into 3 doses) for 8 weeks; and 12 subjects (mean± se for age and BMI, 28 ± 1 and 43 ± 1, respectively) received placebo. Compared with the placebo group, DZ subjects had greater weight loss (9.5 ± 0.69% vs. 4.6 ± 0.61%, P &lt; 0.001), greater decrease in body fat (P &lt; 0.01), greater increase in fat-free mass to body fat ratio (P &lt; 0.01), and greater attenuation of acute insulin response to glucose (P &lt; 0.01). However, there was no significant difference in insulin sensitivity and glucose effectiveness, as determined by the insulin-modified iv glucose tolerance test (Bergman’s minimal model) and no significant difference in glycohemoglobin values. Conclusion: 8 weeks treatment with DZ had a significant antiobesity effect in hyperinsulinemic obese adults without inducing hyperglycemia.

HDL Containing Apolipoprotein C-III is Associated with Insulin Sensitivity: a Multi-Center Cohort Study

2021 ◽  
Author(s):  
Rain Yamamoto ◽  
Majken K Jensen ◽  
Sarah Aroner ◽  
Jeremy D Furtado ◽  
Bernard Rosner ◽  
...  
Keyword(s):  
Cohort Study ◽  
Insulin Sensitivity ◽  
Clinical Investigation ◽  
Biological Effects ◽  
Sandwich Elisa ◽  
Insulin Response ◽  
Protein Composition ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Euglycemic Hyperinsulinemic Clamp

Abstract Context HDL in humans is composed of a heterogeneous group of particles varying in protein composition as well as biological effects. Objective We investigated the prospective associations between HDL subspecies containing and lacking apoC-III at baseline and insulin sensitivity at year 3. Design, Setting, and Participants A prospective cohort study of 864 healthy volunteers drawn from the RISC study, a multi-center European clinical investigation, whose recruitment initiated in 2002 with a follow-up of 3 years. Main Measures Insulin sensitivity was estimated from an oral glucose tolerance test (OGTT) at baseline and year 3, and by euglycemic-hyperinsulinemic clamp at baseline only. The apolipoprotein concentrations were measured at baseline by a sandwich ELISA-based method. Results The two HDL subspecies demonstrated significantly opposite associations with insulin sensitivity at year 3 (p-heterogeneity=0.004). The highest quintile of HDL containing apoC-III was associated with a 1.2% reduction in insulin sensitivity (p-trend=0.02), while the highest quintile of HDL lacking apoC-III was associated with a 1.3% increase (p-trend=0.01), compared to the lowest quintile. No significant association was observed for total HDL, and VLDL and LDL containing apoC-III. ApoC-III contained in HDL was associated with a decrease in insulin sensitivity even more strongly than plasma total apoC-III. Conclusion Both HDL containing apoC-III and apoC-III in HDL adversely affect the beneficial properties of HDL on insulin response to glucose. Our results support the potential of HDL-associated apoC-III as a promising target for diabetes prevention and treatment.

scholarly journals 4-Hydroxyisoleucine: experimental evidence of its insulinotropic and antidiabetic properties

1999 ◽  
Vol 277 (4) ◽  
pp. E617-E623 ◽  
Author(s):  
Christophe Broca ◽  
René Gross ◽  
Pierre Petit ◽  
Yves Sauvaire ◽  
Michèle Manteghetti ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Insulin Response ◽  
Oral Glucose ◽  
Dependent Manner ◽  
Insulin Dependent ◽  
Glucose Tolerance Tests ◽  
Insulin Dependent Diabetic ◽  
Single Intravenous Administration

We have recently shown in vitro that 4-hydroxyisoleucine (4-OH-Ile), an amino acid extracted from fenugreek seeds, potentiates insulin secretion in a glucose-dependent manner. The present study was designed to investigate whether 4-OH-Ile could exert in vivo insulinotropic and antidiabetic properties. For this purpose, intravenous or oral glucose tolerance tests (IVGTTs and OGTTs, respectively) were performed not only in normal animals but also in a type II diabetes rat model. During IVGTT in normal rats or OGTT in normal dogs, 4-OH-Ile (18 mg/kg) improved glucose tolerance. The lactonic form of 4-OH-Ile was ineffective in normal rats. In non-insulin-dependent diabetic (NIDD) rats, a single intravenous administration of 4-OH-Ile (50 mg/kg) partially restored glucose-induced insulin response without affecting glucose tolerance; a 6-day subchronic administration of 4-OH-Ile (50 mg/kg, daily) reduced basal hyperglycemia, decreased basal insulinemia, and slightly, but significantly, improved glucose tolerance. In vitro, 4-OH-Ile (200 μM) potentiated glucose (16.7 mM)-induced insulin release from NIDD rat-isolated islets. So, the antidiabetic effects of 4-OH-Ile on NIDD rats result, at least in part, from a direct pancreatic B cell stimulation.

Sign in / Sign up

Export Citation Format

Share Document