Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Hormones Regulating Blood Glucose01:16

Hormones Regulating Blood Glucose

Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
Hyperglycemia01:29

Hyperglycemia

Hyperglycemia is an abnormally high blood glucose level. It is diagnosed by fasting glucose ≥126 mg/dL, 2-hour oral glucose tolerance test (or OGTT) ≥200 mg/dL, random glucose ≥200 mg/dL with symptoms, or HbA1c ≥6.5%. However, HbA1c results may be unreliable in certain conditions, such as anemia or hemoglobinopathies, and the diagnosis should be confirmed unless classic symptoms are present. Postprandial hyperglycemia is typically considered significant when glucose levels exceed 180 mg/dL two...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion01:27

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are co-secreted in...
Insulin: The Receptor and Signaling Pathways01:28

Insulin: The Receptor and Signaling Pathways

Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
Diabetes Mellitus: Type 2 and Gestational01:22

Diabetes Mellitus: Type 2 and Gestational

Type 2 diabetes, characterized by insulin resistance, arises when the insulin receptors on cells lose responsiveness to insulin, diminishing the cell's capacity to take up glucose, resulting in elevated blood glucose levels. To receive a diagnosis of Type 2 diabetes, a series of blood glucose tests are necessary to assess whether the blood glucose falls within normal parameters. If the result is out of the normal range, a patient may be diagnosed as prediabetic or diabetic, depending on the...
Hypoglycemia01:26

Hypoglycemia

Hypoglycemia is a blood glucose level below 70 mg/dL. It commonly occurs in individuals using insulin or insulin-secreting drugs, but may also arise in non-diabetic conditions. People with type 1 diabetes are at the highest risk because they depend on exogenous insulin. People with type 2 diabetes are also at risk, especially when treated with insulin or medications such as sulfonylureas, which increase insulin release regardless of blood glucose levels. It develops when insulin levels exceed...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Evidence-based recommendations for the use of continuous glucose monitoring in type 2 diabetes: the Italian guidelines.

Acta diabetologica·2026
Same author

Macklin effect in critically COVID-19 patients: Observational single-center analysis.

Revista espanola de anestesiologia y reanimacion·2025
Same author

Italian guidelines for the management of adult individuals with overweight and obesity and metabolic comorbidities that are resistant to behavioral treatment.

Journal of endocrinological investigation·2024
Same author

Low dose aspirin and clinical outcomes in patients with SARS-CoV-2 pneumonia: a propensity score-matched cohort analysis from the National SIMI‑COVID‑19 Registry.

Internal and emergency medicine·2023
Same author

The evaluation of tactile dysfunction in the hand in type 1 diabetes: a novel method based on haptics.

Acta diabetologica·2022
Same author

The Apparent Asymmetrical Relationship Between Small Bowel Bacterial Overgrowth, Endotoxemia, and Liver Steatosis and Fibrosis in Cirrhotic and Non-Cirrhotic Patients: A Single-Center Pilot Study.

Frontiers in medicine·2022
Same journal

Impact of icosapent ethyl on serum lipoand glycoprotein profiles assessed by <sup>1</sup>H-NMR. A real-world observational study (IPE-NMR).

Nutrition, metabolism, and cardiovascular diseases : NMCD·2026
Same journal

Dysregulated growth hormone-insulin-like growth factor-1 axis in adults with metabolic dysfunction-associated steatotic liver disease: a meta-analysis.

Nutrition, metabolism, and cardiovascular diseases : NMCD·2026
Same journal

Inclisiran-will it fulfill its promise?

Nutrition, metabolism, and cardiovascular diseases : NMCD·2026
Same journal

Incretin-based therapies and craving: a clinical signal pointing to reward reprogramming.

Nutrition, metabolism, and cardiovascular diseases : NMCD·2026
Same journal

Joint associations of accelerometer-measured sleep duration and physical activity with cardiovascular disease and all-cause mortality: a longitudinal cohort study.

Nutrition, metabolism, and cardiovascular diseases : NMCD·2026
Same journal

Liver fibrosis, but not steatosis, provides incremental prognostic value beyond cardiovascular-kidney-metabolic staging.

Nutrition, metabolism, and cardiovascular diseases : NMCD·2026
See all related articles

Related Experiment Video

Updated: May 12, 2026

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults
06:13

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults

Published on: December 1, 2023

Insulin sensitivity, and β-cell function in relation to hemoglobin A1C.

M A Marini1, S Frontoni1, E Succurro2

  • 1Department of Systems Medicine, University of Rome-Tor Vergata, Italy.

Nutrition, Metabolism, and Cardiovascular Diseases : NMCD
|April 23, 2013
PubMed
Summary
This summary is machine-generated.

Individuals with an A1C of 5.7-6.4% show reduced insulin sensitivity and impaired insulin secretion, indicating early type 2 diabetes pathophysiology. This highlights key metabolic defects in those at increased risk for diabetes.

Keywords:
A1CInsulin secretionInsulin sensitivity

More Related Videos

Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes
08:03

Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes

Published on: June 25, 2017

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)
08:13

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)

Published on: January 7, 2018

Related Experiment Videos

Last Updated: May 12, 2026

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults
06:13

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults

Published on: December 1, 2023

Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes
08:03

Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes

Published on: June 25, 2017

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)
08:13

Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)

Published on: January 7, 2018

Area of Science:

  • Endocrinology
  • Metabolic Diseases
  • Diabetes Pathophysiology

Background:

  • The 2010 American Diabetes Association A1C criterion for diabetes risk was not based on underlying pathophysiological abnormalities.
  • Understanding metabolic defects in individuals with A1C 5.7-6.4% is crucial for early diabetes detection and intervention.

Purpose of the Study:

  • To investigate the metabolic abnormalities in individuals with an A1C of 5.7-6.4%, a group identified as at increased risk for type 2 diabetes.
  • To gain deeper insight into the pathophysiological defects associated with prediabetes.

Main Methods:

  • Recruited 338 non-diabetic offspring of type 2 diabetic patients.
  • Assessed insulin secretion via oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT).
  • Measured insulin sensitivity using hyperinsulinemic euglycemic clamp and calculated disposition indexes.

Main Results:

  • Individuals with A1C 5.7-6.4% demonstrated significantly lower insulin sensitivity compared to those with A1C <5.7% (adjusted for age, sex, BMI).
  • While OGTT-derived insulin secretion did not differ, acute insulin response (AIR) during IVGTT and disposition indexes were reduced in the higher A1C group.
  • A sharp decrease in insulin sensitivity and beta-cell function (disposition index) was observed as A1C reached ≥ 5.7%.

Conclusions:

  • Individuals with A1C ≥ 5.7% exhibit both insulin resistance and beta-cell dysfunction, the core pathophysiological defects of type 2 diabetes.
  • These findings suggest that the A1C threshold of 5.7% identifies individuals with established early diabetes pathophysiology.