Endothelial function varies according to insulin resistance disease type
Joshua A Beckman1, Allison B Goldfine, Andrea Dunaif
1Cardiovascular Division, Brigham and Women's Hospital, 75 Francis St., Boston, MA 02115, USA. jbeckman@partners.org
Diabetes Care
|January 31, 2007
Summary
Insulin resistance impacts vascular function differently across conditions. Type 2 diabetes showed impaired endothelium-dependent vasodilation, unlike lipodystrophy or PCOS, suggesting varied insulin resistance mechanisms affect endothelial function.
Area of Science:
- Endocrinology
- Cardiovascular Medicine
- Metabolic Disorders
Background:
- Insulin resistance is a hallmark of type 2 diabetes, lipodystrophic diabetes, and polycystic ovary syndrome (PCOS).
- Vascular dysfunction, particularly impaired vasodilation, is a known complication of metabolic disorders.
- The specific impact of different insulin-resistant states on vascular function requires further elucidation.
Purpose of the Study:
- To investigate the relationship between insulin resistance and vascular function.
- To compare vascular function across three distinct insulin-resistant states: type 2 diabetes, non-HIV lipodystrophic diabetes, and polycystic ovary syndrome (PCOS).
- To identify potential differences in endothelial function associated with varying mechanisms of insulin resistance.
Main Methods:
- Study population included women with type 2 diabetes, lipodystrophic diabetes, PCOS, and healthy controls.
- Insulin sensitivity was assessed using the homeostasis model assessment (HOMA).
- Vascular function was evaluated using high-resolution B-mode ultrasound to measure endothelium-dependent (flow-mediated) and endothelium-independent (nitroglycerin-mediated) vasodilation.
Main Results:
- All insulin-resistant groups (type 2 diabetes, lipodystrophic diabetes, PCOS) exhibited significant insulin resistance compared to controls.
- Flow-mediated vasodilation was significantly reduced only in subjects with type 2 diabetes.
- Nitroglycerin-mediated vasodilation was attenuated in both type 2 diabetic and lipodystrophic subjects, but not in PCOS subjects, compared to controls.
Conclusions:
- Endothelium-dependent vasodilation was impaired exclusively in patients with type 2 diabetes among the studied insulin-resistant conditions.
- These findings suggest that the underlying mechanisms of insulin resistance may differentially influence endothelial function.
- Further research into the specific pathways of insulin resistance is warranted to understand its varied impact on vascular health.
Related Concept Videos
01:26Type I Diabetes II: Pathophysiology
Type 1 diabetes mellitus arises from an immune-mediated destruction of pancreatic β-cells, resulting in an absolute deficiency of insulin. This process develops in genetically susceptible individuals when autoimmunity, environmental exposures, and immunologic dysregulation converge to trigger a targeted attack on the insulin-producing cells of the pancreas. The β-cells are located within the islets of Langerhans and are essential for regulating blood glucose by facilitating cellular uptake of...
01:24Type II Diabetes II: Pathophysiology
PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.
01:22Diabetes 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...
01:22Diabetes Mellitus: Overview and Type I Subtype
Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels due to inadequate insulin production, insulin resistance, or both. The condition affects millions worldwide and can significantly impact their health and quality of life.
Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the body is unable to produce sufficient insulin, and individuals with...
Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the body is unable to produce sufficient insulin, and individuals with...
01:26Type II Diabetes I: Introduction
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by insulin resistance, in which target tissues such as the liver, muscle, and adipose tissue respond poorly to insulin. It is also associated with inadequate compensatory insulin secretion, where pancreatic β-cells fail to produce sufficient insulin. Together, these abnormalities lead to persistent hyperglycemia.EtiologyT2DM develops through a complex interaction of genetic predisposition and environmental or...
01:27Diabetic Retinopathy
DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading...