Related Experiment Video
Updated: Jul 10, 2026
07:09
Experimental and Imaging Techniques for Examining Fibrin Clot Structures in Normal and Diseased States
Published on: April 1, 2015
Homocysteine metabolism in diabetes
E P Wijekoon1, M E Brosnan, J T Brosnan
1Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada A1B 3X9.
Biochemical Society Transactions
|October 25, 2007
Summary
Plasma homocysteine (Hcy) levels are lower in patients with diabetes. This study investigated Hcy metabolism in diabetes, finding altered enzyme activity contributes to reduced Hcy levels in both Type 1 and Type 2 diabetes.
Area of Science:
- Biochemistry
- Metabolic Research
- Endocrinology
Background:
- Elevated plasma homocysteine (Hcy) is a risk factor for cardiovascular disease (CVD).
- CVD is a leading cause of mortality in diabetic patients.
- Understanding Hcy metabolism in diabetes is crucial for disease management.
Purpose of the Study:
- To investigate the alterations in homocysteine metabolism in diabetic patients.
- To identify the specific metabolic pathways and enzymes involved in Hcy regulation in diabetes.
- To elucidate the role of insulin and counter-regulatory hormones in Hcy metabolism during diabetes.
Main Methods:
- Comparative analysis of plasma Hcy levels in diabetic patients (Type 1 and Type 2) and control groups.
- Enzyme activity assays for key enzymes in Hcy metabolism, including trans-sulfuration pathway enzymes and betaine:homocysteine methyltransferase (BHMT).
- In vitro studies to assess the direct effects of insulin and counter-regulatory hormones on enzyme activity.
Main Results:
- Plasma Hcy levels were found to be lower in diabetic patients without renal complications compared to controls.
- In Type 1 diabetes, increased activity of trans-sulfuration enzymes was the primary reason for reduced Hcy.
- In Type 2 diabetes, both trans-sulfuration enzymes and BHMT showed increased activity, contributing to Hcy catabolism.
Conclusions:
- Diabetes mellitus, independent of renal complications, is associated with reduced plasma homocysteine levels.
- Altered activities of trans-sulfuration enzymes and BHMT, influenced by insulin and counter-regulatory hormones, explain the modified Hcy metabolism in diabetes.
- These findings provide insights into the complex interplay between diabetes and Hcy metabolism, potentially impacting CVD risk stratification.
Related Concept Videos
01:19Overview of Carbohydrate Metabolism
Carbohydrate metabolism is a fundamental biochemical process that ensures a constant supply of energy to living cells. The most important carbohydrate is glucose, which can be broken down via glycolysis to enter into the Krebs cycle and eventually lead to the production of ATP through oxidative phosphorylation.
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
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...
01:29Hyperglycemia
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...
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.
01:36Carbohydrate Metabolism
Carbohydrates are polymers composed of molecules containing atoms of carbon, hydrogen and oxygen. One gram of carbohydrate can provide four kilo-calories of energy, which makes it the most efficient instant energy source.
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
01:36Carbohydrate Metabolism
Carbohydrates are polymers composed of molecules containing atoms of carbon, hydrogen and oxygen. One gram of carbohydrate can provide four kilo-calories of energy, which makes it the most efficient instant energy source.
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...