Hyperinsulinism and cerebral microangiopathy

Area of Science:

• Neurology
• Endocrinology
• Vascular Biology

Background:

• High insulin levels are a known risk factor for atherosclerosis.
• The microvascular endothelium is more sensitive to insulin's effects than large-vessel endothelium.
• Elevated insulin can impair fibrinolysis by increasing plasminogen activator inhibitor-1.

Purpose of the Study:

• To investigate the association between elevated serum insulin and C-peptide levels and cerebral small-vessel disease.
• To differentiate the role of insulin in small-vessel versus large-vessel cerebrovascular pathology.

Main Methods:

• 194 patients with symptomatic cerebrovascular disease were categorized into lacunar stroke, subcortical arteriosclerotic encephalopathy, and large-vessel disease groups.
• Control subjects without cerebrovascular disease were also included.
• Fasting blood glucose, insulin, and C-peptide levels were measured in all participants.

Main Results:

• Insulin levels were significantly higher in patients with lacunar strokes and subcortical arteriosclerotic encephalopathy (small-vessel disease) compared to those with large-vessel disease and controls.
• A significant difference in insulin concentrations was observed between the microangiopathy group (lacunes and subcortical arteriosclerotic encephalopathy) and the macroangiopathy and control groups.
• While C-peptide and blood glucose levels showed trends, differences did not reach statistical significance.

Conclusions:

• Elevated insulin levels may be a pathogenic factor in the development of cerebral small-vessel disease, especially in patients with lacunar strokes.
• Further research is needed to determine if this is due to atherosclerotic changes in small penetrating arteries or hemorheological alterations.