Insulin and atheroma. 20-yr perspective.

Area of Science:

• Cardiovascular Medicine
• Endocrinology
• Metabolic Syndrome

Background:

• Clinical studies indicate elevated insulin response to oral glucose in patients with ischemia (heart, lower limbs, brain).
• Hyperinsulinemia is observed in atherosclerosis patients, suggesting a link to arterial disease rather than general tissue injury.
• Normal fasting and intravenous insulin responses suggest a gastrointestinal factor in oral glucose-induced hyperinsulinemia.

Purpose of the Study:

• To investigate the association between hyperinsulinemia and cardiovascular disease.
• To explore the relationship between hyperinsulinemia and various cardiovascular risk factors.
• To examine the potential role of insulin in the development and progression of arterial disease.

Main Methods:

• Review of clinical studies on insulin response to oral glucose in ischemic conditions.
• Analysis of population studies correlating insulin levels with cardiovascular disease risk.
• Examination of experimental animal studies on insulin's effects on arterial tissue.

Main Results:

• Hyperinsulinemia is associated with a cluster of cardiovascular risk factors: hypertriglyceridemia, low HDL cholesterol, hypertension, hyperglycemia, and upper-body obesity.
• Insulin sensitivity appears normal or enhanced in atherosclerosis patients regarding glucose and lipid metabolism.
• Prospective studies support an independent association between hyperinsulinemia and ischemic heart disease.
• Experimental studies show insulin can promote arterial wall thickening and inhibit atherosclerosis regression.

Conclusions:

• Hyperinsulinemia is strongly linked to multiple cardiovascular risk factors, forming a metabolic cluster.
• Insulin may play a direct role in the pathogenesis of atherosclerosis and arterial disease.
• Further research is needed to clarify insulin's role in sex differences in ischemic heart disease incidence.