Insulin and endothelial function: physiological environment defines effect on atherosclerotic risk

Area of Science:

• Cardiovascular Science
• Endocrinology
• Molecular Biology

Background:

• Population studies link hyperinsulinaemia to cardiovascular atherosclerosis.
• Insulin acts as both a vasoregulatory and glucoregulatory peptide.
• Insulin stimulates nitric oxide (NO) release from endothelial cells, an anti-atherosclerotic effect.

Purpose of the Study:

• To review the evidence for insulin's dual role (pro- and anti-atherosclerotic) in cardiovascular disease.
• To clarify the complex relationship between insulin, endothelial function, and atherosclerosis risk.
• To focus on endothelial cell-derived NO bioavailability.

Main Methods:

• Review of in-vitro studies dissecting insulin's NO release pathway.
• Analysis of gene-modified murine models of insulin signaling and hyperinsulinaemia.
• Synthesis of data from in-vivo and ex-vivo models.

Main Results:

• Insulin's stimulation of NO release is blunted in insulin-resistant conditions.
• Insulin's vascular effects are complex and context-dependent.
• Evidence suggests insulin can be both pro- and anti-atherosclerotic.

Conclusions:

• Hyperinsulinaemia's role in atherosclerosis is linked to endothelial nitric oxide bioavailability.
• Insulin's impact on endothelial function is intricate and influenced by the cellular environment.
• Further clarification of insulin's role in atherosclerosis is needed.