The lack of insulin in type 1 diabetes contributes to cardiovascular risk primarily through which metabolic change?

• A. High glucose levels irritate and shrink vessels.
• B. Inadequate metabolism of proteins, which causes ketosis.
• C. Increased fatty acid levels.
• D. Increased metabolism of ketones, which causes hypertension.

Answer: (C)

Insulin normally blocks fat breakdown in adipose tissue. Without insulin in type 1 diabetes, lipolysis rises, and circulating free fatty acids increase. The liver uses these fatty acids to make triglycerides and release more VLDL, producing a dyslipidemic, atherogenic lipid profile. This shift in lipid metabolism—elevated fatty acids driving abnormal lipids—is a key driver of cardiovascular risk in type 1 diabetes. Ketone production also rises from the same fatty acid supply, but the cardiovascular risk link is primarily through the increased fatty acids and consequent lipid abnormalities, not ketone metabolism or hyperglycemia alone.