Effect of intra-arterial insulin on tissue cholesterol and fatty acids in alloxan-diabetic dogs – Cruz (1961)

CRUZ AB Jr, AMATUZIO DS, GRANDE F, HAY LJ.

Effect of intra-arterial insulin on tissue cholesterol and fatty acids in alloxan-diabetic dogs.

Circ Res. 1961 Jan;9:39-43.
DOI: 10.1161/01.RES.9.1.39

pubmed

Summary: 21 dogs were studied.  3 controls.  19 dogs were given diabetes by a single injection of alloxan to knock out their beta cells.  Their fasting glucose was established and they were subsequently injected with from 1 to 3 iU of insulin/kg depending on their fasting glucose.  The controls were  injected with 1 iU/kg.  The insulin was injected into the femoral artery supplying one leg and an equal amount of saline was injected into the femoral artery supplying the other leg.  All dogs were fed the same diet.  The diabetic dogs were sacrificed and autopsied at intervals over 28 days, and samples of the arteries and muscles of each leg were preserved.

Results: Analysis of the arteries and muscles show an increase in cholesterol and total fatty acids in both tissues of the insulin injected side as compared with the saline injected leg for all dogs sacrificed after 4 weeks.  The control dogs saw an increase in cholesterol and total fatty acids in arteries,  but no significant difference in muscle tissue.

We reckon: This shows if you give insulin directly to the arteries in just one leg of a dog, you give just that one leg cardiovascular disease.

This shows that one of the reasons why type 2 diabetics have a higher incidence of Cardiovascular disease is due to the chronic high insulin they subject their blood vessels to over decades as their disease progresses.