L-arginine improves endothelium-dependent vasodilation in hypercholesterolemic humans
The purpose of this study was to determine whether infusion of L-arginine improves endothelium (inner lining of blood vessels) vasodilation in patients with high cholesterol levels (hypercholesterolemia). Vasodilation is the widening of blood vessels that results from relaxation of the muscular walls of the vessels. 11 healthy participants and 14 hypercholesterolemic patients were included in the study. The results showed that endothelium vasodilation was impaired in people with high blood pressure. According to the study authors, this abnormality can be improved by the administration of L-arginine. Further details can be found in the study.
Lipid disorders are characterized by imbalanced levels of fatty substances (i.e. cholesterol and triglycerides) in the bloodstream. These lipids are carried in the blood stream in form of microscopic round particles, called lipoproteins. Thus, these conditions are also called lipoprotein disorders. There are, generally speaking, two types of cholesterol-transporting lipoproteins: a) the “bad cholesterol” are those lipoproteins that carry cholesterol and other fatty substances to the sites of tissue repair, e.g. in the artery walls; the most common representatives of this group are Low-density-lipoproteins (LDL) and, a newer one, Lipoprotein(a), Lp(a). b) the “good cholesterol” are those lipoproteins that carry cholesterol and other fatty substances away from the sites of tissue repair and transport it back to the liver where it is biologically “burnt” One of the most frequent causes why “bad cholesterol” particles are elevated in the blood stream is micronutrient deficiency. This can be easily explained: A deficiency of vitamins causes structural damage to the artery walls and other organs and the body (liver) reacts with an increased production of “repair factors” like LDL and Lp(a). Because the elevation of these risk factors in the blood is already a reaction damage of our body tissue caused by vitamin deficiency, they are considered “secondary” risk factors.
MA Creager, SJ Gallagher, XJ Girerd, SM Coleman, VJ Dzau, and JP Cooke. L-arginine improves endothelium-dependent vasodilation in hypercholesterolemic humans. J Clin Invest. 1992 Oct; 90(4): 1248–1253.