ADMA (vascular health)

ADMA (asymmetric dimethylarginine) is the principal endogenous inhibitor of NO synthase (eNOS) and is therefore looked at with questions about the function of the inner vessel wall (endothelium). Raised ADMA slows NO production; in studies it has been associated with high blood pressure and arteriosclerosis. ADMA is looked at in cardiovascular diagnostics alongside the lipid values. Included in Prevent 360.

What ADMA does in the body

In many proteins, arginine building blocks are given methyl groups by enzymes (protein arginine methyltransferases); the donor is S-adenosylmethionine, from which homocysteine is eventually formed in the process. When these proteins are broken down, asymmetric dimethylarginine (ADMA) is released. ADMA resembles L-arginine, the starting material of NO synthase, and occupies its binding site without being converted. Nitric oxide (NO) from the inner vessel wall activates guanylate cyclase in the smooth vascular muscle; the resulting cGMP makes the muscle relax and the vessel widen. NO also inhibits the adhesion of platelets and white blood cells. ADMA is broken down mainly by the enzyme DDAH into citrulline and dimethylamine, a smaller part via the kidneys.

Low ADMA – what does it mean?

A low value shows that little ADMA is being produced or that the enzyme DDAH is breaking it down promptly. NO synthase is then hardly slowed and can convert L-arginine into NO unhindered. Lower values have been observed in pregnancy, which are linked with the widening of the vessels during this time. According to current knowledge, low ADMA values have no pathological significance of their own.

High ADMA – what happens in the body?

When ADMA rises, the inner vessel wall produces less NO: the vessels widen less well when more blood is needed, platelets and white blood cells adhere more easily, and the vascular muscle is restrained less. When NO synthase lacks sufficient arginine, it can become uncoupled and produce superoxide radicals instead of NO; this oxidative stress in turn inhibits the ADMA-degrading enzyme DDAH, so that ADMA accumulates further. Because erection and blood flow in small vessels also depend on NO, they can be affected as well. Raised values occur with reduced kidney function, liver disease, insulin resistance and raised blood sugar, smoking and chronic inflammation; in studies they were associated with raised homocysteine.

The interpretation is given in your report.