ADMA/SDMA/h-ARG
ADMA/SDMA/h-ARG
ADMA/SDMA/h-ARG
There is a thin layer of endothelial cells on the inside of your arteries. The cells are in constant contact with the blood and therefore play an important integral role in immunity, blood clotting and blood pressure. When the endothelial cells are damaged, it can mean that you are at increased risk of cardiovascular disease or kidney failure.
What are ADMA and SDMA?
ADMA, one of the methylated forms of the amino acid arginine (Arg), is an endogenous inhibitor of nitric oxide (NO) production from arginine by nitric oxide synthase (NOS). It is one of the markers of endothelial dysfunction. There is another closely related compound, a stereoisomer of ADMA, symmetric dimethylarginine (SDMA), which does not inhibit NOS, but can compete with arginine for cellular uptake, limiting substrate availability of NOS, and is known as an endogenous marker of renal function. Modest deterioration in renal function has been recognized as a cardiovascular risk factor.
Unlike ADMA and SDMA, homoarginine (hArg), a methylene (CH2) homolog of Arg, which has an extra CH2 group in the carbon chain, is also known as a substrate of NOS. hArg can increase the availability of NO in two different ways: (1) hArg itself serves as a precursor to NO, (2) it may increase the intracellular concentration of L-Arginine, the substrate for NOS, by inhibiting the enzyme arginase that competes with NOS. HArg is thus positively related to endothelial function.
What Causes Elevated ADMA/SDMA Levels?
Elevated plasma levels of ADMA strongly suggest the possibility of cardiovascular disease, endothelial dysfunction and especially various cancers such as breast cancer, colon cancer, lung cancer and gastric cancer. In addition, in patients with a hematopoietic tumor, atherosclerosis, hypertension and type II diabetes have also been shown to have high levels of ADMA. Young adults with chronic CT calcification of the coronary artery and high levels of ADMA have a much higher incidence of stroke-like episodes.
Plasma SDMA is an early biomarker of progressive renal failure. It reflects the glomerular filtration rate (GFR) most sensitively and accurately, and was added to the International Renal Interest Society (IRIS) CKD guidelines to complement creatinine testing. The endogenous biomarker, creatinine, has poor sensitivity and specificity and is influenced by extra-renal factors such as age, gender, diet, muscularity and medication. The levels of SDMA are more likely to increase in CKD, with an average reduction in GFR of 40-50%, while in the case of an elevated level of creatinine, a reduction in GFR of at least 70-80% is required. Also unlike creatinine, SDMA is not affected by lean body mass. In our lab using the LC MSMS methodology, we found that the increased levels of SDMA are positively correlated with decreased GFR.
In contrast to high levels of ADMA and SDMA, low levels of plasma homoarginine (hArg) have been shown to correlate with adverse cardiovascular outcome. These low levels have also been found in diabetic patients on hemodialysis, patients with peripheral arterial disease, patients after ischemic stroke, patients referred for coronary angiography and in kidney transplant recipients.
Blood tests to choose from:
WHL can test for single ADMA, SDMA, hgARG or for a panel. There is also a possibility to order
NO
and
Amino Acids.
WHL adviced you that you fast overnight before the blood draw.
LITERATURE:
- Asymmetric Dimethylarginine (ADMA) and Symmetric Dimethylarginine (SDMA) Concentrations in Patients with Obesity and the Risk of Obstructive Sleep Apnea (OSA) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6616493/