Effect of folic acid and betaine on fasting and postmethionine‐loading plasma homocysteine and methionine levels in chronic haemodialysis patients

Abstract

In chronic haemodialysis patients, fasting as well as postmethionine-loading plasma tHcy levels depend on folate status and decrease after folic acid therapy. Increased postload homocysteine levels in these patients therefore do not necessarily indicate an impaired transsulphuration capacity only; alternatively, folate may indirectly influence transsulphuration. The elucidation of the complex pathogenesis of hyperhomocysteinaemia in chronic renal failure requires further investigation.

Hyperhomocysteinemia Induced by Guanidinoacetic Acid Is Effectively Suppressed by Choline and Betaine in Rats

“…Previous studies have shown that betaine is effective in suppressing methionine-induced hyperhomocysteinemia in humans 33,34) and rats. 35,36) In rats, Yagisawa et al 35,36) found that hyperhomocysteinemia induced by intravenous injection with methionine was suppressed by concurrent injection with betaine or dietary supplementation with betaine.…”

L-methionine reduces oxidant stress in endothelial cells: Role of heme oxygenase-1, ferritin, and nitric oxide

“…The effects of L-methionine were observed at high micromolar and low millimolar concentrations of L-methionine, which are well within the range of plasma levels after methionine loading. 31 Higher concentrations between 5 and 20 mM L-methionine were required to confirm increased HO-1 activity in a cell-free assay of bilirubin. This inevitable loss of sensitivity during the "ex vivo" measurement of specific enzyme activity in a broken cell system has been reported previously and is a result of induced HO-1 not being fully recoverable during the complex preparation of lysate from intact cells that were preexposed to inducing agents.…”

The association of homocysteine and coronary artery disease

“…Supplementation with betaine, starting at 3 g twice a day, is experimental and has yielded conflicting results, but can be used in very highrisk patients. 79,80 Once the patient is within goal range, a fasting tHcy can be repeated on a yearly basis. 9…”