Interaction of Choline/Betaine Metabolysm and Homocysteine Plasma Levels

Abstract number: P1678

Gori¹ AM, Sofi¹ F, Fedi¹ S, Bandinelli¹ B, Attanasio¹ M, Casini² A, Surrenti² C, Moneti³ G, Abbate¹ R, Gensini¹ GF

¹¹Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ¹¹Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ²²Department of Clinical Pathophysiology, Unit of Clinical Nutrition, University of Florence, Italy ³³Department of Pharmacology, University of Florence, Florence, Italy

Betaine is an alternate methyl donor for homocysteine remethylation, derived from choline oxidation; betaine homocysteine methyltrasferase (BHMT) transfer the methyl group from betaine to homocysteine, resulting in demethylated betaine (dimethylglycine, DMG) and methionine. The influence of betaine supplementation on circulating homocysteine concentration has been studied mainly in clinical settings. Betaine treatment combined with folic acid normalized fasting plasma homocysteine concentrations in patients with severe inborn hyperhomocysteinemia. Little published information is available concerning the effect of betaine on plasma homocysteine concentration in subjects with normal to mild elevated homocysteine levels. Aim of the study was to examine the interaction between homocysteine and choline/betaine metabolism in a group of healthy subjects with normal vitamin status (folic acid, vitamin B6 and B12). We analyzed choline, betaine and DMG in 72 healthy subjects (32F; 40M; median age: 58 years). Determination of choline, betaine and DMG was obtained by a high-throughput method based on normal-phase chromatography-tandem mass spectrometry. Homocysteine and choline plasma levels were found to be significantly related (R = 0.33; P < 0.001), but no significant correlation was observed between homocysteine, betaine and DMG plasma levels. DMG levels were significantly different among males and females (1.8 ± 0.9 vs. 1.4 ± 0.5 uM, P= 0.01), whereas no significant difference was observed for betaine and choline plasma levels. Choline plasma levels were significantly (P < 0.001) higher (16.7 ± 6.8 µM) in subjects with hyperhomocysteinemia (M > 15; F > 13 µmol/L) respect to those (11.3 ± 3.1 µM) with normal values of homocysteine. These preliminary data show the possible interaction between choline and homocysteine levels.