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Effect of homocysteine (Hcy) lowering vitamins on S‐adenosylmethionine (SAM) and S‐adenosylhomocysteine (SAH) in older people.
Author(s) -
Green Tim,
Skeaff C Murray,
Venn Bernard,
Innis Sheila
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.904.8
Subject(s) - homocysteine , placebo , medicine , vitamin b12 , b vitamins , plasma homocysteine , endocrinology , vascular disease , gastroenterology , pathology , alternative medicine
Background Elevated plasma Hcy is a risk factor for vascular disease but lowering Hcy with B‐vitamins, including folate, has generally not reduced vascular events in clinical trials. Elevated plasma SAH concentration may be a more sensitive indicator of vascular disease than Hcy (AJCN 2007;86:1581). However, SAH was not correlated with folate concentrations in one study indicating that folate supplementation may not lower SAH (Eur J Clin Invest 2003;33:17). The effect of Hcy lowering vitamins on plasma SAH is not clear. Aim To determine in healthy older people with mildly elevated Hcy (Mean = 17.1 µmol/L) whether lowering Hcy with B vitamins effects plasma SAM and SAH concentrations. Methods This was part of a larger trial to determine the effect of B vitamins on cognition in which 276 healthy participants (= 65 y) were randomized to receive a supplement containing folate (1 mg), vitamin B12 (500 µg) and B6 (10 mg), or placebo, for two years. Of these participants, we selected the first 50 from each treatment group and determined SAM and SAH at baseline and two years by HPLC MS/MS. Results Plasma Hcy was 4.4 (95% CI 3.2, 5.6; P<0.001) µmol/L lower at 2 years in the Vitamins group compared with the Placebo group. At 2 years, there were no significant differences in plasma SAM [+4% (95% CI ‐2, 10); P=0.18], SAH [+2 (95% CI ‐10, 10); P=0.61], or the SAM:SAH ratio [+10% (95% CI 0, 20); P=0.10] between the Vitamins and Placebo groups. Conclusion Supplementation lowered plasma Hcy but had no effect on SAM or SAH concentration.