In:
British Journal of Nutrition, Cambridge University Press (CUP), Vol. 103, No. 11 ( 2010-06-14), p. 1629-1634
Kurzfassung:
Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease but lowering tHcy with B-vitamins, including folate, has generally not reduced vascular events in secondary prevention trials. Elevated plasma S -adenosylhomocysteine (AdoHcy) concentration may be a more sensitive indicator of vascular disease than plasma tHcy. However, unlike tHcy, plasma AdoHcy did not correlate with folate concentration in one study indicating that folate supplementation may not lower AdoHcy. Our aim was to determine whether providing B-vitamin supplements to healthy older people with elevated tHcy ( 〉 13 μmol/l) affects plasma AdoHcy and S -adenosylmethionine (AdoMet) concentrations. Healthy older participants ( n 276; ≥ 65 years) were randomised to receive a daily supplement containing folate (1 mg), vitamin B 12 (500 μg) and vitamin B 6 (10 mg), or placebo, for 2 years. Of these participants, we selected the first fifty participants in each treatment group and measured plasma AdoHcy and AdoMet. Plasma tHcy 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 AdoMet (+4 % (95 % CI − 2, 11); P = 0·19), AdoHcy ( − 1 % (95 % CI − 10, 8); P = 0·61) or the AdoMet:AdoHcy ratio (0·22 (95 % CI − 0·04, 0·49); P = 0·10) between the two groups. In conclusion, B-vitamin supplementation of older people lowered plasma tHcy but had no effect on plasma AdoMet or AdoHcy concentration. If elevated plasma AdoHcy is detrimental, this may explain why B-vitamins have generally failed to reduce vascular events in clinical trials.
Materialart:
Online-Ressource
ISSN:
0007-1145
,
1475-2662
DOI:
10.1017/S0007114509993552
Sprache:
Englisch
Verlag:
Cambridge University Press (CUP)
Publikationsdatum:
2010
ZDB Id:
2016047-1
SSG:
12
SSG:
21
