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Homocysteine-lowering vitamins do not lower plasma S-adenosylhomocysteine in older people with elevated homocysteine concentrations.
Br J Nutr. 2010 Jun; 103(11):1629-34.BJ

Abstract

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 micromol/l) affects plasma AdoHcy and S-adenosylmethionine (AdoMet) concentrations. Healthy older participants (n 276; > or = 65 years) were randomised to receive a daily supplement containing folate (1 mg), vitamin B12 (500 microg) and vitamin B6 (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) micromol/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.

Authors+Show Affiliations

Food, Nutrition, and Health, University of British Columbia, Vancouver, BC, Canada. tim.green@ubc.caNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

20089204

Citation

Green, Timothy J., et al. "Homocysteine-lowering Vitamins Do Not Lower Plasma S-adenosylhomocysteine in Older People With Elevated Homocysteine Concentrations." The British Journal of Nutrition, vol. 103, no. 11, 2010, pp. 1629-34.
Green TJ, Skeaff CM, McMahon JA, et al. Homocysteine-lowering vitamins do not lower plasma S-adenosylhomocysteine in older people with elevated homocysteine concentrations. Br J Nutr. 2010;103(11):1629-34.
Green, T. J., Skeaff, C. M., McMahon, J. A., Venn, B. J., Williams, S. M., Devlin, A. M., & Innis, S. M. (2010). Homocysteine-lowering vitamins do not lower plasma S-adenosylhomocysteine in older people with elevated homocysteine concentrations. The British Journal of Nutrition, 103(11), 1629-34. https://doi.org/10.1017/S0007114509993552
Green TJ, et al. Homocysteine-lowering Vitamins Do Not Lower Plasma S-adenosylhomocysteine in Older People With Elevated Homocysteine Concentrations. Br J Nutr. 2010;103(11):1629-34. PubMed PMID: 20089204.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Homocysteine-lowering vitamins do not lower plasma S-adenosylhomocysteine in older people with elevated homocysteine concentrations. AU - Green,Timothy J, AU - Skeaff,C Murray, AU - McMahon,Jennifer A, AU - Venn,Bernard J, AU - Williams,Sheila M, AU - Devlin,Angela M, AU - Innis,Sheila M, Y1 - 2010/01/21/ PY - 2010/1/22/entrez PY - 2010/1/22/pubmed PY - 2010/6/19/medline SP - 1629 EP - 34 JF - The British journal of nutrition JO - Br J Nutr VL - 103 IS - 11 N2 - 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 micromol/l) affects plasma AdoHcy and S-adenosylmethionine (AdoMet) concentrations. Healthy older participants (n 276; > or = 65 years) were randomised to receive a daily supplement containing folate (1 mg), vitamin B12 (500 microg) and vitamin B6 (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) micromol/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. SN - 1475-2662 UR - https://www.unboundmedicine.com/medline/citation/20089204/Homocysteine_lowering_vitamins_do_not_lower_plasma_S_adenosylhomocysteine_in_older_people_with_elevated_homocysteine_concentrations_ L2 - https://www.cambridge.org/core/product/identifier/S0007114509993552/type/journal_article DB - PRIME DP - Unbound Medicine ER -