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Vitamins B6, B12, and folate: association with plasma total homocysteine and risk of coronary atherosclerosis.
J Am Coll Nutr 1998; 17(5):435-41JA

Abstract

OBJECTIVES

To investigate the association of status of vitamins B6, B12 and folate with plasma fasting total homocysteine (tHcy) and with risk of coronary atherosclerosis; and to establish whether associations between vitamins and risk of coronary atherosclerosis are mediated by tHcy.

METHODS

The study population consisted of 131 patients with angiography-defined severe coronary atherosclerosis and 88 referents with no or minor coronary stenosis. Previous analyses in this study population have shown that fasting tHcy is an independent risk factor for coronary atherosclerosis. In the present analyses, using multiple linear regression, we estimated differences in tHcy concentrations between subjects in the lowest and highest quartiles of concentrations of each of the vitamins, adjusting for age, gender, total:HDL cholesterol ratio, smoking habits, alcohol intake, blood pressure, serum creatinine, body mass index and the two other vitamins. We used logistic regression analysis conditional on the set of potential confounders described above to study the association between vitamin concentration and risk of coronary atherosclerosis. By comparing these estimated odds ratios (ORs) with those that were additionally adjusted for fasting tHcy, we determined whether the vitamins exerted their effects on disease risk via homocysteine metabolism.

RESULTS

Cases who were in the upper quartile of serum vitamin B12 and erythrocyte folate concentrations showed statistically significantly lower tHcy concentrations (-4.00 and -4.71 mumol/L, respectively) than those in the lowest quartile. Referents in the upper quartile of plasma B6 showed significantly lower tHcy concentrations (-2.36 mumol/L) than referents in the lowest quartile. Subjects in the lowest quartile of vitamin B12 concentrations had higher risk of coronary atherosclerosis (OR: 2.91; 95% CI: 1.10, 7.71) compared to those in the highest quartile. The ORs and 95% CIs for low B6 and low folate were 0.86 (95% CI: 0.33, 2.22) and 0.58 (95% CI: 0.23, 1.48), respectively. Additional adjustment for fasting tHcy weakened associations, although data indicated that low vitamin B12 concentration is a risk factor for coronary atherosclerosis, independently of tHcy.

CONCLUSION

The presently accepted view that vitamin B6 mainly affects tHcy after methionine loading, and not fasting tHcy, is contradicted by our findings in referents. Low vitamin B12 concentrations were associated with an increased risk of coronary atherosclerosis, partly independently of tHcy. Although low folate status was a strong determinant of elevated tHcy concentrations, it was not associated with increased risk of coronary atherosclerosis.

Authors+Show Affiliations

Department of Food Technology and Nutrition Sciences, Wageningen Agricultural University, The Netherlands.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

9791839

Citation

Siri, P W., et al. "Vitamins B6, B12, and Folate: Association With Plasma Total Homocysteine and Risk of Coronary Atherosclerosis." Journal of the American College of Nutrition, vol. 17, no. 5, 1998, pp. 435-41.
Siri PW, Verhoef P, Kok FJ. Vitamins B6, B12, and folate: association with plasma total homocysteine and risk of coronary atherosclerosis. J Am Coll Nutr. 1998;17(5):435-41.
Siri, P. W., Verhoef, P., & Kok, F. J. (1998). Vitamins B6, B12, and folate: association with plasma total homocysteine and risk of coronary atherosclerosis. Journal of the American College of Nutrition, 17(5), pp. 435-41.
Siri PW, Verhoef P, Kok FJ. Vitamins B6, B12, and Folate: Association With Plasma Total Homocysteine and Risk of Coronary Atherosclerosis. J Am Coll Nutr. 1998;17(5):435-41. PubMed PMID: 9791839.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Vitamins B6, B12, and folate: association with plasma total homocysteine and risk of coronary atherosclerosis. AU - Siri,P W, AU - Verhoef,P, AU - Kok,F J, PY - 1998/10/29/pubmed PY - 1998/10/29/medline PY - 1998/10/29/entrez SP - 435 EP - 41 JF - Journal of the American College of Nutrition JO - J Am Coll Nutr VL - 17 IS - 5 N2 - OBJECTIVES: To investigate the association of status of vitamins B6, B12 and folate with plasma fasting total homocysteine (tHcy) and with risk of coronary atherosclerosis; and to establish whether associations between vitamins and risk of coronary atherosclerosis are mediated by tHcy. METHODS: The study population consisted of 131 patients with angiography-defined severe coronary atherosclerosis and 88 referents with no or minor coronary stenosis. Previous analyses in this study population have shown that fasting tHcy is an independent risk factor for coronary atherosclerosis. In the present analyses, using multiple linear regression, we estimated differences in tHcy concentrations between subjects in the lowest and highest quartiles of concentrations of each of the vitamins, adjusting for age, gender, total:HDL cholesterol ratio, smoking habits, alcohol intake, blood pressure, serum creatinine, body mass index and the two other vitamins. We used logistic regression analysis conditional on the set of potential confounders described above to study the association between vitamin concentration and risk of coronary atherosclerosis. By comparing these estimated odds ratios (ORs) with those that were additionally adjusted for fasting tHcy, we determined whether the vitamins exerted their effects on disease risk via homocysteine metabolism. RESULTS: Cases who were in the upper quartile of serum vitamin B12 and erythrocyte folate concentrations showed statistically significantly lower tHcy concentrations (-4.00 and -4.71 mumol/L, respectively) than those in the lowest quartile. Referents in the upper quartile of plasma B6 showed significantly lower tHcy concentrations (-2.36 mumol/L) than referents in the lowest quartile. Subjects in the lowest quartile of vitamin B12 concentrations had higher risk of coronary atherosclerosis (OR: 2.91; 95% CI: 1.10, 7.71) compared to those in the highest quartile. The ORs and 95% CIs for low B6 and low folate were 0.86 (95% CI: 0.33, 2.22) and 0.58 (95% CI: 0.23, 1.48), respectively. Additional adjustment for fasting tHcy weakened associations, although data indicated that low vitamin B12 concentration is a risk factor for coronary atherosclerosis, independently of tHcy. CONCLUSION: The presently accepted view that vitamin B6 mainly affects tHcy after methionine loading, and not fasting tHcy, is contradicted by our findings in referents. Low vitamin B12 concentrations were associated with an increased risk of coronary atherosclerosis, partly independently of tHcy. Although low folate status was a strong determinant of elevated tHcy concentrations, it was not associated with increased risk of coronary atherosclerosis. SN - 0731-5724 UR - https://www.unboundmedicine.com/medline/citation/9791839/Vitamins_B6_B12_and_folate:_association_with_plasma_total_homocysteine_and_risk_of_coronary_atherosclerosis_ L2 - http://www.tandfonline.com/doi/full/10.1080/07315724.1998.10718790 DB - PRIME DP - Unbound Medicine ER -