Holo-transcobalamin is an early marker of changes in cobalamin homeostasis. A randomized placebo-controlled study.

نویسندگان

  • Ebba Nexo
  • Anne-Mette Hvas
  • Øyvind Bleie
  • Helga Refsum
  • Sergey N Fedosov
  • Stein Emil Vollset
  • Jorn Schneede
  • Jan Erik Nordrehaug
  • Per Magne Ueland
  • Ottar Kjell Nygard
چکیده

BACKGROUND We examined the effect of oral vitamin B(12) treatment on fluctuations in plasma total cobalamin and its binding proteins transcobalamin (TC) and haptocorrin (HC). METHODS Patients (n = 88; age range, 38-80 years) undergoing coronary angiography (part of the homocysteine-lowering Western Norway B-Vitamin Intervention Trial) were allocated to daily oral treatment with (a) vitamin B(12) (0.4 mg), folic acid (0.8 mg), and vitamin B(6) (40 mg); (b) vitamin B(12) and folic acid; (c) vitamin B(6); or (d) placebo. EDTA blood was obtained before treatment and 3, 14, 28, and 84 days thereafter. RESULTS The intraindividual variation for patients not treated with B(12) was approximately 10% for plasma total cobalamin, total TC, apo-TC, and apo-HC, and <20% for holo-TC and TC saturation. In B(12)-treated patients, the maximum change in concentrations was observed already after 3 days for total TC (-16%), holo-TC (+54%), and TC saturation (+82%). At this time holo-HC (+20%) and plasma total cobalamin (+28%) showed an initial burst, but had increased further at 84 days. All changes were highly significant compared with the control group (P <0.0001). CONCLUSIONS Oral vitamin B(12) treatment produces maximal effects on total TC, holo-TC, and TC saturation within 3 days, whereas maximal increases in holo-HC and plasma total cobalamin occur later. The results support the view that holo-TC is an early marker of changes in cobalamin homeostasis.

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عنوان ژورنال:
  • Clinical chemistry

دوره 48 10  شماره 

صفحات  -

تاریخ انتشار 2002