Objectives: Hyperhomocysteinemia is associated with premature cerebral, peripheral and coronary vascular disease. Evaluation of the significance of changes in plasma total homocysteine (tHcy) results obtained by analysis of serial specimens may be accomplished only by taking into account biologic (between-person and within-person) as well as analytical variation. Since the repeatability of a measurement significantly determines our ability to associate tHcy level with the presence of disease, this study was performed to evaluate various components of variation in tHcy values. Design and methods: We report the within-person, between-person, and methodological variability of tHcy, both fasting and postmethionine load (PML) values, in 20 healthy volunteers from whom samples were drawn weekly for 4 weeks. Results: The short-term reliability coefficient (R) was 0.72 for fasting tHcy and 0.83 for PML tHcy. Conclusions: The current study demonstrates for the first time that the short-term reliability coefficient for PML tHcy is relatively high (0.83), suggesting that an individual's PML tHcy, like fasting tHcy, is relatively constant over at least one month, and that a single measurement should provide a reasonable characterization of an individual's PML tHcy concentration.
Bibliographical noteFunding Information:
This study was supported in part by a grant from the American Heart Association, Minnesota Affiliate and an NIH Program Project Grant in Transplantation, NIH DK 13083 to 31, entitled Organ Transplantation in Animals and Man: Homocysteine as a Risk Factor for Cardiovascular Disease in Renal Transplant Recipients.
Copyright 2008 Elsevier B.V., All rights reserved.
- Cardiovascular diseases
- Postmethionine loading
- Reliability coefficient
- Variation, source of