Plasma total homocysteine

Nygird 0, Refsum H, Ueland PM, Stensvold I, Nordrehaug JE, Kv le G, Vollset SE. (1997). Coffee consumption and plasma total homocysteine the Hordaland Homocysteine Study. Am J Clin Nutr. 65(1) 136-43. 

Nhgard, O., H. Refsum, P. M. Ueland, et al. Coffee consumption and plasma total homocysteine the hordaland and... 

Nedrebo BG, et al. Plasma total homocysteine levels in hyperthyroid and hypothyroid patients. Metabolism 1998 47(1) 89-93. 

Voutilainen S, et al. Enhanced in vivo lipid peroxidation at elevated plasma total homocysteine levels. Arterioscler Thromb Vase Biol 1999 19(5) 1263-1266. 

Podda G, et al. No effect of fasting plasma total homocysteine on protein C activity in vitro. Blood 2003 101 (6) 2446-2447. 

Giltay EJ, Hoogeveen EK, Elbers JM, Gooren U, Asscheman H, Stehouwer CD. 1998. Insulin resistance is associated with elevated plasma total homocysteine levels in healthy, non obese subjects. Atherosclerosis 139 197-198. 

He was diagnosed with moderate hyperhomocysteinemia and treated with 2.0 mg folic acid daily. He continued to take warfarin and clopidogrel. After 1 month, his plasma total homocysteine level had decreased to 9 pmol/L. He had no further episodes of weakness or other neurological symptoms during the ensuing 12 months. 

An alternative reaction for the remethylation of homocysteine to methionine can be accomplished by betaine homocysteine methyltrans-ferase, which uses betaine instead of 5-MTHF as the methyl donor. Unlike the MS reaction, which is believed to be ubiquitously present in all tissues, the betaine homocysteine methyl-transferase reaction occurs only in the liver and kidney. Betaine is not a required nutrient since the liver can synthesize betaine from choline. Betaine supplements, however, have been shown to lower plasma total homocysteine concentrations successfully in subjects with deficient homocysteine remethylation due to defects in MTHFR or MTRR and in those with deficient CBS activity. 

V5. Voutilainen, S., Morrow, J. D., Roberts, L. J., II, Alfthan, G., Alho, H., Nyyssonen, K., and Salonen, J. T., Enhanced in vivo lipid peroxidation at elevated plasma total homocysteine levels. Arterioscler. Thromb. Vase. Biol. 19, 1263-1266 (1999). 

Bates CJ, Mansoor MA, van der Pols J, Prentice A, Cole TJ, Finch S (1997) Plasma total homocysteine in a representative sample of972 British men and women aged 65 and over. Eur J Chn Nutr 51(10) 691-697... 

M. Amadottir, B. Hultberg, P. Nilsson-Ehle and H. Tysell, The Effect of Reduced Glomerular Filtration Rate on Plasma Total Homocysteine Concentration, Journal of Clinical Laboratory Investigations 56 (1996) 41-46. 

Garcia, A.J. Apitz-Castro, R. Plasma total homocysteine quantitation An improvement of the classical high-... 

Nexo E, Engbaek F, Ueland PM, Westby C, O Gorman P, et al. Evaluation of novel assays in clinical chemistry quantification of plasma total homocysteine. Chn Chem 2000 46 1150-6. 

Pfeiffer CM, Huff DL, Smith SJ, Miller DT, Gunter EW. Comparison of plasma total homocysteine measurements in 14 laboratories an international study. Clin Chem 1999 45 1261-8. 

Powers HJ, Moat SJ. Developments in the measurement of plasma total homocysteine. Curr Opin Clin Nutr Metab Care 2000 3 391-7. 

VoUset SE, Refsum H, Irgens LM, Emblem BM, Tverdal A, Gjessing HK, et al. Plasma total homocysteine, pregnancy complications, and adverse outcomes the Hordaland Homocysteine Study. Am J Clin Nutr 2000 71 962-8. 

Indirect tests assess the functional adequacy of vitamin Bi2. Serum methylmalonic acid concentration is increased when a lack of adenyl-Cbl causes a block in the conversion of methylmalonyl-CoA to succinyl-CoA. It is a sensitive test of status, being often the first analyte to be raised in sub-clinical vitamin B12 deficiency. It has a further advantage in that it is unaffected by folate deficiency. Early methods for methylmalonic acid lacked sensitivity and specificity, a situation that has been resolved by the adoption of gas chromatographic-mass spectrometric methods,though these require specialized handling. Plasma total homocysteine concentration is a sensitive indicator of vitamin B status, because methyl-Cbl is required for the remethylation of... 

Several analytes are known to be indicative of folate metabolism. Plasma total homocysteine increases when there is a deficiency of 5-MTHF, such that the methylation of homocysteine to methionine is compromised. However, though plasma homocysteine is considered to be a sensitive functional indicator, it is not specific because its concentration can be influenced by deficiency of other vitamins (Bg and B12) involved in the metabolism of homocysteine. Similarly the methylation of DNA is dependent upon adequate 5-MTHF. A sensitive new method for the rapid detection of abnormal methylation patterns in global DNA patterns has been reported and may have promise as a functional marker, as may the measurement of the degree of uracil incorporation into DNA, 5,10-metliylene THF being required for die conversion of deoxyuridine monophosphate (dUMP) to dTMP by thymidylate synthetase. ... 

A. G. Bostom, H. Silbershatz, I. H. Rosenberg, et al. Nonfasting plasma total homocysteine levels and all-cause and cardiovascular disease mortality in elderly Framingham men and women. Archives of Internal Medicine 159, 1077(1999). 

Husemoen, L.L.N., T.F. Thomsen, M. Fenger, and T. Jorgensen. 2004. Effect of lifestyle factors on plasma total homocysteine concentrations in relation to MTHFR (C677T) genotype. Inter99 (7). Eur. J. Clin. Nutr. 58(8) 1142-1150. 

Randomised, crossover trial, 45 subjects, 5 weeks 3 experimental diets with the inclusion of various fats (30% energy) in high-protein diets PA-rich palm olein (PO), a lauric- and myristic-acid-rich CO diet, and VOO rich in OA. The postprandial total cholesterol and fasting lipid index for the VOO diet were significantly lower than for the CO diet. No significant differences were observed in the effects of the three diets on plasma total homocysteine and inflammatory markers. (Voon et al., 2011)... 

Bostom, A.G., Rosenberg, I.H., Silbershatz, H., Jacques, P.F., Selhub, J., D Agostino, R.B., Wilson, P.W., and Wolf, P.A., 1999. Nonfasting plasma total homocysteine levels and stroke incidence in elderly persons the Framingham Study. Annals of Internal Medicine. 131 352-355. 

Siri, P.W., Verhoef, P., and Kok, F.J., 1998. Vitamins Bg, B12 and folate association with plasma total homocysteine and risk of coronary atherosclerosis. Journal of the American College of Nutrition. 17 435-441. 

Modified from V. Herbert et at Am J Clin Nutr 1994 holoTC - Knim holatranseolialainm IHcy = plasma total homocysteine iB j = serum total vilaniin... 

Vitamin B12 deficiency is generally assessed based on serum vitamin B12 concentration, plasma homocysteine concentration and serum methylmalonic acid (MMA) concentration (Savage et al. 1994). Serum vitamin B12 concentration has been reported by many researchers, including us, to be similar in patients with CKD and healthy individuals (Koyama et al. 2002). However, plasma total homocysteine level is elevated in an inverse relationship with the reduction in renal function (Bostom and Lathrop 1997). 

In patients with CKD, plasma total homocysteine level are elevated in an inverse relationship with the reduction in renal function. 

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