| [ Summary ] |
There is substantial evidence that homocysteine is a vascular-injuring amino acid,and even moderate hyperhomocysteinemia is an independent risk factor for atherosclerosis and premature vascular disease. Meta-analysis of published data showed that for every 5 micro mol/l increase in plasma total homocysteine(tHcy), men had a 1.6 fold increase in coronary heart disease risk. A 5 micro mol/l increase in tHcy is equivalent to an increase in total serum cholesterol of 20 mg/dl. The tHcy variation is skewed toward higher values in normal subjects.Men had higher tHcy concentrations than women at every age. In men, there is a steady increase in homocysteine with age. Women, however, did not show an apparent increase until menopause,when they showed a rapid increase.At this point the sex-related differences in tHcy concentrations were reduced. Most individuals with increased levels of tHcy have suboptimal in takes of folate, vitamin B6 and B12; and supplementation of these vitamins results in a significant reduction in tHcy levels. A reference range should be determined in a population with adequate vitamin intake. The age-and gender-theme central 95% intervals after vitamin supplementation are as follows: 4.6-8.1 micro mol/l for <30years: 6.3-11.2 micro mol/l and 4.5-7.9 micro mol/l for men and women 30-59 years, 5.8-11.9 micro mol/l for subjects at> 60 years. Epidemiological study shows that tHcy in the range of 11.4-14.3 is associated with increased risk of cerebrovascular disease, OR=1.6. |