Green Ralph, Miller Joshua W
Department of Medical Pathology and Laboratory Medicine, University of California, Davis, Sacramento, CA 95817, USA.
Clin Chem Lab Med. 2005;43(10):1048-51. doi: 10.1515/CCLM.2005.183.
Prevalence rates for folate deficiency and hyperhomocysteinemia have been markedly reduced following the introduction of folic acid fortification in the United States. We report the prevalence of hyperhomocysteinemia in a population of community-dwelling elderly Latinos in the post-folic acid fortification era. We measured homocysteine, total vitamin B12, holotranscobalamin, red blood cell folate, and serum creatinine in 1096 subjects aged > or =60 years. Hyperhomocysteinemia (>13 micromol/L) was observed in 16.5% of the subjects. The population attributable risk percentages for hyperhomocysteinemia were 29.7% for total B12 <148 pmol/L, 36.4% for holotranscobalamin <35 pmol/L, and 41.4% for creatinine >115 micromol/L. In contrast, the population attributable risk percentage for hyperhomocysteinemia was only 0.3% for red blood cell folate <365 nmol/L. We conclude that in the post-folic acid fortification era, low vitamin B12 status has become the dominant nutritional determinant of hyperhomocysteinemia. Steps to either reduce the prevalence of vitamin B12 deficiency or to identify and treat individuals with vitamin B12 deficiency could further reduce the prevalence of hyperhomocysteinemia.
在美国引入叶酸强化措施后，叶酸缺乏和高同型半胱氨酸血症的患病率显著降低。我们报告了在叶酸强化时代社区居住的老年拉丁裔人群中高同型半胱氨酸血症的患病率。我们测量了1096名年龄≥60岁受试者的同型半胱氨酸、总维生素B12、全转钴胺素、红细胞叶酸和血清肌酐。16.5%的受试者出现高同型半胱氨酸血症（>13 μmol/L）。总B12<148 pmol/L时，高同型半胱氨酸血症的人群归因风险百分比为29.7%；全转钴胺素<35 pmol/L时为36.4%；肌酐>115 μmol/L时为41.4%。相比之下，红细胞叶酸<365 nmol/L时，高同型半胱氨酸血症的人群归因风险百分比仅为0.3%。我们得出结论，在叶酸强化时代，低维生素B12状态已成为高同型半胱氨酸血症的主要营养决定因素。采取措施降低维生素B12缺乏的患病率或识别和治疗维生素B12缺乏个体，可能会进一步降低高同型半胱氨酸血症的患病率。
