An elevated homocysteine level in the blood has been identified as an independent risk factor for vascular disease, including coronary atherosclerosis and venoembolic disease. A deficiency of vitamins B6, B12, or folate in the blood can cause increased blood levels of homocysteine. We set out to determine whether there was a relationship between blood levels of folate and B12 and the subsequent development of cardiovascular disease and mortality in old old ambulatory men and women.
Four hundred forty subjects (mean age, 79 years; 64% female) were followed in the Bronx Longitudinal Aging Study, a prospective study of 10 years duration, designed to assess risk factors for cardiovascular and cerebrovascular diseases and dementia in an ambulatory old old cohort.
Serum levels of vitamin B12 and folate were measured and related to the incidence of total all-cause mortality, stroke, myocardial infarction, coronary heart disease, and cardiovascular disease.
No statistical gender- or age-related differences were found itn the mean levels of folate or B12. The concentration of folate in the blood was not related to the incidence of mortality, myocardial infarction, stroke, or overall cardiovascular disease. However, by logistical regression and Cox proportional-hazards regression analyses, there was an increased incidence of mortality and coronary heart disease in those subjects having increased vitamin B12 levels in the blood. Each 100-pg increase in B12 was associated with a 10% increase in mortality and coronary heart disease incidence.
These results suggest that in elderly subjects, vitamin B12 supplementation should not be routinely provided unless there are clear indications for doing so (a deficiency state), and then only to replace enough B12 to correct the deficiency. A suggested treatment paradigm is provided for managing vitamin deficiency states and hyperhomocysteinemia in elderly subjects.
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