B Vitamin Plasma Levels and the Risk of Ischemic Stroke and Transient Ischemic Attack in a German Cohort

Abstract

Background and Purpose-Data from prospective studies on the associations between B vitamin plasma levels and the risk of stroke are limited. We investigated the individual and combined effects of plasma folate, vitamin B12, and pyridoxal 5-phophate (PLP) levels on the risk of ischemic stroke and transient ischemic attack (TIA) in a large, prospective German cohort. Methods-Incident cases of ischemic stroke or TIA were identified among 25 770 participants (age 35 to 65 years) of the European Prospective Investigation into Cancer and Nutrition-Potsdam Study during 6.0Ϯ1.5 years of follow-up. The present analysis is based on a case-cohort study comprising 779 subjects free from cardiovascular disease and 188 incident cases of cerebral ischemia (ischemic stroke or TIA). Multivariable Cox proportional-hazard models were applied to evaluate the association between B vitamin levels and risk of cerebral ischemia. Results-Participants in the lowest tertile of vitamin B12 values were at increased risk of cerebral ischemia compared with subjects in the highest tertile; this was not observed, however, for either folate or PLP. In subgroup analyses, the relative risks were similar in magnitude for stroke and TIA. When various combinations of B vitamin tertile levels were analyzed, only combined low folate and vitamin B12 levels (relative risk, 2.24; 95% CI, 1.10 to 4.54) were significantly related to an increased risk of cerebrovascular ischemia. Conclusions-Our data suggest that low vitamin B12 plasma levels, particularly in combination with low folate levels, increase the risk of cerebral ischemia. This effect may be mediated at least partly through elevations of homocysteine levels.

Periventricular White Matter Lucencies Relate to Low Vitamin B12 Levels in Patients With Small Vessel Stroke

“…So far, vitamin B12 has been mainly related to cerebrovascular disease by its effect on lowering serum homocysteine (HCys) levels. 6,7 Elevated HCys levels are considered to damage vascular endothelium and have, apart from stroke, been associated with WML. 8,9 However, vitamin B6 and folate also influence HCys levels, but analyses on the relation between these vitamins and WML were not accounted for vitamin B12 levels in studies so far.…”

Atherosclerotic and Thrombophilic Risk Factors in Patients With Ischemic Central Retinal Vein Occlusion

“…13,[37][38][39][40] In a recent study, 41 folic acid in the lowest tertile, independent of Hcy levels, was found to be significantly related to an increased risk of having RVO, confirming the pathogenetic role of the deficiency of this vitamin on the occurrence of this disease. The present finding of an association of low folic acid levels with ischemic CRVO might have therapeutic implications.…”

Plasma Cystathionine and Risk of Incident Stroke in Patients With Suspected Stable Angina Pectoris

“…Model 1 included age (years) and sex, and the multivariate model 2 additionally included the categorical variables, obesity, diabetes mellitus, hypertension, smoking, previous acute myocardial infarction, and atrial fibrillation. Because B‐vitamins are crucial in the metabolism of cystathionine20, 21 and systemic B‐vitamin levels have been associated with CVD risk,22, 23 we did not include these variables in the main multivariate model. However, to assess their potential influence on any cystathionine‐stroke relationship, these variables were additionally included in an extended model, as was eGFR, because elevated circulating cystathionine concentrations have been reported in renal patients 21…”