Low vitamin B6 but not homocyst(e)ine is associated with increased risk of stroke and transient ischemic attack in the era of folic acid grain fortification.
OBJECTIVE
The introduction of cereal grain folic acid fortification in 1998 has reduced homocyst(e)ine (tHcy) concentrations in the US population. We performed a case-control study to determine the risk of stroke and transient ischemic attack (TIA) associated with tHcy and low vitamin status in a postfortification US sample.


METHODS
Consecutive cases with new ischemic stroke/TIA were compared with matched controls. Fasting tHcy, folate, pyridoxal 5'-phosphate (PLP), B12, and MTHFR 677C-->T genotype were measured.


RESULTS
Mean PLP was significantly lower in cases than controls (39.97 versus 84.1 nmol/L, P<0.0001). After stroke risk factors were controlled for, a strong independent association was present between stroke/TIA and low PLP (adjusted odds ratio [OR], 4.6; 95% CI, 1.4 to 15.1; P<0.001) but not elevated tHcy (OR, 0.92; 95% CI, 0.4 to 2.1).


CONCLUSIONS
Low B6 but not tHcy was strongly associated with cerebrovascular disease in this postfortification, folate-replete sample.
Stroke Service, Department of Neurology, VBK 802, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA. pjkelly@partners.org
Peter J
PJ
Kelly
Vivian E
VE
Shih
J Philip
JP
Kistler
Megan
M
Barron
Hang
H
Lee
Roseann
R
Mandell
Karen L
KL
Furie
D016022:Case-Control Studies; D015897:Comorbidity; D002523:Edible Grain; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood; D005527:Food, Fortified; D006710:Homocysteine / Q000097:blood*; D006711:Homocystine / Q000097:blood*; D006801:Humans; D002546:Ischemic Attack, Transient / Q000097:blood* / Q000453:epidemiology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D016017:Odds Ratio; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics; D011732:Pyridoxal Phosphate; D018570:Risk Assessment; D012307:Risk Factors; D012709:Serum Albumin / Q000032:analysis; D020521:Stroke / Q000097:blood* / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D014805:Vitamin B 12 / Q000097:blood; D025101:Vitamin B 6 / Q000097:blood*
D012709:Serum Albumin; D006710:Homocysteine; D006711:Homocystine; D011732:Pyridoxal Phosphate; D025101:Vitamin B 6; D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12