Effects of multivitamins and low-dose folic acid supplements on flow-mediated vasodilation and plasma homocysteine levels in older adults.
BACKGROUND
Hyperhomocysteinemia is associated with aging, endothelial dysfunction, and increased risk of coronary heart disease in older adults; however, the effects of homocysteine-lowering therapy on vascular reactivity in older persons are unknown. The objective of this study was to determine the effects of multivitamins (MV) and folic acid (FA) supplements on flow-mediated vasodilation (FMD) in older adults.


METHODS
Individuals > or =70 years old with homocysteine levels > or =10 micromol/L were recruited for this 40-week, prospective, single-blinded study. All subjects were treated sequentially, with each of the following daily therapies for 10 weeks: (1) placebo, (2) MV (400 microg FA, 6 mg vitamin B6, 25 microg vitamin B12), (3) placebo, then (4) MV + FA (total FA, 1400 microg). FMD, folate intake, and laboratory values were measured at each visit. Investigators were blinded to subject treatment phase when measuring vessel diameters and calculating FMD.


RESULTS
Twenty subjects (mean +/- SEM age, 78.0 +/- 1.2 [range, 70 to 88] years, 9 women) completed the MV and 17 completed the MV + FA interventions. FMD was impaired at baseline (2.0% +/- 1.2%). During the 40-week study, homocysteine levels decreased by 1.4 +/- 0.9 micromol/L (p(trend) = 0.034) from a baseline of 12.8 +/- 0.6 micromol/L; however, FMD did not change significantly (p(trend) = 0.874). FMD did not improve after therapy with MV alone (3.0% +/- 0.9% [week 10] vs 2.4% +/- 1.1% [week 20], P =.716) or with MV + FA (2.6% +/- 0.9% [week 30] vs 1.9% +/- 0.7% [week 40], P =.484).


CONCLUSIONS
At doses commonly prescribed in clinical practice, MV and FA supplements did not improve FMD in older adults with hyperhomocysteinemia.
Carlsson
Cynthia M
CM
Section of Cardiovascular Medicine, University of Wisconsin Medical School, and the Veterans Affairs Geriatrics Research, Education, and Clinical Center (GRECC), Madison, Wis 53705, USA. cmc@medicine.wisc.edu
Pharo
Lisa M
LM
Aeschlimann
Susan E
SE
Mitchell
Carol
C
Underbakke
Gail
G
Stein
James H
JH
D000368:Aged; D000369:Aged, 80 and over; D001916:Brachial Artery / Q000187:drug effects / Q000502:physiology; D019587:Dietary Supplements; D004338:Drug Combinations; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D011446:Prospective Studies; D016037:Single-Blind Method; D014664:Vasodilation / Q000187:drug effects*; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000494:pharmacology*; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000494:pharmacology*; D014815:Vitamins / Q000494:pharmacology / Q000627:therapeutic use
D004338:Drug Combinations; D014815:Vitamins; D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D014805:Vitamin B 12