Plasma B vitamins, homocysteine, and their relation with bone loss and hip fracture in elderly men and women.
BACKGROUND
Elevated homocysteine is a strong risk factor for osteoporotic fractures among elders, yet it may be a marker for low B-vitamin status.


OBJECTIVE
Our objective was to examine the associations of plasma concentrations of folate, vitamin B12, vitamin B6, and homocysteine with bone loss and hip fracture risk in elderly men and women.


METHODS
This was a longitudinal follow-up study of the Framingham Osteoporosis Study.


METHODS
Community dwelling residents of Framingham, MA, were included in the study.


METHODS
A total of 1002 men and women (mean age 75 yr) was included in the study.


METHODS
Baseline (1987-1989) blood samples were used to categorize participants into plasma B-vitamin (normal, low, deficient) and homocysteine (normal, high) groups. Femoral neck bone mineral density (BMD) measured at baseline and 4-yr follow-up was used to calculate annual percent BMD change. Incident hip fracture was assessed from baseline through 2003.


RESULTS
Multivariable-adjusted mean bone loss was inversely associated with vitamin B6 (P for trend 0.01). Vitamins B12 and B6 were inversely associated with hip fracture risk (all P for trend < 0.05), yet associations were somewhat attenuated and not significant after controlling for baseline BMD, serum vitamin D, and homocysteine. Participants with high homocysteine (>14 micromol/liter) had approximately 70% higher hip fracture risk after adjusting for folate and vitamin B6, but this association was attenuated after controlling for vitamin B12 (hazard ratio = 1.49; 95% confidence interval 0.91, 2.46).


CONCLUSIONS
Low B-vitamin concentration may be a risk factor for decreased bone health, yet does not fully explain the relation between elevated homocysteine and hip fracture. Thus, homocysteine is not merely a marker for low B-vitamin status.
McLean
Robert R
RR
Institute for Aging Research, Hebrew SeniorLife, 1200 Centre Street, Boston, MA 02131, USA. rmclean@hrca.harvard.edu
Jacques
Paul F
PF
Selhub
Jacob
J
Fredman
Lisa
L
Tucker
Katherine L
KL
Samelson
Elizabeth J
EJ
Kiel
Douglas P
DP
Cupples
L Adrienne
LA
Hannan
Marian T
MT
D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D012111:Residence Characteristics; D012307:Risk Factors; D014803:Vitamin B Complex / Q000097:blood*
D006710:Homocysteine; D014803:Vitamin B Complex