Risk for hip fracture and associated osteoporosis is two to four times higher among stroke patients than among age-matched controls; it is also higher in paretic limbs than in unaffected limbs. High homocysteine levels and deficiencies in folate or vitamin B12 might play a role, given the observed association between homocysteine levels and fracture risk (Journal Watch Jun 1 2004).
Japanese investigators randomized 628 stroke patients (age, ≥65) without previous fractures to daily supplementation with folate (5 mg) plus mecobalamine (1500 µg) or double placebo. Subjects had high baseline homocysteine levels and low vitamin B12 levels, relative to reference levels in healthy older Japanese people.
By 2 years, 6 hip fractures had occurred in the treatment group, and 27 had occurred in the placebo group; relative risk reduction with treatment was 0.78, and absolute risk reduction was 6.7%, which yielded a number needed to treat (NNT) of 15 to prevent 1 fracture. In both treatment and control groups, mean BMD was significantly lower on the hemiplegic side than on the unaffected side, and BMD had not improved in either hip at 2-year follow-up.
These results are unexpectedly large in magnitude and deserve replication in both stroke and nonstroke populations. The magnitude of benefit is similar to that found in trials of alendronate and raloxifene, with considerably less potential risk. The fact that BMD did not change suggests the benefit derives from quality, rather than quantity, of bone.
Thomas L. Schwenk, MD
Sato Y et al. Effect of folate and mecobalamin on hip fractures in patients with stroke: A randomized controlled trial. JAMA 2005 Mar 2; 293:1082-8.
Journal Watch. 2005;4(3) © 2005 Massachusetts Medical Society
Cite this: Folate and Vitamin B12 Prevent Hip Fracture in Stroke Patients - Medscape - Mar 25, 2005.