Homocysteine as a Predictive Factor for Hip Fracture in Older Persons

To the Editor: In their study of homocysteine as a predictive factor for hip fracture in older persons, McLean et al. (May 13 issue) 1 do not thoroughly discuss the role of physical activity, which may influence the association between homocysteine levels and the risk of fracture. Several previous studies and systematic reviews suggested that exercise increases bone mineral density and reduces or prevents bone loss in patients with osteoporosis. 2 , 3 Physical activity is also effective in preventing falls. 4 Plasma total homocysteine levels are inversely related to exercise, and this relation is not substantially changed by adjustment for intake of vitamin . . .