Letter to the EditorRe: 'DXA in vivo BMD methodology: An erroneous and misleading research and clinical gauge of bone mineral status, bone fragility, and bone remodelling' by H.H. Bolotin {Bone 2007; 41:138-154)

摘要

We should like to comment on the recent paper by Bolotin "DXA in vivo BMD methodology: An erroneous and misleading research and clinical gauge of bone mineral status, bone fragility, and bone remodelling" , The limitations imposed by variable fat distribution on the accuracy of DXA measurements stem from there being three components, bone mineral, fat and lean soft tissue, with different attenuation coefficients but only two photon energies. These limitations are well established, but we agree with Bolotin that they are insufficiently appreciated. We do not agree with him that they are such as to condemn DXA in the way he does. A necessary assumption regarding extra-osseus fat, which Bolotin does not spell out, is that the fat distribution overlying bone, which cannot be derived from the DXA measurements, can be related to the measured fat distribution in the adjacent soft tissue. The validity of such assumptions can only be assessed by independent measurements of fat distribution in vivo. A few such experiments have been performed.