Advantage of hand bone calcium content measurement by local neutron activation analysis for following up hemodialysis patients.

Hand bone calcium content [Ca] has been measured by local neutron analysis in hemodialyzed patients free of signs of osteomalacia before and 6-12 months after treatment with vitamin D metabolites, and it has been compared to some iliac bone histomorphometric parameters. With 1,25-(OH)2D3 alone, [Ca] increases significantly at the 6th month of treatment (p less than 0.001) but not from the 6th to the 12th month. With 1 alpha-(OH)D3 + 25-(OH)D3 the same phenomenon is observed at the 6th and 12th months of treatment. Before treatment, [Ca] was correlated negatively with the osteoid surfaces (OS) (r = -0.62, p = 0.01) and the number of osteoclasts per square millimeter (Ocl/mm2) (r = -0.79, p less than 0.001). At the 6th month of treatment, [Ca] was still correlated negatively with OS (r = -0.42, p = 0.05) and with Ocl/mm2 (r = -0.60, p less than 0.005). At the 12th month, the two negative correlations decreased but remained significant (r = -0.42, p = 0.05; r = -0.45, p = 0.05). These data suggest that (1) hand bone calcium analysis by neutron activation permits to follow up the peripheral bone mineral content in hemodialyzed patients and (2) the [Ca] increase only observed during the first months of treatment with vitamin D metabolites probably result from an attenuation of secondary hyperparathyroidism.