Renal osteopenia - an assessment of long-term therapy with vitamin D analogues.

Renal bone disease was assessed for an average of 5.5 years in 9 patients on maintenance haemodialysis. The investigative methods included serial biochemical estimations, radiographic skeletal surveys and quantitative bone histology. Repeated bone mineral analyses and neutron activation analyses of a hand were also performed in order to monitor changes in skeletal calcium content. Before treatment, progressive osteodystrophy was demonstrated by all techniques. Following therapy with the vitamin D analogues, all patients noted symptomatic improvement; serum alkaline phosphatase reverted to normal and serum parathyroid hormone concentrations decreased. Radiographically, subperiosteal erosions healed while the histological features of osteomalacia and osteitis fibrosa were abolished. Both bone mineral and neutron activation analyses indicated that progressive skeletal demineralisation had been halted. However, a sustained increase in the overall mineral content of bone was not demonstrated. Thus, vitamin D therapy although improving the biochemical, radiological, and histological features of renal osteodystrophy may not restore bone mass to osteopenic bone.