[Evaluation of bone mineralization in patients on maintenance hemodialysis]

Bone loss and bone formation and mineralization abnormalities resulting from disturbances in calcium and phosphorus metabolism are frequent in chronic renal failure. Haemodialysis permits long-term survival of patients with end-stage renal disease. This is the reason, why renal osteodystrophy became an important diagnostic and therapeutical problem. Very low occurrence of fractures among haemodialysed patients in our clinic, stimulated our efforts to elucidate the causes of this phenomenon. The aim of this study was to compare bone mineral densities in haemodialysed patients and healthy volunteers. 47 patients on maintenance haemodialysis (16 F, 31 M) and 55 healthy volunteers (33 F, 22 M) with normal renal function were investigated. Endocrinopathy or any other diseases that could cause changes in bone metabolism were excluded. Age distribution in both groups was similar. Patients maintained on low sodium and phosphorus diet additionally were supplemented with large doses of calcium carbonate. Haemodialyses were performed using reverse-osmosis water. BMD (Bone Mineral Density) was measured using QCT (Quantitative Computed Tomography) and was expressed as an average hydroxyapatite content in lumbar vertebraes L1-L4. The obtained results indicate high BMD of vertebral bones in haemodialysed patients from our Dialysis Department. BMD was similar to that observed in healthy volunteers. This could at least partially explain low occurrence (2 in 142 pts-years) of fractures in ou uraemic patients. However we were unable to point exactly the simple factor responsible for this positive phenomenon. We hope that introduction of our haemodialysis scheme can help patients to avoid renal osteodystrophy.