Reduced speed of sound in tibial bone of haemodialysed patients: association with serum PTH level

Background. In end-stage renal disease, average bone mineral density has been reported to be normal or only modestly reduced, more so in the cortical bone. The purpose of the present study was to explore the potential use of quantitative ultrasound, a method reflecting both quantitative and qualitative properties of bone, in assessing bone status in patients on maintenance haemodialysis. Methods. We studied 71 patients (age 17-81 years, time on dialysis 0-18 years). The speed of sound waves (tSOS; m/s) propagating along the cortical bone has been determined at the tibial shaft. tSOS results were expressed as Z scores, i.e. units of standard deviations from age- and sex-matched normal mean values, and correlated with relevant clinical and biochemical variables. Results. SOS Z score averaged —2.0 (range —6.8 to 0.6; P =0.08), but this could be accounted for by longer time on dialysis. Conclusions. tSOS is substantially reduced in the majority of haemodialysed patients and is related to time on dialysis and serum PTH level. The clinical value of this novel method needs further exploration.