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<0.001) and was negative in 93% of the patients. Significant inverse correlations were found between SOS Z score and both time on dialysis (r=-0.52; P<0.0001) and serum PTH (r=-0.39; P=0.0002). Markedly reduced SOS Z score, below -2, was found in 80% of the patients whose PTH levels exceeded 34 pmol/l (five times the upper normal limit), compared with 43% of the patients whose PTH levels were below 34 pmol/l(P=0.04). Compared to patients without bone pain (n=51), subjects with bone pain (n=20) had somewhat lower SOS Z scores -2.5+/-2.0 versus -1.8+/-1.4; 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.
Foldes
A J
AJ
The Jerusalem Osteoporosis Center, Hadassah University Hospital, Jerusalem, Israel.
Arnon
E
E
Popovtzer
M M
MM
D000162:Acoustics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D006435:Renal Dialysis; D013977:Tibia / Q000000981:diagnostic imaging; D014463:Ultrasonography
D010281:Parathyroid Hormone