Bone mineral density in children with primary hyperoxaluria type I.
BACKGROUND
In primary hyperoxaluria type I (PH 1), hepatic overproduction of oxalate leads to its deposition in various organ systems including bone (oxalosis). To evaluate skeletal status non-invasively in PH 1 we measured bone mineral density (BMD).


METHODS
Peripheral quantitative computed tomography of the distal radius was performed in 10 children with PH 1 (mean chronological age 9+/-3.1, mean skeletal age 8.3+/-3.0 years): seven were on conservative treatment (CT) including one patient after pre-emptive liver transplantation (PH1-CT) and three were studied with end-stage renal disease on peritoneal dialysis (PH1-ESRD).


RESULTS
Mean trabecular bone density (TBD) was significantly increased in PH1-ESRD compared with both age-matched healthy and uraemic controls (65227 vs. 168+/-63 and 256+/-80 mg/cm(3); P<0.002 and P<0.007, respectively), while cortical bone density (CBD) was elevated to a lesser degree (517+/-23 vs. 348+/-81 vs. 385+/-113 mg/cm(3); P<0.02 and P<0.04, respectively). In PH 1, CBD and, even more so, TBD were significantly correlated with serum creatinine (r=0.91 and r=0.96, P<0.0001, respectively) and plasma oxalate levels (r=0.86 and r=0.94, P<0.001 and P<0.0001, respectively). In children with PH 1 and normal glomerular function, both CBD and TBD were comparable with healthy controls.


CONCLUSIONS
These preliminary data suggest that in PH 1 BMD is significantly increased in ESRD, probably due to oxalate disposal. Measurement of BMD may be a valuable and non-invasive tool in determining and monitoring oxalate burden in this disorder.
Behnke
B
B
Department of Paediatric Nephrology, University Hospital Eppendorf, Hamburg, Germany.
Kemper
M J
MJ
Kruse
H P
HP
Müller-Wiefel
D E
DE
D015519:Bone Density; D002648:Child; D002675:Child, Preschool; D006801:Humans; D006960:Hyperoxaluria, Primary / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D007676:Kidney Failure, Chronic / Q000150:complications; D011884:Radius / Q000000981:diagnostic imaging; D012016:Reference Values; D014057:Tomography, X-Ray Computed