Changes in bone mineral density in patients with Paget's disease treated with risedronate.
OBJECTIVE
To study changes in bone mineral density (BMD) in patients with Paget's disease of bone treated with risedronate.


METHODS
Whole body dual energy x ray absorptiometry (DXA) scans were carried out on 20 patients with Paget's disease treated with oral risedronate. DXA scanning was carried out at baseline and 11 months. Whole body bone mineral content (BMC) was measured. In addition, regions of interest were drawn around the skull, individual lumbar vertebrae, hemipelvis, femora, and tibiae to obtain BMD for these sites. An uncoupling index was also calculated as the area under the curve for serum alkaline phosphatase (ALP) divided by the area under the curve for hydroxyproline excretion (HYPRO) for the period of treatment.


RESULTS
Median whole body BMC increased from 3057 g to 3156 g (p < 0.001) resulting from an increase in pagetic and non-pagetic BMD. From the analysis of regions of interest it was found that pagetic trabecular bone showed the largest increase in BMD. The pretreatment HYPRO and the uncoupling index were significantly related to the change in BMD for all pagetic sites for a patient (r = 0.65, p < 0.01 and r = 0.57, p < 0.05 respectively).


CONCLUSIONS
Bisphosphonate treatment of Paget's disease results in an increase in BMD of pagetic bone without redistribution of mineral from non-pagetic bone. The remodelling space and extent of uncoupling are significantly related to increases in BMD at pagetic sites.
Patel
S
S
Medical Research Centre, City Hospital, Nottingham.
Pearson
D
D
Bhallah
A
A
Maslanka
W
W
White
D A
DA
Hosking
D J
DJ
D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010001:Osteitis Deformans / Q000188:drug therapy*; D000068296:Risedronic Acid
D002121:Calcium Channel Blockers; D000068296:Risedronic Acid; D012968:Etidronic Acid