Effects of once-weekly oral alendronate on bone in children on glucocorticoid treatment.
OBJECTIVE
To determine the effects of once-weekly oral alendronate on indices of bone size, density and resorption in children with chronic illness being treated with glucocorticoids.


METHODS
Twenty-two children with chronic illness treated with prednisone were randomized to receive 1 year's treatment with either once-weekly oral placebo or alendronate (1-2 mg/kg body weight) in a double-blind study. The main outcome measures were changes in lumbar spine and femoral shaft size and volumetric density (measured by dual energy X-ray absorptiometry) and N-telopeptide excretion (a marker of bone resorption).


RESULTS
Once-weekly alendronate was well tolerated, and there were no major adverse events. In both groups bone size and bone mineral content increased through growth. Volumetric bone density of the lumbar spine increased significantly in the alendronate group (P = 0.013), but not in the placebo group. There were no differences between the groups in growth in the cortical width of the femoral shaft, but the cross-sectional moment of inertia per unit length-a derived estimate of mechanical strength-increased significantly in the alendronate group (P = 0.014) but not in the placebo group. Urine N-telopeptide excretion was suppressed significantly in the alendronate group (P = 0.007) but not in the placebo group. Height velocity was positively correlated with changes in both lumbar spine area and the total width of the femoral shaft (P = 0.015, P = 0.026, respectively).


CONCLUSIONS
Once-weekly oral alendronate is well tolerated, suppresses bone resorption and may improve volumetric bone density at the lumbar spine and mechanical strength of the femoral shaft in children with chronic illness taking glucocorticoids. It does not affect bone growth. Larger controlled studies are needed to determine if these changes translate into reduced fracture incidence or greater peak bone mass. This study highlights the importance of differentiating between changes in bone size and changes in volumetric bone density in assessing bone in children, and also having control subjects in intervention studies.
Rudge
S
S
Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1, New Zealand.
Hailwood
S
S
Horne
A
A
Lucas
J
J
Wu
F
F
Cundy
T
T
D000284:Administration, Oral; D000293:Adolescent; D019386:Alendronate / Q000008:administration & dosage*; D001171:Arthritis, Juvenile / Q000188:drug therapy / Q000378:metabolism; D001827:Body Height / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001862:Bone Resorption / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D003094:Collagen / Q000652:urine; D024042:Collagen Type I; D003882:Dermatomyositis / Q000188:drug therapy / Q000378:metabolism; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005269:Femur / Q000187:drug effects* / Q000473:pathology; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008159:Lumbar Vertebrae / Q000187:drug effects* / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D010455:Peptides / Q000652:urine; D011241:Prednisone / Q000627:therapeutic use*; D013314:Stress, Mechanical
D024042:Collagen Type I; D005938:Glucocorticoids; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D003094:Collagen; D011241:Prednisone; D019386:Alendronate