Zoledronic acid to prevent bone loss in the first 6 months after renal transplantation.
BACKGROUND
Bisphosphonates can prevent bone mineral density loss after renal transplantation, but their effect on trabecular mineralization and bone morphology, two key factors of bone stability, remains unknown.


METHODS
In a 6-month, randomized, placebo-controlled study, 20 kidney transplant recipients received either 4 mg zoledronic acid or placebo twice within 3 months after engraftment. At transplantation and after 6 months, mean trabecular calcium concentration and trabecular morphometry were measured in bone biopsies. Bone mineral density (BMD) of the femoral neck and the lumbar spine were evaluated by dual-energy x-ray absorptiometry, and serum biochemical markers of bone metabolism were determined monthly.


RESULTS
Trabecular calcium content increased significantly in the zoledronic acid group, but remained unchanged in the placebo group. BMD at femoral neck showed no change in the zoledronic acid group, but decreased in the placebo group. BMD of the lumbar spine was increased in the zoledronic acid group without change in the placebo group. High-turnover bone disease resolved similarly in both groups, as evidenced by a significant decrease of eroded bone surface, osteoclast and osteoblast surface. Serologic markers of bone formation and resorption were significantly lower in zoledronic acid-treated patients throughout the study. Kidney transplant function was stable after zoledronic acid therapy.


CONCLUSIONS
Our results show that administration of zoledronic acid improves the calcium content of cancellous bone after kidney transplantation. The beneficial effect of bisphosphonate therapy is further evidenced by an increase of lumbar spine BMD, and stabilization of femur BMD.
Haas
Martin
M
Department of Internal Medicine III, University Vienna, Austria.
Leko-Mohr
Zdenka
Z
Roschger
Paul
P
Kletzmayr
Josef
J
Schwarz
Christoph
C
Mitterbauer
Christa
C
Steininger
Rudolf
R
Grampp
Stefan
S
Klaushofer
Klaus
K
Delling
Günter
G
Oberbauer
Rainer
R
D015415:Biomarkers; D015519:Bone Density / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000188:drug therapy* / Q000517:prevention & control*; D004164:Diphosphonates / Q000627:therapeutic use*; D005260:Female; D005272:Femur Neck / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use*; D016030:Kidney Transplantation; D008159:Lumbar Vertebrae / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000188:drug therapy / Q000517:prevention & control; D000077211:Zoledronic Acid
D015415:Biomarkers; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid; D002118:Calcium