Pathogenesis of bone loss in heart transplant candidates and recipients.
BACKGROUND
Heart transplantation (HTX) is associated with decreased bone mineral density and changes in bone metabolism. We conducted this study to evaluate the pathophysiology of bone metabolism in HTX candidates and recipients.


METHODS
Thirty-six HTX recipients were compared with 36 HTX candidates concerning biochemical parameters of bone metabolism and bone mineral density.


RESULTS
Osteocalcin, bone-specific alkaline phosphatase, cross-linked-N-telopeptide of type I collagen, estradiol, serum creatinine, and blood urea nitrogen concentrations were significantly higher, whereas the calcium-creatinine ratio, thyrotropin, thyroxine, and bone mineral density were significantly lower in HTX recipients than in HTX candidates. Compared with a control group, HTX candidates had decreased renal function and increased bone resorption, whereas HTX recipients additionally had increased alkaline phosphatase and osteocalcin levels. In HTX recipients, we found positive correlations between creatinine clearance and bone mineral density; daily and cumulative cortisone doses were not associated with bone mineral density.


CONCLUSIONS
In HTX candidates, disturbances in bone metabolism with increased bone resorption may be caused partly by existing low-grade renal insufficiency, regular intake of loop diuretics, and restriction of mobility. In HTX recipients, immunosuppressive therapy-glucocorticoids and cyclosporine-seem to be responsible for changes in bone metabolism.
Kerschan-Schindl
Katharina
K
Department of Physical Medicine and Rehabilitation, University of Vienna, Vienna, Austria . Katharina.Kerschan@akh-wien.ac.at
Strametz-Juranek
Jasmine
J
Heinze
Georg
G
Grampp
Stephan
S
Bieglmayer
Christian
C
Pacher
Richard
R
Maurer
Gerald
G
Fialka-Moser
Veronika
V
Pietschmann
Peter
P
D000328:Adult; D000368:Aged; D015519:Bone Density / Q000502:physiology; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D001862:Bone Resorption / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D001842:Bone and Bones / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000378:metabolism / Q000601:surgery; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged