title: Mechanisms of rapid bone loss following cardiac transplantation.
abstract: Rapid bone loss after orthoptic cardiac transplantation (OHTX) is a major problem; however, the mechanisms are poorly understood. To investigate these mechanisms we measured biochemical and hormonal indices of bone turnover serially in 25 patients (21 men, 4 women) after OHTX. Serum osteocalcin was reduced immediately post-OHTX (2.2 +/- 0.5 ng/ml) but rose significantly by 6 and 12 months (14.1 +/- 2.5 and 15.7 +/- 2.2 respectively). Bone resorption indices (urinary hydroxyproline/creatinine and calcium/creatinine ratios) were increased immediately post-OHTX but fell by 6 months. Serum testosterone was reduced in males but recovered towards normal values by 6-12 months. Regression analysis showed lumbar bone loss was predicted independently by the change in both serum osteocalcin and testosterone. The data suggest that bone loss post-OHTX is due to a combination of accelerated turnover and hypogonadism.
authors: Bone and Mineral Research Division, Garvan Institute of Medical Research, St. Vincent's Hospital, Darlinghurst, NSW, Australia.
authors: P N
authors: PN
authors: Sambrook
authors: P J
authors: PJ
authors: Kelly
authors: D
authors: D
authors: Fontana
authors: T
authors: T
authors: Nguyen
authors: A
authors: A
authors: Keogh
authors: P
authors: P
authors: Macdonald
authors: P
authors: P
authors: Spratt
authors: J
authors: J
authors: Freund
authors: J A
authors: JA
authors: Eisman
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D001862:Bone Resorption / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000209:etiology*; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000652:urine; D003401:Creatine / Q000652:urine; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D006909:Hydroxyproline / Q000652:urine; D007166:Immunosuppressive Agents / Q000009:adverse effects; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D011183:Postoperative Complications; D012727:Sex Characteristics; D013739:Testosterone / Q000097:blood
chemical_list: D007166:Immunosuppressive Agents; D015675:Osteocalcin; D013739:Testosterone; D003401:Creatine; D006909:Hydroxyproline; D002118:Calcium