Mineralisation of precardiac transplantation patients: A key role for parathormone

Abstract

A bstract:Most studies find that precardiac transplantation patients are poorly mineralized; up to 35~ them suffer from vertebral crush fracture after transplantation. We studied 30 consecutives males cardiac transplant candidates. The mean age was 50.2-+1.5 years (mean-+SE). Creatinine clearance (82.3-+5.l ml/mn), 25 OH vitamin D (8.9--+0.7 ng/ml) and osteocalcin level (22.6+2.4 ng/ml) were in the normal ranges. Mean bone mineral density was low either at lumbar spine (0.905-+ 0.027 gr--+cm 2) or at femoral neck (0.829-+0.021 gr/cm 2) (Hologic QDR 1000). Mean Z scores were also low: -1.30-+0.24 at lumbar spine, -1.61-+0.19 at femoral neck. Parathormone (1-84) level was elevated (53.1-+6.8 ng/ml). Parathormone level was highly correlated with lumbar (r=0.512; p=0.004) or femoral @--0.579; p=0.001) bone mineral density as with lumbar @=0.524; p=0.003) or femoral @=0.606; p=0.0004) Z scores. Two parameters are highly correlated with parathormone level : _ daily posology of furosemide @=0.609 ; p=0.0005) _ atrial natriuretic factor level @=0.449 ; p=0.0128) Thus, most of the demineralisation of the cardiac transplant candidates is iatrogenic and result from furosemid therapy. Cardiac insufficiency could have a direct role, but the exact mechanism remain unclear.

Recent progress in PTH/PTHrP research

“…Tominaga [22] showed indication of PTX: high PTH, enlarged parathyroid glands and high turnover metabolism of bone. Oberlin [23] studied bone and calcium metabolism in patients who are going to have cardiac transplantation. While PTH level was elevated in these patients and correlated negatively with bone mineral density of lumbar spine and femoral neck and positively with daily dose of furosemide and serum levels of atrial natriuretic factor.…”