Elevation of intact parathyroid hormone level is a risk factor for low bone mineral density in pretransplant patients with liver diseases

The purpose of this study was to investigate the frequency and risk factors for low bone mineral density (BMD) among patients awaiting liver transplantation. BMD of the lumbar spine (LS) and femoral neck (FN), measured by dual-energy X-ray absorptiometery (DEXA), were obtained in 64 pretransplant patients. We measured markers of bone metabolism including serum calcium, phosphorus, serum 25-hydroxyvitamin D (25-OH D), intact parathyroid hormone (iPTH), bone alkaline phosphatase (BAP), osteocalcin (OC), and urinary deoxypyridinoline/creatinine (DPD/Cr) ratio. Osteoporosis and osteopenia (low BMD) were observed in 36 patients (36/64, 56.2%), including 6 cases of osteoporosis (6/64, 9.3%) and 30 cases of osteopenia (30/64, 46.9%). Of all variables, cholestatic liver disease and elevated levels of iPTH were significantly associated with low BMD. Moreover, elevated iPTH level was identified as an independent risk factor for low BMD (P<.05, OR=1.017, 95% CI=1.001-1.032) by multivariate analysis. The median level of iPTH was increased to 55.6 pg/mL (range, 7.8-337 pg/mL) in the low BMD group, while the median level was 33 pg/mL (range, 3-162 pg/mL) in the normal BMD group (P<.05). This study revealed a high incidence of low BMD in the pretransplant patients with liver diseases. The elevated iPTH level was the predominant risk factor for low BMD. We suggest that both BMD and iPTH examinations be considered routine tests to identify the status of bone mass and bone metabolism among recipients prior to liver transplantation.