Bone disease after liver transplantation: A long-term prospective study ofbone mass changes, hormonal status and histomorphometric characteristics

After liver transplantation there is a high incidence of fractures, with im portant rates of bone loss during the first months. However, the long-term evolution of bone mass and metabolism parameters have been scarcely studied . In order to determine the incidence and risk factors involved in the deve lopment of skeletal fractures and to analyze the long-term evolution of bon e mass, bone turnover and hormonal status after liver transplantation a 3-y ear prospective study was performed in 45 patients following liver transpla ntation. Serum osteocalcin, parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH D) and testosterone levels (men), and bone mass at the lumbar spine and femur were measured before and sequentially at different time points du ring 3 years. Spinal X-rays were obtained during the first year. Histomorph ometric analysis of bone biopsies obtained in 24 patients within the first 12 hours after surgery and 6 months after transplantation was performed. Fi fteen patients (33%) developed fractures after liver transplantation, and p re- transplant risk factors for fractures were age and low bone mass (odd's ratio for osteoporosis, 95% confidence interval. 5.69, 1.32-24.53). Serum PTH, osteocalcin, 25-OH D, testosterone and creatinine levels increased aft er transplantation. Moreover, PTH con-elated with creatinine and osteocalci n values. Bone mass decreased during the first 6 months and reached baselin e values at the lumbar spine the second year, with posterior significant re covery at the femoral neck. Long term evolution of femoral neck BMD correla ted with PTH levels. Six months after transplantation bone histomorphometri c data showed an increase in bone formation parameters. After liver transpl antation there is a high incidence of fractures, specially in elderly patie nts and those with osteoporosis. Bone mass decreased in the short-term peri od and improved, initially at the lumbar spine and later at the femur, acco rding to histomorphometric evidences of an increase in bone formation. The increase in creatinine values induces a secondary hyperparathyroidism that influences the changes in femoral bone mass. Treatment of osteoporosis shor tly after liver transplantation may be important in the prevention of bone fractures, particularly in patients with low bone mass.