Continuing loss of vertebral mineral density in renal transplant recipients

This cross-sectional study examined bone abnormalities by digital radiography, bone densitometry and biochemical tests in 44 clinically asymptomatic renal transplant recipients 6-195 months after renal transplantation. Abnormal radiographs were obtained in 40 of the 44 patients. Dual-energy X-ray absorptiometry (DXA) performed at the lumbar spine (L2-L4)/showed a negative Z score in all patients, ranging from -1 to -1.9 in 28 patients and less than -2.0 in 16 patients. The severity of osteopenia increased with the length of time after transplantation and there was a significant correlation with parathyroid hormone values in patients with normal and low glomerular filtration rates. Our data suggest that decreased bone density values (Z score less than -2) are present in about one-third of patients with renal transplants. Bone loss appears to continue after transplantation. Steroid therapy and immunotherapy are probably the cause of this bone loss. Bone mineral measurements alone are helpful in identifying asymptomatic patients with low bone mass after transplantation.