Bone metabolism and mineral density following renal transplantation

To study bone turnover following renal transplantation using a panel of biochemical markers and to correlate the results with both areal and volumetric bone mineral density (BMD).

A total of 31 patients aged 18.1 years were transplanted 5.4 years before this study. Control patients (n = 31) were age and gender matched.

In addition to measurement of biochemical markers, BMD was measured by single photon absorptiometry and peripheral quantitative computed tomography on the non-dominant radius.

Patients had reduced glomerular filtration rate, raised concentrations of serum phosphate, serum procollagene type I carboxy terminal propeptide, osteocalcin, and serum procollagene type I cross linked carboxy terminal telopeptide. The differences were still significant if only patients with normal intact parathyroid hormone were considered. BMD single photon absorptiometry Z score for age was significantly decreased. Following standardisation for height the differences were no longer present. With volumetric techniques patients had normal trabecular but decreased cortical and total BMD compared to age matched controls, but there was no difference from height matched controls.

Markers of bone turnover are increased following renal transplantation. However, the biochemical analysis did not allow conclusions to be drawn on the bone mineral content. BMD single photon absorptiometry Z score corrected for height and BMD measured by quantitative computed tomography compared to height matched controls were normal in paediatric renal transplantation patients. Height matched controls should be used in both areal and volumetric BMD measurements in states of growth failure.