WEIGHT- HEIGHT-RELATED BONE-MINERAL DENSITY IS NOT REDUCED AFTER RENAL-TRANSPLANTATION/

Growth retardation is a frequent finding in patients after renal trans plantation (Tx). Areal bone mineral density (BMD) in these patients ha s usually been reported to be low for age. We investigated the possibl e influence of height and weight retardation on the measurement of BMD in lumbar spine (BMDL2-4) and total body (BMDbody) using dual-energy X-ray absorptiometry in 44 (13 female) pediatric Tx patients with a me dian age of 13.1 (range 3.3-23.1) years. Patients were studied at 2.9 (range 1-10) years after Tx. Median body height in female and male pat ients was -2.10 (-3.6 to -0.3) and -2.35 (-5.3 to +1.0) standard devia tion score (SDS), respectively. BMD expressed as grams per square cent imeter bone area according to age was below the 5th percentile in 10 o f 44 patients, but only 1 patient had low values for BMDL2-4, and none for BMDbody, when the data were corrected for height or weight. BMDbo dy was closely correlated with height, weight, and body surface area ( r=0.88), whereas the correlation for BMDL2-4 was less (r=0.76). In 6 p atients who achieved final height, height SDS was -2.27 (4.3-0.3). Z-s cores for BMDbody related to age, height, and weight were -1.0 (-2.6 t o -2.3), 1.25 (0.1-3.4), and 0.81 (0.0-2.4), respectively. There was n o age-dependent change when areal BMD values (g/cm(2)) were corrected for vertebral size to obtain bone volumetric density (BMDvol, g/cm(3)) . Independent of height, cumulative methylprednisolone dose correlated negatively with BMDL2-4 only in patients who had received a total dos e of more than 6 g/m(2) of the drug (r = -0.54, P = 0.045). In conclus ion, BMD in pediatric patients after Tx is no longer diminished when t he data are corrected for height or weight rather than age, or when th e data are expressed as bone volumetric density.