Bone mineral content and collagen metabolites in children receiving steroid treatment for nephrotic syndrome

Bone mineral density (BMD) and content (BMC) were measured in nine children treated with corticosteroids for nephrotic syndrome and in age-matched con trols, using dual-energy X-ray absorptiometry (DEXA). The urinary excretion of cross-linked N-telopeptide (NTx) released from collagen type I as a spe cific marker of bone resorption was also measured. There were no significan t differences in body size, BMD results or NTx urinary concentrations betwe en patients and controls, nor could any significant differences be found wh en the six patients given a cumulative corticosteroid dose of > 15 g were a nalysed separately. The lack of significant differences could be due to the small number of patients included in the study. But when the measured BMD and BMC were analysed according to methods that corrected for body size and puberty stage, values well within the normal range were found in patients as well as in controls. There was, however, a significant, negative correla tion between the urinary excretion of NTx and the cumulative dose of cortic osteroids. Conclusion: Despite treatment for long periods with high, cumulative doses of corticosteroids, the skeletons of the patients had a normal mineral cont ent, which is encouraging for all those in need of steroids for nephrotic s yndrome. A negative correlation between urinary collagen degradation produc ts and the cumulative steroid dose might point to a reduced growth velocity in patients on high doses of steroids earlier than an effect on bone miner alization.