Reduced bone mineral density in adults treated with high-dose corticosteroids for childhood nephrotic syndrome

Background. Children with minimal change nephrotic syndrome (MCNS) receive repeated courses of high dose oral prednisolone. No previous study has investigated the impact of this on final bone mineral density (BMD). Young adults previously reported in a large follow-up study of children with MCNS were invited to participate in a cross-sectional study. Areal BMD (aBMD) of the spine (L1-4), left femoral neck, and total left hip was measured using dual x-ray absorptiometry (DXA), and volumetric BMD (vBMD) of the distal radius was measured by pQCT. BMD results were compared with reference data provided by the manufacturers of the densitometers. Methods. Thirty-four (24 male) of the original cohort of 62 participated in the study. The mean (SD) final height Z score of the cohort was -0.45 (0.92) (P= 0.007) and mean BMI Z score 1.62 (1.53) (P < 0.0001). Results. There was a highly significant reduction in distal radial trabecular vBMD; the mean Z score was -0.95 (0.99) and T score -1.04 (1.01) (both P < 0.0001); however, there was no reduction in distal radial total vBMD, the mean Z score being 0.00 (0.95) and T score -0.08 (0.99), (P= 0.99 and 0.66, respectively). The aBMD of the lumbar spine and femoral neck also showed a reduction in T scores [-0.45 (1.27), P= 0.045 and -0.49 (0.86), P= 0.002, respectively], but not Z scores [-0.37 (1.28) and -0.15 (0.87), respectively, both P= NS]. Total hip aBMD was not different from the control population. Conclusion. Adult survivors of childhood MCNS have a significant reduction in forearm trabecular vBMD, placing them at increased fracture risk at this site.