Relationship Between Bone Mineral Density and Serum Cystatin C in Nephrotic Syndrome

Abstract

Abstract Background The aim of this study was to investigate the effect of steroid therapy on bone metabolism in children with nephrotic syndrome to demonstrate that serum cystatin C is a parameter of bone resorption, and to detect early stages of bone resorption.Methods The study included 69 patients with idiopathic nephrotic syndrome and 21 controls. Patients were divided into three groups for the study. Biochemical markers of bone metabolism ,serum cystatin C levels and Lumbar Bone Mineral Dencity Z score of patients was measured.Results Our study found that patients with nephrotic syndrome who received steroid therapy had a lower lumbar BMD-Z score than those who did not receive steroid therapy and higher serum cystatin C values. Serum cystatin C levels of patients in remission who continued steroid treatment were found to be higher than those in remission who did not receive steroid treatment and controls (p = 0.007), (p = 0.037). The Bone Mineral Dencity-Z score of patients treated with steroids in remission and active nephrotic period was found to be statistically significantly lower than that of healthy children (p = 0.016), (p = 0.003).Conclusion Bone mineral density decreases while serum cystatin C levels increase in patients with nephrotic syndrome treated with steroids. This suggested that an increase in cystatin C could be an early sign of bone resorption and could be used as a parameter of bone resorption.