Status of Metabolic Bone Disease in Pediatric Steroid Resistant Nephrotic Syndrome: Study from North India

Abstract

Background: Children with steroid resistant nephrotic syndrome (SRNS) are at a greater risk of metabolic bone disease due to biochemical derangements by corticosteroids and immunosuppressant therapy. The present study was undertaken to evaluate the calcium-vitamin D status in children with SRNS. Method: A cross-sectional case control study was performed to investigate the calcium-vitamin D status in 50 patients of SRNS and 40 healthy controls. Serum levels of 25 hydroxy vitamin D [25(OH) D], calcium, phosphorus, alkaline phosphatase (ALP) and parathyroid hormone (PTH) were estimated. The SRNS patients were further divided into 3 groups according to their Up:Uc ratio: Group A) 16 patients in complete remission, Group B) 14 patients in partial remission and Group C) 20 patients in relapse. Results: Vitamin D and calcium levels were significantly lower in the SRNS patients (p<0.0001). Lower levels of vitamin D and calcium were found in the relapse phase (p<0.01 and p=0.001). PTH and ALP levels were higher (p<0.05 and p=0.001). Up:Uc ratio with vitamin D and calcium showed a significant negative correlation (p<0.01 and p<0.05) whereas a positive correlation was seen with PTH and ALP ( p<0.05 for both). Conclusion: There is a clear diminution of serum 25 (OH) D in patients with SRNS which reverts rapidly to normal after cessation of proteinuria which may associate with severe nephrotoxicity. Prophylactic therapy with vitamin D should be routinely advocated in these patients.