Bone mineral density in children with relapsing nephrotic syndrome: A hospital-based study

Abstract

This cross-sectional analytical study was conducted from January 2012 to November 2014 in the Department of Pediatric Nephrology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh, to evaluate the bone mineral density (BMD) values in children with relapsing nephrotic syndrome (NS). Thirty relapsing nephrotic patients were enrolled in this study. They were divided into two groups: Group I – Frequent Relapse (FR) with 21 patients and Group II – Infrequent Relapse (IFR) with nine patients. Children included were both males and females aged between four and 15 years with relapsing NS with normal renal function. Steroid-resistant NS or those with abnormal renal functions or who were on cyclosporine and calcium supplement with Vitamin D or children with secondary NS were excluded from the study. All the study population underwent dual-energy X-ray absorptiometry scan to see the BMD value. Mean age of the patients of Group I (8.43 ± 2.61 years) was lower than that of Group II (9.41 ± 2.94 years (P = 0.4043). Mean BMD Z-scores of Group I was significantly lower than that of Group II (-2.70 ± 1.28 vs. -1.30 ± 1.54, respectively; P = 0.0317). A significantly higher cumulative dose of prednisolone was administered to Group I compared with Group II (P = 0.00003). On multivariate analysis, the total dose of prednisolone (P = 0.03693), body mass index (BMI) (P = 0.00703), and age of onset of disease (P = 0.03465) had a linear relationship with dependent variable BMD Z-score. On univariate regression analysis, statistically significant inverse relationship was observed between cumulative dose of prednisolone (in grams) (P = 0.049) and BMI (P = 0.00) with BMD Z-score, but no relation was observed with duration of illness. Children with relapsing NS, especially those receiving higher doses of steroids, were at risk for low BMD.