Correlation between serum sclerostin level and bone density status in children on regular hemodialysis

Abstract

Bone disease is frequently observed in chronic kidney disease (CKD) and increases a patient’s risk for fracture. Sclerostin is an osteocyte-derived negative regulator of bone formation. We aimed to assess serum sclerostin level as a bone marker in children with CKD on regular hemodialysis (HD) and detect the association between this and bone density status. This cross-sectional comparative study was conducted on 25 children with CKD on HD and 25 age- and sex-matched healthy children, as controls. Their ages ranged from 4 to 18 years. Serum sclerostin levels were measured and dual-energy X-ray absorptiometry scan was performed in the same line with the traditional bone markers. There was a significant increase in serum sclerostin level in patients (1.754 ± 1.31 ng/mL) compared to controls (0.290 ± 0.074 ng/mL) with P = 0.001. Nine patients (36%) had low bone mineral density (BMD) with z score under -2.0, eight of whom had low BMD in both the neck of femur and lumbar spines. There was a significant increase in serum sclerostin levels in the patient-group with low BMD (2.38 ± 0.85 ng/mL) compared with patients with normal BMD (1.4 ± 0.98 ng/mL) (P = 0.001). A significant positive correlation was found between serum sclerostin level and alkaline phosphtase, parathormone with negative correlation with serum calcium. Sclerostin was 100% specific and sensitive in predicting CKD-mineral and bone disorder. Elevated sclerostin levels were consistent with low BMD and appear to be an independent predictor of reduced BMD in children on regular HD.