Assessment of bone turnover markers to predict mineral and bone disorder in men with pre-dialysis non-diabetic chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is commonly associated with disturbances in mineral metabolism and bone disease. Bone biopsy is the gold standard in diagnosing mineral bone disorder. Hence the search for non-invasive assessment of bone health gains importance. We undertook to assess the bone health in men with stage 4 and 5 chronic kidney Disease.

METHODS: We recruited 32 male subjects with Stage 4 and 5 chronic kidney disease and 32 age-matched healthy male controls. 25-hydroxyvitamin D, intact parathyroid hormone, and bone-specific alkaline phosphatase were assayed. Bone mineral density (BMD) was estimated using dual-energy X-ray absorptiometry.

RESULTS: CKD is associated with significantly higher levels of bone-specific alkaline phosphatase and intact parathyroid hormone and lower levels of 25-hydroxyvitamin D and bone mineral density, when compared to controls. In the multivariate linear regression model, bone-specific alkaline phosphatase emerged as an independent predictor of reduced BMD. Receiver Operator Characteristic analysis for prediction of reduced BMD in CKD showed both intact parathyroid hormone and bone-specific alkaline phosphatase have significant predicting power.

CONCLUSION: The combination of bone-specific alkaline phosphatase and intact parathyroid hormone has more significant predicting power and is a more reliable index for non-invasive assessment of bone health in men with chronic kidney disease, than either marker when used alone.