Bone mineral density and bone metabolism biochemical markers in patients with chronic kidney disease at the hemodialysis treatment

Abstract

Introduction: Chronic kidney disease (CKD) is associated with bone and mineral metabolism disorders.Objectives: This investigation studied the bone mineral density (BMD) and bone metabolism biochemical markers in patients with CKD at the hemodialysis treatment among a group of Iranian hemodialysis patients. We also sought to test the possible association of risk factors and biochemical parameters with BMD.Patients and Methods: In this cross sectional study, 77 patients with CKD stage 5D at the hemodialysis treatment. BMD was measured by dual-energy X-ray absorptiometry (DXA) at the anteroposterior lumbar spine (LS) (L1-L4) and left proximal femur. Biochemical markers, including calcium (Ca), phosphorus (P), intact parathyroid hormone (iPTH), serum specific alkaline phosphatase (ALP) and 25-hydroxy-vitamin D (25(OH)D) were measured to assess BMD loss.Results: Around two (2.6%) patients had normal levels of 25(OH) D (mean levels 17.67 ± 11.66 nmol/l). We found a reduction of BMD in comparison with age and gender-matched normal population values at the femoral neck (FN) (T-score = -1.92 ± 1.29), at the total hip (TH) (T-score = -1.79 ± 1.25) and at the lumbar spine (LS) (T-score = -1.55 ± 1.84). The prevalence of T-scores ≤ -2.5 SD was 28.6%, 35.1% and 13.0% according to LS, FN and three bone sites T scores respectively. BMD negatively correlated: with age at the proximal femur, with serum ALP at the lumbar spine and with age of menopause at the femoral neck.Conclusion: Patients with end-stage renal disease at the hemodialysis treatment had a high prevalence of osteoporosis in the general population. Bone mineral density at the all bone sites was below the expected average for gender and age.