Bone mineral density in chronic hemodialysis patients and its correlation to biochemical markers

ABSTRACT

Renal osteodystrophy may result in considerabli morbidity for patients with end-stage renal disease. Secondary hyperparathyroidism, adynamic bone disease and osteomalacia, the main bony problems in chronic renal failure, may all be responsible for a reduction in bone mineral density [BMD]. The aim of this study is to investigate the biochemical parameters and bone mineral density in patients undergoing regular hemodialysis and to assess their possible correlation to different variables, Patients and Methods: thirty nine patients with end-stage renal disease maintained on regular hemodialysis for variable intervals were participated in the study. Osteocalcin, type1-C terminal collagen propeptide [CICP], Osteoprotegrin [OPG], receptor activator of nuclear factor kB ligand [RANKL], parathyroid hormone [PTh], serum total calcium, inorganic phosphorus and alkaline phosphatase were estimated to all patients. Bone mineral density[BMD] was measured by dual energy X ray absorptiometry [DEXA] in lumbar spine and femoral neck with estimation of BMD t-score. Body mass index [BMI] was calculated. Assessment of correlation between clinical, laboratory data and BMD was done. There was a positive correlation between age, BMD and CICP, between BMI and RANKL and also between BMD hip and spine. BMD in both sites correlated inversely, with PTH [P< 0.01], there was a significant correlation between duration of dialysis and PTH [P< 0.001], calcium level and hip t-score were the most important variable for prediction of reduced BMD. Osteopenia was frequent in patients on hemodialysis and those with hyperparathyroidism and longer duration of hemodialysis were more susceptible to reduced BMD developing osteoporosis