Adynamic bone and chronic renal failure: an overview

Renal osteodystrophy may present with a wide spectrum of bone lesions, ranging from high bone turnover to low bone turnover. Decreased serum calcium and 1,25-dihydroxy vitamin D synthesis and retention of phosphate are involved in the pathogenesis of high bone turnover. However, several factors may influence the evolution of this disorder. The use of different therapeutic approaches (such as calcium supplements, phosphate binders, vitamin D metabolites, etc.), the type of treatment (either hemodialysis or continuous ambulatory peritoneal dialysis), and also the changes in the type of patients to whom we are offering dialysis (more diabetics and older patients are currently included in dialysis programs) may have introduced changes modifying the form of presentation of the bone metabolic disorders. As a result, recent studies reported a greater prevalence of adynamic forms of renal osteodystrophy. Patients with adynamic bone (with or without aluminum) would have more difficulties in handling and buffering calcium loads; consequently, they would have a higher risk of extraosseous calcifications.