Chronic Kidney Disease-Mineral Bone Disorder: Definitions and Rationale for a Systemic Disorder

Over the past decade there has been an increasing awareness of the complexity of bone and mineral complications observed in chronic kidney disease (CKD) and recognition that the consequences of these abnormalities affect not only the skeleton, but also the cardiovascular system. These scientific advances led to the naming of a systemic disorder, “Chronic Kidney Disease-Mineral Bone Disorder” (CKD-MBD) defined as abnormalities in mineral-related biochemistries, bone modeling/remodeling and strength, and extraskeletal calcification. CKD-MBD begins early in the course of progressive CKD, at estimated glomerular filtration rates of 60 ml/min or earlier, with progression such that all dialysis patients have one or more components. The older term, renal osteodystrophy is one component of CKD-MBD and should be used exclusively to define the histopathologic abnormalities of CKD-related bone remodeling. This diagnostic criteria has been further refined using a new classification system “turnover, mineralization, and volume”, that defines bone turnover, mineralization, and volume to allow for a more complete evaluation of renal osteodystrophy. The recognition of this inter-relationship between biochemical changes, bone, and extraskeletal calcification as the systemic disorder CKD-MBD allows for enhanced communication, increased awareness/diagnosis, and improved treatment approaches with the ultimate goal of improving morbidity and mortality in patients with CKD.