Renal Bone Disease: Thinking Outside the Skeleton

New York, NY
April 13, 2007

Experts are urging doctors to diagnose disorders of bone and mineral metabolism earlier in the course of chronic kidney disease (CKD), when interventions will be most effective, according to a session titled “Extending the Controversy:Answers to Managing Bone, Vascular and Mineral Metabolism in CKD” presented here today at the National Kidney Foundation 2007 Spring Clinical Meetings.

“The best time to diagnose bone and mineral disorders is in the beginning stages of CKD, so we can intervene earlier, and try to prevent progression of these complications,” says Kevin Martin, MB, BCh, FACP of St. Louis University, Co-Chair of today’s session, #279.

Disturbances in mineral and bone metabolism begin early in the course of kidney disease and worsen as kidney function declines, becoming essentially universal in stage 5 CKD. These systemic disorders are an important cause of morbidity and decreased quality of life in CKD patients. Apart from the musculoskeletal abnormalities, the long-term effects of these disorders include altered cardiovascular function related to extraskeletal calcification.

“Traditionally, we’ve believed bone diseases, even when associated with kidney disease, are simply about bones,” says Dr. Martin. “Recently, new data have shown that the scope and importance of CKD-related bone disorders extends far beyond the skeleton.”

Some recent recommendations from Dr. Martin and his colleagues include:

• Use the term renal osteodystrophy (ROD) to describe bone morphology changes in CKD patients based on histologic examination of a bone biopsy
• The clinical, biochemical, and imaging abnormalities that have previously been identified as correlates of ROD should be defined more broadly as a clinical entity or syndrome dubbed Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). This is defined as a systemic disorder of mineral and bone metabolism due to CKD, manifested as disturbances in bone physiological processes.
• All adults with CKD in stages 3 or above should be evaluated for MBD.
• Initial evaluation should include measurement of serum PTH, calcium (either ionized or total corrected for albumin), phosphorus, alkaline phosphatase (total or bone-specific), and bicarbonate concentrations.

Dr. Martin will provide more detailed information, along with recent data on the important role of phosphorus and inflammation in CKD-MBD, during his lecture entitled ROD or CKD-MBD: KDIGO Goes Beyond this Definition that will be presented during this session.

Kidney Disease: Improving Global Outcomes (KDIGO) is a not-for-profit Belgian foundation with an international Board that is managed by the National Kidney Foundation. Its mission is to improve outcomes for kidney patients worldwide through coordination, development and implementation of practice guidelines.