Bone mineral metabolism in patients with chronic kidney disease: review of its pathophysiology and morbimortality

Abstract

Mineral Bone Disorder (MBD) is a broad term that includes abnormal serum calcium, phosphorus, vitamin D, parathyroid hormone, growth abnormalities, bone mineralization and/or extraskeletal calcifications in patients with chronic kidney disease (CKD ). It is present in almost all patients on dialysis and may not always improve with a kidney transplant. New factors and hormones have been identified, such as Klotho and fibroblast growth factor-23 (FGF-23) that interact with vitamin D and the parathyroid hormone in the renal management of calcium and phosphorus. Some reports indicate that they are early markers of the development of MBD, even when kidney function is slightly decreased and parathyroid hormone levels are normal. MBD has been associated with higher mortality, mainly because of its link with vascular calcification. This process leads to an increase in cardiovascular events which are the leading cause of morbidity and mortality in CKD patients, especially those who are on dialysis, regardless of the modality that the patients follow. The presentation of the BMD can be of high or low turnover. Although it is not completely defined what determines that a particular form of presentation is expressed, it has been found that the low turnover disease is related to malnutrition, inappropriate use of calcitriol and inefficient dialysis. Knowledge of BMD is relevant for its association with  the complications mentioned above and because it constitutes a parameter for assessing the instituted therapy.