Impact of Ca/P disorders on risks and comorbidities

Cardiovascular morbidity and the mortality rate are manifoldly greater in chronic kidney disease (CKD) patients. Mineral metabolism (MM) derangements and particularly changes in calcium (Ca) and phosphate (P) metabolism have been included among the large array of putative causal factors of this poor clinical outcome due to their possible negative effects on the vascular calcification process. However, these opinions are mainly based on experimental in vitro studies or retrospective association studies which cannot be considered definitive demonstrations for a cause-effect link between MM changes and the observed increased mortality rate. Furthermore, there is some evidence that Ca and/or P changes appear in later stages of CKD, in contrast with the observation of a very early increase in the mortality rate over the course of CKD. Finally, no evidence has been as yet produced that the correction of the MM parameters might be followed by an improvement in clinical outcome. In conclusion, even if many experimental and retrospective clinical studies strongly suggest a possible involvement of Ca and P derangements as causal factors in the increased mortality rate of CKD patients, there is still not any convincing clinical data giving evidence that the correction of the MM parameters may, at least in part, improve the clinical outcome of these patients.