Association of Calcium Phosphorus Product and Coronary Artery Calcification in End Stage Renal Disease Patients on Dialysis

ABSTRACT

Patients with End Stage Renal Disease (ESRD) on dialysis have 2- to 5-fold more coronary artery calcification than age-matched individuals. One hypothesis for the disproportionate calcification burden in these patients is high serum phosphate levels; patients with chronic kidney disease (CKD) have elevated serum phosphate and calcium phosphorus product as a consequence of both reduced phosphate filtration and secondary hyperparathyroidism. Methods: This study was done on 50 CKD – ESRD patients on maintenance dialysis sand 20 normal subjects. Blood sample were obtained for serum Calcium, Phosphate, Parathyroid hormone of all CKD-ESRD patients prior to dialysis and of normal controls. All subjects were subjected to Multi Row Spiral Computed Tomography for detection of coronary artery calcification scoring (CACS). Results: The mean value of corrected Calcium Phosphorus product was 50.9 ± 15.6 mg2/dl2 in ESRD patients. The minimum value was 26.04mg2/dl2 and maximum value of the product 85.7 mg2/dl2 in ESRD patients. The mean CACS in 50 patients with ESRD was 91.4 ± 32.7agatston units. For CACS score 0-10,11-100,101-400 agatston unit the Calcium Phosphorus product was 26.04 ± 0, 45.18 ± 12.75, 63.31 ± 10.18 mg2/dl2. With increase in CACS, the Calcium Phosphorus (CaXPO4) products increased and this association was statistically significant. The CACS values in normal subjects were 7.75 ± 6.5 Agatston units. Conclusion: Our study results suggest a positive association between Calcium Phosphorus product and CAC in ESRD patients. Controlling Calcium Phosphorus product will reduce the coronary artery calcification burden.