Calcium phosphorus metabolism in dialysis patients with and without mitral anular calcium: Analysis of 30 patients

Abstract

To test the hypothesis that accelerated metastatic calcification in the mitral anulus results from abnormalities in calcium phosphorus and parathyroid hormone, 10 patients with end-stage renal disease having echocardiographically proven mitral anular calcium (MAC) (Group I) and 20 patients without MAC (Group II) were evaluated over 12 consecutive months. Serum levels of total calcium, phosphorus, intact and carboxyl-terminal parathyroid hormone, serum ionized calcium, and total calcium-phosphorus product were compared for both groups. In addition, other variables such as sex, supine systolic and diastolic blood pressure, age, duration of hemodialysis, type of renal disease, and diabetes also were compared in both groups. Although both groups had elevated intact and carboxyl-terminal parathyroid hormone levels. Group I did not differ significantly from Group II. Total serum calcium levels were within normal limits in both groups and were not significantly different. However, the serum ionized calcium level was significantly higher in Group I with MAC versus Group II without MAC (p It is concluded that MAC in patients with chronic renal failure occurs in the setting of secondary hyperparathyroidism. However, it is found more often in patients with increased ionized calcium and serum phosphorus levels and significantly higher calcium-phosphorus product levels. In chronic renal failure, MAC does not appear to be the result of a degenerative process and high ventricular systolic pressure as has been previously described.