Relationship between Calcium-Phosphorus Product and Severity of Valvular Heart Insufficiency in Patients Undergoing Chronic Hemodialysis

Abstract

Background: Recent interests have mainly focused on the roles of serum calcium and phosphorus and their product (Ca-P product) in the development of valvular heart disease. The present study assessed the relationship between the Ca-P product and the severity of valvular heart disease in end-stage renal disease (ESRD) patients undergoing chronic hemodialysis.
Methods: This cross-sectional study reviewed the clinical course of 72 consecutive patients with the final diagnosis of ESRD candidated for chronic hemodialysis. The severity of valvular heart disease was determined using M-mode two-dimensional echocardiography. The serum calcium and phosphate values adopted were those values measured on the day between the two consecutive dialyses, and the Ca-P product was calculated. 
Results: The most common causes of ESRD were diabetic nephropathy, malignant hypertension, and chronic glomerulonephritis. The mean Ca-P product level in the dialysis patients was 50.44 ± 17.78 mg²/dL². The receiver-operator characteristic (ROC) curve illustrated that a Ca-P product level > 42 mg²/dL² was the optimal value in terms of sensitivity and specificity for predicting the presence of valvular insufficiency. Aortic insufficiency was directly associated with a high Ca-P product value after adjustment for age, gender, serum albumin, diabetes, hypertension, hyperlipidemia, coronary artery disease, and serum creatinine (β = 0.412, SE = 158, p value= 0.011).
Conclusion: A positive relationship between the Ca-P product value and the severity of aortic insufficiency is expected. Achieving an appropriate control of the Ca-P product level may decrease aortic valve calcification and improve the survival of patients on chronic hemodialysis.