Risk factors of chronic kidney disease influencing cardiac calcification

Abstract

We sought to determine the influence of risk factors of chronic kidney disease (CKD) on cardiac calcification. We studied the correlation between coronary artery calcium score (CACS) and the type and duration of dialysis as well as the presence of diabetes mellitus and hypertension. The relation between calcium score and mortality was also analyzed. Patients with CKD attending the outpatient department or admitted in our hospital were included. They were subjected to high-resolution computerized tomography of the thorax to determine their CACS. Serum levels of intact parathyroid hormone (iPTH), highly sensitive C-reactive protein (hCRP), homocysteine, calcium, phosphorus, and calcium × phosphorus product were measured. Out of the 50 patients studied, 39 were hypertensive (78%), 32 were diabetic (64.4%), 20 were on hemodialysis, and 13 were on continuous ambulatory peritoneal dialysis. The mean CACS was 388.6. Twenty-nine patients had high iPTH levels and 92.9% of them had calcium score >400 (P = 0.013). Twenty-eight patients had high hCRP and 85.7% of these patients had calcium score >400 (P = 0.048). Patients on dialysis for more than two years had higher calcium score >400 (P = 0.035). 43% of diabetics had calcium score >400 (P = 0.008). All the six patients who died had calcium score >400 (P = 0). There was statistically no significant association noted between hypertension, high calcium x phosphorus product, and high homocysteine levels, and high calcium score. Our study suggests that higher values of iPTH, hCRP, and longer duration on dialysis are associated with accelerated cardiac calcification. Calcification scores >400 are associated with increased mortality.