The progression of coronary artery calcification in predialysis patients on calcium carbonate or sevelamer

Abstract

Coronary artery calcification is more prevalent in dialysis patients than in patients without kidney disease and this is associated with high serum phosphorus. In this study, we evaluate the effect of calcium carbonate or sevelamer treatments on the progression of calcification in 90 predialysis patients. Inclusion criteria were stable serum calcium, phosphorus, parathyroid hormone, and a similar baseline total calcium score (TCS). These patients were not treated by phosphate binder, vitamin D, or statin. They were given low-phosphorus diets without or with daily calcium carbonate or sevelamer throughout the study that averaged 2 years. Baseline demographic or clinical characteristics along with biochemical parameters were not different among the three groups. The TCS significantly increased in patients on the low-phosphorus diet alone, to a lesser extent in calcium carbonate-treated patients, and not at all in sevelamer-treated patients. The progression of coronary calcification paralleled that of the calcium score. Our study shows that sevelamer treatment should not be restricted to dialysis patients; however, a larger study should be undertaken to confirm these results.

Lanthanum Carbonate Reduces Phosphorus Burden in Patients with CKD Stages 3 and 4

“…In the "steady-state" condition, the amount excreted in the urine is proportional to the amount absorbed. As a result, measurement of urinary phosphorus excretion can be used as a marker of intestinal phosphorus absorption, and thus as an indicator of phosphorus-binding efficacy (19,25). Lanthanum carbonate treatment resulted in a substantial decrease in intestinal phosphorus absorption as demonstrated by the reduction in urinary phosphorus excretion compared with placebo (P ϭ 0.04).…”

“…Lanthanum carbonate treatment resulted in a substantial decrease in intestinal phosphorus absorption as demonstrated by the reduction in urinary phosphorus excretion compared with placebo (P ϭ 0.04). Studies in healthy volunteers and patients with CKD stages 3 and 4 (with known dietary phosphorus intake) indicate that up to 75% of dietary phosphorus is absorbed (19,25). Thus with a daily phosphorus intake of 1200 mg, intestinal absorption may approach 900 mg (25).…”

“…Both short-and long-term clinical studies have demonstrated efficacy and an acceptable safety profile (15)(16)(17)(18). This study was designed to evaluate the efficacy and safety of lanthanum carbonate for use in patients with CKD stages 3 and 4, a population in which randomized, controlled clinical trials of phosphate binders are sparse (19).…”

Relationships between vascular calcification, calcium metabolism, bone density, and fractures

“…(5,6) In patients with renal failure, calcium supplements accelerate vascular calcification and increase mortality in both dialysis and predialysis populations. (7)(8)(9) Calcium supplements also have been associated with increased cardiovascular event rates in a randomized, controlled trial in older women (10) and subsequent meta-analysis. (11) The mechanism of the association between calcium metabolism and vascular disease is unknown.…”

Phosphate Binders in CKD

“…21 Of note, the assessment of changes in arterial calcium scores in the study by Block et al was possible only in a subset of 90 patients (60 active and 36 placebo) and was effectively performed only in those with non-zero calcium scores at baseline (n581; 55% of the original cohort). Moreover, the baseline characteristics of this subgroup of 81 patients have not been reported separately in the manuscript, and lack of perfect matching between active treatment and placebo groups therefore remains possible.…”