Potential role of Niacin as Adjuvant to Sevelamer on Serum levels of Inorganic phosphorus, Calcium and Calcium-phosphorus product in Hemodialysis patients with Hyperphosphatemia

Abstract

Hyperphosphatemia is a serious biochemical abnormality that affected almost patients undergoing maintenance hemodialysis and has independent association with high risk of mortality due to cardiovascular diseases. The mechanism linking hyperphosphatemia to cardiovascular mortality is vascular calcification that it is promoted by elevated serum phosphorus level. The control of hyperphosphatemia remains a major challenge. All currently phosphate binders have requirement for dosing with each meals that contributed to high pill burden and reduce patient compliance. Calcium-based binders preferred to be avoided due to their high risk of vascular classification, while the expensiveness of non-calcium based binder represent their major drawbacks. Niacin; a naturally occurring water-soluble vitamin and the first used antidyslipidemic drug, has been demonstrated to show therapeutic potential for hyperphosphatemia treatment in hemodialysis patients. It decreases phosphorus absorption in the GIT, thereby lowering serum phosphorus level. This study is designed to evaluate the efficacy of niacin as adjuvant therapy to sevelamer carbonate (as a phosphate binder) in hemodialysis patients. This prospective, randomized clinical trial was conducted among patients with hyperphosphatemia. Seventy nine patients were enrolled in this study; only 39 patients completed the study. Thirty nine patients were assigned randomly into two groups; group (1) 19 patients treated with sevelamer alone (2400mg/day), group (2) 20 patients treated with a combination of sevelamer (2400mg/day) and niacin (1000 mg/day) for 2 months . Clinical outcomes (Pi, Ca, Ca x P product) serum levels were evaluated at time of enrolment, after 1 month and after 2 month of treatment. Results of this study showed that the patients who administered orally niacin as adjuvant to sevelamer had the superiority over using sevelamer alone in the reduction of both serum phosphorus level and (Ca x P) product level (-30% and -37%) respectively after 2 months of treatment in respect to baseline levels. Meanwhile, there was no statistically significant difference observed in serum calcium level. Administration of niacin for hemodialysis patients is an effective strategy for reducing the serum levels of inorganic phosphorus and calcium-phosphorus product which subsequently reduce risks of cardiovascular diseases associated with hyperphosphatemia.