DENVER—Once-daily extended-release niacin (ERN) treatment lowers serum phosphorus levels in patients with normal renal function and dyslipidemia associated with the metabolic syndrome, according to researchers.
Previous studies have shown that niacin reduces serum phosphorus levels in patients with end-stage renal disease.
Andrew Bostom, MD, of The Rhode Island Hospital in Providence, and colleagues studied 60 patients with the metabolic syndrome, of which dyslipidemia was a component, and normal kidney function. After six weeks of a placebo run-in, investigators randomized patients to eight-weeks of treatment with placebo (31 patients) or once-daily ERN (Niaspan) at a dosage of 2 g/day (29 patients).
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The eight-week change from baseline in mean serum phosphorus level was significantly greater in the ERN-treated patients than the placebo recipients (0.40 vs. 0.9 mg/dL), after adjusting for baseline phosphorus level, the researchers reported in a poster. The calcium × phosphorus product decreased by 4.28 mg2/mL2 in the ERN-treated patients and 1.08 mg2/mL2 in placebo recipients, after adjusting for baseline calcium × phosphorus product. ERN treatment had no significant effect on serum calcium levels.
Unlike calcium- and non-calcium-containing phosphate binders—which trap meal-related phosphorus liberated in the gut—the hypophosphatemic effect of niacin compounds results from specific inhibition of active-transport-mediated intestinal phosphorus absorption, according to the investigators.
Thus, compared with once-daily ERN, “current thrice daily phosphorus-lowering binder regimens are requisitely timed to each meal, and impose an onerous pill burden, negatively affecting compliance and quality of life,” the authors observed.
In light of clinical trial evidence showing that niacin treatment reduces the risk of recurrent cardiovascular disease (CVD) events, the new findings indicate that an ERN treatment arm “merits serious consideration” for any future CVD prevention trials targeting mildly hyperphosphatemic stage 2-4 CKD patients.
