POS-255 NIACIN LOWERS SERUM PHOSPHATE LEVELS IN NIGERIAN CHRONIC KIDNEY DISEASE PATIENTS.A RANDOMIZED CONTROL TRIAL

Abstract

Hyperphosphatemia is an important complication of reduced renal function and is associated with several clinical consequences including vascular calcification, bone disease severe constipation and haemodynamic disturbances. Its reduction in CKD patients is thus necessary in reducing morbidity and mortality. Available phosphate lowering agents including calcium and non calcium containing phosphate binders have had limited success in the control of hyperphosphatemia because of adverse effects of most calcium based binders and the high cost of non calcium based binders. Several studies have highlighted the benefits of niacin in the control of hyperphosphatemia at reduced cost and with tolerable side effects. Aims: This study was aimed at determining the effect of niacin on serum phosphate, calcium,calcium phosphate products. It also aimed at determining the frequency and pattern of adverse effects due to niacin. This study was a randomized double blind placebo - controlled crossover trial carried out at DELSUTH, Oghara. One hundred and twenty adult CKD patients were recruited for the study and were divided into 2 arms, group (1) and group (2). The group 1 received placebo for 8 weeks and then crossed over to niacin for another 8 weeks after a 2 week washout period and the reverse was the case for the group 2. The niacin protocol was 500 mg tablet daily for the first 4 weeks and increased to a maximum of 1g daily for the subsequent 4 weeks. One hundred and twenty patients with a mean age of 54.9 ±11.8 years participated in this study. Sixty seven (55.8%) were males. In the niacin group mean change in phosphate levels, calcium phosphate and high density lipoprotein levels level were -0.61 ± 0.31 (p=< 0.0001), -4.51 ± 3.38 ( p= < 0.0001) and 6.06 ± 0.23 (p= <0.0001) respectively, but no significant changes were noticed while on placebo. Calcium, low density lipoproteins and tryglyceride levels showed no significant change with intake of niacin or placebo. The commonest adverse events were cutenous flush (12.5%), nausea (7.5%) and diarrhoea (5%). 25% and 22.5% of these patients hadearly and mild adverse events respectively. Only 3% of patients studied, discontinued medications due to adverse effects. Thirty one (25.8%) patients withdrew from the study and the commonest reason for withdrawal was loss to follow up (10%). This study showed that niacin reduces serum phosphate levels and calcium phosphate levels and also increases HDL levels in CKD stages 3-5 patients. Mild to moderate adverse events most notably flush nausea and diarrhoea were common, but rarely required discontinuation of the drug.