---

Background: Recent studies have shown that nicotinic-amide and niacin induce significant reductions in serum phosphorous in patients undergoing hemo-dialysis. The aim of the present study was to determine the effect of nicotinic acid on serum phosphorous level in patients undergoing long-term hemodialysis. Materials and Methods: In an 8-week cross-over randomized double-blind clinical trial, 37 patients were assigned to nicotinic acid or placebo groups with titration from 400 to 1000 mg/ daily. A 2-week washout preceded the switch from nicotinic acid to placebo or vice versa. Statistical analysis was performed using paired- sample t test. Results: The mean dose of nicotinic acid at the end of the period was 740±204 mg/daily. Nicotinic acid showed a significant decrease in serum phosphorus after the 8-weeks treatment however no significant changes occurred in the placebo group (P =0.01). Also, nicotinic acid resulted in an increase of HDL cholesterol levels after 8 weeks. Conclusion: Nicotinic acid can lead to a decrease and an increase in serum phosphorous and HDL cholesterol levels, respectively. However, there is need for longer trials with larger sample sizes for determining the most effective doses of this drug.

---

Background: Adequately delivered hemodialysis dose has been shown to have a distinct impact upon the morbidity and mortality of patients on chronic dialysis therapy. Online conductivity monitoring (OCM) using sodium flux as a surrogate for urea allows for repeated measurement of hemodialysis adequacy in each treatment session. Materials and Methods: In this cross-sectional study, 156 treatment sessions in patients undergoing chronic hemodialysis were assessed by measurement of the conductivity performed by Diascan in AK 96 dialysis machines. Dialysis adequacy was measured by daugirdas logarithmic estimates of single-pool Kt/V. Values of calculated Kt/V and simultaneously obtained online Kt/V were compared. Statistical analysis was performed using paired sample t-test. Results: There was a statistically significant difference between calculated Kt/V and online Kt/V in this study. The mean calculated Kt/V was 1.1±0.18 and mean online Kt/V was 0.77±0.32 (p<0.001). There was a moderate correlation between calculated Sp Kt/V and on-line Kt/V (r =0.44, p=0.012). Conclusion: Despite the underestimation of hemodialysis adequacy by online conductivity monitoring in comparison with Sp Kt/V, it is a useful tool in clinical practice.