RESUMO
Background: Hyperphosphatemia is linked to increased mortality and morbidity in patients on hemodialysis. Currently, the phosphate intake and dialytic removal in predominantly vegetarian patients on twice-weekly dialysis is not well studied. Materials and methods: This prospective, study recruited patients on twice-weekly dialysis of at least 3 months duration. Baseline clinical variables were measured. Dietary protein and phosphorus intake was assessed using a validated food frequency questionnaire. Phosphate binder use was assessed, hourly blood was collected for serum phosphorus during dialysis, and spent dialysate was collected to estimate cumulative phosphorus removal during the session. Results: Forty (67%) of the 60 patients studied were vegetarians. Twenty-eight (48%) were hyperphosphatemic, and 15 (25%) had serum parathormone (PTH) >500 pg/ml. The mean phosphorus intake was 1247 (±312) mg/day, the mean serum phosphorus was 5.49 (±2.01) mg/dl, and the mean dialytic phosphorus removal was 910 (±383) mg/session. Up to 67% of the study population took calcium-based phosphate binders, 25% took sevelamer carbonate, and 40% took activated vitamin D preparation. The lowest tertiles of phosphorus intake correlated with low energy-adjusted protein intake and hypoalbuminemia. Hyperphosphatemic subjects had better nutritional indices (mid-upper arm circumference and body mass index). Dietary intake and serum phosphorus levels were not mutually associated, but both were strongly correlated with total phosphorus removal in the spent dialysate. Serum phosphorus levels fell by 32% by thefirst hour of hemodialysis. Conclusion: Twice-weekly dialysis is often practised in resource-limited Asian countries. However, due to a predominantly vegetarian diet, hyperphosphatemia was noted only in up to half of the patients, despite twice-weekly hemodialysis schedules. This reinforces the fact that plant-based dietary phosphate is less well absorbed.
RESUMO
BACKGROUND: Provision of oral protein in hemodialysis (HD) is desirable due to improved compliance to protein requirements and better nutritional status, but the risks of hypotension and underdialysis need to be considered. This study compared 2 different timings for administering oral nutritional supplements (ONS), predialysis and mid-dialysis, with respect to hemodynamics, dialysis adequacy, urea removal, and tolerability. METHODS: This single-center, prospective crossover study analyzed 72 stable patients with ESRD on twice a week maintenance HD with a mean age of 38.7 (±11.2) years and a dialysis vintage of 28.2 (±13.1) months. In the first week, all the patients received ONS (450 kcal energy, 20 g protein) 1 h prior to start of dialysis (group 1) and in the next week, the supplement was administered after 2 h of start of dialysis (group 2), with a predialysis fasting period of at least 3 h in both groups. Blood pressures, serum, and spent dialysate samples were collected and nausea occurrence was noted by severity. RESULTS: Predialytic intake (group 1) was associated with higher predialysis and 1st hour blood urea, dialysis adequacy, and urea removal than group 2. Both groups achieved mean Kt/V > 1.2, and the occurrence of symptomatic hypotensive episodes and nausea was not significantly different between the groups. On repeated measures ANOVA, changes in blood urea over time showed significant group effect. CONCLUSIONS: Predialytic supplementation was associated with better dialysis adequacy and urea removal than intradialytic supplementation. However, both timings were equally tolerated and not associated with underdialysis.