부산대학교 도서관

BACKGROUND: Hyperphosphatemia is associated with mortality in patients on maintenance hemodialysis. Daily, as opposed to thrice-weekly, dialysis might improve phosphorus control; however, studies of short (2.0-2.5 h) daily sessions have generated conflicting results. OBJECTIVE: To investigate the effect of daily 3 h hemodialysis on phosphorus control. DESIGN AND INTERVENTION: Adults receiving hemodialysis at the Texas Diabetes Institute, San Antonio, TX were eligible to enter this prospective, controlled study of daily hemodialysis (six 3 h sessions/week). Enrollment took place during 2003 and follow-up continued for 12 months. The control group comprised eligible individuals who did not enter the study and, therefore, remained on conventional hemodialysis (three 4 h sessions/week). The control patients were chosen so that they would have similar demographic and clinical characteristics to the daily hemodialysis group. Five patients were randomly selected from each group to enter a 2-week substudy of phosphorus removal (as assessed by measurement of phosphorus levels in effluent dialysate). Serum and dialysate phosphorus levels were quantified colorimetrically. OUTCOME MEASURES: The end points included serum phosphorus level; prevalence of phosphate binder use; weekly phosphorus removal; and the proportions of patients who achieved mineral metabolism goals for serum phosphorus (1.13-1.78 mmol/l [3.5-5.5 mg/dl]), calcium (2.10-2.37 mmol/l [8.4-9.5 mg/dl]), calcium × phosphorus product (<4.44 mmol/l [<55 mg/dl]) and parathyroid hormone (150-300 ng/l). RESULTS: There were no significant demographic or clinical differences between the 26 patients who received daily hemodialysis and the 51 controls who received conventional hemodialysis, but the controls had significantly higher baseline serum calcium levels and significantly lower baseline serum phosphorus and calcium × phosphorus levels (P = 0.0005; P = 0.0006 and P = 0.0385, respectively). No patient withdrew early from or died during the study. After 12 months, the patients receiving daily hemodialysis had a significantly lower mean serum phosphorus level than those receiving conventional hemodialysis (1.36 mmol/l vs 1.62 mmol/l [4.20 mg/dl vs 5.02 mg/dl]; P<0.0001). The prevalence of calcium acetate and sevelamer use decreased significantly from baseline to 12 months in the daily hemodialysis group (P = 0.01), but did not change in the control group (P = 0.03 for between-group comparison). The patients who received daily hemodialysis had significantly higher weekly phosphorus removal than those who received conventional hemodialysis (+56%; 2,452 mg vs 1,572 mg; P = 0.04). The proportion of patients achieving at least three mineral metabolism targets increased from 15% at baseline to 46% after 12 months in those on daily hemodialysis (P = 0.046), but did not change significantly among the controls; however, the proportion was higher at baseline in the control group than in the daily hemodialysis group. CONCLUSION: The authors concluded that 3 h daily hemodialysis is associated with better control of serum phosphorus than thrice-weekly hemodialysis.