Volume control and blood pressure management in patients undergoing quotidian hemodialysis

Abstract

Background: Hypertension and interdialytic weight gain are associated with left ventricular hypertrophy (LVH), an important predictor of cardiovascular mortality in hemodialysis (HD) patients. Methods: In the London Daily/Nocturnal Hemodialysis Study, a group of patients receiving quotidian HD, either short daily (n = 11) or long nocturnal (n = 12), were followed for up to 18 months. Patients were assessed for effects of quotidian HD therapy on blood pressure, interdialytic weight gain, extracellular fluid volume (ECFV), intensity of antihypertensive therapy, and homocysteine levels. Results: Significant reductions in predialysis mean arterial blood pressure were observed in the daily HD group at 6 months ( P < 0.04) and in the nocturnal HD group at 9 months ( P < 0.03); these improvements persisted throughout the study period. The daily HD group had a 60% reduction in mean number of antihypertensive tablets per day at 1 month and an 8.8-fold reduction by 18 months. Nocturnal HD patients experienced a 3.3-fold reduction, and control patients, a 1.4-fold increase in mean number of tablets per day by 18 months. By 3 months, the daily HD group showed a significant decrease in interdialytic weight gain ( P < 0.0005) and lower ECFV than controls ( P < 0.05). The nocturnal HD group had a transient, but significant, increase in interdialytic weight gain at 6 and 15 months ( P < 0.05) and no difference in ECFV compared with controls, suggesting a different mechanism of blood pressure control. Homocysteine levels were significantly lower for both quotidian HD groups compared with conventional HD patients. Conclusion: Quotidian HD is a promising therapy with potent antihypertensive effects, resulting in improved blood pressure control. This, together with improved homocysteine levels, may be beneficial in the long term with regard to cardiovascular mortality.