Long term reduction of cardiovascular risk factors associated with three hour daily dialysis: A prospective, cohort study

Introduction

Daily hemodialysis (DHD) compared to conventional hemodialysis (CHD) leads to improvements in left ventricular hypertrophy and mineral metabolism at 1-year follow-up. However, there is no information from prospective studies on the long terms effects of DHD on these key cardiovascular risk factors.

Methods

We conducted a 4 year, prospective cohort study of 26 DHD and 51 matched CHD patients on the effect of DHD (six sessions/week × 3 h) versus CHD (three sessions/week × 4 h), 15 DHD, and 26 CHD patients completed 4-years follow-up. Measures of left ventricular mass index (LVMI), blood pressures, hemoglobin, and mineral metabolism markers were performed.

Results

Systolic and diastolic blood pressures were significantly lower in the DHD group than the CHD group at 4-year follow-up, 128 mmHg (95% CI, 111–143) versus 148 mmHg (95% CI, 137–158) (p < 0.05) and 60 mmHg (95% CI, 56–63) versus 71 mmHg (95% CI, 64–76) (p < 0.05). DHD was associated with fewer patients taking any anti-hypertensive drug therapy than CHD, 50% versus 80% (p < 0.05). DHD was associated with improved attainment of mineral metabolism goals for phosphorus (adjusted HR 3.6, p = 0.002) and calcium × phosphorus product (adjusted HR 3.66, p = 0.001) at 4-years follow-up compared to CHD. At 4 years, there was a nonsignificant trend toward lower LVMI in the DHD than in the CHD group: 116 g/m² (95% CI, 97–136) versus 138 g/m² (95% CI, 115–172) (p = 0.23). Similarly, improvements in hemoglobin also persisted at 4 years follow-up.

Conclusion

DHD is associated with long-term (4 year) improvements in key cardiovascular risk factors: blood pressure, mineral metabolism, and anemia with trends toward improved LVMI.