It improves left ventricular mass better than conventional treatment.
BARCELONA—Nocturnal hemodialysis (NHD) improves both cardiac and metabolic parameters and reduces the need for medication compared with conventional hemodialysis (CHD), according to a head-to-head comparison of the two modalities presented here at the 44th Congress of the European Renal Association-European Dialysis and Transplant Association.
Bruce Culleton, MD, associate professor of medicine at the University of Calgary in Alberta, and colleagues compared the effects of NHD and CHD on left ventricular mass (LVM)—the primary end point—and systolic BP and health-related quality of life (QOL)—secondary end points.
Ten hemodialysis units at the University of Calgary and the University of Alberta were involved in the study and inclusion criteria were “quite lenient” to make findings more applicable, Dr. Culleton noted. Patients were trained in NHD at each center for two to six weeks before performing it at home without monitoring five to six nights a week, six to eight hours per session.
Fifty-one patients enrolled in the study. Of these, 22 in each group were included in the primary endpoint analysis. At six months, the mean LVM for patients on NHD was 13.8 grams less than baseline measurements compared with a mean increase of 1.5 grams for those in the CHD group, or a mean between-group difference of 15.3 grams.
All 51 patients were included in the secondary endpoint analyses. QOL declined in the CHD patients but remained stable in the NHD patients. The difference was not statistically significant, however, perhaps reflecting the fact that prior to randomization both groups may have had an “anticipatory improvement” in QOL, only for this improvement to return to baseline in the CHD patients after randomization.
Systolic BP dropped by 7 mm Hg in the NHD group but increased by 4 mm Hg in the CHD group, a significant difference of 11 mm Hg between the groups. The decrease in systolic BP occurred despite a concomitant reduction in the mean number of antihypertensive medications that NHD patients required (from 1.7 medications at baseline to 0.6 at six months).
In contrast, the CHD patients had no change in the mean number of required anti-hypertensive medications. Mean serum phosphate levels declined by 0.37 mmol/L in NHD patients but rose by 0.11 mmol/L in CHD patients. Calcium intake decreased by 750 mg per day in the NHD group but remained unchanged in CHD patients.
The investigators were concerned that the NHD group would have an increased incidence of vascular access complications, but the rate of these complications was similar in the two groups, as was the mean number of hospitalizations and hospital length of stay.
The new study adds to a growing body of evidence showing the benefits of nocturnal hemodialysis. For example, Christopher T. Chan, MD, and his colleagues at the University of Toronto, reported recently on a study showing that patients who converted from conventional to nocturnal hemodialysis (five to six sessions per week, six to eight hours per session) experienced improvements in exercise duration and capacity (Nephrol Dial Transplant. 2007; published online ahead of print.) Exercise was performed before and two and three to six months after the switch.