Ambulatory blood pressure monitoring in hemodialysis patients

The aim of our study was the detection of blood pressure (BP) variability during a dialysis session and in the interdialytic period in normotensive and hypertensive hemodialysis (HD) patients using ambulatory blood pressure monitoring (ABPM). Twenty-two HD patients aged 54 (range, 33-78) years who were on HD for a mean of 17.7 (range, 1-70) months were studied. Twelve patients were hypertensives, while the remaining 10 were normotensives (BP < 140/90 mm Hg). In all patients ABPM was performed for a total of 48 h including an HD session. A significant decrease in systolic BP, diastolic BP and mean BP was observed at the end of a dialysis session in hypertensive HD patients. However, in only five patients a reduction of more than 5% In mean arterial BP was noticed. No significant differences were observed in the BP values between the first and the second day after the HD in hypertensive HD patients. Interdialytic BP (both systolic and diastolic) was significantly higher than the postdialysis BP measured either in the clinic or with the ABPM in these patients. Normotensive HD patients exhibited a normal diurnal variation of BP during the first day after the HD session (decrease in BP during the night). On the second day after the HD session an increase in BP (mainly of systolic BP), as well as a loss of diurnal variation were observed. On the contrary, hypertensive HD patients did not exhibit the normal diurnal variation of BP during the first or the second day after the HD session. Hypertensive HD patients exhibited increased daytime and night time BP loads. On the other hand, normotensive HD patients presented with BP loads within normal limits, even though a small increase in these loads was observed on the second day after dialysis. In conclusion, while hypertensive HD patients present a loss of the normal diurnal variation of BP, normotensive HD patients exhibit normal variation during the first day after the HD session. The loss of the diurnal variation during the second day in these patients suggests a volume-dependent state.