#2249 Morning blood pressure and heart rate surge in peritoneal dialysis patients

Abstract Background and Aims The increased surge of blood pressure (BP) early in the morning and the parallel increase of heart rate (HR) are risk factors for cardiovascular disease in general and CKD populations. Early morning changes in these parameters have not been investigated in peritoneal dialysis (PD) patients. The aim of the study is to correlate the morning fluctuations of BP and HR with left ventricular hypertrophy and cardiovascular risk. Method This was a cross-sectional study of PD patients followed-up in our Peritoneal Dialysis Unit (PDU). At their regular visit to our PDU, a 24-hour ambulatory BP measurement (Mobil-o-graph®) was performed. A diary was given to the patients in order to record the time they performed their evening exchange (continuous ambulatory peritoneal dialysis- CAPD) or connection to the automated peritoneal dialysis (APD) machine, the time they laid down, the time they approximately fell asleep, when they woke up in the morning, when they inclined from the bed and the time they performed the morning exchange or disconnection. The 24-hour BP recordings were analyzed in the available software and calculations were done based on the diary information; pre-awakening BP, HR surges, nocturnal dipping, weighted 24 h systolic BP and HR variability. Demographic, laboratory data and left heart hypertrophy parameters of the patients were also recorded. 35 patients were eligible for participation in the study; 2 denied participation, 1 was rejected due to ongoing cancer therapy and two patients were declined due to invalid BP measurements. Finally 30 patients (10 males and 20 females) were analyzed, 9 were on CAPD and 21 were on APD. Results The mean age of the patients was 60.5 ± 12.6 years old and the median PD vintage was 21.5 months (8.25-58) (Table 1). Left Ventricular Mass index (LVMi) was 99.01 ± 28 g/m2 (Table 1). The 24h systolic BP was 125.66 ± 10.9 mmHg and the diastolic BP was 79.59 ± 7.7 mmHg (Table 2). The mean pre-awaking Systolic BP surge was 10.76 ± 9.7 mmHg, the median non-dipping blood pressure 8.6 (IQR 1.11-12.86), the mean heart rate surge was 3.3 ± 4.7 /min and the mean non-dipping HR was 9.7 ± 5.9/min (Table 2). There was no statistically significant correlation of the parameters above with the LVMi. Patients with high cardiovascular risk (diabetes, coronary heart disease, heart failure) had statistically higher non-dipping BP (27 vs 12.3 mmHg, p = 0.034) and higher nighttime SPB (27 vs 20.74 mmHg, p = 0.024). When compared patients in CAPD vs APD, there were no differences in the pre-awaking BP or the rest of the measurements performed, although APD patients recorded interrupted sleep due to the alarms of the APD machine. Conclusion PD patients with high cardiovascular risk had higher nondipping BP and nighttime systolic BP compared with patients without cardiovascular disease. There were no correlations of BP and heart rate morning surge with left ventricular hypertrophy or PD mode.