Diurnal rhythm of blood pressure, heart rate and adrenergic activity in patients with normotension treated with continuous ambulatory peritoneal dialysis and haemodialysis

Baranowicz-Gąszczyk I, Jóźwiak L, Bednarek-Skublewska A, Książek A

Abstract

Purpose: People with normotension and with essential hypertension are subjected to the diurnal rhythm of blood pressure (BP) with higher values during the day than during the night. Among dialysed patients nocturnal reduction of BP is blunted. The aim of the study was to evaluate diurnal BP rhythm and adrenergic activity measured as values of catecholamines.
Material and methods: Study was performed among dialysed patients with normotension: 13 haemodialysed patients (HD), 8 patients treated by continuous ambulatory peritoneal dialysis (CAPD) and 10 controls (C). Ambulatory BP monitoring (ABPM) was done by using Micro SJ7400 AMP device. Catecholamines concentrations were measured by HPLC-ED method before and after cold pressure test. 
Results: There was no significant difference between manual measurements of BP done by dialysis nurses and mean values of 24-hours ABPM in CAPD group and C group and 48-hours ABPM among HD patients. Diurnal BP was blunted in 80% of HD patients during the day of haemodialysis, 70% during the day without haemodialysis and in CAPD group in 50%. Heart rate (HR) variability was comparable in HD and CAPD groups and significant lower than in C group. Baseline noradrenaline (NA) as well as NA (ng/ml) post cold pressure test levels were significantly higher among HD patients (463±21, 546±31) and CAPD patients (452±76, 527±92) as compared with C (206±53*, 315±61*). (x±SD), *p<0.001
Conclusions: Despite increased adrenergic activity and altered diurnal rhythm of BP and HR exist in dialysed patients we didn’t find directly relationship. Another or composed factors could affect diurnal rhythm of BP and HR. 

Key words: 	noradrenaline, dialysis, ambulatory blood pressure monitoring, diurnal rhythm.