Non-dipping is a potent predictor of cardiovascular mortality and is associated with autonomic dysfunction in haemodialysis patients.
BACKGROUND
Lack of nocturnal blood pressure (BP) fall (non-dipping) is common among haemodialysis (HD) patients, but much less is known regarding its association with cardiovascular (CV) disease morbidity and mortality.


METHODS
Eighty HD patients initially underwent 24 h ambulatory BP monitoring (ABPM), and then they were defined as either 'dippers' (n=24, nocturnal BP fall > or = 10%) or 'non-dippers' (n=56, fall <10%). Coronary angiography was performed in the patients who had signs and/or symptoms of coronary artery disease (CAD). Twenty-four hour ambulatory ECG was recorded in 20 dippers and 20 non-dipper HD patients, and in 20 normal subjects. All patients were followed for up to 5.8 years (33.0+/-19.1 months). The outcome events studied were the hospitalisations due to CV diseases and CV death.


RESULTS
Compared with dippers, non-dippers initially had a higher incidence of coronary artery stenosis (P<0.05) along with left ventricular asynergy (both Ps<0.01). The circadian rhythm of autonomic function was impaired in non-dippers. The incidences of CV events and CV deaths were 3.5 and 9 times higher in non-dippers than in dippers. The cumulative CV event-free survival and CV survival rates were lower in non-dippers than in dippers (P=0.02 and P=0.005, respectively). Based on Cox analysis, non-dipping was associated positively with CV events and CV mortality [hazard ratio (HR) 2.46, 95% CI 1.02-5.92, P=0.038 and HR 9.62, 95% CI 1.23-75.42, P=0.031, respectively]. Meanwhile, nocturnal systolic BP fall, diurnal systolic BP and diurnal pulse pressure were negatively associated with CV event/death. The clinic BP was not associated with CV event/death.


CONCLUSIONS
The non-dipping phenomenon is closely related to a high incidence of CV diseases, a poor long-term survival and profound autonomic dysfunction. ABPM is useful in predicting long-term CV prognosis in HD patients.
Liu
Manchang
M
Division of Clinical Immunology, Department of Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Takahashi
Hiroshi
H
Morita
Yoshiki
Y
Maruyama
Shoichi
S
Mizuno
Masashi
M
Yuzawa
Yukio
Y
Watanabe
Midoriko
M
Toriyama
Takanobu
T
Kawahara
Hirohisa
H
Matsuo
Seiichi
S
D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000150:complications* / Q000401:mortality* / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality* / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000401:mortality* / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011379:Prognosis; D006435:Renal Dialysis