Autonomic dysfunction and ambulatory blood pressure in renal transplant recipients.
BACKGROUND
Abnormal circadian blood pressure (BP) rhythm (nondipping) and autonomic dysfunction are both common in end-stage renal disease (ESRD). It is not known whether these abnormalities are related or if they are associated with greater left ventricular hypertrophy.


METHODS
Nineteen renal transplantation (RT) recipients, aged 22-67 years, who were transplanted at least 12 months (1-29 years) previously, were studied with 24-hr ambulatory blood pressure monitoring (ABPM). Autonomic function was tested by automated analysis of heart rate variations and echocardiography was used to estimate left ventricular mass index (LVMI).


RESULTS
Thirteen patients (68%) were nondippers. Although seven (37%) patients had significant parasympathetic dysfunction, this was not related to dipper status. Neither abnormality showed a tendency to diminish with time after RT. Systolic hypertension, diagnosed by ABPM, occurred in 5% of patients during the awake period and in 52% during sleep, whereas diastolic hypertension occurred in 47% when awake and in 63% when asleep. Awake systolic BP was the strongest predictor of LVMI (r=0.7, P<0.001), and was considerably better than systolic BPs recorded at the clinic (r=0.48, P<0.05).


CONCLUSIONS
Nondipping is common after RT but is not related to the degree of autonomic dysfunction. These findings suggest that autonomic dysfunction is not a major contributor to nondipping in ESRD. In RT patients, ABPM is a more sensitive measure of hypertension and a stronger predictor of LVMI than clinic BP.
McGregor
D O
DO
Department of Nephrology, Christchurch Hospital, New Zealand. davidm2@chhlth.govt.nz
Olsson
C
C
Lynn
K L
KL
D000293:Adolescent; D000328:Adult; D001342:Autonomic Nervous System Diseases; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000517:prevention & control; D007223:Infant; D007676:Kidney Failure, Chronic / Q000601:surgery; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D008875:Middle Aged