Impaired autonomic function is associated with increased mortality, especially in subjects with diabetes, hypertension, or a history of cardiovascular disease: the Hoorn Study.
OBJECTIVE
Measures of baroreflex sensitivity, heart rate variability (HRV), and the classical Ewing test parameters are currently used for the diagnosis of diabetic autonomic neuropathy and for mortality risk stratification after myocardial infarction. However, the strengths of the associations of these measures of autonomic function with risk of mortality have never been compared in one study population. Furthermore, no evidence is available on the possible effect of glucose tolerance on these associations.


METHODS
The study population (n = 605) consisted of a glucose tolerance-stratified sample from a general population (50-75 years of age). Cardiac cycle duration and continuous finger arterial pressure were measured under two conditions: at rest and on metronome breathing. From these readings, seven parameters of autonomic function were assessed (one Ewing, five HRV, and one baroreflex sensitivity).


RESULTS
During 9 years of follow-up, 101 individuals died, 43 from cardiovascular causes. Subjects with diabetes and low levels of the autonomic function parameters, indicating impaired autonomic function, had an approximately doubled risk of mortality. This association was consistent, though not statistically significant, for all parameters. The elevated risk was not observed in subjects without diabetes, hypertension, or prevalent cardiovascular disease.


CONCLUSIONS
Impaired autonomic function is associated with all-cause and cardiovascular mortality. Moreover, the results of the present study suggest that cardiac autonomic dysfunction in patients already at risk (diabetes, hypertension, or history of cardiovascular disease) may be especially hazardous.
Gerritsen
J
J
Department of Clinical Physics and Informatics, Vrije Universiteit, Amsterdam, the Netherlands.
Dekker
J M
JM
TenVoorde
B J
BJ
Kostense
P J
PJ
Heine
R J
RJ
Bouter
L M
LM
Heethaar
R M
RM
Stehouwer
C D
CD
D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000401:mortality*; D017704:Baroreflex; D002318:Cardiovascular Diseases / Q000150:complications*; D048909:Diabetes Complications; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000150:complications*; D008297:Male; D008875:Middle Aged; D012119:Respiration; D012307:Risk Factors; D013484:Supination