Spectral analyses of R-R interval and systolic blood pressure in diabetic autonomic neuropathy.
We studied autonomic nervous system function using the principle of maximum entropy (ME) to perform spectral analyses of the R-R interval and systolic blood pressure in 32 diabetic patients and 40 healthy controls. The R-R interval and systolic blood pressure were measured using a continuous, noninvasive monitoring system. The power spectra of both the R-R interval (RR) and systolic blood pressure (SYS) were obtained using ME and the areas of two frequency components were measured: a low- (LFC) and a high-frequency component (HFC). The RR-LFC, RR-HFC and SYS-LFC of diabetic patients were significantly smaller than those of healthy controls. The results of the spectral analyses in diabetic patients correlated with neither disease duration nor nephropathy, while the SYS-LFC showed significant correlations with both retinopathy and the delay in median motor nerve conduction velocity. In the mild autonomic neuropathy group, the RR-LFC and SYS-LFC were not differ from those of healthy controls or patients without autonomic neuropathy. However, the RR-HFC was significantly smaller than that of healthy controls or patients without atonomic neuropathy. In the setting of mild diabetic autonomic neuropathy, it was suggested that cardiac parasympathetic dysfunction preceded both alpha and beta sympathetic dysfunction.
Oka
H
H
Third Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.
Mochio
S
S
Sato
K
K
Sato
H
H
Katayama
K
K
Watanabe
S
S
Nohara
T
T
Hasunuma
T
T
Houi
K
K
Isogai
Y
Y
D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology*; D003080:Cold Temperature; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D011187:Posture / Q000502:physiology; D013599:Systole / Q000502:physiology