title: Power spectral analysis of heart rate variation in diabetic patients with neuropathic foot ulceration.
abstract: OBJECTIVE
  To evaluate the relationship between diabetic autonomic neuropathy and diabetic neuropathic foot ulceration, we used power spectral analysis (PSA) of heart rate variation, which provides the accurate simultaneous quantification of parasympathetic and sympathetic activities, to assess autonomic function in diabetic patients.
  
  
  METHODS
  We studied 55 NIDDM patients including 10 diabetic patients without neuropathy, 23 diabetic patients with neuropathy and no history of foot ulceration, and 22 diabetic patients with neuropathic foot ulceration. We performed PSA of 100 R-R intervals at rest and analyzed the results by fast Fourier transformation.
  
  
  RESULTS
  The low frequency (LF) power, which reflects sympathetic activity, and the high frequency (HF) power, which reflects parasympathetic (vagal) activity, were inversely correlated with the duration of diabetes and the fasting plasma glucose (FPG) levels. By multiple regression analysis, the FPG remained with significant influence on both LF and HF powers. The LF and HF powers were positively correlated with motor nerve conduction velocity (MCV) and sensory nerve conduction velocity (SCV) in the upper and lower limbs and the coefficient of variation of R-R intervals. The LF and HF powers were significantly reduced in patients with neuropathy and patients with foot ulceration compared with patients without neuropathy. Although the median MCV and SCV were similar between diabetic patients with neuropathy and patients with foot ulceration, both the LF and HF powers were significantly decreased in patients with foot ulceration compared with patients with neuropathy. There was no difference in the value of the LF:HF ratio, an index of sympathovagal balance, among three subgroups. We observed a positive correlation between LF and HF power in all subjects; however, the LF and HF powers were not correlated in the subgroups of patients with foot ulceration.
  
  
  CONCLUSIONS
  These results showed that diabetic patients with neuropathic foot ulceration have a greater impairment in spectral indexes of autonomic activity obtained by PSA than patients with neuropathy and no history of foot ulceration, whereas no difference was present in nerve conduction velocities.
authors.affiliation: Department of Medicine, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Aso
authors.forename: Y
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Inukai
authors.forename: Y
authors.initials: Y
authors.lastname: Takemura
mesh_terms: D000367:Age Factors; D001341:Autonomic Nervous System / Q000503:physiopathology; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D017719:Diabetic Foot / Q000150:complications / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000150:complications / Q000503:physiopathology*; D004562:Electrocardiography / Q000379:methods*; D005215:Fasting; D005260:Female; D005583:Fourier Analysis; D006442:Glycated Hemoglobin / Q000378:metabolism; D006321:Heart / Q000294:innervation / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D012044:Regression Analysis; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin