Diabetes Care, Vol 21, Issue 7 1173-1177, Copyright © 1998 by American Diabetes Association
Power spectral analysis of heart rate variation in diabetic patients with neuropathic foot ulceration
Y Aso, Y Fujiwara, T Inukai and Y Takemura
Department of Medicine, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan.
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. RESEARCH DESIGN AND
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.