Differences in heart rate variability in non-hypertensive diabetic patients correlate with the presence of underlying cerebrovascular disease.

We previously showed that diabetes contributes to the development of sclerotic lesions in cerebral arteries. In this study, we attempted to clarify whether differences in heart rate variability in non-hypertensive diabetic patients were dependent on the presence or absence of underlying cerebrovascular disease. Thirty diabetic subjects between 40 and 59 years of age and who had no prior history of hypertension were used in this study. Lacunar lesions (LA) were detected with magnetic resonance imaging and atherosclerotic lesions (AS) were detected using intra- and extracranial magnetic resonance angiography, and by ultrasonographic scanning of the carotid artery. Patients underwent a full clinical laboratory screening and a power spectrum analysis of their heart rate variability. Subjects were divided into two groups: those with and without LA. The low frequency/high frequency ratio (LF/HF ratio) was found to be significantly increased (P<0.01) in subjects with LA (2.2 +/- 0.3) compared to those without LA (1.3 +/- 0.1). When subjects were divided into groups based on their presence or absence of AS, high-frequency power was found to be significantly reduced (P<0.05) in the subjects with AS (12.8 +/- 3.4 ms) compared to those without AS (19.4 +/- 1.7 ms). The LF/HF ratio was found to be significantly increased (P<0.05) in the subjects with AS (2.2 +/- 0.3) compared to those without AS (1.4 +/- 0.1). Our data suggested that atherosclerotic lesions in cerebrovascular diseased linked to decrease of vagal nerve activity in non-hypertensive diabetic patients.