Measurement of heart rate variability (HRV) is a non-invasive technique that can be used to investigate functioning of the autonomic nervous system, especially the balance between sympathetic and vagal activities. It is reported that dilatation of coronary microcirculation by augmentation of sympathetic nerve activity (SNA) caused by cold exposure was impaired in diabetes. The question of whether or not SNA in HRV could respond to coronary ischemia was evaluated by cold exposure in diabetic rats. It was found that diabetes with weight loss significantly increased SNA both in baseline and cold exposure, compared with control. A correspondence was also found with coronary ischemia. It can be concluded that measurement of HRV may provide useful information regarding the coronary risk of cold exposure in diabetes.
The measurement of ankle-brachial pressure index (ABI) and brachial-ankle-pulse wave velocity (baPWV) has recently made the diagnosis of peripheral arterial disease (PAD) easy and quick in common clinical practice. A one-day mass survey of PAD, ABI, and baPWV was performed in 1,007 applicants, mainly elderly over 70 years old, during the Respect-for-Senior-Citizens Day in 2010. The questionnaire was distributed simultaneously to assess their atherosclerotic risk factors such as age over 70 years, smoking history, and presence of diabetes, hypertension, and dyslipidemia. With the cut-off level of ABI less than 0.9 for PAD, the incidence of PAD was 1.1% over-all and 1.5% in a selected high-risk group of 613 patients. The incidence of abnormal baPWV was 59% over-all and 62% in the selected high-risk group. In the high-risk group, approximately 90% of patients with abnormal ABI had intermittent claudication, the incidence of which was significantly higher (p<0.001) compared with the normal ABI group. Regarding baPWV, patients with abnormal baPWV also had hypertension (p<0.001) and diabetes (p=0.040) at higher rates. A one-day mass survey of PAD over 1,000 applicants can be performed smoothly with ABI and baPWV.