Novel application of multiscale entropy in assessment of atherosclerosis in aged and diabetic subjects

Although previous studies have shown the successful use of pressure-induced reactive hyperemia as an assessment tool of endothelial function, the sensitivity remains questionable. This study aims at investigating the feasibility and sensitivity of a novel multiscale entropy index (MEI) in detecting subtle endothelial dysfunction in healthy and diabetic subjects. Totally 66 subjects were recruited from Hualien Hospital, Taiwan, and categorized into healthy aged group (Group 1), well- (Group 2) and poorly-controlled diabetic patients (Group 3). Arterial pulse wave signals were acquired from the wrist with air pressure sensing system (APSS), followed by MEI and dilatation index (DI) analyses. The results showed that MEILS(RH) succeeded in detecting significant differences among the three groups, whereas there was no notable difference in MEISS(Baseline), MEILS(Baseline), MEISS(Baseline) and DIEEMD between Group 2 and Group 3. In conclusion, MEILS(RH) may serve as a sensitive indicator of subtle endothelial dysfunction.