Assess Spontaneous Baroreflex in Diabetic Subjects and Aged Persons Using Pressure Pulse Analysis

Cardiac autonomic dysfunction is a serious condition in elderly and diabetic subjects. Baroreflex sensitivity (BRS), measured from pulse intervals and blood pressure, has been proven as an effective indicator. This paper proposes an index that replaces blood pressure with amplitudes of the pressure pulse. 89 subjects were recruited and divided into three groups: healthy young subjects (Group 1, n = 33), healthy elders (Group 2, n = 28), and type-2 diabetic patients (Group 3, n = 28). The wrist pulse pressures of each subject were measured for 5 min to obtain pulse-pulse intervals and amplitudes. The spontaneous sequence technique was then used to calculate the pulse-pulse interval to amplitude ratio (PAR). The reproducibility of the PAR and agreement with spectral analysis of heart rate variability in Group 1 participants were verified. Significant differences between different groups in the PAR (Group 1 vs. Group 2: 0.79 ± 0.40 vs. 0.54 ± 0.23, P = 0.032; Group 2 vs. Group 3: 0.54 ± 0.23 vs. 0.47 ± 0.26, P = 0.009) and a negative linear relationship between the PAR and risk factors of autonomic dysfunction were found. The proposed index does not require blood pressure calibration or professional expertise for conducting measurements, making it convenient for assessing autonomic function at home.