Multiscale Cross-Approximate Entropy Analysis as a Measurement of Complexity between ECG R-R Interval and PPG Pulse Amplitude Series among the Normal and Diabetic Subjects

Table 2

Comparison of MC-ApEn, MSE, PAR, and HRV between Groups 1 and 2.

Parameter	Group 1	Group 2	P value
MC-ApEnSS	5.18±0.59	5.22±1.02	𝑃=0.869
MC-ApEnLS	5.32±0.50	4.74±0.78	P = 0.003
MSERRI, SS	5.17±0.48	5.11±1.08	𝑃=0.509
MSERRI, LS	5.28±0.47	4.85±0.88	P = 0.038
MSEPPGA, SS	4.14±1.09	4.03±1.21	𝑃=0.664
MSEPPGA, LS	4.65±0.95	3.93±1.19	P = 0.017
PAR	0.46±0.14	0.34±0.10	P = 0.006
LHR	1.94±1.21	1.32±1.00	P = 0.031
LFP	311.66±274.85	100.87±95.96	P < 0.001
HFP	206.50±184.93	126.02±148.70	P = 0.024

Group 1: healthy upper middle-aged subjects. Group 2: upper middle-aged subjects with type 2 diabetes. MC-ApEn: multiscale cross-approximate entropy. MSE: multiscale entropy. RRI: R-R intervals. PPGA: photoplethysmography amplitude. SS: small scale (the sum of the algorithm between scale factors 1–3). LS: large scale (the sum of the algorithm between Scale factors 4–6). PAR: pulse-pulse interval and amplitude ratio. LHR: low-frequency-power/high-frequency power ratio. LFP: low-frequency power. HFP: high-frequency power.