Table 4.
Correlation analysis between time-domain parameters of HRV, mean interstitial tissue glucose, and indices of glycemic variability.
| Variable | Mean interstitial tissue glucose | MAGE | SD of mean glucose | M-value | ||||
|---|---|---|---|---|---|---|---|---|
| r | P | r | P | r | P | r | P | |
| SDRR (t) | −0.29 | 0.052 | −0.06 | 0.70 | −0.23 | 0.13 | −0.28 | 0.06 |
| SDRR (n) | −0.28 | 0.058 | −0.19 | 0.20 | −0.39 | 0.007 | −0.40 | 0.006 |
| PNN30 (t) | −0.07 | 0.64 | −0.02 | 0.87 | −0.15 | 0.32 | −0.25 | 0.09 |
| PNN30 (n) | −0.14 | 0.36 | −0.06 | 0.72 | −0.19 | 0.22 | −0.27 | 0.07 |
| PNN50 (t) | −0.11 | 0.47 | −0.06 | 0.72 | −0.14 | 0.36 | −0.27 | 0.07 |
| PNN50 (n) | −0.20 | 0.19 | −0.10 | 0.49 | −0.23 | 0.12 | −0.35 | 0.02 |
| SDANN (t) | −0.29 | 0.054 | −0.04 | 0.79 | −0.21 | 0.16 | −0.27 | 0.07 |
| SDANN (n) | −0.25 | 0.09 | −0.18 | 0.22 | −0.38 | 0.009 | −0.37 | 0.01 |
| RMMSD (t) | 0.05 | 0.75 | 0.03 | 0.86 | −0.04 | 0.80 | −0.14 | 0.36 |
| RMSSD (n) | −0.01 | 0.93 | 0.02 | 0.87 | −0.08 | 0.62 | −0.18 | 0.24 |
Data are adjusted for HbA1c and duration of diabetes.
All variables are log-transformed due to skewness.
(t): Total; (n): night.
Night period: 23:00–06:00
SDRR: Standard deviation of all normal-to-normal RR intervals
PNN30: Number of pairs of adjacent NN intervals differing >30 ms in the entire recording divided by the total number of all NN intervals
PNN50: Number of pairs of adjacent NN intervals differing >50 ms in the entire recording divided by the total number of all NN intervals
SDANN: 5 min, standard deviation of the changes of NN intervals in all 5-minute segments of the entire recording
RMSSD: The square root of the mean of the sum of the squares of differences between adjacent NN intervals.