This study aimed to investigate heart rate variability (HRV) characteristics of cold pattern with repeated
measurement data. Participants were taken from a Daejeon University cohort study from 2015 to 2018. Forty-seven of
the participants studied displayed cold pattern while 23 showed signs of non-cold pattern. HRV was measured in
supine position for 5 minutes at each year, and an 8-item cold pattern questionnaire was used for the diagnosis of
cold pattern. SDNN (standard deviation of the NN intervals) and RMSSD (the square root of the mean squared
differences of successive NN intervals) were used as time domain analysis, and TP (total power), VLF (power in very
low frequency range), LF (power in low frequency range), HF (power in high frequency range), LF norm (LF power in
normalized units), HF norm (HF power in normalized units) and LF/HF were used as frequency domain analysis. In
the Mann-Whitney U test, LF norm, HF norm, and LF/HF showed differences between the cold pattern group and
non-cold pattern group at every measurement, and in the independent t-test, the differences were also observed at
three points except for the baseline (2015). In the repeated measures ANOVA, the interaction effects were not
observed in all HRV parameters, but the time period effects were observed in SDNN, RMSSD, TP, VLF, LF and HF.
There were significant differences between those two groups in LF norm, HF norm and LF/HF. This study suggests
that LF norm, HF norm and LF/HF might be a useful indicator of cold pattern properties. |
