Association of plasma BDNF with HRV parameters.

Pearson's correlation coefficients between the HRV parameters and BDNF were calculated. All parameters of HRV and BDNF were natural logarithm-transformed (ln) to achieve a normal distribution. HRV; heart rate variability, SDNN; standard deviation of the NN(RR) interval, SDANN5; standard deviation of average of NN intervals for each 5 minute period, CVRR; coefficient of variation R-R interval, LF; low frequency power, HF; high frequency power, LF/HF; the ratio of LF to HF, BDNF; brain-derived neurotrophic factor.