Table 3: Time domain and frequency domain indices of HRV in controls, Grade I and Grade II NAFLD.

Controls ()Grade I ()Grade II () value

Diabetics (, %)16, 51.6%8, 44.4%0.62
Time domain indices
SDNN (ms)40.728.30.010
SDSD (ms)
pNN50 (%)
Frequency domain indices
LF nu40.237.844.50.435
HF nu29.219.723.10.650
LF : HF ratio1.
Total power (ms2)1166.5515.00.006

Values are expressed as median (IQR); versus control.
SDNN: standard deviation of all NN intervals; SDSD: standard deviation of differences between adjacent NN intervals; pNN50%: NN50 count divided by the total number of all NN intervals; LF: low frequency (0.04–0.15 Hz); HF: high frequency (0.15–0.40 Hz); nu: normalized unit.