
Male n=303 
Female n=266 
p value 
SDNN (ms) 
135.1 ± 48.3 
128 ± 44.5 
<0.0001 
RMSSD (ms) 
44.2 ± 5.42 
43.1 ± 34.9 
Ns 
SDNN index (ms) 
45.6 ± 31 
41.3 ± 35.2 
Ns 
pNN50 (%) 
9 ± 7.2 
7.7 ± 6.9 
Ns 
mean RR (ms) 
884.9 ± 161 
840.5 ± 169.3 
0.023 
mean HR (bpm) 
69 ± 12.7 
73.3 ± 11.1 
<0.0001 
Triangular HRV 
17.6 ± 6.4 
17.5 ± 5.9 
Ns 
TINN (ms) 
531.3 ± 212.5 
546.9 ± 203.1 
Ns 
SDNN: Standard deviation of all NN interval; RMSSD: Standard deviation of
differences between adjacent NN, square root of the mean of the sum of the square
of the differences between adjacent NN intervals; pNN50: Number of adjacent NN
intervals differing by more than 50 ms divided by the total number of all NN intervals;
Mean RR: Mean RR intervals; Mean HR: Mean Heart Rate; TINN: Triangular
Interpolation of NN Interval 