Table 2: Heart rate variability indices in severely obese subjects with type 2 diabetes before and after treatment.
(a) 24 hour

Control groupTreatment group
PrePostPrePost

N13121616
Mean NN (ms)768 ± 86786 ± 111775 ± 102796 ± 101
SDNN (ms)106 ± 34106 ± 30102 ± 25112 ± 23
SDANN (ms)93 ± 3891 ± 3588 ± 2297 ± 22
rMSSD (ms)26 ± 1528 ± 1624 ± 1030 ± 10*
pNN50 (%)7 ± 108 ± 106 ± 79 ± 8*
HF (ln)4.4 ± 1.04.6 ± 0.94.5 ± 0.94.9 ± 0.7*
LF (ln)5.6 ± 0.95.7 ± 0.75.7 ± 1.05.9 ± 0.7
LF/HF ratio3.7 ± 1.93.4 ± 1.73.3 ± 1.12.8 ± 1.3*

(b) Daytime

Control groupTreatment group
PrePostPrePost

N13121616
Mean NN (ms)733 ± 100762 ± 133734 ± 104742 ± 105
SDNN (ms)80 ± 2985 ± 3080 ± 2284 ± 22
SDANN (ms)68 ± 2369 ± 2663 ± 1866 ± 21
rMSSD (ms)21 ± 1826 ± 2021 ± 825 ± 9
pNN50 (%)5 ± 137 ± 134 ± 56 ± 7
HF (ln)3.8 ± 1.24.3 ± 1.24.1 ± 1.04.6 ± 0.8
LF (ln)4.9 ± 0.95.4 ± 0.85.5 ± 1.05.7 ± 0.7
LF/HF ratio3.8 ± 2.43.7 ± 2.54.0 ± 1.83.2 ± 1.2*

(c) Night time

Control groupTreatment group
PrePostPrePost

N13121616
Mean NN (ms)840 ± 86827 ± 96851 ± 112890 ± 105
SDNN (ms)88 ± 4586 ± 3083 ± 2585 ± 23
SDANN (ms)57 ± 3960 ± 3157 ± 1853 ± 16
rMSSD (ms)32 ± 1730 ± 1131 ± 1536 ± 16*
pNN50 (%)10 ± 1210 ± 1011 ± 1215 ± 14
HF (ln)5.1 ± 1.14.9 ± 0.95.0 ± 1.05.4 ± 1.0
LF (ln)6.2 ± 1.15.9 ± 0.96.0 ± 1.06.2 ± 0.9
LF/HF ratio3.7 ± 2.63.2 ± 2.02.9 ± 1.42.6 ± 1.7

Mean ± standard deviation; * : pre versus post; : control versus treatment; ln: logarithmic transformation; HF: High frequency; LF: Low frequency; Mean NN: Mean value of all RR intervals; pNN50: Percentage of intervals differing of ≥50 ms than the preceding interval; rMSSD: square root of the mean squared difference of successive RR intervals; SDANN: Standard deviation of the mean NN intervals for each 5 minutes period; SDNN: Standard deviation of the RR intervals.