Table 2

HRV indices in TODAY participants versus obese control subjects

VariableTODAY, n = 397Obese control subjects, n = 133P value
UnadjustedAdjusted
SDNN (ms)*58.1 ± 29.667.1 ± 25.4<0.0001<0.0001
RMSSD (ms)*53.2 ± 36.767.9 ± 35.2<0.0001<0.0001
PNN50 (%)*26.3 ± 23.739.7 ± 23.0<0.0001<0.0001
LF Power (n.u.)47.3 ± 20.039.5 ± 19.70.0001<0.0001
HF Power (n.u.)*52.7 ± 20.060.5 ± 19.70.0001<0.0001
LF:HF ratio1.4 ± 1.71.0 ± 1.1<0.0001<0.0001
  • Unadjusted means ± SD are shown in the table. Total power for TODAY participants was 2,576 ± 2,919. P value from general linear model comparing mean of the obese control subjects to the TODAY participants. SDNN, RMSSD, and LF:HF ratio were log transformed prior to testing because of skewed distribution. A nonparametric rank-based test was used to compare the PNN50 values. Unadjusted and adjusted P values for age, sex, race-ethnicity, smoking, and BMI are given for the cardiac autonomic function measures. n.u., normalized units.

  • * Lower = worse.

  • Higher = worse.