Table 4.
Associations of Age With HRV Indices in Unadjusted and Adjusted (for race, CVD status, diabetes, and beta-blocker use) Linear Regression Models
Unadjusted Model |
Adjusted Model |
|||
Coefficient | p Value | Coefficient | p Value | |
SDNN | .02 | .83 | .002 | .98 |
RMSSD | .12 | .12 | .13 | .08 |
pNN50 | .13 | .09 | .14 | .07 |
VLF | −.11 | .13 | −.14 | .06 |
LF | .07 | .35 | .06 | .43 |
HF | .11 | .14 | .13 | .10 |
LF/HF | −.07 | .17 | −.10 | .05 |
PC1 | .15 | .36 | .15 | .37 |
PC2 | −.19 | <.01 | −.23 | <.001 |
Note: HRV = heart rate variability; CVD = cardiovascular disease; VLF = very low frequency; LF = low frequency; HF = high frequency; SDNN = standard deviation of N-N intervals; pNN50 = proportion of all N-N intervals that are larger than 50 ms; RMSSD = root-mean-squared differences of successive N-N intervals; PC = principal components.