Sex differences in heart rate variability measures (ln transformed) in supine position
| Measures | Controlled for age | Controlled for age and heart rate | |||||
|---|---|---|---|---|---|---|---|
| Men mean (SD) | Women mean (SD) | p | Men mean (SD) | Women mean (SD) | p | ||
| Free breathing | |||||||
| SD | 3.71 (0.49) | 3.57 (0.34) | 0.007 | 3.70 (0.40) | 3.65 (0.29) | 0.191 | |
| RMSSD | 3.26 (0.49) | 3.26 (0.42) | 0.916 | 3.25 (0.36) | 3.38 (0.34) | 0.003 | |
| Area very low | 5.80 (0.98) | 5.44 (0.72) | 0.001 | 5.78 (0.83) | 5.59 (0.65) | 0.029 | |
| Area low | 5.40 (1.13) | 5.02 (0.78) | 0.001 | 5.40 (0.96) | 5.14 (0.73) | 0.010 | |
| Area high | 4.84 (1.12) | 4.85 (0.93) | 0.920 | 4.83 (0.86) | 5.09 (0.77) | 0.008 | |
| Total PS | 6.61 (0.98) | 6.33 (0.68) | 0.005 | 6.61 (0.78) | 6.49 (0.58) | 0.156 | |
| Ratio (low to high) | 5.19 (0.77) | 4.78 (0.79) | < 0.001 | 5.18 (0.76) | 4.65 (0.74) | < 0.001 | |
| Metronomic breathing | |||||||
| SD | 3.60 (0.44) | 3.55 (0.34) | 0.290 | 3.59 (0.38) | 3.61 (0.31) | 0.631 | |
| RMSSD | 3.22 (0.47) | 3.26 (0.45) | 0.477 | 3.20 (0.37) | 3.36 (0.37) | < 0.001 | |
| Area very low | 5.47 (0.96) | 5.29 (0.73) | 0.040 | 5.48 (0.86) | 5.37 (0.71) | 0.243 | |
| Area low | 4.98 (1.00) | 4.66 (0.80) | 0.003 | 4.96 (0.91) | 4.76 (0.77) | 0.047 | |
| Area high | 4.77 (1.09) | 4.97 (1.01) | 0.103 | 4.74 (0.90) | 5.20 (0.87) | < 0.001 | |
| Total PS | 6.35 (0.88) | 6.24 (0.69) | 0.240 | 6.32 (0.74) | 6.37 (0.62) | 0.546 | |
| Ratio (low to high) | 4.81 (0.80) | 4.30 (0.90) | < 0.001 | 4.82 (0.78) | 4.18 (0.84) | < 0.001 | |
SD, standard deviation of RR interval; RMSSD, root mean square of differences of successive RRs; area very low, the area at very low frequency (0.0033 to < 0.04 Hz); area low, the area at low frequency (0.04 to < 0.15 Hz); area high, the area at high frequency (0.15 to < 0.40 Hz); total PS, total power spectrum (0.0033 to < 0.40 Hz); ratio low to high, ratio of low frequency to high frequency.
The values for the SD and RMSSD are in ms and the values for the areas and total power are in ms2.
p values from t test for differences in means.