Table 2

1 Year change of heart rate variability and frequency of premature complexes between baseline and the 1 year measurement

	Day workers	Shift workers	p Value of difference between day and shift worker
n	22	49
Mean number of night shifts worked between the baseline and repeated measurement	0	63
Frequency of premature complexes (%):
Decrease of PAC	54.6	43.7	0.6^2-151
No change in PAC	4.6	0.0
Increase in PAC	40.9	56.3
Decrease of PVC	45.4	20.4	0.03^2-151
No change in PVC	27.3	30.6
Increase in PVC	27.3	48.9
Heart rate variability:
Heart rate (bpm)	1.83	−2.08^2-150	0.08
SDNNi (ms)	−7.0^2-150	−2.0	0.2
Loglow (10⁻³ log ms)	−36.9	−29.9	0.84
Loghigh (10⁻³ log ms)	−83.9^2-150	−16.2	0.06
% lf	1.99	−0.72	0.16

PAC=premature atrial complexes; PVC=premature ventricular complexes; SDNNi=mean of all 5 minute standard deviations of NN intervals; Loglow=power in the low frequency range (0.05–015 Hz) in logarithmic units; Loghigh=power in the high frequency range (0.15–0.40 Hz.) in logarithmic units; % lf=low frequency power (0.05–0.15 Hz) in normalised units.
↵2-150 p<0.05 v baseline.
↵2-151 p Value according to Wilcoxon two sample test.