Autonomic nervous system activity under rotational shift programs: effects of shift period and gender

Figures

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  Fig. 1.. Experimental protocol. Male (n=40) and female (n=40) nurses who were under rotational shift program were sampled twice (once in the day-shift between 08:00-10:00 h a.m. and again in their night shift between 08:00-10:00 h p.m.) for blood pressure and heart rate variability (HRV, by 5 min continuous electrocardiogram). They also filled in questionnaires once about sleep parameters (Pittsburgh Sleep Quality Index, PSQI) and perceived stress level (State and Trait Anxiety Inventory-Trait, STAI-T) related to the last month.

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  Fig. 2.. Individual plots and median values (vertical lines) for heart rate (beats per minute), systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) recorded at day-shifts and night-shifts in males and females who were working under rotational shift regiments. Heart rate did not differ between the genders and between the shifts (p>0.05). Males had higher systolic and diastolic pressures than females (***: p<0.001) but there was no difference between the shift periods. NS, non-significant.

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  Fig. 3.. Individual plots and median values (vertical lines) for time domain parameters of the heart rate variability (HRV). Males had significantly lower SDNN (ms), pNN50 (%) and RMSSD (ms) values than the females but shift time did not have any significant effect (p>0.05). NS, non-significant, *p<0.05, ***p≤0.001.

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  Fig. 4.. Individual plots and median values (vertical lines) for frequency domain parameters of the heart rate variability (HRV). Males had significantly lower VLF (ms2) and HF (ms2) values than the females but shift time did not have any significant effect except in males for HF (p<0.01). NS, non-significant, *p<0.05, ***p≤0.001.

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  Fig. 5.. Individual plots and median values (vertical line) for LF/HF values. Males had significantly higher LF/HF levels than females but there was no statistically significant difference between the shift types. NS, non-significant, ***p≤0.001.