Low heart rate variability is associated with extended pain-related sick leave among employed care-seekers

To examine the association between autonomic regulation and length of pain-related sick leave in subjects receiving a cognitive behavioural therapy-based return to work intervention.

Sixty-five persons (29 men, 36 women) on pain-related sick leave participated in the study. Electrocardiograms were recorded in the clinic during supine rest, passive head-up tilt, standing, and seated rest, and in the home during seated rest and sleep. Spectral components of heart rate variability were derived from short-term (5 min) segments of electrocardiogram recordings. The number of days on sick leave was obtained from register data for 3 months before to 6 months after seeking care at the primary healthcare clinic.

Extended sick leave (> 121 days) compared with short sick leave (< 29 days) was associated with higher heart rate, and lower heart rate variability in supine rest and the seated position. The associations in supine rest were marginally weakened by adjusting for offensive behaviours at work. (for example, exposure to bullying, sexual harassment, unpleasant teasing, etc.)

Higher heart rate and lower heart rate variability measured in the awake resting condition predicts extended sick leave in care-seeking individuals. Further research is needed to clarify the underlying nature and causal role of altered autonomic regulation with regard to extended pain-related sick leave.