Psychological distress, disturbed sleep and physical activity during the night in chronic low-back pain patients

This study investigates the relationship between psychological distress and disturbed sleep characteristics in patients with chronic low-back pain. Higher levels of psychological distress are expected to be related to lower sleep quality, more pain and stiffness in the morning and a different physical activity pattern during the night. Patients were divided into a group with a high level (PD-subjects, n = 13) and a group with a low level (ND-subjects, n = 13) of psychological distress, using the Distress-and-Risk-Assessment-Method. Also, 12 non-symptomatic subjects (NS-subjects) participated. Pain intensity, stiffness and sleep quality when waking up were measured alongside activity pattern during the night. Results showed relationships between psychological distress and sleep quality; PD-subjects experienced significantly more pain and stiffness in the low back when waking up and a lower sleep quality compared to ND and NS-subjects. PD-subjects also had a significant lower lying time, a higher general activity level but moved less while lying down.