Temporal relationships between sleep improvement and pain relief in patients with musculo-skeletal pain treated with two types of acupuncture

Although there is a close relationship between sleep disorders and musculo-skeletal pain, no general agreement exists on which of the two factors is the cause and which the consequence. This relationship was addressed in the present study. One hundred and eighteen consecutive patients (38 men, 80 women), aged 20-70 years, suffering from musculo-skeletal pain in the cervical and/or lumbar region(s) for more than 3 months were treated with eight acupuncture sessions during a 6-week period plus two more optional treatment sessions during the following 2 months. Two types of acupuncture were used showing no significant difference between the two (data not provided in this study). Sleep and pain were estimated by standard visual analogue scales in the morning, at noon and in the evening immediately before the start of treatment and at 1 week, and 1, 3 and 6 months after treatment cessation. Only the patients who showed improvement in pain in the evening during the study period experienced improved sleep in the succeeding night (Friedman's ANOVA: p < 0.0001 and p < 0.01, respectively). Correspondingly, the patients with improved sleep during the study period experienced pain reduction in the morning (p < 0.0001 and p < 0.01, respectively). It can be concluded that improvement of pain in the evening promoted a favourable development of sleep; correspondingly, improved sleep promoted pain relief in the morning.