Sleep Fragmentation Hypersensitizes Healthy Young Women to Deep and Superficial Experimental Pain

Abstract

The effect of sleep deprivation on pain sensitivity has typically been studied using total and partial sleep deprivation protocols. These protocols do not mimic the fragmented pattern of sleep disruption usually observed in individuals with clinical pain conditions. Therefore, we conducted a controlled experiment to investigate the effect of sleep fragmentation on pain perception (deep pain: forearm muscle ischemia, and superficial pain: graded pin pricks applied to the skin) in 11 healthy young women after 2 consecutive nights of sleep fragmentation, compared with a normal night of sleep. Compared with normal sleep, sleep fragmentation resulted in significantly poorer sleep quality, morning vigilance, and global mood. Pin prick threshold decreased significantly (increased sensitivity), as did habituation to ischemic muscle pain (increased sensitivity), over the course of the 2 nights of sleep fragmentation compared with the night of normal sleep. Sleep fragmentation did not increase the maximum pain intensity reported during muscle ischemia (no increase in gain), and nor did it increase the number of spontaneous pains reported by participants. Our data show that sleep fragmentation in healthy, young, pain-free women increases pain sensitivity in superficial and deep tissues, indicating a role for sleep disruption, through sleep fragmentation, in modulating pain perception.

Perspective: Our findings that pain-free, young women develop hyperalgesia to superficial and deep muscle pain after short-term sleep disruption highlight the need for effective sleep management strategies in patients with pain. Findings also suggest the possibility that short-term sleep disruption associated with recurrent acute pain could contribute to increased risk for future chronic pain conditions.

Keywords: Pain; forced awakening; sleep disturbance; sleep fragmentation; women.