Sleep Disturbance in Patients with Low Back Pain

Despite yearly healthcare expenditures totaling billions of dollars, the annual prevalence of low back pain (LBP) remains near 40% in the adult population1 and the condition continues to be a prominent cause of physical disability and psychological distress.2  Recent findings have indicated a high prevalence of sleep disturbance in patients suffering from chronic and acute LBP3 which may further worsen physical and psychological symptoms of LBP in addition to contributing to the development of other chronic diseases such as obesity, type-2 diabetes, hypertension, and coronary artery disease.3,4

A meta-analysis, consolidating data across severalmajor LBP studies, determined that nearly 60% of LBP patients reported “yes” to the questionnaire item: “I sleep less well because of my back”.3  Although this constitutes quantitative evidence of a significant association between LBP and sleep disturbance, the directionality of that relationship is not yet well understood.5   

Commonly, pain is perceived to be the agent responsible for reduced quality sleep6 but there is, in fact, cause to believe that the relationship between LBP and sleep disturbance is bidirectional.5  This conclusion is supported by recent clinical evidence that has suggested that sleep and pain exist in a reciprocal relationship,6,7 leading to the proposition that LBP and sleep disturbance may exacerbate each other.  Multiple laboratory experiments have demonstrated that the disturbance of normal sleep patterns may induce musculoskeletal pain in healthy subjects and worsen pain intensity in those who suffer from existing musculoskeletal or osteoarthritic pain.8,9,10  These findings, which illustrate the important analgesic role that sleep may have in mediating existing pain, have resulted in the proposition that LBP and sleep disturbance exist in a reciprocal, cyclical relationship, in which LBP contributes to poor sleep quality which, in turn, may worsen the intensity of LBP.5

In the first longitudinal study directly evaluating the possibility that LBP and sleep disturbance exist in a bidirectional relationship, evidence was found in support of this hypothesis.5  The study measured patients’ rate of sleep disturbance through both subjective measures, defined by subjects’ perception of sleep quantity and quality, and through objective measures, characterized by biometric data obtained while patients slept.  It was found that nights, during which patients experienced higher rates of sleep disturbance, were, on average, followed by days during which patients experienced increased pain intensity.  In turn, higher rates of daytime LBP resulted in lower quality sleep the following night by both subjective and objective measures, thereby supporting the conclusion that there exists a reciprocal, causal relationship between LBP and sleep disturbance.5  Further, the relationship was demonstrated to be independent of potential confoundssuch as the chronicity of LBP as well as psychological factors.5

While this study constitutes strong evidence for the existence of a bidirectional relationship between the conditions of LBP and sleep disturbance and is supported by several other studies on the general relationship between sleep and musculoskeletal pain,9,10 it should be noted that there also exist several studies in which patients, with other forms of chronic pain, did not experience a significant pain-sleep relationship.11,12  Across different studies, it is difficult to standardize the construct of sleep quality and, further, patients’ assessment of pain intensity is subjective; these two factors may account for these conflicting findings.5

What is known for certain is that there is a significant association between sleep disturbance and LBP, and that these conditions, more than likely, exacerbate each other in at least some capacity.  Although there have been some promising findings in long-term longitudinal studies, suggesting that reducing sleep problems may improve the long-term prognosis of chronic LBP,13 it is imperative that further research be conducted in order to better define the relationship between LBP and sleep disturbance and to develop a better understanding of how to effectively manage both conditions.5

References:

  1. Hoy, D., Bain, C., Williams, G., March, L., Brooks, P., Blyth, F., … Buchbinder, R. (2012). A systematic review of the global prevalence of low back pain. Arthritis & Rheumatism, 64(6), 2028–2037. https://doi.org/10.1002/art.34347
  2. Kelly, G. A., Blake, C., Power, C. K., OʼKeeffe, D., & Fullen, B. M. (2011). The Association Between Chronic Low Back Pain and Sleep. The Clinical Journal of Pain, 27(2), 169–181. https://doi.org/10.1097/ajp.0b013e3181f3bdd5
  3. Alsaadi, S. M., McAuley, J. H., Hush, J. M., & Maher, C. G. (2010). Prevalence of sleep disturbance in patients with low back pain. European Spine Journal, 20(5), 737–743. https://doi.org/10.1007/s00586-010-1661-x
  4. Haack, Monika, & Mullington, J. M. (2005). Sustained sleep restriction reduces emotional and physical well-being. Pain, 119(1–3), 56–64. https://doi.org/10.1016/j.pain.2005.09.011
  5. Alsaadi, S. M., McAuley, J. H., Hush, J. M., Lo, S., Bartlett, D. J., Grunstein, R. R., & Maher, C. G. (2014a). The Bidirectional Relationship Between Pain Intensity and Sleep Disturbance/Quality in Patients With Low Back Pain. The Clinical Journal of Pain, 30(9), 755–765. https://doi.org/10.1097/ajp.0000000000000055
  6. Moldofsky, H. (2001). Sleep and pain. Sleep Medicine Reviews, 5(5), 385–396. https://doi.org/10.1053/smrv.2001.0179
  7. Haack, M., Scott-Sutherland, J., Santangelo, G., Simpson, N. S., Sethna, N., & Mullington, J. M. (2012). Pain sensitivity and modulation in primary insomnia. European Journal of Pain, 16(4), 522–533. https://doi.org/10.1016/j.ejpain.2011.07.007
  8. Kundermann, B., Spernal, J., Huber, M. T., Krieg, J.-C., & Lautenbacher, S. (2004). Sleep Deprivation Affects Thermal Pain Thresholds but Not Somatosensory Thresholds in Healthy Volunteers. Psychosomatic Medicine, 66(6), 932–937. https://doi.org/10.1097/01.psy.0000145912.24553.
  9. Smith, M. T., Edwards, R. R., McCann, U. D., & Haythornthwaite, J. A. (2007). The Effects of Sleep Deprivation on Pain Inhibition and Spontaneous Pain in Women. Sleep, 30(4), 494–505. https://doi.org/10.1093/sleep/30.4.494
  10. Roehrs, T., Hyde, M., Blaisdell, B., Greenwald, M., & Roth, T. (2006). Sleep Loss and REM Sleep Loss are Hyperalgesic. Sleep, 29(2), 145–151. https://doi.org/10.1093/sleep/29.2.145
  11. Tang, N. K. Y., Goodchild, C. E., Sanborn, A. N., Howard, J., & Salkovskis, P. M. (2012). Deciphering the temporal link between pain and sleep in a heterogeneous chronic pain patient sample: a multilevel daily process study. Sleep, 35(5), 675-87A. https://doi.org/10.5665/sleep.1830
  12. Lewandowski, A. S., Palermo, T. M., De la Motte, S., & Fu, R. (2010). Temporal daily associations between pain and sleep in adolescents with chronic pain versus healthy adolescents. Pain, 151(1), 220–225. https://doi.org/10.1016/j.pain.2010.07.016
  13. Skarpsno, E. S., Mork, P. J., Nilsen, T. I. L., & Nordstoga, A. L. (2019b). Influence of sleep problems and co-occurring musculoskeletal pain on long-term prognosis of chronic low back pain: the HUNT Study. Journal of Epidemiology and Community Health, 74(3), 283–289. https://doi.org/10.1136/jech-2019-212734