Is a Lack of Sleep Affecting your Back Pain?

Article by Simon Bell (osteopath)

Analyses estimate up to 90% of people have suffered with sleep deprivation at some point, and up to 30% meet the diagnostic criteria for insomnia. This means a large percentage of the population have issues maintaining regular sleep. A lack of adequate sleep has been strongly linked to depression, anxiety, stress and even weight gain due to increases in the hormone ghrelin, which makes you feel hungrier and crave foods high in saturated fat and sugar. So, not good news if you’re on a diet! But what about your back pain?

The Links Between Sleep and Pain:

Surprisingly enough, there is a plethora of evidence to suggest sleep and pain are interlinked. One way in which this is noted is increased pain levels reduce the quality of sleep (pretty obvious to anyone who has suffered with a bad back!) More interesting is fact chronicity of pain (how long you’ve suffered with it) also seems intertwined with the length of time and severity of sleep disturbance. Even after tissue damage has subsided, if a patient’s pain persist, the likelihood of having sleepless nights and even developing insomnia increases too.

PH Finan and colleagues have noted in several papers the association with long term pain and lack of sleep. Even estimating, up to 88% of chronic pain sufferers can present with problems with their sleep patterns. These findings are mirrored closely in several other papers, some of which note increases in injury or reinjury risk with insomnia and associated sleep disorders.

In 2014, Milewski et al. examined this further by trying to discover the reasons why student athletes were suffering injuries at such high rates. The researchers found athletes experiencing less than 8 hours of sleep per night had a 1.7 x greater risk of injury! This risk was worsened with the length of time students had been exposed to sleep deprivation and the grade they were in (i.e. it increased with time).

Interesting stuff. So, we know pain and a lack of sleep are related. Yet, as I first thought when I researched these correlations early in my career, surely that’s obvious? Pretty much every patient I see in practice who’s suffered with pain finds it difficult to sleep. Of course this is usually true but what’s fascinating is these sleep disturbances aren’t just a consequence of pain, they could even be a cause of it.

Chicken or the Egg?

Several studies have now emerged suggesting that, especially in cases of persistent pain, sleep disturbances are a better predictor of pain than vice versa, leading us to the intriguing question of which comes first? Or rather, which of these comorbidities is the likely cause of the other? Well believe it or not it’s a complex question to answer! Several mechanisms are thought to be at play here including central sensitisation, dopaminergic (DA) signalling and opioidergic signalling. With the mechanism of the former two suggesting that at least in theory, long term pain alters nerve signalling in the brain and spinal cord which can cause dysfunctional sleep patterns, especially given the importance of DA on arousal. The latter however implies that the opposite may be true, and that disturbed sleep has a dysfunctional effect on descending opioid signals… which are well known to be essential in controlling pain and the severity of it.