Sleep disturbance affects about a third of the American population, but is particularly common in patients diagnosed with IBS. As many as 74% of people with IBS characterise themselves as poor sleepers. People with IBS often report that their sleep has been disturbed and they do not feel rested when they get up in the morning. Recordings of the electrical activity of the brain in people with IBS show a lack of restorative deep sleep.
Sleep deprivation changes both mood and physiology. It is associated with irritability, overeating, infections, lack of concentration, difficulty remembering things, pain in various parts of the body and sensitive and erratic bowels. A recent study on women with IBS reported that sleep disturbance was associated with pain, anxiety and fatigue the next day. Health professionals who commonly experience disrupted sleep patterns; nurses on rotating shifts and junior doctors on call commonly report abdominal pains and other physical symptoms. Experimental sleep deprivation in patients with gastro-oesophageal reflux disease (GERD) showed an enhanced sensitivity to the infusion of acid into the oesophagus.
Sleep deprivation changes both mood and physiology. It is associated with irritability, overeating, infections, lack of concentration, difficulty remembering things and of course, sensitive and erratic bowels. IBS is often complicated by sleep disturbance. The association goes both ways. A traumatic event can both sensitise the gut and disrupt sleep. Disrupted sleep impairs memory and learning and causes frustration and irritability, which may trigger symptoms in a sensitive gut. In a previous post, ‘Perchance to dream: sleep and the nightmare of IBS’,I mentioned our observation that people with the erratic bowels of IBS also reported erratic moods and disrupted sleep patterns. So is sleep deprivation a cause of IBS, a consequence of IBS or a symptom of some global mind body state of dysphoria? A recent study from Washington University School of Medicine has attempted to answer that question.
The investigators used objective data from wrist actigraphs (movement detectors) together with and symptom and psychological questionnaires to assess the relationship between sleep disturbance and IBS and other symptoms in 50 people, being investigated in a specialist centre for IBS, and 26 age and sex matched healthy volunteers. Surprisingly, the results did not confirm that people with IBS slept any less than normal, but they did demonstrate evidence of sleep disruption; light sleep and frequent awakenings. They were not, however, being awakened by IBS symptoms. Neither was their sleep disturbance related to the severity of IBS symptoms the previous day, though it may have been the result of anxiety that day.
Nevertheless, the data suggested that sleep disturbance predicted increased severity and prevalence of abdominal pain the subsequent day, though there was no statistically significant effect on bloating or bowel disturbance. Sleep disruption also affected pain in other parts of the body and it induced feelings of anxiety and depression.
These and other results suggest that sleep deprivation can induce hyperalgesia, not only in the gut but in other parts of the body. This effect is associated with a diminished capacity for regulating emotional reactivity and an enhanced susceptibility to depression. Sleep disturbance is a major component of anxiety and depression; we have all experienced a dip in our mood if we have not had enough sleep.
The regions in our brain that modulate cognitive and emotional responses to pain, are also involved in processing mood. Previous studies have shown that sleep deprivation releases pro-inflammatory cytokines, releases cortisol, increases sympathetic nervous activity and reduces activity in the parasympathetic nervous system and makes us particularly responsive to irritating or painful stimuli. The latter is thought to be due to a sensitisation of spinal sensory neurones by a reduction in inhibition from centres in the brain stem, where mood and sensory function share same neurocircuitry.
So this latest study would seem to support the notion that disturbances in mood and sleep are essential components of IBS and other painful conditions, associated with an enhanced emotional, visceral and somatic sensitivity. What is cause and what effect remains controversial and may be an irrelevant question. Instead, this study could be seen to support the hypothesis that what we call IBS is one expression of a state of dysphoria or disturbance affecting both the mind and the body, any component of which can make people feel so much worse. So an upsetting situation or event, an increase in bodily symptoms and sleep disturbance can all ramp up the dysphoria and undermine our well being.
The challenge for patients and for the health professionals who are trying to help them is to break the vicious cycle. There are several means to that end. They include drugs and diets to reduce symptoms and antidepressants and various therapies to help manage the effects of life, but this study might suggest that other therapeutic measures to improve quality of sleep might also help.
Shakespeare recognized how sleep ‘knits up the ‘ravelled sleeve of care’ 400 years ago. Since then doctors have endeavoured to optimize sleep in order to promote health and wellbeing. Unfortunately many sedatives, antidepressants and tranquillisers disrupt sleep cycles, but recently clinical scientists have found that bright lights or hormones such as melatonin can reset a more natural sleep/wake cycle and one small pilot study has shown positive effects on IBS symptoms using melatonin.
There are, however, simple changes we can all make to try to ensure a good night’s sleep. These include eating earlier in the evening, reducing alcohol or caffeine consumption, not working on computers or watching television late at night, resting in the evening and going to bed at the same time every night and not too late. A balance or routines is important. Routines help to regulate our physiology, balance our activity, ensuring there is adequate time for work, for physical exercise, eating, socialisation, rest and sleep. They render life predictable, so we have more time to contemplate and reflect on what we are doing and why we are doing it. Routines are the basis of mindfulness and a good nights sleep.