In May 2012, Dr Jason Ellis at Northumbria University was awarded £11,550* for his study, A case controlled study exploring the qualitative experience of sleep, the roles of sleep architecture and diurnal patterns of salivary cortisol in M.E./CFS.
The overall aim of this 18-month study was to explore the relationship between daytime fatigue and poor sleep in M.E./CFS. In the first stage, the team interviewed people with M.E./CFS to explore their experiences of sleep and identify any common patterns or disturbances.
The second stage involved monitoring sleep for three nights using wireless sleep equipment in patients’ own homes. Levels of the stress hormone salivary cortisol were assessed upon waking and at points throughout the day. This was the first study of its kind to explore in detail the role of sleep in M.E./CFS.
*This funding was part of a £61,000 investment in research, announced during M.E. Awareness Week. The charity’s initial October 2011 call for proposals had stated that, thanks to a generous gift from an anonymous private donor, a research fund of £50,000 would be available. However, following independent scientific review, Action for M.E. decided to fund three projects at a total cost of more than £61,000, drawing on funds provided by our Supporting Membership for research purposes.
Layman's summary of the sleep study research by Professor Jason Ellis
Sleep and fatigue are both connected – if a person can’t sleep, they feel fatigued, but fatigue can also disrupt normal sleeping patterns, which can lead to long-term sleep disorders. This is particularly true of people who have M.E./CFS.
As well as feeling overwhelming and persistent fatigue, 87 – 95% of people who have M.E./CFS also report experiencing sleep that is either unrefreshing or of poor quality. That said, where previous research has demonstrated physiological abnormalities in the sleep structure of this population (people with M.E./CFS), there is no consistent pattern underlying these abnormalities.
It is for that reason that the current project, funded by ActionforME, was undertaken to create a systematic evaluation of sleep and fatigue in people with ME.
Starting with a series of qualitative interviews, we aimed to examine how sleep is affected, and affects individuals, over the course of the disease. Moreover, we aimed to examine the impact of both poor sleep on fatigue and vice versa from the patient’s own point of view. Here we felt it was important to go back to those directly affected to gain their insight and experiences which may not necessarily be heard in the typical research process. The second part of the study was a more in-depth examination of sleep physiology and hormonal functioning. One of the main differences between this study and previous research was the decision to examine both sleep and the physiology of the autonomic nervous system together in one protocol and to examine sleep over three consecutive nights (sleep is usually studied over one or two nights but doing so for such a short amount of time may not reflect the sleep physiology accurately). This was undertaken with two central aims - to examine the feasibility of conducting an in-home three night sleep study and to determine the extent and types of sleep abnormalities that exist in this population.
Data from 11 interviews were used in the qualitative study (Qualitative research does not try to quantify anything or use statistical methods, but seeks to understand other people’s perspectives and motivations). 14 interviews were undertaken but the data from the 11 captured all the themes and experiences of all patients. All the patients saw sleep as one of the key drivers behind their experiences, from the onset of their illness right through their struggle to get a diagnosis and in living with their condition. That said, there were significant differences in the types of sleep problems that our patients reported. Three main themes underpinned why patients felt sleep was such an important phenomenon and were characterised as - sleep disturbances, attempts at coping / sleep management, and critically, the link between poor sleep and daytime functioning. In terms of the first, sleep disturbances, our patients reported that there was a degree of unpredictability that occurred and patients did not know whether they would have a disrupted night or not.
In terms of coping, sleep hygiene was already well known and utilised by our patients and as such suggests that this does not, as a stand-alone treatment, have the capacity to resolve sleep problems in this group. As such our patients tried alternative techniques, accepting their sleep would always be disturbed and attempting to adapt by adopting new sleep rituals and routines. The final theme really demonstrated how patients felt their sleep impacted on their quality of life, adding another weight by increasing their symptoms. Another key finding was that patients reported that their sleep appeared to change over the trajectory of their illness in terms of quality and quantity and as such we should be mindful of this in future research and in treatment plans.
The results from the three night sleep study with 22 patients showed that the process itself was acceptable to patients and well tolerated by them. Even so, we have to be mindful of the burden that a three night protocol puts on patients and provide additional considerations over the period of assessment as some patients felt that the protocol did increase their levels of fatigue following the first night assessment. This additive fatigue in patients tended to dissipate after the first night of recording and so this should be the focus on future sleep studies in patients with ME. Interestingly, 2 participants (9.01%) of those who took part in the study had to be excluded for meeting criteria for Obstructive Sleep Apnea and this poses a question about whether treating the Apnea in those two individuals would result in a significant reduction in their levels of fatigue.
The findings from the study demonstrated considerable variability between, and within, the sleep problems reported and demonstrated objectively by patients. Where some clearly demonstrate problems going to sleep, others have problems staying asleep and wake for long periods during the night. What this suggests is that the sleep problems in patients with M.E. are not all the same and there may be various groups with different sleep profiles that may be treated for their sleep in different ways. One finding which is of note is that there was considerable variability in the amount of stage two sleep different patients demonstrated. This tentatively suggests that there may be specific issues or cortical arousal (i.e. the brain being sensitive and responsive to noises and sensations during sleep) and we intend to follow this line of enquiry. Finally, as we showed that there were very few differences in sleep between nights two and three, we can conclude that two nights of recording are sufficient to capture the sleep physiology of patients with M.E.