Linking Insomnia and Sleep Apnea
As described in the posts about our six posters going into the conference we continue to encourage sleep specialists, both medical or psychological professionals, to place more emphasis on this extremely common co-morbidity. Our three posters on the use of ASV and ABPAP therapies for the treatment of OSA/UARS in insomnia patients were well received, although many viewers raised the immediate question, “why ASV if there are no central apneas?” This point touched off many useful conversations to explain our working theory that ABPAP and ASV therapies, irrespective of the presence of centrals, show greater capability in decreasing RERAs (the flow limitation events of UARS) without provoking expiratory pressure intolerance. Once this specific observation was thoroughly explained, the viewers understood the rationale and were more impressed with the studies and results.
The early results clearly show that both CPAP and ASV are highly effective in decreasing insomnia severity, but when looking closer at additional findings, we see the potential for ASV to yield greater improvements in subjective and objective sleep quality as well as facilitating greater hours of device use and further reductions in symptoms related to daytime impairment. Again, these results are only preliminary in the first 16 patients who completed the study.
The exciting news on this front was the increase in posters and presentations that at least touched on this topic. One of the most interesting studies that received considerable attention was highlighted with both a poster and a presentation. It looked at four groups of insomnia patients, all of whom were being treated with CPAP therapy while also receiving various other treatments such as CBT-I, a stimulant medication, and a placebo pill. Unfortunately, none of the groups were just on CPAP only. Nonetheless, it was an intriguing study attempting to look at improvements in both insomnia and sleepiness in patients receiving a mix of therapies. At the presentation, a member of the audience asked the speaker a question about the potential effect of the CPAP on the patients’ insomnia in particular, but because every participant in the research started all the therapies simultaneously, including CPAP, CBT-I, stimulants, etc., there was no way to know how much CPAP had affected the improvements. The researchers acknowledged this issue and the need to design studies that can more accurately address this question.
Numerous other researchers with whom I spoke at the posters sessions and presentations were routinely describing relationships between insomnia and OSA/UARS. Some of these studies were about prevalence to look at how the two disorders influence each other, and some studies were about treatment effects such as to what extent CBT-I can be used for insomnia patients with or without OSA/UARS and what types of differences or lack thereof should be anticipated.
Regrettably, there was no major speaker or keynote presentation on the topic, which has been a continuing and disappointing pattern at the annual sleep conference. Arguably, the single most common sleep disorder at any sleep medical center would be the combination of chronic insomnia and OSA/UARS, and thus we would expect more coverage on this theme. This point may not be readily obvious to all sleep specialists, but there is some basis to support this idea. At least 25% or more of patients seeking treatment at sleep centers report insomnia, yet a large majority also suffer from a contributing problem of OSA/UARS; another 50% to 75% of treatment-seeking patients at sleep centers report sleep breathing problems. Yet, among these patients, there’s at least a 50% chance they also suffer insomnia. Thus, 50% of all patients presenting to a sleep center may suffer both insomnia and OSA/UARS.
As usual, there was the discussion about adding sedatives to the mix of patients with “complex insomnia,” the term we use to describe the co-morbidity of insomnia and OSA/UARS. But, I did not see this point highlighted as in the past. Its most common use still seems to be as an adjunctive therapy for the insomniac who cannot get used to PAP therapy or who reports difficulty falling asleep with PAP. With increasing use of CBT-I, sedative use to improve PAP adherence may be less utilized.
Last, in discussing complex insomnia with a renowned insomnia expert, he proposed that a very important study would pit PAP against CBT-I. I agreed with him, because there are many patients who simply will not attempt PAP therapy and would find themselves gravitating towards CBT-I. Prior studies have already shown that CBT-I for insomnia in patients with OSA/UARS still works and may work very well, clearly indicating that certain aspects of insomnia are psychophysiological not purely physiological. On the other hand, many insomnia patients are literally thrilled to hear that they have been diagnosed with OSA/UARS, because it seems to relieve them of the burden that the whole problem is all in the mind. These individuals gravitate toward PAP or oral appliances or airway surgery, because they embrace the logic that sleep breathing events could trigger awakenings and thus insomnia. For my money, I would bet the largest improvements among chronic insomnia patients will be realized when both PAP and CBT-I are used together, but it may turn out that the sequencing of treatments must be tailored to individual personality. At our center, we generally look to use both concurrently; however, despite such recommendations, a large majority of these patients focus on PAP in the beginning stages of treatment and put aside the educational resources we have made available to them through our books on sleep and insomnia.
See previous: Trends from SLEEP 2016: Part I