Chicken Or Egg? The Relationship Between Sleep And Pain In Our Patients
By: CARRA | December 8, 2016 | What Caught Our Eye
Teenagers are notorious for poor sleeping habits. (And probably pediatric rheumatologists aren’t much better, at least not the ones I know.) The average teenager gets about 7 hours of sleep each night, but needs about 9 hours or more.
I’ve had a personal interest in sleep, especially its relationship with pain, in my patients for years. I’ve followed a large number of chronic pain patients who report poor sleep; for many of these children, formal sleep studies have shown abnormalities (often in the deep stages of sleep).
I suspect that this relationship (that is, between poor sleep and more pain) also exists for the inflammatory diseases that we treat. In fact, Yoni Butbul published a study with us showing that children with rheumatic illness often sleep poorly, and that poor sleep is linked to increased pain.
Can we improve children’s suffering by improving sleep? That’s really the important question, I think. It’s really a chicken and egg thing. Is the poor sleep somehow causing pain (for example, by lowering the threshold at which stimulae are perceived as being noxious), or is it the result of pain?
It was with this in mind, that I read with interest this report by Drs. Meltzer and colleagues, from National Jewish Health in Denver.
The group did a very interesting randomized, crossover trial in a small number of teens with asthma. For the first week, the patients went to bed and woke at their usual hours. Sleep was monitored by a wrist device, and the teens did flow meter readings morning and night. After the first week, half were randomized to go to bed earlier (in order to get 10 hours of sleep) and half were randomized to get only 6.5 hours of sleep each night. After that week they went back to their chosen bedtime for a weekend of ‘washout’. The two groups then switched for the third week, so that those who had a long sleep were now to go to bed late and have a short sleep, and vice versa.
Strikingly, during the ‘healthy’ (i.e. long) sleep week, the teens had the perception that their asthma bothered them considerably less than during the sleep-deprived week. While this may have been due to some ‘threshold of noxious stimulus’ adjustment (as mentioned above), their asthma also improved! FEV and peak flow improved significantly with healthier sleep. And, the asthma improvement was concordant with the symptom improvement.
It would seem, if these results can be replicated, that the chicken and egg thing may be solved. (At least, may be solved for asthma.)
Why did this happen? It could be that changes in sleep induce changes in the immune system. For example, many studies have shown unfavorable changes in IL-1 beta, TNF-alpha, IL-6 and CRP due to experimental deprivation of sleep. (However, many of these studies are small; also, the experimental protocols and results have not all been consistent.)
Can this knowledge help us in the clinic? Importantly, in the Meltzer study only 10 of 55 identified patients were finally enrolled and analyzed. There were a number of reasons for ineligibility (for example, 15% of their asthma patients had a BMI > 98th% …!) and patients were only analyzed if they actually did change their sleep.
But, it does seem possible to convince teenagers to change their sleep habits. In one Dutch study, in which healthy teens were given 30 Euro gift certificates for participating (so, maybe, bribing is the answer), a combination of progressively earlier bedtimes and sleep hygiene instruction improved sleep and depressive mood significantly.
Chicken or egg? I suppose time, and more studies like the Meltzer paper, will answer this for us. For me? I am certainly going to try to get my teen patients to sleep better, and – hopefully – it will do them some good.
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