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Interview Javier Puertas MD, PhD – Head, Department of Clinical Neurophysiology and Sleep Unit, La Ribera University Hospital, Alzira

January 31, 2022
F Javier Puertas MD, PhD – Head, Department of Clinical Neurophysiology and Sleep Unit, La Ribera University Hospital, Alzira

“I believe in telemedicine and in new technologies to offer better treatment”
In an interview for Neurovirtual, the Spanish doctor, Javier Puertas, shares his points of views about sleep disorders, diagnosis, quality of life, the impact of weather on sleep and other perspectives.


NN: The sleep unit at La Ribera University Hospital is a reference in Spain for this field. How does it work and what are its main differences?

Dr. Puertas: The sleep unit at La Ribera Hospital opened in 1999 and, since the beginning, it has been structured to make the exchange possible between different fields of study, as this has already happened in other European countries or in the United States. This means that the sleep laboratory, patient’s beds, and polysomnography studies are located in a place where it is possible to have collaboration between other specialties, such as pulmonology, neurophysiology, and pediatrics. Thus, every one to two weeks, patients are examined by other colleagues. The unit was planned to enable sleep studies could be an integrated part of the diagnostic process and patient’s treatment, in a way that it is not just a test or a medical return, but coordination between various specialists. Another difference is that the unit was one of the largest in Spain when it opened, with four beds working every night of the week.

NN: Since 2007 there has been a subspecialty for sleep medicine in the United States. How do you see the professional development of sleep medicine in Europe?

Dr. Puertas: Since the late 1990s, there has been a recognition of sleep medicine as a subspecialty in Germany. Recently, France has also joined. The subspecialty can allow accessibility and collaboration with other segments, such as neurology, psychiatry, pulmonology, pediatrics, and otolaryngology. With France and Germany recognizing sleep medicine, I believe that it is a very important aspect to influence other European countries, such as Spain and Italy, for their health authorities to advance in their recognition as an area of knowledge. This means that, as a medical discipline, this could provide an integrated view of the patient’s sleep disorders beyond the partial view that some specialties may have. I believe there may be a rapid advance in the recognition of sleep medicine as a subspecialty in other countries, especially in the European Union.

NN: Returning to the sleep unit at La Ribera Hospital, you have conducted in-depth studies and clinical trials that contribute to the development of medications for sleep disorders such as insomnia, restless legs syndrome, and others. What are the recent results of those studies? Are you following the results of the drugs that are currently being tested?

Dr. Puertas: Fortunately, we have collaborated on several clinical trials for some sleep disorders, and we are seeing some slowing down in terms of drug development. There is a new group of molecules in some drugs that are being researched that have shown results for both insomnia and restless legs, as well as narcolepsy or idiopathic hypersomnia. Studies from a few years ago and other more recent ones reveal a very important group of molecules that can help patients with sleep disorders, mainly in the field of insomnia, for example, that act with mechanisms different from the gabaergic effect as hypocretin antagonists. With regard to restless legs syndrome, we found an important group of clinical trials that point to intravenous iron, for example, as helping patients who respond poorly to other medications. We also helped develop some epilepsy antagonists, and there are currently a number of trials with new drugs to improve the sleepiness of narcolepsy, such as histamine H3 inverse receptor antagonists, that may help patients with narcolepsy and complement other narcolepsy drugs.

NN: You were a board member of the World Association of Sleep Medicine, as well as other European ones – a great expert in the field of sleep. How do you see the evolution of studies and treatment for sleep disorders worldwide? Are there any studies that are more frequently or that address a specific specialty?

Dr. Puertas: Well, I believe that the perception of sleep disorders has changed in the last few years, no longer being considered as an outsider in hospitals, as it used to be, and especially the sense of seriousness that sleep disorders had among the general population and primary care physicians. Nowadays, in my consultations, I have received many patients with sleep disorders, referred by general doctors, sometimes with symptoms that started very recently, which gives me the impression that primary care physicians are asking more and more about sleep disorders for the general population. This change has a good part and a difficult part. The good part is that sleep is starting to be seen as an important health problem and this is essential because it is an important factor in the quality of life and overall health. It is also true that as some sleep disorders, such as insomnia, apnea, and restless leg syndrome are generally prevalent, we are starting to see a lot more pressure for concern on the public hospital sleep units. This means that the sleep units in hospitals need to facilitate campaigns or training actions so that general doctors could also start managing sleep disorders, as we cannot directly receive a large number of patients with some degree of sleep pathology. I believe that in the medium-term this will make health authorities realize that sleep is a real health concern that generates the demand for treatment. Although it’s difficult for sleep units to grow a lot in Europe, as they have in the United States – where there are sleep units with 20 beds or 20 rooms – it’s true that we have to look for ways to diagnose or facilitate outpatient diagnosis. I think that telemedicine can facilitate both, diagnosis and patient monitoring/ treatment, since we can’t have bigger and bigger sleep units in hospitals, we have to look for alternatives to network with general practitioners to diagnose and treat patients. We, doctors, who work with sleep medicine hope that telemedicine and information and communication technologies will make it easier for us to reach more patients to provide better treatments. In this sense, companies that are working on new diagnostic techniques will also have to get out of the hospital diagnostic realm a little bit and look for other parameters, diagnostics like algorithms, that help us see heart rate, body temperature, and other symptoms. And when we have technologies that allow us to analyze a lot of data, we will be able to integrate them with sleep studies, in order to have a better perception of what healthy sleep is for patients.

NN: As a percentage of the population, looking mainly at Spain, what is the percentage of people who continue to suffer from sleep disorders without ever being diagnosed because they have not been referred by general practitioners to a specialist?

Dr. Puertas: Our impression, and we think it’s no different from other countries, is that basically half of the general population has some sleep disorder, and half of them, in the last year, have required ongoing medical attention. In general terms, we are talking about 20% of the population. It is unlikely that we are giving access to the hospital to less than 5% of the population, considering patients with insomnia, sleep apnea, narcolepsy, and parasomnias, so we have something like 15-20% of the population that are waiting for help with their sleep problem.

NN: Is there any type of disorder more frequent in any specific Spain region?

Dr. Puertas: We did some researches with the Ministry of Health’s data. For example, we found that in the northern regions of Spain more hypnotics are consumed than in the south. We don’t know very well the reason, whether it is because there is less light or because it is colder, but the consumption of sleeping drugs is almost double than in the southern regions. They are also more developed regions, in socioeconomic terms, and there may be more stress or easier access to general medicine, but in general, the reality in Spain is not very different from other western countries. There is a widespread problem: stress. The cities and the crisis have generated more insomnia, in addition to the issue of obesity, which affects both, adults and children, increasing the potential for patients with sleep apnea associated with being overweight. This is often seen in developing countries: Mexico, in particular, has the highest percentage of childhood obesity in the world. One consequence is increased pediatric sleep apnea, changing the profile of hypertrophy and tonsils. The treatment and risk factor for each of these children is different. A small child, under 6 years old, with hypertrophy is operated on if there is an indication that they have apneas, but we realize that a 7-, 8-, 9- or 10-year-old obese child with many apneas sometimes needs a CPAP.

NN: It is known that more developed societies have a higher rate of people with sleep disorders. Do you think there is any explanation for this?

Dr. Puertas: I believe so. There are several factors that clearly influence more industrialized societies, such as a higher percentage of the population that works during night shifts. The more industrialized society is, more 24-hour or 24/7 service is required. More urbanized societies also use more time in transportation, and most jobs are sedentary rather than outdoors. Getting less sleep has a metabolic impact, favoring obesity while getting less exercise and spending too much time in the car and at work. We also expose ourselves less to natural light. When we leave the house, we go into the garage, get in the car, go to work, where there is usually a parking lot, and sometimes, without going out into the street, we go up to work without even seeing daylight. And for most of the day, we are exposed to artificial light. This series of habits is tremendously harmful, not only for health but also for sleep, if we compare it to what our bodies were programmed for: in the past, in an agricultural or hunting society, we were societies in which we had exposure to ambient light and physical activity associated with work. Industrialized societies are noisy; we live in buildings, there are streets and cars generating continuous ambient noise, and that’s when you don’t live near airports or next to highways. It has been proven through sleep electroencephalograms that during the first year that we live next to an airport, our bodies wake up slightly when an airplane arrives. In the second year, these awakenings fall down, but the cardiac reactivity persists, and we never fully adapt to noise or a potentially threatening environment, because it is a physiological thing. So, we have a number of elements in our environment that together are detrimental to health. If we stop to think about it, how much stress did our ancestors in the Paleolithic era suffer when a bear chased them? But if we add lack of exercise, lack of exposure to light, sedentary lifestyle, sleeping in a noisy environment, among others, we have a set of factors that not only impact our quality of life, but also the quality of sleep. We have to take these factors into account, insofar as we live in an urban environment, and try to improve as we can. That is, we should avoid when we get home after work, technology, tablet light, excessive technology, television, artificial lights. We should allow ourselves a period of disconnection from the stress of work when we go to sleep. With this, we improve family relationships, human communication in the family environment, generating a habit that breaks a little of the artificiality that we have in the cities. Everybody knows a little bit about how to do this. Sometimes those who work shifts can’t avoid disturbing their sleep, but we have to take this into account in order to acquire better habits, such as avoiding alcohol before going to bed or avoiding coming home from work exposed to dawn light. Sometimes coming home from night works with sunglasses on makes it easier to sleep at home in the morning with curtains and a mask. In other words, these cases need to be individualized, but in general, we take on lifestyle habits that are detrimental to our health.

NN: Recently, you gave an interview about the difficulties of sleeping when the weather is too hot. How does the weather influence the quality of sleep?

Dr. Puertas: We know that there is an important relationship between the regulation of body temperature and the quality of sleep, which means, that to sleep well, especially in the first half of the night, our body needs the internal body temperature to decrease. To do this, we need the peripheral skin temperature to increase, as it is the way our feet and hands act as antennae to exchange heat with the environment. Women especially know that you can’t sleep with cold feet and hands, inspired by their grandmothers who slept with hot water bags in bed when there was no heating or air conditioning. So, when we have a low-temperature difference between our body and the outside, we eliminate heat with difficulty, and with this, the depth of our sleep is less. Therefore, it is more difficult to sleep at night in hot and humid environments, because we are not able to regulate our body temperature and, consequently, sleep becomes more superficial. In winter, if we have cold hands and feet, we will not be able to sleep deeply. Also, with age, body temperature regulation becomes less effective, one of the factors that we believe is associated with worsening sleep quality as we age. On the other hand, we know that levels of melatonin, a hormone related to sleep quality, decrease with age. At night, the higher the melatonin peaks, the better the depth of sleep. And melatonin also helps produce peripheral dilation of the hands and feet, contributing to the elimination of heat. This is why sometimes taking melatonin helps us to rest, because of its effect and the fact that it helps us to regulate body temperature. For these reasons, there is an important relationship between the regulation of body temperature and room temperature: when it is close to Fahrenheit 86 and with a significant degree of room humidity, it is more difficult to eliminate heat and the tendency is to sleep poorly.

NN: In the long run, can extended heat, for example in a place like North Africa or even in Florida where it is always hot, help develop a specific sleep disorder?

Dr. Puertas: There are no studies that indicate that living in one climate or another affects sleep. It is true that in this life the contrast helps all the biological rhythms, developed from the rotation of the Earth and the light-dark cycles. So, the heat-cold contrast at night also helps to sleep well, but at the same time the human body has an incredible capacity to adapt, that is, we find ourselves from the Berbers of the Sahara, who cover themselves with a robe, to the Eskimos. We are in extreme temperature conditions, but we have no evidence that this has a long-term effect on the quality of sleep, and we believe that this is because the body is able to adapt to almost any situation on Earth.

NN: Is there any kind of contraindication when it’s very cold, which can cause some injury to sleep? You told us that there must be a difference in body temperature. When it is very cold, is there any prejudice?

Dr. Puertas: Cold produces peripheral vasoconstriction, that is, in order for us not to get too cold or lose heat, our skin arteries constrict and prevent blood from reaching the skin in a significant way, so that heat is not lost. There is no significant damage. What happens is that sleep will be of lower quality in extreme temperatures. The ideal temperature for sleeping is between Fahrenheit, 64 and 68, in an environment that is not too humid. It’s not always easy to achieve this and we recommend not sleeping all night with the air conditioner on, because this causes problems with dryness of the mucous membranes and some people wake up with pharynx irritation. Empirical evidence shows that ceiling fans, such as those that exist in tropical countries, which turn slowly during the night, make it easier to sleep than air conditioning all night because the moving air helps to balance body heat.

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