Too little or too much sleep can be harmful, researchers find
Host Amber Smith: Upstate Medical University in Syracuse, New York, invites you to be The Informed Patient, with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith.
Research by an associate professor at Upstate found that insomnia is linked to a substantially higher risk of heart attack. Here to tell about his study is Dr. Hani Aiash. He's an assistant dean of interprofessional research at Upstate, and he holds appointments in neurology, surgery, medicine and cardiovascular perfusion.
Welcome to "The Informed Patient," Dr. Aiash.
Hani Aiash, MD, PhD: Welcome. How are you, Amber?
Host Amber Smith: Well, I don't want to alarm listeners, because I think many people struggle with sleep, but please tell us how you found this link. I know your work is listed as a "meta-analysis." What is that?
Hani Aiash, MD, PhD: Meta-analysis is the top of the pyramid of evidence-based medicine, so this is one of the most important studies doing it.
Meta-analysis is a statistical analysis that combines the results of multiple scientific studies, also can be performed when there is multiple scientific studies addressing the same question, with each individual study reporting measurements that are expected to have some degree of error, the general statistical power and more ability to extrapolate fully the greater population's evidence base more likely to observe an effect due to combining small studies into one large study, increase accuracy because small studies are pooled and analyzed also in this study. So meta-analysis, one of the top research methods to study any subjects.
Host Amber Smith: So you take and look at a bunch of studies together.
How many people do you think were part of this whole meta-analysis sample?
Hani Aiash, MD, PhD: Our sample was 1, 184, 256 patients, originated from six different countries, U.S., U.K., Norway, Germany, Taiwan and China. This is to increase the general viability of our finding.
Host Amber Smith: Now, did you start out with the idea that insomnia might be connected to heart attack, or myocardial infarction?
Hani Aiash, MD, PhD: Yes, myocardial infarction, is clots (clogs) in our coronary artery, which supply our hearts, which can cause damage and death of our heart muscles. This disease is considered to be the first cause of mortality all over the world. And it's a lot of studies about this disease.
What we are looking for: to prevent. Prevention is very important. There is a lot of causes of myocardial infarction -- modifiable, something we can change, and non-modifiable, something we cannot change.
So if we look at something we can change, it will be great to decrease the incidence and the mortality and morbidity of this horrible disease. The easy stuff we can do to prevent this serious disease is our natural habits or quality of life.
One of them is sleep. Sleep will not cost anything.
Just simple stuff. We can protect at a very low cost with great benefits on prevention.
My background: I practiced medicine as a cardiologist, many countries before I came here, so, always I'm looking for something to decrease this mortality. I saw a lot of people dying from this disease.
So when we said, sleep is medicine, diet is medicine, or food is medicine, this is what we are looking for. So our rationale: to discover very easy stuff and can protect our health, our heart, from very serious disease.
Host Amber Smith: So you thought sleep would have an impact on a person's risk, but how much of an increased risk did you think you might find in people who have insomnia?
Hani Aiash, MD, PhD: We have now evidence. We have a good sample size, 1,180,000 patients. This is very big sample size.
We calculate about the cardiac risk for every patient, as I told you, modifiable -- like, diabetes, hypertension, dyslipidemia (imbalance of cholesterol or other lipids), all of this stuff, obviously stress, all of this stuff can induce myocardial infarction.
And also there is non-modifiable, like age. You cannot control your age, you cannot control your family history, you cannot control your race.
But let's go to the calculation. So, insomnia, before we did this research, we don't know exactly how much it can decrease the incidence of myocardial infarction.
But we have these results now as evidence that we have something to say about sleep. Our results denote a lot of stuff, like, we have 69 percentage decrease in incidence of myocardial infarction if we sleep well. And this is big number, so around 70 percentage decrease in myocardial infarction, if you control insomnia.
Host Amber Smith: So you can improve your risk -- that's a huge amount, 70% -- if you're able to get good-quality sleep.
Hani Aiash, MD, PhD: Yes. So, as we said, why sleep? Because as you know, sleep deprivation puts the body under stress.
Triggering the release of ACTH (adrenocorticotropic hormone, involved in stress response) and cortisol (another hormone involved with stress) and this elevation of cortisone and catecholamines, adrenaline and noradrenaline, usually when we sleep, all of these hormones will come down. But during insomnia, the elevated cortisol could accelerate atherosclerosis, leading coronary artery disease.
And subsequent MI (myocardial infarctions). There's a lot of recent studies showing that in one month preceding acute MI, there was a higher concentration of cortisol in the hair compared to the healthy controls. If sleep deprivation leads to higher cortisol, then sufficient sleep will elevate the body from this maladaptive response.
Like a car, you are driving your car 24/7, and you are driving your car 12 hours or 18 hours and there is rest eight hours, what's the difference? The engine will be having trouble.
Also, as I told you, this is very important total, 69 percentage decrease in MI. It's a big number.
Host Amber Smith: Well, let me ask you, if you're saying that people who have poor quality sleep have an increased risk of heart attack, how can you be sure that it's the insomnia that's causing this increased risk as opposed to cotton in the bedsheets or whether or not a person is taking a vitamin at bedtime?
I mean, how do you control for the other things that might interrupt someone's sleep, that may be the cause of the increased risk for heart attack?
Hani Aiash, MD, PhD: We have this systematic review. We compare two groups. One group's insomnia, which is 153,000 people, and the other was non-insomnia.
The other risk factors, or the contributing risk factors, to this from our study, even sleep apnea, we exclude those people, to say that insomnia only is a cause. And after exclusion of other factors and statistical analysis of these factors, we found that insomnia is the reason, and we have statistically significant results that insomnia can do it.
Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith.
I'm talking with Dr. Hani Aiash. He led some interesting research recently that showed a connection between insomnia and an increased risk of heart attack.
Now, your paper was published in the journal Clinical Cardiology, and I know you presented it at an American College of Cardiology conference recently.
What has been the feedback from your peers about this work?
Hani Aiash, MD, PhD: Really, we have a great, unexpected feedback on this paper in Clinical Cardiology and the World Congress of Cardiology conference. They choose our paper to be one of the first five papers to be orally presented from about 4,000 to 8,000 papers applied to this conference.
Host Amber Smith: So there is a lot of interest.
Hani Aiash, MD, PhD: Yes. And there is a lot of debates between American College of Cardiology conference and Clinical Cardiology because Clinical Cardiology was going to publish the paper early. They told them, no, please wait until we do oral presentation for this paper.
After this paper and presentation and the publication, CNN contacted us, and they did interviews with me, and CBS also, a lot of people doing this for us. And it's cited also in many places, but really we didn't expect all of this great impact for this.
And also, this is very important, that we need to continue our work. After all of this peer review, I am planning to do something like, I hope that we can do it, like sleep campaign, that we want to announce and we want to make sure that all the patients, all over the world, know the importance of sleep.
So, if I can, I will construct a team between interdisciplinary sleep medicine, respiratory guys and cardiologists, family, doctors, psychiatrists, psychologists. It will be great to have this campaign together, work together, to improve. If we have this results for the importance of sleep, we will not stop at this point.
Host Amber Smith: Well, let me ask you a little bit more about sleep. What do you mean by the word "insomnia"? Because I wonder if people with chronic trouble falling asleep are at the same risk as someone who only occasionally tosses and turns.
Hani Aiash, MD, PhD: Insomnia, by its definition, we take the two definitions, of DSM (Diagnostic and Statistical Manual of Mental Disorders) and also about the hours of sleep and also difficulty in initiating sleep. So difficulty to go to sleep and difficulty on maintaining sleep. And if you wake up early, you cannot sleep again. This is the definition of ICD (International Classification of Diseases), but also we added the definition of DSM about the hours of sleep. So we discovered that below five hours of sleep, we have a statistically significant association between difficulty initiating and maintaining sleep, what we call DIMS, and increased incidence of myocardial infarction, by about 1.13 times greater risk for MI compared to control group.
And also we have the amount of sleep. If the patient who slept five hours or less had the highest association with MI incidence compared to who slept seven to eight hours, it reached about 56% increased risk.
And the longer duration, this is something also, some people think that they will sleep longer, they will protect their heart. No, if you sleep longer than eight hours, you have the same risk of less than five hours. And also if you compare six hours to nine hours, if you sleep six hours to nine hours, your total increases your risk about 70%.
But the ideal sleep hours will be seven to eight hours, which protects your heart more than 56% compared to less than five hours. And also it will decrease the MI if we compare with all our hours. Increased sleep and decreased sleep is harmful.
Host Amber Smith: So, let me back up just a little.
You mentioned DSM and ICD. Those are what the insurance industry uses to code insomnia. So you went to the technical definition of insomnia, but then you went one step further, and you also looked at the amount of sleep, the number of hours. But too little is bad, and too much is bad.
So there's that sweet spot between five and eight hours a night, basically, right?
Hani Aiash, MD, PhD: Seven to eight hours is the best, and below five is very harmful. Below six is a little above nine.
Host Amber Smith: So does a person's underlying health condition also affect how much their risk rises if they have insomnia?
Hani Aiash, MD, PhD: Yes, we have something very interesting: age. Our mean age in this study was 52 years old. We discovered that if you increase age, about 65, you double the risk. If you have diabetes, you have about 100% more. Diabetes and insomnia; this is horrible.
If you have hypertension, same, about 70%. Dyslipidemia, same.
Usually we said a woman is protected. No, insomnia has no protection for women. If the woman has insomnia, there is 125% more to have MI than others compared. This is big number.
Host Amber Smith: So this is a lot more of a concern for women than men, even.
Hani Aiash, MD, PhD: Yes. And as I told you, most of the people who had underlying diseases, or comorbidities, as we said, like hypertension, diabetes, had higher risk of MI.
Host Amber Smith: What about, I mean, a young athletic person who appears to be in good health may have insomnia, compared with someone who's overweight and has comorbidities, or other health issues, who also has insomnia? Is their risk the same?
Hani Aiash, MD, PhD: No, of course, as we said, there is calculation of coronary heart disease or MI, as I told you, modifiable and unmodifiable. If you have more risk for this stuff, it'll add value to your incidence of MI, or myocardial infarction -- if you are obese, if you are diabetic (not controlled).
But the issue here, that we discover something beside diabetes and hypertension to be controlled, and we have evidence, we have strong evidence on 1,180,000 patients. So we must respect that: The patient must know that if you are not sleeping well, he's exposed himself to MI, like the same as if he's diabetic and (has) hypertension.
And the doctor, when he interviews the patients or examines the patient, he must ask about insomnia. It's not easy now to ignore this subject because you have evidence that insomnia can cause mycardial infarction, same like diabetes, same like hypertension.
And it will not cost you anything. It's very easy to be treated.
Host Amber Smith: Now, a lot of times, as people age, their sleep quality deteriorates. They wake up a lot, or they don't sleep very restfully. Is that insomnia, or is that different, in terms of your study?
Hani Aiash, MD, PhD: We define insomnia according to the difficulty in achieving sleep, difficulty in maintaining sleep, and if the patient wakes up, he cannot return back to normal sleep or the hours of sleep.
So if he has any of this criteria, yes, he has insomnia.
Host Amber Smith: And so I know your hope is that primary care doctors would start asking their patients about insomnia because that's a risk factor that's modifiable. What can be done to help someone who has trouble falling asleep or staying asleep?
Hani Aiash, MD, PhD: There is a lot of stuff and also, many societies talk about sleep.
So, avoiding uncomfortable temperature: If you sleep in cold weather or hot weather, you'll wake up a lot. Proper sleep hygiene is crucial. And light. Light. As you know, if you have light, it will not help to sleep well. (Avoid) noises. Limitation of the (electronic) screen an hour prior to bed.
Use your bed for sleep, this is the most important. Not using other technology. Avoid heavy meals near bedtimes. Avoid caffeine before bedtimes. And also some studies show that cognitive behavior therapy, CPT, is effective in treating insomnia.
And by the way, it's very important: Sometimes insomnia is the iceberg. We must know what's the cause of this insomnia. It's not to treat the symptoms; we want to treat the disease, so we must investigate also what's the cause of this insomnia. There is a lot of diseases can cause insomnias. So the most important stuff for the primary care doctor or PCP (primary care provider), that he must understand what's going on, not the iceberg. We must go in depth to know, to treat, the cause.
Host Amber Smith: And of course, if someone does treat their insomnia effectively, is there evidence that their risk for heart attack drops?
Hani Aiash, MD, PhD: We need more studies for this.
We need more studies. We diagnosed the problem. Here is a cause. But if we treat these people very well, and they are sleeping well, how much percentage of MI will be decreased? This is a good next study, and I hope that we can do it, but it needs a cohort study or prospective study.
This is very important to address, but we have now evidence that yes, if we treat them, we will decrease the instance about 69 percentage. If they sleep seven to eight hours, they will decrease. If they combine the risk factors diabetic and insomnia, and we control diabetes and we control the insomnia, we'll decrease the incidence of MI. This is great.
Host Amber Smith: So what's the message you'd like listeners to come away with regarding your research? What can people do today based on what you've discovered?
Hani Aiash, MD, PhD: My message here is to use our "natural stuff," what we have, to control what we can.
Sleep is medicine.
Food is medicine.
Anti-stress is medicine.
The quality of life is very important to avoid all of this stuff.
If you have sleep disorders, please try to do the natural stuff to control it. If you cannot, go to the doctor, discuss with him, also let him deal with this stuff. If you cannot do this, the doctor must know that maybe he will give you some pills to make you sleep, but don't leave yourself not sleeping well and have a lot of other comorbidities, or many risk factors, and you can be exposed to myocardial infarction.
No. 2, let's return to our health. Our health is bio-psycho-social. If you are (have) well-being, bio-psycho-social well-being, it will be great. Not biologically, not our organs; we are not a group of some organs. We have psychological status, we have social status. All of this status must be well to live well,
Host Amber Smith: Dr. Aiash, thank you so much for making time to tell us about your research.
Hani Aiash, MD, PhD: Thank you very much, Amber. It's my pleasure.
Host Amber Smith: My guest has been Dr. Hani Aiash. He's a researcher at Upstate who also serves as assistant dean of interprofessional research.
"The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.
Find our archive of previous episodes at upstate.edu/informed.
This is your host, Amber Smith, thanking you for listening.