They warn that sleeping little or poorly increases blood pressure and during sleep it is more risky

What is your diet like? Do you eat with a lot of salt? Do you do physical activity? Do you smoke? These are questions that are not usually missing in cardiology consultations. Less common, however, is to investigate sleep habits: How many hours do you sleep? rest well?

Often relegated to the background, there is increasing evidence of the role that sleep plays in cardiovascular health in general and one of its main risk factors: hypertension.

A review of studies to be presented this week at the American College of Cardiology’s Annual Scientific Sessions concluded that sleep less than 7 hours It is associated with a higher risk of developing high blood pressure over time.

“According to the most up-to-date data, the less you sleep, the the more likely you are to develop high blood pressure in the future,” said Kaveh Hosseini, assistant professor of cardiology at Tehran Heart Center Hospital in Iran and principal investigator of the study.

In a press release, Hosseini announced the results of the work Sleep duration and incidence of hypertension, systematic review and meta-analysis, which brings together data from 16 studies conducted between 2000 and 2023, involving more than one million people from six countries, who did not have high blood pressure at baseline and who were followed for a median of five years.

The researchers found that sleeping less than seven hours was associated with a 7% increase in risk of developing high blood pressure and 11% when sleep duration was less than five hours. By comparison, diabetes and smoking raise the risk by 20%, Hosseini said, stating that “sleeping 7 to 8 hours, as recommended by sleep experts, may be best for the heart.”

A higher risk was observed in women, but this is data that must be studied in greater depth, the researcher admitted and acknowledged that the work has several limitations. One of them is that sleep duration was based on self-reported questionnaires and that in the studies analyzed the definition of short sleep varied from 5 to 6 hours.

Beyond those limitations, “we found that a lack of good sleep patterns can increase the risk of high blood pressure, which we know can set the stage for heart disease and stroke“he stressed.

And he highlighted the importance of talking about sleep in the medical consultation, especially in case of suffering from disorders or alterations such as obstructive sleep apnea, which is related to higher rates of high blood pressure, cerebrovascular accident (CVA) and atherosclerosis.

Although the work did not investigate the causes of the relationship between lack of sleep and hypertension, Hosseini pointed out interruption of rest as a potential culprit.

“Under normal conditions, when we sleep, blood pressure drops, something that is often abolished when there are alterations at the level of sleep,” he agreed in dialogue with Clarion Diego Fernández, member of the Argentine Society of Arterial Hypertension (SAHA), who did not participate in the study.

“This was primarily investigated in sleep apnea, a disease that causes pauses in breathing that make air circulation difficult, which generates small awakenings, changes in the stages of sleep and prevents the person from resting, leading to sleep not being able to fulfill its restorative function,” said Fernández, who is a doctor at the Health Services. of Arterial Hypertension at the Julio Méndez Sanatorium and the Ramos Mejía Hospital.

Furthermore, an imbalance occurs in the systems that regulate it, which are the sympathetic and the parasympathetic, with the sympathetic system predominating more, which is the activity system, because we spend more time awake and less time asleep.

This whole process is not harmless. Whether the quantity or quality of sleep is modified, “will determine an increase in nocturnal blood pressure, with the inherent greater risk of developing sustained arterial hypertension and nocturnal arterial hypertension, which It is the riskiest of allbecause in general it is hidden and has to be studied with a pressure test or the so-called ABPM (ambulatory blood pressure monitoring)”, he warned.

Along the same lines, Marcos Marin, former president of the SAHA, stressed that “the lack of physiological nocturnal descent, what we call non dipper, or nocturnal hypertension has the greatest cardiovascular risk.”

When evaluating what happens during sleep, patients can be classified into different categories according to their circadian rhythm patterns: dipper, hyper dipper, non-dipper, and inverted pattern.

night pressure should decrease between 10% and 20% in relation to the diurnal averages. In that case, “the pressure lowers what it has to lower” and we speak of a dipper circadian pattern, explains Fernández.

But when you do not sleep well due to various factors (due to sleep disorders, snoring, apnea, stress, diabetes, kidney disease or other pathologies), blood pressure does not drop as it should. If it drops between 0% and 10%, it is considered a non-dipper pattern. “They are the ones that don’t go down enough”.

But those same situations that encourage the pressure not to drop as much as it needs to, can also cause the values ​​to rise above the daily averages. In those cases, it is called a reverse dipper pattern. “At night they have higher pressure than during the day, and They are the ones most at risk of generating cardiovascular events, such as stroke and heart attack,” the specialist warned.

Around 30% of hypertensive patients will present a non-dipper pattern of the circadian rhythm, states the latest Argentine Consensus on Arterial Hypertension. In some cases, the circadian rhythm is preserved, since it decreases at night, but in an exaggerated manner (> 20%), in which case it is called a hyper-dipper pattern, which is especially related to a higher risk of cerebrovascular events.

“Sleep is thought to help the body control hormones needed to control stress and metabolism. Over time, lack of sleep can lead to hormonal changes. Hormonal changes can generate high blood pressure and other risk factors for heart disease,” describes Francisco Lopez-Jimenez, consultant in the Division of Preventive Cardiology of the Department of Cardiovascular Medicine at the Mayo Clinic, in an article published by the institution.

“Over time,” he says. And it is something that all specialists highlight. Sleeping poorly or occasionally does not represent great risks. Problems arise when this behavior becomes chronic, since the effect is cumulative. Sleeping poorly always or most nights Yes, it is an alarm signal.

Because? The regulation of blood pressure includes among several of its components one in particular called baroreceptors, which function as “buffers” of blood pressure, says Diego Fernández.

When a modification of the sleep period occurs repeatedly, the sensitivity of these baroreceptors is altered, which begins a kind of vicious circle. These “shock absorbers” begin to generate reflections that lead to more adrenaline production“which inevitably leads to increased blood pressure.”

“This high blood pressure at night eventually generalizes and also becomes daytime hypertension, because the regulatory mechanisms are modified,” says the doctor, who will speak on blood pressure and sleep at the next Argentine Congress of Arterial Hypertension, which will take place in Córdoba from April 18 to 20.

—And how did you get up?

According to Fernández, this is a frequent dialogue inside and outside the office. The thing is, duration is not the only important aspect of sleep. The quality is too. And it is not easily measurable on a subjective level.

For an objective measurement, studies such as polygraphy, polysomnography or actigraphy are required, which evaluate muscle relaxation during sleep. “The patient says ‘I sleep 7 hours’“But what you see is that you have muscle tone again when you’re awake at 5,” he exemplifies.

That person slept, but did not rest enough. Sleep did not fulfill (or at least not in its entirety) the restorative function.

With his patients and students, Fernández uses a metaphor to explain the structure of the dream, assimilating it to a four-level underground parking lot. “In order to rest we need to have a percentage of the night in the basement 3 and 4“

—And if I have the rest of the risk factors controlled, but I sleep little or poorly, can I develop hypertension over time?

-Yeah. Sleep is a factor independent of traditional risk factors. Nowadays it is considered secondary, there is not much awareness among doctors to question it. When one researches or studies sleep disorders, 85% of them go unnoticed in the medical consultation because the professional does not ask and the patient interprets them as something normal and as if it were something specific to each person, they do not take it as a problem.

If the patient reports that he sleeps poorly, the doctor should think about how his blood pressure is at night and that – although it is not described in the guidelines, the doctor admits – “is a reason that can lead to the request for an ABPM.”

Pressurometry allows us to draw a “map” of a person’s pressure for an entire day, through a device that performs about 70 measurements (every 15/20 minutes during the day and every half hour at night).

If it is detected that blood pressure does not drop sufficiently during the night or rises more than the daytime average, “treatment adjustment must be made to ensure concentration of drugs in blood at night adequate to control blood pressure,” explains Fernández.

To this, measures must be added that promote the duration and quality of sleep.

Based on scientific evidence, specialists advise sleeping an average of 7 to 9 hours per day. That recommendation was the last to be included in the American Heart Association’s (AHA) Life’s Essential 8 guidelines for cardiovascular health.

Sleep stages (the “undergrounds”) are disrupted by several factors. The screens before bedthe obesity (people who are overweight snore more and have more apnea), diabeteshe excessive alcohol consumption (especially at night), abundant dinnersthe lack of physical activity, smokethe drugshe stressare some of those factors, indicated Fernández.

“That’s why, live as healthily as possible It is the best tool to be able to sleep well,” he concluded.

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