Blood pressure increased during the pandemic, study finds

blood pressure monitor.
New research examines trends in blood pressure during the pandemic. Aleks_G/Getty Images
  • Governments enacted emergency measures in response to the COVID-19 pandemic.
  • These measures significantly altered people’s behavior.
  • In a new study, researchers wanted to see if there was a link between these changes in behavior and effects on people’s blood pressure.
  • The researchers found blood pressure increased during the pandemic compared with previous, non-pandemic years.

In a new study, researchers have found that blood pressure increased in adults in the United States during the pandemic compared with previous, non-pandemic years.

The research, published in the journal Circulation, makes clear that the health effects of the pandemic include not just the COVID-19 disease but also other, indirect health issues.

Blood pressure

According to the Centers for Disease Control and Prevention (CDC), blood pressure describes the pressure blood exerts against a person’s arterial walls.

Doctors measure blood pressure at two points: when a person’s heart is pumping, known as systolic blood pressure, and when a person’s heart is resting between beats, known as diastolic blood pressure.

If a person has high blood pressure, also known as hypertension, they are at a greater risk of stroke or heart disease. Hypertension can also damage a person’s liver, eyes, and brain.

The CDC state that 47% of U.S. adults have hypertension, and in 2019 hypertension was the primary or contributing cause of more than 500,000 deaths.

A person can help maintain healthy blood pressure levels by eating a diet low in salt and high in fruit and vegetables, exercising regularly, avoiding smoking, and limiting alcohol intake.

However, the COVID-19 pandemic significantly disrupted people’s behavior and access to regular medical care.

Researchers are interested to see if this disruption had an effect on people’s blood pressure levels.

Almost half a million participants

To look at blood pressure levels during the pandemic relative to previous years, a group of scientists studied data from an employee wellness program in the U.S covering 2018–2020.

This involved 464,585 participants, 53.5% of whom were women, with an average age of 45.7 years in 2018. The paper offered no information regarding the racial or ethnic makeup of the participants.

The scientists compared blood pressure levels before the pandemic in 2018, 2019, and until March of 2020, when most U.S. states gave stay-at-home orders. They then compared these levels with those recorded from April–December 2020 during the pandemic.

Blood pressure levels increased

The researchers found that before the pandemic, there was no significant change in blood pressure between years.

However, each month during the pandemic, blood pressure increased by an average of 1.1 to 2.5 millimeters of mercury (mmHg) for systolic blood pressure and 0.14 to 0.53 mmHg for diastolic blood pressure. This was the case for both women and men of different ages.

Women, on average, had greater increases for both systolic and diastolic blood pressure. Older participants had greater systolic blood pressure increases, whereas younger participants had greater diastolic blood pressure increases.

Cause?

Speaking to Micro B Life, Dr. Luke Laffin, co-director of the Center for Blood Pressure Disorders at the Cleveland Clinic in Ohio and the study’s lead author, said that “[d]ietary indiscretion, lack of exercise, central obesity, excessive alcohol consumption, and not taking prescribed blood pressure medications can all drive high blood pressure.”

“Other research demonstrates that lifestyle habits like excessive alcohol intake worsened during the pandemic, so it is not surprising that a blood pressure elevation followed.”

“We also know that patients hesitated to see their doctor, particularly in the early part of the pandemic, and that may have contributed to increased blood pressures,” said Dr. Laffin.

Prof. Matthew Bailey, who leads hypertension and renal research at the Centre for Cardiovascular Science at the University of Edinburgh, Scotland, and was not involved in the study, told MBL that the findings were significant and had global implications.

“This paper has examined almost half a million people and clearly shows that the societal changes [and] restrictions imposed in response to the pandemic have increased blood pressure. The effect is particularly large in women, and there is also an unanticipated increase in young people.”

“A rise in blood pressure of this size increases the risk of debilitating heart attack or stroke. For individuals and their families, cardiovascular disease can be devastating. [F]or governments, these conditions are costly to treat and manage. Health budgets are already overstretched.”

“This study is based in the U.S. but is relevant globally. It provides an early warning signal that poor cardiovascular health might be a big problem a few years down the line,” said Prof. Bailey.

Multiple factors at play

Dr. Tarek Antonios, a senior lecturer in physiological medicine at St George’s, University of London in the United Kingdom, and not involved in the study, told MBL the findings were not unexpected.

“I was not surprised when I saw this article. I am concerned about hypertension and the epidemic. If you put the two together — the COVID-19 epidemic and hypertension — there are certain different avenues [that connect] them.”

“The first one is the increased anxiety levels among the population. Lots of people lost their jobs, they became redundant, lost their businesses, and they lost income — all of this created a lot of stress and anxiety, and that can increase blood pressure. So this is one possible explanation.”

“The second is during the lockdown, there were no open gyms, no one was going out for running or sports, and many people — including some of my patients — put on a significant amount of weight. And once you put on weight, your blood pressure goes up as well.”

“The third point is that people are sitting at home most of the time, they order takeaways, and takeaways are full of salt, and therefore people have increased their salt intake. So there is a lot of stuff that may not be directly related to COVID-19, but [was] indirectly affected by this epidemic.”

“Some patients also found it very difficult to get in touch with their GPs and get a refill of their prescriptions. Some stopped taking their medications, and that also increased their blood pressure levels. [T]his is something we need to give information about to patients — that it is very important that they don’t stop the tablets.”

“Many of my patients have bought blood pressure machines so that they can monitor their own blood pressure and make sure that their blood pressure is well-controlled. This is my advice to most patients: get their own blood pressure machines and start measuring their blood pressure at home.”

Prof. Bailey said that he thought low-level stress and low quality sleep might be key factors in the increase in blood pressure.

“High blood pressure is caused by […] lifestyle [and] environmental factors that were difficult to avoid during pandemic restrictions. Many of us ate too much comfort food — high in salt, fat, and sugar — had limited capacity to exercise, and may have indulged in other […] habits such as drinking too much alcohol or smoking. Of these, the study was only able to discount weight gain itself.”

“I think a major factor is chronic low-level stress and poor sleep patterns. I think this will emerge as a big factor once more studies are done,” said Prof. Bailey.

Speaking to MBL, Dr. Helen Flaherty, head of health promotion and education at Heart Research UK and not involved in the study, also agreed that a range of factors may be at play when accounting for the increase in blood pressure.

“As a result of the pandemic, many people have seen a change to their usual lifestyle habits which, in many cases, can impact negatively on their blood pressure and cardiovascular health.”

“People working from home may be less physically active as they miss out on their usual walk to work or a trip to the gym. Physical activity may also be restricted where people are isolated at home due to the pandemic. In addition, changes to dietary habits, such as buying more takeaway foods, which may be higher in salt, can also contribute to raised blood pressure.”

“Many people have found the pandemic to be stressful and long-term stress is also associated with an increase in blood pressure, as well as behaviors that can increase blood pressure, such as smoking and alcohol consumption,” explained Dr. Flaherty.

Direct factors?

As well as possible indirect factors that might account for the rise in blood pressure, Dr. Antonios highlighted that there could be more direct causes.

“The disease itself may cause high blood pressure because of the interaction with certain molecules like the angiotensin-converting enzyme receptors. Moreover, many of my patients called to tell me that once they got the vaccines — especially the first dose — their blood pressure went very high, and they ended up in A&E and casualty with systolic blood pressure exceeding 200 in some of them.”

“What is also interesting is that for many of [my patients], the blood pressure did not settle down and remained high — not as high as 200, but higher than it was before. I am doing some research now to look at the effects of vaccination on blood pressure. And I have at least nine patients who had the same reaction: [their] blood pressure went up, and they ended up in casualty at St George’s [hospital].”

“Since then, there have been two publications — one from Lausanne in Switzerland and the second from Italy — that describe exactly this. Especially with the BioNTech vaccine, the blood pressure goes very high. What we don’t know is why this happens and why it does not settle down,” said Dr. Antonios.

Dr. Antonios also said there could be a connection between long COVID and hypertension. However, this required more research.

“What we don’t know so far is if hypertension is part of the long COVID syndrome. Most papers and reviews have not included hypertension [as part of long COVID]. They have included, for example, chest problems, myocarditis, thromboembolic phenomena, or even diabetes, but hypertension is not yet part of this long COVID syndrome, which we don’t know much about.”

Dr. Laffin said researchers should continue monitoring blood pressure levels:

“It is going to be very important to identify if blood pressure elevations persisted throughout 2021, given that vaccination became more widespread and individuals started returning to see their medical provider. I think it is unlikely that we’ll see a decline to pre-pandemic levels until the current pandemic ends.”

Crucially, there are limitations to the generalizability of the study’s findings. In the U.S., Black adults consistently exhibit significantly higher rates of hypertension, for example, compared with their white counterparts. However, the present study did not characterize blood pressure based on race or ethnicity. This is an important point that researchers should further evaluate during the pandemic.

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