Tag Archives: #bloodpressure

Systolic Blood Pressure Above 120 mmHg Increases Rate of Cardiovascular Disease (Medicine)

Provides insight on what blood pressure targets in patients with hypertension according to glucose status should be.

An estimated 1.13 billion people worldwide have hypertension or high blood pressure, and two-thirds of these individuals are living in low- and middle-income countries. Blood pressure is the force manifested by circulating blood against the walls of the body’s arteries, the major blood vessels in the body. Hypertension is when blood pressure is too high.

Blood pressure is written as two numbers. The first (systolic) number represents the pressure in blood vessels when the heart contracts or beats. The second (diastolic) number represents the pressure in the vessels when the heart rests between beats. Hypertension is diagnosed if, when it is measured on two different days, the systolic blood pressure (SBP) readings on both days is ≥140 mmHg and/or the diastolic blood pressure (DBP) readings on both days is ≥90 mmHg.

Worldwide, high blood pressure is a common and strong risk factor for the development of cardiovascular disease. As reported by previous studies in Asia and elsewhere, as the level of SBP rises, the risk of developing cardiovascular disease increases, too. Similarly, the likelihood of dying from a cardiovascular event increases as the SBP rises. However, whether these observations hold for increases in DBP is not known. Moreover, although a high blood glucose status is itself associated with a high likelihood for the development of cardiovascular disease, it is not known whether the blood glucose status plays any role in the relationship between high blood pressure and cardiovascular events.

This theory led the authors to propose a hypothesis for their study. Commenting further, Dr. Kazuya Fujihara of the Department of Internal Medicine, Faculty of Medicine, Niigata University, said “The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) BP guideline defined blood pressure >130/80 mm Hg as hypertension. This guideline showed that the normal level is less than 120/80 mm Hg and SBP 120-129 mm Hg and DBP<80 mm Hg is elevated BP. However, little is known regarding whether elevated BP versus normal BP is specifically associated with a higher risk for coronary artery disease / cerebrovascular disease according to glucose tolerance status in real-world settings. This is the first study investigating the impact of SBP/DBP levels on coronary artery disease / cerebrovascular disease in the same population according to glucose tolerance status in real-world settings”. Therefore, these concerns lead Dr. Mayuko Harada Yamada and colleagues to investigate the relationships between elevated blood pressure, glucose status and cardiovascular disease (like new-onset coronary artery disease and cerebrovascular disease). “Therefore, our cohort study aimed to determine the associations of SBP and DBP with the incidence of coronary artery disease and cerebrovascular disease according to glucose status” says Prof. Hirohito Sone, the senior author.

In the Diabetes Care paper, the authors addressed these research questions using a nationwide claims-based database that included information on 805,992 people enrolled with a health insurance provider for company employees and their dependents in Japan. In one arm of the study, they compared the cumulative incidence of coronary artery disease according to their SBP in individuals with normal, borderline and elevated blood glucose, separately (Figure). The authors reported that, “a linear relationship was observed between cumulative incidence rates of coronary artery disease and SBP categories across all glucose tolerance status designations using SBP below 119 mmHg as the reference”. In another arm of the study, the investigators compared the cumulative incidence of cerebrovascular disease according to their SBP in individuals with normal, borderline and elevated blood glucose, separately (Figure). Similarly, the authors observed a linear dose-response relationship between cumulative incidence rates of cerebrovascular disease and SBP categories across all glucose tolerance status. Furthermore, the investigators repeated similar analyses using the DBP and reported that “Similar to the relationship between SBP and coronary artery disease and cerebrovascular disease; the coronary artery disease and cerebrovascular disease risk concurrently increased with higher DBP categories”.

Figure: Rates of CAD and CVD: Kaplan-Meier analysis of unadjusted overall time to incidence of coronary artery disease and cerebrovascular disease according to combinations of glucose status and categories of SBP. © Niigata University

The study also found that combined together, the blood glucose status and blood pressure values had a synergistic effect on the incidence of coronary artery disease and cerebrovascular disease. Commenting on the significance of their findings, Prof. Sone said, “Compared to Westerners, Asians have significantly less coronary artery disease, but more stroke. In addition, Asians have a much lower obesity level than Westerners, and the pathogenesis of diabetes mellitus is also very different between the two. Therefore, this data should be an important reference for determining blood pressure thresholds for guidelines for Asians”. Commenting further, Dr. Fujihara said “Recent study [the Systolic Blood Pressure Intervention Trial (SPRINT) Final Report] showed that intensive treatment (SBP, <120 mm Hg) significantly reduced the rates of the primary composite outcome and all-cause mortality compared with standard treatment (SBP, <140 mm Hg). Our findings suggested even if blood pressure levels are slightly higher than normal level, it is essential to engage in lifestyle improvement, including salt reduction, from an early stage”.

While the findings of these analytical study are impressive and provide new insight on what blood pressure targets in patients with hypertension according to glucose status should be, the authors recommended that “Further trials to examine strict BP interventions for preventing cardiovascular diseases should focus on patients with borderline glycemia and diabetes to confirm findings from the current cohort study and apply them to clinical practice”.

Publication Details

Journal: Diabetes Care
Title: Associations of systolic blood pressure and diastolic blood pressure with the incidence of coronary artery disease or cerebrovascular disease according to glucose status
Authors: Mayuko Harada Yamada, Kazuya Fujihara, Satoru Kodama, Takaaki Sato, Taeko Osawa, Yuta Yaguchi, Masahiko Yamamoto, Masaru Kitazawa, Yasuhiro Matsubayashi, Takaho Yamada, Hiroyasu Seida, Wataru Ogawa, Hirohito Sone
DOI: 10.2337/dc20-2252

Provided by Niigata University

Unexpected Discovery Opens A New Way To Regulate Blood Pressure (Medicine)

International research team uncovers underappreciated metal’s role in lowering blood pressure

High blood pressure, or hypertension, is the leading modifiable risk factor for cardiovascular diseases and premature death worldwide. And key to treating patients with conditions ranging from chest pain to stroke is understanding the intricacies of how the cells around arteries and other blood vessels work to control blood pressure. While the importance of metals like potassium and calcium in this process are known, a new discovery about a critical and underappreciated role of another metal – zinc – offers a potential new pathway for therapies to treat hypertension.

The study results were published recently in Nature Communications.

All the body’s functions depend on arteries channeling oxygen-rich blood – energy – to where it’s needed, and smooth muscle cells within these vessels direct how fast or slow the blood gets to each destination. As smooth muscles contract, they narrow the artery and increase the blood pressure, and as the muscle relaxes, the artery expands and blood pressure falls. If the blood pressure is too low the blood flow will not be enough to sustain a person’s body with oxygen and nutrients. If the blood pressure is too high, the blood vessels risk being damaged or even ruptured.

“Fundamental discoveries going back more than 60 years have established that the levels of the calcium and potassium in the muscle surrounding blood vessels control how they expand and contract,” say lead author Ashenafi Betrie, Ph.D., and senior authors Scott Ayton, Ph.D., and Christine Wright, Ph.D., of the Florey Institute of Neuroscience and Mental Health and The University of Melbourne in Australia.

Specifically, the researchers explain, potassium regulates calcium in the muscle, and calcium is known to be responsible for causing the narrowing of the arteries and veins that elevate blood pressure and restrict blood flow. Other cells that surround the blood vessel, including endothelial cells and sensory nerves, also regulate the calcium and potassium within the muscle of the artery, and are themselves regulated by the levels of these metals contained within them.

“Our discovery that zinc is also important was serendipitous because we’d been researching the brain, not blood pressure,” says Betrie. “We were investigating the impact of zinc-based drugs on brain function in Alzheimer’s disease when we noticed a pronounced and unexpected decrease in blood pressure in mouse models treated with the drugs.”

In collaboration with researchers at the University of Vermont’s Larner College of Medicine in the United States and TEDA International Cardiovascular Hospital in China, the investigators learned that coordinated action by zinc within sensory nerves, endothelial cells and the muscle of arteries triggers lower calcium levels in the muscle of the blood vessel. This makes the vessel relax, decreasing blood pressure and increasing blood flow. The scientists found that blood vessels in the brain and the heart were more sensitive to zinc than blood vessels in other areas of the body – an observation that warrants further research.

“Essentially, zinc has the opposite effect to calcium on blood flow and pressure,” says Ayton. “Zinc is an important metal ion in biology and, given that calcium and potassium are famous for controlling blood flow and pressure, it’s surprising that the role of zinc hasn’t previously been appreciated.”

Another surprising fact is that genes that control zinc levels within cells are known to be associated with cardiovascular diseases including hypertension, and hypertension is also a known side effect of zinc deficiency. This new research provides explanations for these previously known associations.

“While there are a range of existing drugs that are available to lower blood pressure, many people develop resistance to them,” says Wright, who added that a number of cardiovascular diseases, including pulmonary hypertension, are poorly treated by currently available therapies. “New zinc-based blood pressure drugs would be a huge outcome for an accidental discovery, reminding us that in research, it isn’t just about looking for something specific, but also about just looking.”

Featured image: This image shows an isolated cerebral arteriole from a mouse model, marked by a live-cell dye. © Osama Harraz, Ph.D., University of Vermont Larner College of Medicine

Reference: Betrie, A.H., Brock, J.A., Harraz, O.F. et al. Zinc drives vasorelaxation by acting in sensory nerves, endothelium and smooth muscle. Nat Commun 12, 3296 (2021). https://doi.org/10.1038/s41467-021-23198-6

Provided by Larner College of Medicine University of Vermont

This press release has been adapted from an article featured by Pursuit and written by Ashenafi Betrie and Scott Ayton from the Florey Institute of Neuroscience and Mental Health, and Christine Wright of The University of Melbourne.

Procedure Using Ultrasound Energy Found To Treat High Blood Pressure (Medicine)

A minimally invasive procedure that targets the nerves near the kidney has been found to significantly reduce blood pressure in hypertension patients

A minimally-invasive procedure that targets the nerves near the kidney has been found to significantly reduce blood pressure in hypertension patients, according to the results of a global multicentre clinical trial led in the UK by researchers at Queen Mary University of London and Barts Health NHS Trust.

The study, published in The Lancet and presented at the American College of Cardiology meeting, suggests that the procedure could offer hope to patients with high blood pressure who do not respond to recommended treatments (resistant hypertension), and are at greatly increased risk of cardiovascular diseases, including stroke and heart attack.

The international clinical trial tested a one-hour procedure called ‘renal denervation’, which uses ultrasound energy to disrupt the nerves between the kidneys and the brain that carry signals for controlling blood pressure.

The study investigated 136 patients who were randomised to receive either renal denervation or a ‘sham procedure’ – the surgical equivalent of a placebo. The UK trial site at St Bartholomew’s Hospital was the largest patient recruiter in the world, with patients also taking part in the United States, France, Germany, the Netherlands and Belgium

The trial showed that renal denervation led to a significant and safe blood pressure lowering effect after two months in patients who were on at least three different blood pressure lowering medications. It was found to reduce blood pressure by 8.0 mmHg, which was a 4.5 mmHg greater drop when compared with patients who had the sham procedure.

Additionally, there were no safety concerns in either the renal denervation or sham groups.

UK Principal Investigator Professor Melvin Lobo from Queen Mary University of London and Barts Health NHS Trust said: “This is probably one of the most important studies in the field of hypertension emerging in the pandemic era. It is conceivable that renal denervation could become a treatment option for patients with hypertension in the very near future and the National Institute for Health and Care Excellence (NICE) will be re-evaluating the technology based upon the recent datasets in the coming months.”

Dr Manish Saxena from Queen Mary University of London and Barts Health NHS Trust said, who ran the study at St Bartholomew’s Hospital, added: “Resistant hypertension patients often suffer from organ damage, including damage to the heart, eyes and kidneys, have poor quality of life and are at a higher risk of cardiovascular events and death.

“Many high risk patients have to manage multiple prescription medications, which can be difficult to adhere to and poses a significant challenge to our health care system and resources.

“Finding other ways to reduce blood pressure in these difficult-to-treat patients, such as renal denervation, will lower their cardiovascular risk, reduce their medication load, improve their quality of life and ultimately lead to cost savings for the NHS.”

49 year old Raenard Gonzalez from Surrey received the procedure as part of the trial. He said: “I’ve been on blood pressure tablets for around 19 years, and for the last nine years, I’ve had to take five different tablets every day. It’s been so difficult to manage, and the dosage was constantly increased by my consultant. I felt lethargic and it was hard to maintain a healthy weight, as I just had to keep eating to combat the tiredness and keep myself awake. I knew something wasn’t right, but there didn’t seem to be any other options for me.

“I heard about the trial and felt I had nothing to lose really. It was all quite straightforward, the procedure wasn’t that invasive and just involved puncturing the skin, and I was able to go home that day, and didn’t feel much pain.

“Since the procedure, I’ve managed to control my weight, and have so much more energy and motivation. My blood pressure used to stay high after any physical activity, but now, it doesn’t matter how much I exert myself, my blood pressure always goes back down, which is great.

“All the medications that I took before the trial have been scrapped and I’m now just taking one triple combination pill. I’m really happy that this treatment may soon be available to other people.”

The study was funded by ReCor Medical, Inc. which manufactures the Paradise®™ Renal Denervation System used in the study and had no role in data interpretation or writing of the report, other than providing assistance in formatting and copy editing.

Research paper: ‘Ultrasound renal denervation for hypertension resistant to a triple medication pill (RADIANCE-HTN TRIO): a randomised, multicentre, single-blind, sham-controlled trial’. The Lancet. DOI: https://doi.org/10.1016/S0140-6736(21)00788-1

Provided by Queen mary University of London

Diabetes Remission Diet Lowers Blood Pressure And Reduces Need For Medication (Medicine)

New research has shown that if people achieve and maintain substantial weight loss to manage their type 2 diabetes, many can also effectively control their high blood pressure and stop or cut down on their anti-hypertensive medication.

A weight management programme, developed by researchers at the Universities of Glasgow and Newcastle for the Diabetes UK-funded DIabetes REmission Clinical Trial (DIRECT), has proved effective at lowering blood pressure and reducing the need for anti-hypertensive medications, as well as bringing remission of type 2 diabetes.

The programme involves an initial 12 weeks on a nutritionally complete formula diet (low calorie soups and shakes) which will induce weight loss of over 15 kg (over 2 stones) if followed fully. Diabetes and blood pressure drugs were stopped at the start, and only re-started if blood sugar or blood pressure rose.

The weight loss phase is followed by support to choose foods and eat wisely for weight loss maintenance. Maintaining the 15 kg weight loss allowed 8 out of 10 people to become free from type 2 diabetes, without the need for diabetes medications for at least 2 years.

This study, published in the journal Diabetologia, looked at 143 people who started the diet programme, with more than half (78 people) on tablets for high blood pressure at the start (and 44 on two or more drugs). The researchers found that, overall, average blood pressure fell steadily as people lost weight. And blood pressure remained lower after the formula diet period finished, and then at 12 and at 24 months.

For those not previously treated for high blood pressure, blood pressures fell sharply from week one. For those who had stopped their blood pressure tablets, blood pressure still fell, although more slowly. Just over a quarter (28%) needed to reintroduce a blood pressure tablet during the formula diet period. However, researchers also found that the same proportion of participants (28%) were able to remain off their medications for at least two years.

Prof Mike Lean, from the University of Glasgow, said: “We wanted to evaluate the safety and efficacy of withdrawing blood pressure medication when beginning our specially-designed weight-loss programme for type 2 diabetes, and we are really pleased with the results.

“Our study shows that, in addition to possible remission from type 2 diabetes, there are other very important health benefits, as weight loss is a very effective treatment for hypertension and its associated serious health risks.

“Currently, over half of all the 4.5 million people with type 2 diabetes in UK also require tablets for hypertension, to reduce serious vascular complications. Being overweight is the main cause, and losing weight can bring a remission from hypertension for many, as well as a remission of diabetes. Withdrawing blood pressure medications is safe, provided people lost weight and blood pressure was checked regularly, in case tablets needed to be reintroduced.

“The DiRECT trial was done entirely in primary care. The evidence shows that GPs can safely offer an evidence-based intensive weight management intervention, aiming for substantial weight loss and remission of type 2 diabetes. The study further highlights the links between diet, weight, type 2 diabetes and hypertension, and how long-term support to maintain weight loss is vital.”

Professor Roy Taylor, from Newcastle University, said: “Guidelines encourage doctors to start tablets but there have been few demonstrations of how tablets can be stopped.

“My patients, like so many, do not like swallowing multiple tablets, and this study is important as we can now reassure them that stopping blood pressure tablets is not only safe but also good for their health. We’ve shown that when substantial weight loss is achieved and maintained, patients can effectively manage both their blood pressure and type 2 diabetes without drugs.”

Dr Wilma Leslie, University of Glasgow, said: “The potential to no longer need medications for blood pressure and diabetes is a big incentive for people. We hope our results will reassure health professionals that this is possible, and encourage the wider provision of diabetes remission services.”

Dr Elizabeth Robertson, Director of Research at Diabetes UK, said: “These important results show that the Diabetes UK-funded DiRECT low-calorie, weight management programme not only helps some people put their type 2 diabetes into remission, but can also lower blood pressure, allowing some people to safely stop taking their blood pressure medication.

“We’re delighted to see more evidence of the life-changing impact of the DiRECT programme on people’s health. This makes us even more determined to make sure as many people as possible have access to type 2 diabetes remission services.”

The study, ‘Antihypertensive medication needs and blood pressure control with weight loss in the Diabetes Remission Clinical Trial (DiRECT),’ is published in Diabetologia.

The study was funded by Diabetes UK, with support in kind (Counterweight-Plus formula diet sachets) provided by Cambridge Weight Plan to Counterweight Ltd.

Reference: Leslie, W.S., Ali, E., Harris, L. et al. Antihypertensive medication needs and blood pressure control with weight loss in the Diabetes Remission Clinical Trial (DiRECT). Diabetologia (2021). https://doi.org/10.1007/s00125-021-05471-x

Provided by University of Glasgow

Zapping Nerves With Ultrasound Lowers Drug-resistant Blood Pressure (Medicine)

Brief pulses of ultrasound delivered to nerves near the kidney produced a clinically meaningful drop in blood pressure in people whose hypertension did not respond to a triple cocktail of medications, reports a new study led by researchers at Columbia University Vagelos College of Physicians and Surgeons and NewYork-Presbyterian.

In a clinical trial of the procedure, called renal denervation, daytime blood pressure after two months had dropped 8 points compared to a 3-point drop in patients who were treated with a sham procedure. Nighttime blood pressure decreased by an average of 8.3 points in the treatment group versus 1.8 points in the sham group.

“For patients with drug-resistant hypertension, a drop in blood pressure of 8 points–if maintained over longer-term follow-up–is almost certainly going to help reduce the risk of heart attack, stroke, and other adverse cardiac events,” says Ajay Kirtane, MD, professor of medicine at Columbia University Vagelos College of Physicians and Surgeons, an interventional cardiologist at NewYork-Presbyterian/Columbia University Irving Medical Center, and co-principal investigator of the trial.

“These results suggest that renal denervation has potential to become an important add-on to medication therapy–including for those who have difficulty managing several medications to control their hypertension.”

Data from the trial, called RADIANCE-HTN TRIO, were presented May 16 at the American College of Cardiology conference and simultaneously published in The Lancet.

The treatment is still experimental, has not been approved for use by the FDA, and is only available through clinical trials. The trial will follow patients for five years to determine if the drop in blood pressure is maintained over time.

Need for Additional Blood Pressure-Lowering Therapies

About two-thirds of people who take medications to lower blood pressure are able to control their condition. But in others, the drugs do not work or people do not take them as directed.

“There are a variety of effective medications for lowering blood pressure, but many people need to take several drugs to control their hypertension, which can have side effects. In addition, many people simply don’t want to take additional medications and are poorly adherent to them,” says Kirtane. “It’s clear that we need additional therapeutic approaches to help patients get their blood pressure under control.”

Why Renal Denervation?

The kidney plays a role in blood pressure by controlling how much water is in the bloodstream (more water = more pressure) and acting as a central signaling center for other systems that regulate blood pressure. Renal denervation, a minimally invasive procedure, uses ultrasound energy to disrupt signals from overactive nerves in the renal arteries. The therapy is delivered via a catheter that is threaded through an artery in the leg.

Targeting these nerves is not a new idea in hypertension treatment; several existing medications reduce renal nerve activity to reduce blood pressure.

“But unlike medications, which are only effective when you take them, renal denervation is a therapy that’s always ‘on,'” Kirtane says.

Initial studies of renal denervation had several flaws–including the lack of an adequate control group, variable measurement of participants’ blood pressure, and frequent changes in background medications–that made the results challenging to interpret.

How the Study Worked

In this study, the researchers tested the effectiveness and safety of a device that delivers two to three short blasts of ultrasound to nerve fibers that travel close to the renal artery.

The study included adults with moderate to severe hypertension despite taking three or more antihypertensive drugs. All of the patients were switched to the same medication regimen for their hypertension. (To help with patient adherence, participants took a single pill that combined three commonly used antihypertensive drugs.)

“In our study, 80% of patients continued to take their medication as directed, and while that’s a good adherence rate, it still means that one in five patients weren’t adherent to the medication regimen,” Kirtane adds.

Of 136 patients whose blood pressure remained high after four weeks on the new regimen, 69 were treated with renal denervation and 67 had the sham procedure.

Previous studies in patients with less severe hypertension who were not taking any antihypertensive medications showed that renal denervation was more effective than a sham procedure in lowering blood pressure.

“Additional studies will be needed to determine if this therapy may be effective for other groups, including older patients with hypertension and those with chronic kidney disease,” says Kirtane.

More Information

The study, titled “Ultrasound renal denervation for hypertension resistant to triple medication pill (RADIANCE-HTN TRIO): a randomised, multicentre, single-blind, sham-controlled trial,” was published online in The Lancet on May 16, 2021.

Michel Azizi (Université de Paris, France) and Ajay J. Kirtane (Columbia University Vagelos College of Physicians and Surgeons and NewYork-Presbyterian), co-corresponding authors, contributed equally to the manuscript. Additional authors are listed in the article.

The study was funded by ReCor Medical, Inc., the manufacturer of the Paradise Renal Denervation System.

Provided by Columbia University Irving Medical Center

Fasting Lowers Blood Pressure by Reshaping the Gut Microbiota (Medicine)

Nearly half of adults in the United States have hypertension, a condition that raises the risk for heart disease and stroke, which are leading causes of death in the U. S.

At Baylor College of Medicine, Dr. David J. Durgan and his colleagues are dedicated to better understand hypertension, in particular the emerging evidence suggesting that disruption of the gut microbiota, known as gut dysbiosis, can have adverse effects on blood pressure.

“Previous studies from our lab have shown that the composition of the gut microbiota in animal models of hypertension, such as the SHRSP (spontaneously hypertensive stroke-prone) rat model, is different from that in animals with normal blood pressure,” said Durgan, assistant professor of anesthesiology at Baylor.

Dr. David Durgan © BCM

The researchers also have shown that transplanting dysbiotic gut microbiota from a hypertensive animal into a normotensive one (one having a healthy blood pressure)  results in the recipient developing high blood pressure.

“This result told us that gut dysbiosis is not just a consequence of hypertension, but is actually involved in causing it,” Durgan said. “This ground work led to the current study in which we proposed to answer two questions. First, can we manipulate the dysbiotic microbiota to either prevent or relieve hypertension? Second, how are the gut microbes influencing the animal’s blood pressure?”

Can manipulating the gut microbiota regulate blood pressure?

To answer the first question, Durgan and his colleagues drew on previous research showing that fasting was both one of the major drivers of the composition of the gut microbiota and a promoter of beneficial cardiovascular effects. These studies, however, had not provided evidence connecting the microbiota and blood pressure.

Working with the SHRSP model of spontaneous hypertension and normal rats, the researchers set up two groups. One group had SHRSP and normal rats that were fed every other day, while the other group, called control, had SHRSP and normal rats with unrestricted food availability.

Nine weeks after the experiment began, the researchers observed that, as expected, the rats in the SHRSP control had higher blood pressure than the normal control rats. Interestingly, in the group that fasted every other day, the SHRSP rats had significantly reduced blood pressure when compared with the SHRSP rats that had not fasted.

“Next, we investigated whether the microbiota was involved in the reduction of blood pressure we observed in the SHRSP rats that had fasted,” Durgan said.

The researchers transplanted the microbiota of the rats that had either fasted or fed without restrictions into germ-free rats, which have no microbiota of their own.

Durgan and his colleagues were excited to see that the germ-free rats that received the microbiota of normally fed SHRSP rats had higher blood pressure than the germ-free rats receiving microbiota from normal control rats, just like their corresponding microbiota donors.

“It was particularly interesting to see that the germ-free rats that received microbiota from the fasting SHRSP rats had significantly lower the blood pressure than the rats that had received microbiota from SHRSP control rats,” Durgan said.

These results demonstrated that the alterations to the microbiota induced by fasting were sufficient to mediate the blood pressure-lowering effect of intermittent fasting.”

Graphical abstract of this work. Image courtesy of the authors/Circulation Research, 2021
How the microbiota regulates blood pressure

The team proceeded to investigate the second question of their project. How does the gut microbiota regulate blood pressure?

“We applied whole genome shotgun sequence analysis of the microbiota as well as untargeted metabolomics analysis of plasma and gastrointestinal luminal content. Among the changes we observed, alterations in products of bile acid metabolism stood out as potential mediators of blood pressure regulation,” Durgan said.

The team discovered that the SHRSP hypertensive animals that were fed normally had lower bile acids in circulation than normotensive animals. On the other hand, SHRSP animals that followed an intermittent feeding schedule had more bile acids in the circulation.

“Supporting this finding, we found that supplementing animals with cholic acid, a primary bile acid, also significantly reduced blood pressure in the SHRSP model of hypertension,” Durgan said.

Taken together, the study shows for the first time that intermittent fasting can be beneficial in terms of reducing hypertension by reshaping the composition of gut microbiota in an animal model. The work also provides evidence that gut dysbiosis contributes to hypertension by altering bile acid signaling.

“This study is important to understand that fasting can have its effects on the host through microbiota manipulation,” Durgan said. “This is an attractive idea because it can potentially have clinical applications. Many of the bacteria in the gut microbiota are involved in the production of compounds that have been shown to have beneficial effects as they make it into the circulation and contribute to the regulation of the host’s physiology. Fasting schedules could one day help regulate the activity of gut microbial populations to naturally provide health benefits.”

Find all the details of this study in the journal Circulation Research.

Other contributors to this work include Huanan Shi, Bojun Zhang, Taylor Abo-Hamzy, James W. Nelson, Chandra Shekar R. Ambati, Joseph F. Petrosino and Robert M. Bryan, all at Baylor College of Medicine.

This work was supported by Public Health grants (RO1HL134838, R01NS102594 and DK56338), NIH grant P30DK056338, CPRIT Core Facility Support Award RP170005, NCI Cancer Center Support Grant P30CA125123, intramural funds from the Dan L. Duncan Cancer Center, and National Cancer Institute Cancer Center Support Grant P30CA125123.

Featured image: The human gastrointestinal tract is home of the gut microbiota, a large community of resident microorganisms known to influence host physiology in health and disease. Image credit: OpenClipart-Vectors

Reference: Huanan Shi, Bojun Zhang, Taylor Abo-Hamzy, James W Nelson, Chandra Shekar R Ambati, Joseph F Petrosino, Robert M Bryan, Jr., and David J Durgan, “Restructuring the Gut Microbiota by Intermittent Fasting Lowers Blood Pressure”, Circulation, 18 Feb 2021. https://doi.org/10.1161/CIRCRESAHA.120.318155

Provided by Baylor College Of Medicine

UofG To Investigate the Effects of COVID-19 On Blood Vessels and Blood Pressure (Medicine)

A project at the University of Glasgow that is aiming to better understand the effects that COVID-19 infection has on blood vessels and blood pressure has received a grant of £250,000 from national charity Heart Research UK

Research has shown that people who are older, obese, male or those who have other medical problems including high blood pressure, heart disease, diabetes, cancer, or chronic lung conditions, have a higher risk of developing severe COVID-19. High blood pressure is a major risk factor for cardiovascular disease and is very common with more than one quarter of adults in the UK affected.

The virus causing COVID-19 enters the body’s cells through a receptor called ACE2 which is found in the lungs, heart, blood vessels, kidneys, liver, and bowel. ACE2 is very important for maintaining many of the body’s important processes including blood pressure, inflammation, and wound healing.

COVID-19 can also cause damage to the walls of the blood vessels which makes the risk of blood clots higher and this has been seen more often in people with high blood pressure. The reasons for this are not yet known which is why we need to understand more about the links between COVID-19 and high blood pressure.

This study, which will be led by Professor Sandosh Padmanabhan, Professor of Cardiovascular Genomics and Therapeutics, aims to answer whether:
• High blood pressure makes COVID-19 infection worse and if so, why.
• COVID-19 infection makes high blood pressure worse and if so, why.
• Monitoring and management of high blood pressure needs to be a greater priority during the pandemic.

The study will look at routinely collected health records for people in the West of Scotland who attended hospital or had a positive test for COVID-19 between April 2020 and April 2021. This will be compared to the records of patients who attended hospital during 2019, for another reason. They will also look in detail at a group of people with high blood pressure.

Prof Padmanabhan’s team will also study a group of people that have recovered from COVID-19 infection. They will undergo blood pressure monitoring, and tests of heart and blood vessel health. These tests will be repeated after 12 and 18 months to see if there have been any changes. They will be compared to a group of people who have not had COVID-19.

Finally, the study will look at markers in the blood (biomarkers) with the aim of identifying any which are linked with high blood pressure, cardiovascular disease, or death in COVID-19.

This study will give us a better understanding of the links between COVID-19 infection and high blood pressure, and help to improve the long-term outcomes for survivors of COVID-19. Also, the findings may lead to recommendations on the monitoring and management of blood pressure during the pandemic.

Prof Padmanabhan said: “The current COVID-19 pandemic, caused by the SARS-CoV-2 virus, has exposed unexpected cardiovascular vulnerabilities at all stages of the disease. The mechanism by which the SARS-CoV-2 virus causes infection is believed to directly and indirectly affect the cardiovascular system potentially resulting in new-onset hypertension, heart failure and stroke and represents an insidious feature of long-COVID.

“The burden of hypertension as a consequence of the COVID-19 pandemic is unknown, but given the scale of the infection especially among the young this will be a major concern for the future. In this project, we plan to generate valuable evidence that will inform hypertension management strategies and reduce cardiovascular risk for survivors of COVID-19.”

Kate Bratt-Farrar, Chief Executive of Heart Research UK, said: “We are delighted to be supporting the work of Professor Padmanabhan and his team, who are conducting vital research into one of the biggest medical challenges the world has ever faced.

“We have known for some time that those with pre-existing cardiovascular conditions are more susceptible to developing severe complications from COVID-19. We hope that this research will help to explain why this is the case, reduce the risk for this vulnerable group and, ultimately, help to save more lives.

“Our grants are all about helping patients. They aim to bring the latest developments to those who need them as soon as possible.

“The dedication we see from UK researchers is both encouraging and inspiring, and we at Heart Research UK are proud to be part of it.”

Provided by University of Glasgow

Patient Education Program With Mental Health Component Reduces Cardiovascular Disease Risks (Medicine)

People who participated in a health education program that included both mental health and physical health information significantly reduced their risks of cardiovascular disease and other chronic diseases by the end of the 12-month intervention – and sustained most of those improvements six months later, researchers found.

People who participated in the integrated mental and physical health program maintained significant improvements on seven of nine health measures six months after the program’s conclusion. These included, on average, a 21% decrease in fasting blood sugar, a 17% decrease in low-density lipoprotein cholesterol and a 12% decrease in their body mass index.

However, patients in the group that focused only on physical health information maintained their improvements on just two risk factors – BMI and systolic blood pressure.

Data collected at the conclusion of the 12-month intervention indicated that patients in the program with the mental health component improved on eight of nine health measures, while their peers in the traditional program improved on just three.

“The gains achieved by patients in the integrated program were greater than those of their counterparts in the other group and had greater lasting effects,” said University of Illinois Urbana-Champaign social work professor Tara M. Powell, the first author of a study on the project, published in the journal Preventive Medicine Reports.

Social work professor Tara Powell found that people at risk of cardiovascular disease achieved significant improvements in their weight, blood pressure and other metrics that lasted six months after completing an informational program that included both physical health and mental health information. Photo by L. Brian Stauffer

Study participants were 213 Syrian refugees and 382 Jordanians who were patients of three health clinics in Irbid, Jordan, a border community that has experienced a large influx of people fleeing the civil war in Syria.

Powell conducted the research in partnership with the health-focused relief and development nonprofit organization Americares and the Royal Health Awareness Society, Jordan.

Powell’s group explored the efficacy of a health education intervention called the Healthy Community Clinic, delivered in clinics throughout Jordan to improve patients’ management of chronic conditions such as cardiovascular disease and diabetes, and reduce their risks of complications. Trained health educators or nurses led 20 interactive educational sessions that patients attended twice a month for one year.

Patients’ outcomes in the traditional HCC program were compared with those of peers who received routine health care only and with a group who participated in an expanded HCC program that integrated four additional sessions focused on mental health.

The mental health sessions included discussions of topics such as grief and physical and emotional traumatic stress reactions. Participants also learned tangible coping skills for reducing emotional distress such as deep-breathing exercises and walking.

“This study is among the first to illustrate how an integrated physical and mental health educational intervention can improve health outcomes and ultimately help reduce cardiovascular disease risk in refugees and low-income populations,” said co-principal investigator Dr. Shang-Ju Li, Americares’ senior director of monitoring and evaluation. “We are thrilled to share this groundbreaking research and look forward to making even more progress as we continue to look for ways to improve health outcomes for people affected by poverty or disaster.”

Additional co-authors of the study were Michelle Thompson, an associate director of emergency response, Americares; sociology graduate student Yuan Hsiao of the University of Washington; Aseel Farraj, a program manager of the Royal Health Awareness Society; Mariam Abdoh, a senior population and health advisor/project management specialist, USAID; and Dr. Rami Farraj, of the King Hussein Medical Center.

Based upon the findings of this research, the Royal Health Awareness Society has since deployed the HCC with the mental health component to public health centers across Jordan, Powell said.

In a prior study with the same participants that examined the impact of social support on mental and physical health, Powell and her colleagues found that more than half of the participants had experienced at least one traumatic event. Among Syrians, the most frequently reported traumatic experience was living in a war zone (73%), while among Jordanians it was witnessing a violent death (18%).

That study, published in PLOS ONE, was co-written by Li, Hsiao and U. of I. graduate student Oe Jin Shin.

“Because mental health conditions such as depression and anxiety often co-occur with chronic physical problems and with poverty, patient education programs that integrate mental and physical health information are critical for countries such as Jordan,” Powell said. “Making these integrated programs widely available can reduce the burden of noncommunicable diseases on marginalized populations and increase their access to care.”

Featured image: A mother and daughter participated in the patient education program at a clinic in Irbid, Jordan. Photo by Kathy Kukula, Americares

Reference: (1) The paper “An integrated physical and mental health awareness education intervention to reduce non-communicable diseases among Syrian refugees  and Jordanians in host communities: A natural experiment study” is available online DOI: 10.1016/j.pmedr.2021.101310  (2) The paper “Post-traumatic stress, social and physical health: A mediation and moderation analysis of Syrian refugees and Jordanians in a border community” is available online DOI: 10.1371/journal.pone.0241036

Provided by Illinois News Bureau

High Blood Pressure Causes Atrial Fibrillation (Medicine)

The first evidence from genetic data that high blood pressure is causally associated with the most common heart rhythm disorder is published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).1

Study author Dr. Georgios Georgiopoulos of King’s College London, UK and National and Kapodistrian University of Athens, Greece said: “Establishing that elevated blood pressure causes atrial fibrillation provides further impetus for public health strategies aimed at improving blood pressure control in the general population and for individual efforts to keep levels in check.”

Atrial fibrillation is the most common heart rhythm disorder, affecting more than 40 million individuals globally.People with the disorder have a five times greater risk of having a stroke. Previous studies have shown an association between high blood pressure and developing atrial fibrillation, but there was no strong evidence of direct causality.

To investigate whether blood pressure has a direct impact on the risk of atrial fibrillation, the researchers conducted a naturally randomised controlled trial – called Mendelian randomisation. They used data from the largest genome-wide association study (GWAS) on blood pressure and atrial fibrillation which included more than one million individuals of European ancestry – of which 60,620 had atrial fibrillation and 970,216 did not.

The first step was to identify 894 genetic variants associated with blood pressure. Next, the researchers analysed which of those variants play a role in atrial fibrillation. To conduct the naturally randomised controlled trial, the 894 genetic variants were randomly allocated to all participants at conception, giving each individual a blood pressure level. The investigators then analysed the association between blood pressure and atrial fibrillation.

Elevated blood pressure was associated with an increased risk of atrial fibrillation. Specifically, 1 mmHg rises in systolic blood pressure, diastolic blood pressure and pulse pressure were associated with 1.8%, 2.6% and 1.4% relative increases in the risk of atrial fibrillation, respectively.

Dr. Georgiopoulos said: “The results provide strong evidence of a causal relationship between blood pressure and atrial fibrillation. Using genetic information in the analyses minimises the likelihood of reverse causality (i.e. that atrial fibrillation causes high blood pressure) or that other traits linked with atrial fibrillation (confounders) were responsible. Our study showed that the relationship was not driven by other conditions including coronary artery disease and obesity.”

He concluded: “Our findings confirm the hypothesis that atrial fibrillation is preventable. This indicates that strict blood pressure control could be an effective strategy to stop atrial fibrillation and its complications, which include stroke, heart failure, dementia, and depression.”

Featured image: Atrial Fibrillation © Johns Hopkins Medicine

References: (1) Georgiopoulos G, Ntritsos G, Stamatelopoulos K, et al. The relationship between blood pressure and risk of atrial fibrillation: a Mendelian randomization study. Eur J Prev Cardiol. 2021. doi:10.1093/eurjpc/zwab005. (2) Hindricks G, Potpara T, Nikolaos Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2020. doi:10.1093/eurheartj/ehaa612.

Provided by European Society of Cardiology

About the European Society of Cardiology

The European Society of Cardiology brings together health care professionals from more than 150 countries, working to advance cardiovascular medicine and help people lead longer, healthier lives.