Researchers Advise Caution about Recent US Advice on Agressively Lowering Blood Pressure

Medical researchers at Trinity College Dublin, Ireland, are advising caution when treating blood pressure in some older people — after results from a study contrasted with recent advice from the US to attempt to aggressively lower blood pressure in all adults to targets of 120mmHg.

Researchers from the Irish Longitudinal Study on Ageing (TILDA) at Trinity College Dublin, in collaboration with Beaumont Hospital, Dublin, have recently published the findings in the Journal of the American Medical Association (JAMA Internal Medicine).

A large randomised blood pressure trial led by US investigators — the Systolic blood Pressure Intervention Trial (SPRINT) — demonstrated that lowering systolic blood pressure to levels of 120mmHg or less compared with 140mmHg or less in adults (over 50 years with cardiovascular risk) significantly reduced death (from all causes and from heart failure and heart attacks). The study also reported that common side effects of low blood pressure such as falls, injuries, blackouts, and drops in blood pressure after standing were not increased by aggressive treatment — even in people over 75 years old.

Because the latter findings were clinically counter intuitive, the TILDA team tested whether they held true outside of a trial setting. Focusing on people in Ireland over 75 years, they examined rates of falls, injuries, blackouts and excessive drops in standing blood pressure in those who met the criteria for the treatment proposed in SPRINT and were followed up with for 3½ years — the same time period as SPRINT.

The researchers reported starkly contrasting results — falls and blackouts were up to five times higher than reported in SPRINT and drops in blood pressure on standing were almost double that reported in SPRINT. Therefore, in people over 75 years, intensive lowering of blood pressure to 120mmHg could result in harm and TILDA researchers recommend that a better understanding of who, over 75 years, will or will not benefit, is necessary before widespread adaptation of the SPRINT results.

The TILDA team is now assessing how best to determine which people may benefit from SPRINT, and which people are more at risk from aggressive blood pressure lowering.

First author of the journal article, Research Fellow at TILDA, Dr Donal Sexton, said: “SPRINT was a landmark study of hypertension treatment. While the benefits of lowering blood pressure seen in this study are not in dispute, we are highlighting to physicians that we need to be cognisant of the fact that the trial was not powered for adverse events such as falls causing injury. Physicians ought not to expect a similarly low rate of adverse events in clinical practice as was observed in the trial when lowering blood pressure in older people. Overall what we are saying is that the risks and benefits of lowering blood pressure should be individualised for each patient. ”

Professor Rose Anne Kenny, founding Principal Investigator with TILDA and lead author of the journal article commented: “Our work and that of other groups has shown that low blood pressure and particularly drops in standing blood pressure are linked not only to falls, fractures and fall- and blackout-related injuries, but also to depression and possibly other brain health disorders.”

“These outcomes can seriously impact on independence and quality of life and we advise caution in applying the SPRINT recommendations to everyone over 75 years without detailed assessment of an individual’s risk versus possible benefit until such a time as we can provide more clarity re treatment.”

Source: Science Daily

Higher BMI Linked with Increased Risk of High Blood Pressure, Heart Disease, Type 2 Diabetes

Results of a new study add to the evidence of an association between higher body mass index (BMI) and increased risk of cardiometabolic diseases such as hypertension, coronary heart disease, type 2 diabetes, according to a study published by JAMA Cardiology.

A connection between higher BMI and cardiometabolic disease risk usually arise from observational studies that are unable to fully account for confounding by shared risk factors. Mendelian randomization (a method of analysis using genetic information) is an approach that partially overcomes these limitations. Using mendelian randomization, Donald M. Lyall, Ph.D., of the University of Glasgow, Scotland, and colleagues conducted a study that included 119,859 participants in the UK Biobank (with medical, sociodemographic and genetic data) to examine the association between BMI and cardiometabolic diseases and traits.

Of the individuals in the study, 47 percent were men; average age was 57 years. The researchers found that higher BMI was associated with an increased risk of coronary heart disease, hypertension, and type 2 diabetes, as well as increased systolic and diastolic blood pressure. These associations were independent of age, sex, alcohol intake, and smoking history.

The authors write that the results of this study has relevance for public health policies in many countries with increasing obesity levels. “Body mass index represents an important modifiable risk factor for ameliorating the risk of cardiometabolic disease in the general population.”

A limitation of the study was that the sample lacked data on a complete range of potential mediators, such as lipid traits and glucose levels.

Source: The JAMA Network

Smaller Dose Combos of Blood Pressure Medicines May Have Fewer Side Effects

Quarter-dose combinations of blood pressure lowering medications appear to be effective in treating hypertension and result in fewer side effects for patients than a single dose of one drug, according to new research in the American Heart Association’s journal Hypertension.

“Widespread control of blood pressure is generally low, even in high-income countries. The largest global survey of hypertension patients showed 88 percent of those aware of hypertension are treated with medications, but only one in three were able to gain control of their blood pressure,” said Anthony Rodgers, M.B.Ch.B., Ph.D., study author and professor at The George Institute for Global Health, University of New South Wales in Sydney, Australia. “Because high blood pressure is so common and serious, even small improvements in management can have a large impact on public health.”

There are a variety of classes of high blood pressure medications and each includes a list of different possible side effects, such as weakness, dizziness, insomnia, headache, muscle cramps and more.

In this first review to compare quarter-dose therapy to both standard dose and placebo, researchers analyzed and compared results from 42 trials, involving 20,284 people with high blood pressure on various doses of medications or taking no medication. The review included many different types of medications from the five main classes of drugs to treat hypertension, including ACE inhibitors, angiotensin receptor blockers, beta blockers, calcium channel blocker and thiazides.

They found:

  • Two medications in combination, each at a quarter dose, was just as effective as one blood pressure lowering medication at standard dose.
  • Four medications in combination, each at a quarter dose, was nearly twice as effective as taking one blood pressure lowering medication at the standard dose.
  • The side effects from single and dual quarter-dose therapies were about the same as from placebo and much less than from a standard dose of a single antihypertensive medication. There was little information on side effects for the quadruple quarter dose therapy.

While low-dose combinations for blood pressure control is promising, there still isn’t enough research to warrant a change in how doctors prescribe blood pressure lowering therapies and there are also few low dose combinations currently available, researchers said.

“This new approach to treatment needs more research before it can be recommended more widely,” Rodgers said. “The findings have not yet been tested in large long-term trials. People should not reduce the doses of their current medications.”

Source: American Heart Association


Today’s Comic

There’s Increasing Evidence that Healthy People Don’t Need to Worry about Salt Intake

Kevin Loria wrote . . . . . . .

There’s one simple ingredient that makes just about any food better: salt.

And if you look at most nutrition guidelines and dietary assessments, they usually tell us we should be eating less of the delicious substance.

But is salt really so dangerous that that everyone needs to avoid it? Maybe not — at least, there’s more debate about the topic than the blanket recommendations would make it seem.

The American Heart Association (AHA) recently published a study that found that the average American adult consumes 3,400 mg of sodium every day — well above the recommended limit of 2,300 mg, which is even lower (1,500 mg) for many people because of age, race, ethnicity, or blood pressure. (The AHA advocates for lowering the recommended limit to 1,500 mg for everyone.)

Several recent studies show, however, that many of our common assumptions about sodium intake aren’t correct in the first place. At least one study found it didn’t have much of an impact on blood pressure in healthy people, adding to existing research indicating that not everyone needs to worry too much about salt.

Most recently, a pair of studies on Russian cosmonauts found a number of characteristics about salt so surprising that Gina Kolata of the New York Times wrote they indicate our basic understanding of how salt works in the human body “may be completely wrong.” Basically, those two studies, published in The Journal of Clinical Investigation, indicate that salt makes people less thirsty (people may feel thirsty after eating salt, but they need to drink less) and that salt makes mice burn calories faster (making them want to eat more).

Those studies tell us that salt may not be fully understood, but they don’t necessarily tell us much about salt and blood pressure. But another study recently presented at the Experimental Biology 2017 meeting does. In that study, part of a larger study on heart health, researchers followed 2,632 men and women ranging from ages 30 to 64, all who started with normal blood pressure. After 16 years, they found that people who ate the recommended amount of sodium, less than 2,500 mg per day, had higher blood pressure on average than people who had saltier diets.

That’s an observational study, so we can’t say that eating more salt improved people’s blood pressure — that may be due to another factor. But it’s not the only research that indicates eating more than the recommended amount of sodium isn’t necessarily harmful for people who have healthy blood pressure to start off.

In 2011, a major study in the Journal of the American Medical Association that looked at 3,681 people that didn’t have cardiovascular problems found that higher salt consumption did raise one component of blood pressure but didn’t increase risk for hypertension (abnormally high blood pressure) and didn’t increase risk for cardiovascular problems. People who seemed to consume the least salt, based on measurements of sodium excretion, had increased cardiovascular death rates.

None of these studies are a prescription for eating more sodium. But they do indicate that people who eat more sodium than the recommended amount don’t seem to suffer from it if they aren’t already suffering from high blood pressure.

This isn’t a license to eat unlimited ramen and Doritos. Highly processed foods aren’t good for you, and we know that for people that already struggle with hypertension, which can kill you, lowering sodium intake can help.

Perhaps the most useful thing is to be aware of how much salt we’re eating in the first place. The recent AHA study found that 70% of the salt study participants consumed came from restaurant food and processed food bought in stores, while sodium naturally found in foods provided about 14.6% of sodium intake. Salt added to food being cooked at home was 5.6% of intake, while sodium added at the table accounted for 4.9%.

The easy takeaway from that study is that the most effective way to reduce sodium consumption (especially unconscious consumption) isn’t to avoid using a salt shaker, it’s limiting consumption of processed foods. That also happens to be the easiest way to improve your diet in the first place. If you’re preparing food for yourself or at least know that your food is coming from whole ingredients and isn’t largely processed, you’re probably not consuming an excessive amount of salt (though if your doctor recommends lowering intake, you should listen to them).

But in general, there’s more and more research to indicate that salt doesn’t need to be a primary concern for people who don’t have issues with blood pressure.

As Melinda Wenner Moyer wrote for Scientific American in 2011, “if the U.S. does conquer salt, what will we gain? Bland french fries, for sure. But a healthy nation? Not necessarily.”

Source: Business Insider

Low-sodium Diet Might not Lower Blood Pressure

Steering clear of salty foods might not be as helpful for your heart health as previously thought, a new study claims.

Participants in a long-range heart study did not appear to derive any health advantage from a low-salt diet, said lead researcher Lynn Moore.

“People who were on a lower-sodium [salt] diet in general over the next 20 or 30 years actually had no benefit, specifically in terms of their blood pressure or their risk of developing heart disease,” said Moore, an associate professor with the Boston University School of Medicine.

On the other hand, these people did enjoy better health when they increased their intake of potassium, a mineral that helps the heart in a couple of ways, Moore and her colleagues found.

“Higher intakes of potassium were strongly associated with both a lower blood pressure and a lower risk of heart disease,” Moore said. “The same was true for magnesium.”

But before you reach for the shaker, consider that a leading proponent of low-sodium diets, the American Heart Association (AHA), questioned the study’s validity and said it would continue to recommend limiting salt intake.

“When there are really well-conducted clinical trials that show a direct and progressive relationship between sodium and blood pressure, I would pause before I did anything based on what’s reported in this abstract,” said AHA spokeswoman Cheryl Anderson. She’s an associate professor of cardiovascular epidemiology with the University of California, San Diego School of Medicine.

The AHA recommends no more than 2,300 milligrams — about a teaspoon — of sodium a day, and an ideal limit of no more than 1,500 milligrams (mg) daily for most adults.

Moore said her results show that Americans’ average sodium intake — around 3,000 to 3,500 milligrams (mg) a day — should be healthy, particularly if they also get enough potassium and magnesium.

“There seems to be no real added risk in that range,” Moore said. “I think the average American is probably doing OK in terms of sodium, but almost all Americans need to increase their intake of potassium.”

Foods rich in potassium include dark leafy greens, potatoes, beans, squash, yogurt, salmon, avocados, mushrooms and bananas.

The new study comes on the heels of another controversial paper published last May. It suggested that restricting dietary salt to less than 3,000 mg a day appeared to increase the risk of heart disease as much as eating more than 7,000 mg a day. The AHA also disputed the earlier study, which appeared in The Lancet.

Moore’s findings are based on data from more than 2,600 men and women participating in the Framingham Heart Study, a long-range heart health study of people from Framingham, Mass.

Participants had normal blood pressure at the study’s start. But, over the next 16 years, those who consumed less than 2,500 milligrams of sodium a day tended to have higher blood pressure than participants who consumed more sodium, the researchers reported.

The investigators also found that people with higher intake of potassium, calcium and magnesium had lower long-term blood pressure.

But the research team relied on six days of detailed dietary records to estimate people’s intake of sodium and other various minerals, which is a relatively unreliable method, Anderson said.

The gold standard for tracking sodium levels is through urine samples taken across multiple days, she said. Food diaries can be inaccurate.

“They may not have captured sodium intake accurately,” Anderson said.

The study’s positive results regarding potassium have been supported by other studies, Anderson added.

Potassium helps the kidneys flush salt from the body, reducing blood levels of sodium, Moore said.

The mineral also helps relax the blood vessels and make them more flexible, which can help lower blood pressure, Moore and Anderson said.

People who consume a lot of salt — 5,000 milligrams per day — should cut back, Moore said.

Also, “for that subset of the population that’s sensitive to salt in the diet, a really critical thing is how much they’re getting of other minerals, in particular potassium but perhaps magnesium as well,” Moore said.

Moore was scheduled to present her findings Tuesday at the American Society for Nutrition’s annual meeting, in Chicago. The results should be considered preliminary until the data is peer-reviewed for publication in a medical journal.

Source: HealthDay