Improved Fitness Can Mean Living Longer without Dementia

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“It is important to say that it is never too late to begin exercising. The average participant in our study was around 60 years old at baseline, and improvement in cardiorespiratory fitness was strongly linked to lower dementia risk. Those who had poor fitness in the 1980s but improved it within the next decade could expect to live two years longer without dementia,” says Atefe Tari of the Cardiac Exercise Research Group (CERG) at the Norwegian University of Science and Technology (NTNU).

Tari is lead author of a new study that was recently published in Lancet Public Health, a highly ranked journal in the prestigious Lancet family.

“Persistently low fitness is an independent risk factor for dementia and death due to dementia,” the authors concluded.

The higher, the better

Dementia involves a progressive decline in cognitive functions, severe enough to interfere with the ability to function independently. Alzheimer’s disease is the most common form of dementia.

By 2050, it is estimated that 150 million people in the world will have dementia – a tripling of the incidence of the disease today. There is no cure. Men live on average five years after being diagnosed with dementia, while women live for seven years on average after the diagnosis.

“As there is currently no effective drug for dementia, it is important to focus on prevention. Exercise that improves fitness appears to be one of the best medicines to prevent dementia,” says Tari.

Tari’s study is far from the first to show a link between good fitness and lower risk of getting dementia. What is unique, however, is that Tari and her research colleagues have measured the fitness level of participants twice ten years apart.

Thus, they have been able to evaluate how changes in fitness over time are related to dementia risk. And the results were clear.

Exercise that improves fitness appears to be one of the best medicines to prevent dementia.

“If you increase your cardiorespiratory fitness from poor to good you almost halve the risk of getting dementia. You also reduce the risk of dying from or with dementia. In our study, each increase of 1MET was associated with a 16% lower risk of getting dementia and a 10% lower risk of dementia-related death. This is an improvement that is very achievable for most people”, says Tari.

A MET is a measurement unit used by researchers to quantify the rate at which a person expends energy relative to their body weight.

Followed for 30 years

Between 1984 and 1986, almost 75,000 Norwegians participated in the first wave of the HUNT Survey (HUNT1). Eleven years later, HUNT2 was organized, and 33,000 of the same people participated. More than 30,000 of them answered enough questions to be included in Tari’s analyses.

The researchers calculated cardiorespiratory fitness with a formula previously developed and validated by the Cardiac Exercise Research Group, called the Fitness Calculator.

Previous studies have shown that those who score poorly on this calculator have an increased risk of heart attack, atrial fibrillation, depression and non-alcoholic fatty liver disease, and also that they generally die younger than people who achieve a higher fitness level.

The new study links results from the Fitness Calculator to the risk of dementia and dementia-related deaths up to 30 years later. To investigate these associations, Tari has used data from two different databases, the Health and Memory Study in Nord-Trøndelag and the Norwegian Cause of Death Registry.

Almost half the risk

Between 1995 and 2011, 920 people with dementia were included in the Health and Memory Study in Nord-Trøndelag. A total of 320 of them had also participated in both HUNT1 and HUNT2 and provided enough information about their own health to be included in the analyses.

It turned out that poor cardiorespiratory fitness in both the 1980s and 1990s was significantly more common in this group than among otherwise comparable HUNT participants who had not been diagnosed with dementia.

In fact, the risk of developing dementia was 40% lower for those who were among the 80% with the best fitness in both the 1980s and 1990s. Furthermore, it was 48% lower if one had changed from poor to higher fitness levels between the two surveys.

All participants were followed until death or end of follow-up in the summer of 2016. Via the Norwegian Cause of Death Registry, the NTNU researchers found 814 women and men who had died from or with dementia during the period. This means that dementia was stated as the underlying, immediate or additional cause of death.

The risk was lowest for those who had good fitness at both HUNT surveys. However, also those who had changed from poor to better fitness over the years had a 28% reduced risk.

Cause or coincidence?

In observational studies, there will always be questions about cause-effect relationships. For example, one might ask what causes what: Is it bad fitness that weakens the brain, or do people with cognitive impairment find it more difficult to be physically active and increase their fitness?

“Our study made it easy to see which came first. We estimated the fitness of the participants for the first time in the 1980s, and looked for dementia cases and deaths from 1995 onwards. We have also done separate analyses where we excluded those who got dementia or died during the first few years of the follow-up period, and the results were the same,” says Tari.

It’s also reasonable to ask if the association is random; it might not be the poor fitness that increases the risk of dementia, but people with poor fitness might also have several of the more well-known risk factors for dementia – such as high blood pressure, low level of education and a family history of brain diseases. That is an unlikely explanation, says Tari.

“The HUNT studies give us very broad information about the health of the participants, including body composition, smoking habits, educational level, blood pressure, diabetes, cholesterol levels and family history of stroke. By adjusting the analyses for these factors, we have ruled out that they fully explain the relationship between fitness and dementia risk in our study,” she says.

Physical activity vs. fitness

In other words, the study provides very good evidence that maintaining good fitness is also good for the brain. However, Tari points out that this does not necessarily mean that everyone who is physically active on a regular basis is guaranteed that a good effect on brain health.

“High-intensity exercise improves fitness faster than moderate exercise, and we recommend that everyone exercise with a high heart rate at least two days each week. Regular exercise that makes you sweaty and out of breath will ensure your fitness will be good for your age. Our study suggests that good fitness for your age can delay dementia by two years and that you can also live two to three years longer after being diagnosed with dementia,” she said.

Source: Norwegian SciTech News

Higher Fitness Level Can Determine Longer Lifespan After Age 70

Researchers have uncovered one more reason to get off the couch and start exercising, especially if you’re approaching your golden years. Among people over age 70, physical fitness was found to be a much better predictor of survival than the number of traditional cardiovascular risk factors in a study being presented at the American College of Cardiology’s 68th Annual Scientific Session.

While high blood pressure, high cholesterol, diabetes and smoking are closely linked with a person’s chance of developing heart disease, these factors are so common in older people that the total number of risk factors becomes almost meaningless for predicting future health, researchers said. The new study suggests doctors can get a better picture of older patients’ health by looking at how fit they are, rather than how many of these cardiovascular risk factors they have.

“We found fitness is an extremely strong risk predictor of survival in the older age group—that is, regardless of whether you are otherwise healthy or have cardiovascular risk factors, being more fit means you’re more likely to live longer than someone who is less fit,” said Seamus P. Whelton, MD, MPH, assistant professor of medicine at Johns Hopkins School of Medicine and the study’s lead author. “This finding emphasizes the importance of being fit, even when you’re older.”

Doctors use cardiovascular risk factors to help guide decisions about preventive measures and medications. Previous studies have shown that quitting smoking and controlling blood pressure, cholesterol and diabetes can reduce heart disease risk. However, most studies of cardiovascular risk factors have focused on middle-aged people, leaving a knowledge gap regarding the importance of these risk factors in older people, Whelton said.

The team analyzed medical records from more than 6,500 people aged 70 years and older who underwent an exercise stress test at a Henry Ford Health Systems-affiliated medical center between 1991 and 2009. They assessed fitness based on patients’ performance during the exercise stress test, which required patients to exercise on a treadmill as hard as they could. They divided patients into three groups reflecting their fitness based on the number of METs (metabolic equivalents, a measure of exercise workload) they achieved during the test: most fit (10 or more METs), moderately fit (six to 9.9 METs) and least fit (six or fewer METs). For this study, the researchers grouped patients with zero, one, two, or three or more cardiovascular risk factors.

On average, participants were 75 years old when they underwent the stress test. Researchers tracked the patients for an average of just under 10 years, during which time 39 percent of them died. Over this period, the researchers found higher fitness was associated with significantly increased rates of survival. The most fit individuals were more than twice as likely to be alive 10 years later compared with the least fit individuals.

In contrast, a patient’s total number of cardiovascular risk factors was not associated with their risk of death and patients with zero risk factors had essentially the same likelihood of dying as those with three or more risk factors.

Whelton said the findings demonstrate that fitness level is an important indicator of an older patient’s health that doctors could benefit from considering more often. While an exercise stress test using a treadmill or stationary bicycle provides the most precise way to measure fitness, doctors can also get a general idea of a patient’s fitness level by asking about their exercise routine.

“Assessing fitness is a low-cost, low-risk and low-technology tool that is underutilized in clinical practice for risk stratification,” Whelton said.

The study did not account for any changes in fitness level that the participants may have experienced over time. However, previous studies have suggested that improving fitness can help improve heart health, even late in life.

“People who aren’t exercising or are sedentary would likely benefit from starting a routine of low- to moderate-intensity exercise, though they should talk with their physician first,” Whelton said.

Source: American College of Cardiology


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Today’s Comic

Women Are Naturally More Fit than Men

When it comes to getting and staying fit, women may have an aerobic edge over men, new research suggests.

In a small new study, investigators compared oxygen uptake and muscle oxygen extraction in 18 young men and women while they worked out on a treadmill. Oxygen uptake is an important measure of aerobic fitness.

Women consistently processed oxygen about 30 percent faster than men, according to researchers at the University of Waterloo in Ontario, Canada.

“The findings are contrary to the popular assumption that men’s bodies are more naturally athletic,” study author Thomas Beltrame said in a university news release.

Another researcher put it this way.

“We found that women’s muscles extract oxygen from the blood faster, which, scientifically speaking, indicates a superior aerobic system,” said Richard Hughson. He is a professor with the faculty of applied health sciences at Waterloo and is also an expert in vascular aging and brain health.

Because women process oxygen faster, women are less likely to accumulate molecules linked with muscle fatigue, effort perception and poor athletic performance, the researchers explained.

The findings were published recently in the journal Applied Physiology, Nutrition, and Metabolism.

“While we don’t know why women have faster oxygen uptake, this study shakes up conventional wisdom,” Beltrame said. “It could change the way we approach assessment and athletic training down the road.”

Source: University of Waterloo


Today’s Comic

‘Fat But Fit’ a Myth?

No amount of extra weight is good for your heart, no matter how fit you are by other measures, new British research shows.

“Our findings suggest that if a patient is overweight or obese, all efforts should be made to help them get back to a healthy weight, regardless of other factors,” said study co-author Camille Lassale, from Imperial College London’s School of Public Health.

“Even if their blood pressure, blood sugar and cholesterol appear within the normal range, excess weight is still a risk factor,” Lassale said in a university news release. In fact, the increased risk of developing heart disease was more than 25 percent, the study found.

The study used statistics about the health of people in 10 European countries. Researchers focused on weight and signs of heart disease, when blood vessels become clogged.

The authors looked at more than 7,600 people who had cardiovascular events such as death from heart attack, and compared them to 10,000 people who didn’t have heart problems.

After adjusting their figures so they wouldn’t be thrown off by other lifestyle factors, the researchers found that people with three or more heart risk factors like high blood pressure, high cholesterol or large waist sizes (more than 37 inches for men and 31 inches for women) were more than twice as likely to have heart disease, regardless of whether their weight was normal or above normal.

But those who were considered overweight yet healthy were still 26 percent more likely to develop heart disease than their normal-weight peers. Those considered healthy but obese had a 28 percent higher risk, the study found.

The findings, which don’t prove that extra weight causes heart risks to rise, were published Aug. 14 in the European Heart Journal.

“I think there is no longer this concept of healthy obese,” said study co-author Ioanna Tzoulaki, a senior lecturer in epidemiology at the university.

“If anything, our study shows that people with excess weight who might be classed as ‘healthy’ haven’t yet developed an unhealthy metabolic profile. That comes later in the timeline, then they have an event, such as a heart attack,” she said.

Source: HealthDay


Today’s Comic

Lack of Fitness Second Only to Smoking as Predictor of Early Death: Study

Poor physical fitness ranks right behind smoking as leading risk factors for an early death, new long-term research suggests.

Analyzing nearly 800 men starting at midlife, Swedish scientists also found that each measurable increase in fitness levels translated into a 21 percent lower risk of death over 45 years of follow-up.

“Fitness in middle age is of importance for mortality risk for several decades,” said study author Per Ladenvall, a researcher in the department of molecular and clinical medicine at University of Gothenburg. “Persons with low fitness are associated with an increased mortality risk throughout life.”

“Smoking was the risk factor that was [most strongly] associated with mortality,” Ladenvall added. “We were somewhat surprised that the effect of aerobic capacity was even more pronounced than that of high cholesterol and high blood pressure.”

Heart problems caused by narrowed heart arteries, also known as ischemic heart disease, is the most common cause of death worldwide, according to the World Health Organization.

Using exercise testing, which is traditionally used to diagnose ischemic heart disease, the study authors set out to determine the impact of physical fitness on early death from all causes. They also looked at established risk factors of heart disease such as smoking, high cholesterol and high blood pressure.

The new research analyzed 792 men born in 1913 who performed an exercise test in 1967, at 54 years of age. More than 650 of the healthiest men also did an exercise test measuring maximal oxygen uptake, called VO2 max. The higher a person’s VO2 max measurement, the more physically fit they are.

Tracking the men and using information from several physical exams in intervening years, the researchers obtained data on deaths from all causes. To determine the association between predicted VO2 max (physical fitness) and death, study participants were divided into three groups ranging from low to high VO2 max.

Each increase in predicted VO2 max (physical fitness) levels was linked with a 21 percent lower risk of death over 45 years of follow-up, even after adjusting for other risk factors such as smoking, blood pressure and cholesterol levels.

But the study didn’t prove a cause-and-effect link between aerobic fitness and early death risk, just an association.

The findings were published online in the European Journal of Preventive Cardiology.

U.S. cardiologists agreed with Ladenvall that the study’s long follow-up period strengthens the value of the findings.

“The surprising part of the finding is that [physical fitness] is prognostically important so many years down the line,” said Dr. William Zoghbi, chief of cardiology at Houston Methodist Hospital in Texas.

“A message we’ve heard before is that physical fitness is really a major determinant of longevity,” added Zoghbi, past president of the American College of Cardiology. “This study supports it.”

But how much exercise is enough to lower a person’s risk factors for dying earlier?

This question wasn’t addressed in the study, Ladenvall said, “but on a general note, the amount of exercise needed to increase fitness is dependent on the baseline fitness in that individual.”

“In people with low fitness, even small increases in activity levels can have beneficial effects,” he said.

Dr. William Weintraub, chair of cardiology and founding director of the Center for Outcomes Research at Christiana Care Health System in Wilmington, Del., agreed.

“It doesn’t have to be fast, and people don’t have to go out and run marathons,” Weintraub said. “We need to think of something on the order of 30 minutes to an hour a day of activity. Get home from work and go for a walk. There’s evidence that more activity is better up to a point, but any activity is good.”

Source: U.S. Department of Health and Human Services