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Medical News Today: Ageotypes: Why do people age differently?

Everyone ages differently, but why is that? A team of researchers has pinpointed four "ageotypes" — main biological pathways for aging — that could help us answer that question.

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The identification of four ageotypes may help explain why our bodies age in different ways.

Everyone ages, but not in the same way. Getting older can often mean learning to cope with different health problems — but again, different people face different issues. Why?

That is the question that a team of researchers from the Stanford University School of Medicine in California has begun to investigate in a new study.

The team's research involved a group of 43 healthy participants between the ages of 34 and 68 years who agreed to undergo assessing for molecular biology markers at least five different times over 2 years.

The Stanford scientists chose this longitudinal approach to help them build detailed aging profiles to "map" individuals' different aging parameters.

"We know already there are a handful of nice molecular and clinical markers, such as high cholesterol, that are more common in older populations," says the study's senior author Prof. Michael Snyder.

"But we want to know more about aging than what can be learned from population averages. What happens to an individual as they age? No one has ever looked at the same person in detail over time," he explains.

Prof. Snyder and his colleagues' new study — the findings of which appear in the journal Nature Medicine — identified four different biological pathways characterizing four main types of aging.

By understanding the type — or types — of aging to which a person is predisposed, it may be possible to come up with ways to delay or slow down that form of aging, the researchers argue.

Researchers find 4 ageotypes

"Our study captures a much more comprehensive view of how we age by studying a broad range of molecules and taking multiple samples across years from each participant," explains Prof. Snyder.

"We're able to see clear patterns of how individuals experience aging on a molecular level, and there's quite a bit of difference," he notes.

The researchers analyzed a range of biological samples — including blood and stool samples — that they collected periodically from the participants. In these, they were looking for changes in the presence and activity of various microbes and telltale molecules, including proteins, metabolites, and lipids (fats).

Through their analysis, the researchers pinpointed four different "ageotypes," or aging pathways. These were: metabolic (relating to the buildup and breakdown of substances in the body), immune (relating to immune responses), hepatic (relating to liver function), and nephrotic (relating to kidney function).

Prof. Snyder and his colleagues explain that people with a predisposition to metabolic aging may have a higher risk of developing conditions such as diabetes. As they age, these individuals may also have elevated levels of hemoglobin A1c, which is a measure of blood sugar levels.

Yet the team also notes that people can be predisposed to not just one but two or more types of aging, thus facing a combined risk for different health problems.

In addition to aging types, the team found differences in aging rates among individuals. These findings, say the researchers, have the potential to offer people more control over their lives.

If we understand what form or forms of aging we are predisposed to, we are also empowered to come up with a strategy to prevent specific health problems and possibly slow down certain aging processes.

"The ageotype is more than a label; it can help individuals zero in on health-risk factors and find the areas in which they're most likely to encounter problems down the line. Most importantly, our study shows that it's possible to change the way you age for the better."

Prof. Michael Snyder

The research into aging processes is far from over, however. "We're starting to understand how that happens with behavior, but we'll need more participants and more measurements over time to fully flesh it out," says Prof. Snyder.

Possibilities to slow down aging

Prof. Snyder and his team also looked at other factors that may contribute to aging differently. More specifically, they compared the aging profiles of healthy individuals who were insulin sensitive with those of insulin resistant participants whose bodies were unable to process blood sugar effectively.

"The differences in aging between healthy and insulin resistant folks is something that's never been looked at before," says the senior researcher.

"Overall, we found there were about 10 molecules that significantly differed between insulin sensitive and insulin resistant folks as they aged," he notes. Of those molecules, many played a role in the functioning of the immune system.

But the researchers also made another remarkable find: Over the 2 years during which they collected data about the participants, not everyone showed a change in ageotype markers.

Even more remarkably, for some people who changed their lifestyle — particularly in terms of diet — the ageotype markers even decreased for a time, which, in some cases, meant that these individuals were aging at a slower rate.

In some participants, age-related changes in the levels of the key molecules hemoglobin A1c and creatine, which links to kidney function, occurred at a slower rate.

Some of the individuals in whom creatine levels dropped — suggesting an improvement in kidney health — were receiving treatment with statins, the researchers explain.

In some people who made lifestyle changes, though, no improvements were obvious at the time of the study.

Prof. Snyder, who also analyzed his own biological samples over time, hopes that his lifestyle changes will prove more effective.

"I started lifting weights […]," he says, explaining that he was disappointed to see that he "was aging at a pretty average rate." However, he thinks that his effort may pay off in the long run.

"It'll be interesting to see if that influences my aging pathways in another year's time," says Prof. Snyder.

The team also notes that their current findings are just the beginning of a long and complex journey toward understanding how aging works. Many mysteries remain, and, in time, the researchers hope to uncover more answers.

Original Article

Medical News Today: Marathon running may reverse a risky part of the aging process

People have long been aware of the benefits of exercise. Now, a new study finds that one particular aspect of fitness — that is, training for a specific goal — may be particularly advantageous.

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A new study has shown that training for and running a marathon can reverse vascular aging.

The value of goal-oriented exercise ties directly into the aging process. As a person gets older, their arteries are more likely to stiffen.

Aerobic exercise can reduce arterial stiffening, which the medical community sees as a predictor of cardiovascular events.

However, it is difficult for doctors to recommend a form of fitness that is likely to work for everyone.

Recent findings, however, suggest that training for and running a marathon could be an excellent choice for people looking to improve their cardiovascular health.

A total of 138 people running in the 2016 and 2017 London Marathons participated in the study, which appears in the Journal of the American College of Cardiology.

Training for the marathon

None of the participants had completed a marathon before, and none had any significant medical history or preexisting heart disease.

They were also all running a maximum of 2 hours a week before starting the study.

Just over half of the participants were female, with the average age of the group being 37 years.

The researchers advised each of the runners to follow the marathon's Beginner's Training Plan, which consists of about three runs every week for 17 weeks leading up to the race.

As the weeks went on, the weekly exercise became more intense.

A 4 year reduction

Before the participants began their marathon training, the research team measured their blood pressure and aortic stiffness using cardiovascular magnetic resonance.

The researchers calculated the biological age of each individual's aorta using their actual age and the aortic stiffness measurements from three levels of the artery.

They then took the same measurements between 1 and 3 weeks after the marathon.

An analysis of the average finish times of 27,000 runners suggested that the participants were running between 6 and 13 miles a week in training.

Of the participants, the men took an average of 4.5 hours to complete the race while the women took 5.4 hours.

When the researchers compared the measurements from before and after the race, they found that both blood pressure and aortic stiffness had reduced in the first-time marathon runners.

Notably, the changes in aortic stiffness were equivalent to a 4 year decrease in vascular age.

Interestingly, older male runners who were slower and had a higher baseline blood pressure gained the most from the training regimen and race.

Never too late to change

Senior author Dr. Charlotte H. Manisty, who works at the Institute of Cardiovascular Science at University College London and Barts Heart Centre in London, United Kingdom, comments on the findings:

"Our study shows it is possible to reverse the consequences of aging on our blood vessels with real-world exercise in just 6 months."

Dr. Charlotte H. Manisty

"These benefits were observed in overall healthy individuals across a broad age range," she adds, "and their marathon times are suggestive of achievable exercise training in novice participants."

People with greater arterial stiffness and hypertension may benefit even more from this form of exercise, although future studies would need to test this theory.

However, it is not possible to conclude that exercise alone produced the above effects.

The more healthful lifestyle choices that often accompany marathon training, such as a better diet and sleeping pattern, may have had a part to play.

It is also possible that some participants adopted a different training regimen to the recommended plan, meaning that further research will need to take a standardized approach.

Nevertheless, the findings highlight "the importance of lifestyle modifications to slow the risks associated with aging, especially as it appears to never be too late as evidenced by our older, slower runners," Dr. Manisty states.

Original Article

Medical News Today: Misconceptions may lead to dehydration in older adults

A new study looks at what keeps older adults from getting sufficient fluids to avoid negative health outcomes.

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New research stresses the importance of staying hydrated as we get older.

Staying hydrated seems simple enough. Yet studies have shown that somewhere between about one-third and one-half of older adults may be dehydrated, increasing their risk of health problems.

Dehydrated people hospitalized with a stroke are more than twice as likely to experience impairment afterward.

According to a paper appearing in Age and Ageing, widespread misconceptions about maintaining proper hydration are partly to blame.

Cini Bhanu, from the Department of Primary Care and Population Health at University College London, United Kingdom, is the first and corresponding author of the new study.

"Keeping well hydrated is key to good health among older people, reducing the risk of hospital admissions and other poor health outcomes. However, many do not link hydration to good health and are unsure of how much to drink."

Cini Bhanu

The study's participants

The goal of the study was to examine the factors that might be preventing older adults from consuming enough fluids.

The researchers interviewed 24 generally healthy people aged 75 years or older living in their own homes in north and central London in the U.K. They selected the interviewees by age, gender, ethnicity, and frailty status.

The team excluded people living in nursing homes and anyone receiving treatment for cancer or palliative care. They also chose not to include people who lacked the ability to provide consent or exhibited signs of dementia.

Likewise, they did not conduct any interviews with those who had health-related dietary restrictions, were unable to swallow, or could not feed themselves.

Bhanu and team also interviewed nine caregivers.

The seeming impossibility of hydration

The study identified several misunderstandings about hydration that discouraged interviewees from even trying to drink enough fluids.

How much is enough?

A number of participants revealed confusion regarding the recommended level of fluids necessary to maintain healthy hydration. Older people have certainly seen medical opinions change over the years regarding what is healthy and what is not.

"Quite frankly, I don't know. I know that everything has changed: sometimes it's three or four, [and] at one stage we were told we ought to drink 3 liters of water a day or something like that."

Male interviewee, age 80–84 years

Doctors currently recommend that older women drink eight glasses of water per day, while men should drink 10.

Water, water, everywhere

While people often think that adequate hydration is achievable only with the consumption of water, this is not the case. Enjoyable liquids of almost any kind — including coffee, tea, soda, and even some types of alcohol — make sustaining hydration easier and more pleasant than some might assume.

The authors suggest that empowering older people to drink beverages that they prefer and that fit their lifestyle can help make it easier to remain hydrated.

Deciding to drink

According to Bhanu, a prevalent mistake is to believe "that thirst is a reliable indicator of when you need to drink, when this may no longer be the case for older people."

Although a desire for liquids tends to reduce with age, the need for them does not. As a result, people may need to start viewing their consumption as a matter of discipline more so than desire.

"Everybody tells me I should drink more. But to tell you the truth, I can't say I have a need to … sometimes I force myself. Apart from taking my tablets this morning, I've had two black coffees; I haven't had any more drinks."

Female interviewee, age 90+ years

Age-related obstacles

One caregiver talks about her client, saying, "Her generation has a chronic panic about not managing to get to the loo quickly enough because she moves slowly, that's the thing, although she is completely continent."

The study findings suggest that older adults may worry about the stigma attached to losing bladder control and that this prompts some to avoid liquids consciously out of fear.

Obviously, for those who are incontinent, consuming enough fluids to remain hydrated requires precautions to avoid mishaps.

One interviewee in the study noted the intimidating number of stairs that she needed to climb to get to her bathroom as her reason for drinking less than she should.

Recommendations

The paper says it is clear that there is a need for "better education on healthy drinking for community-dwelling older people."

"Education should target what fluids count, the poor reliability of thirst perception in later life, and when fluid intake may need to be deliberately increased (e.g., acute illness) and how this can be achieved."

For those concerned about or dealing with incontinence, counseling may help encourage the sufficient consumption of fluids.

The authors also note that the media tend to broadcast public warnings about the dangers of dehydration only in times of emergency, such as during a heatwave.

More frequent, consistent public health announcements about the importance of hydration could help overcome misconceptions that put older adults at unnecessary risk.

Original Article