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HEALTH<br />

THURSDAY,<br />

JULY 5, <strong>2018</strong><br />

5<br />

Artificial ovary to enable<br />

women conceive after<br />

chemotherapy<br />

We make up for some of the calories we burn during exercise, but not all.<br />

Photo: iStock<br />

Exercise results in weight<br />

loss, if done enough<br />

Gretchen Reynolds<br />

Can working out help us to drop<br />

pounds after all? A provocative new<br />

study involving overweight men and<br />

women suggests that it probably can,<br />

undercutting a widespread notion that<br />

exercise, by itself, is worthless for<br />

weight loss.<br />

But the findings also indicate that, to<br />

benefit, we may need to exercise quite a<br />

bit. In theory, exercise should<br />

contribute substantially to weight loss.<br />

It burns calories. If we do not replace<br />

them, our bodies should achieve<br />

negative energy balance, use stored fat<br />

for fuel and shed pounds.<br />

But life and our metabolisms are not<br />

predictable or fair, as multiple exercise<br />

studies involving people and animals<br />

show. In these experiments,<br />

participants lose less weight than<br />

would be expected, given the energy<br />

they expend during exercise.<br />

The studies generally have concluded<br />

that the exercisers had compensated<br />

for the energy they had expended<br />

during exercise, either by eating more<br />

or moving less throughout the day.<br />

These compensations were often<br />

unwitting but effective.<br />

Some researchers had begun to<br />

wonder, though, if the amount of<br />

exercise might matter. Many of the past<br />

human experiments had involved<br />

about 30 minutes a day or so of<br />

moderate exercise, which is the amount<br />

generally recommended by current<br />

guidelines to improve health.<br />

But what if people exercised more,<br />

some researchers asked. Would they<br />

still compensate for all the calories that<br />

they burned. To find out, scientists<br />

from the University of North Dakota<br />

and other institutions decided to invite<br />

31 overweight, sedentary men and<br />

women to a lab for measurements of<br />

their resting metabolic rate and body<br />

composition.<br />

The volunteers also recounted in<br />

detail what they had eaten the previous<br />

day and agreed to wear a sophisticated<br />

activity tracker for a week. The<br />

scientists then randomly divided them<br />

into groups. One group began a<br />

program of walking briskly five times a<br />

week on a treadmill until they had<br />

burned 300 calories, which took most<br />

of them about 30 minutes. (The<br />

sessions were individualized.)<br />

The men and women in the group<br />

that had burned 1,500 calories a week<br />

with exercise proved to have<br />

compensated for nearly 950 of those<br />

calories, the numbers indicated.<br />

Interestingly, those in the other<br />

group had also compensated for some<br />

of the calories they had burned, and to<br />

almost the exact same extent as those<br />

who had exercised less, adding back<br />

about 1,000 calories a week, the<br />

calculations showed.<br />

But since they had expended 3,000<br />

calories a week, they had wound up<br />

with a weekly deficit of about 2,000<br />

calories from exercise and lost fat, the<br />

researchers concluded. The findings<br />

were published in the American<br />

Journal of Physiology-Regulatory,<br />

Integrative and Comparative<br />

Physiology. How the volunteers had<br />

compensated was not absolutely clear,<br />

says Kyle Flack, an assistant professor<br />

at the University of Kentucky, who<br />

conducted the experiment as part of his<br />

graduate research. People's resting<br />

metabolic rates had not changed<br />

during the study, he says, whichever<br />

group they had been in. Their activity<br />

monitors also showed few differences<br />

in how much or little they moved<br />

during the day.<br />

So the caloric compensation must<br />

have involved overeating, he says. But<br />

the volunteers did not think so. "Their<br />

food recall did not show differences" in<br />

how much they reported eating at the<br />

start and end of the study, Dr. Flack<br />

says.<br />

Over the course of the week, these<br />

volunteers burned 1,500 extra calories<br />

with their exercise program. The other<br />

group began working out for twice as<br />

long, burning 600 calories per session,<br />

or about 3,000 calories per week.<br />

The exercise program lasted for 12<br />

weeks. The researchers asked their<br />

volunteers not to change their diets or<br />

lifestyles during this time and to wear<br />

the activity monitors for a few days.<br />

After four months, everyone returned<br />

to the lab and repeated the original<br />

tests.<br />

The results must have been<br />

disconcerting for some of them. Those<br />

men and women who had burned<br />

about 1,500 calories a week with<br />

exercise turned out to have lost little if<br />

any body fat, the tests showed. Some<br />

were heavier. But most of those who<br />

had walked twice as much were thinner<br />

now. Twelve of them had shed at least 5<br />

percent of their body fat during the<br />

study. The researchers then used<br />

mathematical calculations, based on<br />

each person's fat loss (if any), to<br />

determine whether and by how much<br />

they had compensated for their<br />

exercise.<br />

Keep seeing the same doctor<br />

contributes in lower death rates<br />

Nice to see you again, doc.<br />

Seeing the same doctor doesn't just<br />

give you the comfort of a familiar face -<br />

it might save your life. Denis Pereira<br />

Gray of St Leonard's Medical Practice<br />

and colleagues at the University of<br />

Exeter, UK analysed the results of 22<br />

studies from nine countries with<br />

different health systems. Eighteen of<br />

the studies found that people who saw<br />

the same doctor over time had<br />

significantly lower death rates.<br />

Because the studies use different<br />

ways to measure continuity, it wasn't<br />

possible to get an overall estimate for<br />

how big the reduction in mortality is.<br />

One recent study looked at 396,838<br />

patients with diabetes in Taiwan. In<br />

those with a high level of continuity, the<br />

death rate was half as high as those<br />

with low continuity.<br />

The benefits of continuity were not<br />

limited to family doctors or GPs, but<br />

applied to specialist physicians,<br />

psychiatrists and surgeons too. The<br />

Photo: Hero Images<br />

relationship could be<br />

because people with poor<br />

health need to see more<br />

different doctors, but the<br />

studies tried to account for<br />

this.<br />

Studies have shown that<br />

patients who see the same<br />

doctor consistently have<br />

higher satisfaction, are<br />

more likely to follow<br />

medical advice, take up<br />

preventative care such as<br />

immunisations more often<br />

and have significantly<br />

fewer unnecessary<br />

hospital admissions.<br />

"When a patient sees a<br />

doctor they know and get<br />

on with, they talk more<br />

freely and give that doctor<br />

much more relevant<br />

information, sometimes<br />

quite<br />

personal<br />

information or anxieties<br />

they have, and the doctor<br />

can then tailor the advice<br />

and management plans<br />

much more subtly," says<br />

Pereira Gray.<br />

However, being able to<br />

give patients continuity is<br />

increasingly challenging<br />

because of a shortage of<br />

GPs. According to a recent<br />

study in England, the chance of seeing<br />

the same GP fell by 27 per cent between<br />

2012 and 2017.<br />

The importance of continuity is<br />

seriously underappreciated in health<br />

systems, says Pereira Gray. "It's seen in<br />

hospitals and general practices as a<br />

kind of convenience to give the patient<br />

they want to see," he says. "It's<br />

becoming clearer that this is about the<br />

quality of medical practice."<br />

Health Desk<br />

Scientists have taken<br />

further steps in creating<br />

an artificial ovary that<br />

could one day used to<br />

help women who have<br />

been left infertile after<br />

cancer treatment.<br />

Researchers from the<br />

Rigshospitalet in<br />

Copenhagen, Denmark,<br />

took ovarian tissue from<br />

cancer patients and<br />

stripped it of cells. They<br />

then transplanted this<br />

structure into mice and<br />

found that it could<br />

support the survival and<br />

growth of the follicles.<br />

Twenty follicles were<br />

transplanted in and a<br />

quarter of them survived<br />

for at least three weeks.<br />

It is hoped that this<br />

artificial ovary could be<br />

implanted back into<br />

women and restore their<br />

fertility after cancer<br />

treatment. "This is the<br />

first time that isolated<br />

human follicles have<br />

survived in a<br />

decellularised human<br />

scaffold," said Susanne<br />

Por, who presented the<br />

work at the European<br />

Society of Human<br />

Reproduction and<br />

Embryology (ESGRE)<br />

annual meeting in<br />

Barcelona today.<br />

Cancer treatments can<br />

often damage the<br />

ovaries, blocking the<br />

production of eggs and<br />

A scanning electron microscope image of a human ovary.<br />

making pregnancy<br />

impossible. Women<br />

diagnosed with cancer<br />

can have their eggs<br />

frozen. Sometimes,<br />

doctors may offer to<br />

remove or freeze all or<br />

part of an ovary for retransplantation<br />

after<br />

treatment. However,<br />

this runs the risk of<br />

reintroducing cancer<br />

cells, as some cancers<br />

can spread to the<br />

ovaries. An "artificial<br />

ovary" could reduce this<br />

risk.<br />

Nick Macklon, medical<br />

director at London<br />

Women's Clinic, said<br />

this is an "exciting<br />

development" but added<br />

that further research is<br />

needed to prove its<br />

usefulness in humans.<br />

Stuart Lavery,<br />

consultant gynaecologist<br />

at Hammersmith<br />

Hospital, said that if this<br />

is shown to be effective,<br />

it offers huge advantages<br />

over IVF and egg<br />

freezing.<br />

"Because potentially<br />

these small pieces of<br />

tissue will have<br />

thousands of eggs and<br />

clearly if it does work,<br />

there's the advantage of<br />

then getting pregnant<br />

the old-fashioned way,"<br />

says Lavery. Artificial<br />

ovaries could also one<br />

day help relieve women<br />

of some of the symptoms<br />

of the menopause.<br />

Marriage may be good for<br />

your heart<br />

Nicholas Bakalar<br />

Being married may reduce the risk of<br />

heart disease and cardiovascular<br />

death, a review of studies has found.<br />

Researchers pooled data on more than<br />

two million participants in 34 studies<br />

carried out in the United States,<br />

Britain, Japan, Russia, Sweden, Spain,<br />

Greece and eight other countries.<br />

They found that compared with<br />

married people, those who were<br />

unmarried - whether never married,<br />

widowed or divorced - were 42<br />

percent more likely to have some form<br />

of cardiovascular disease and 16<br />

percent more likely to have coronary<br />

heart disease. The unmarried also had<br />

a 43 percent increased likelihood of<br />

coronary heart disease death and a 55<br />

percent increased risk for death from<br />

stroke. Stroke risk was increased for<br />

the unmarried and divorced, but not<br />

for the widowed.<br />

The authors acknowledge that the<br />

study, published in Heart, has several<br />

weaknesses. While most analyses<br />

adjusted for multiple variables, these<br />

varied across studies, and some<br />

factors were not accounted for,<br />

including financial stability,<br />

medication adherence and social<br />

support. Being married may reduce<br />

the risk of heart disease and<br />

cardiovascular death, a review of<br />

studies has found.<br />

Researchers pooled data on more<br />

than two million participants in 34<br />

studies carried out in the United<br />

States, Britain, Japan, Russia,<br />

Sweden, Spain, Greece and eight other<br />

countries. They found that compared<br />

Being widowed, divorced or never married increases the risk of heart disease.<br />

Photo: Manfred Kag<br />

with married people, those who were<br />

unmarried - whether never married,<br />

widowed or divorced - were 42<br />

percent more likely to have some form<br />

of cardiovascular disease and 16<br />

percent more likely to have coronary<br />

heart disease. The unmarried also had<br />

a 43 percent increased likelihood of<br />

coronary heart disease death and a 55<br />

percent increased risk for death from<br />

stroke. Stroke risk was increased for<br />

the unmarried and divorced, but not<br />

for the widowed.<br />

The authors acknowledge that the<br />

study, published in Heart, has several<br />

weaknesses. While most analyses<br />

adjusted for multiple variables, these<br />

varied across studies, and some factors<br />

were not accounted for, including<br />

financial stability, medication<br />

adherence and social support.<br />

Photo: Collected

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