05-07-2018
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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