7 May 2022 | New Scientist | 47hormone also results in nerve signals being
sent to the hypothalamus, a hormone control
centre in the brain, telling it to reduce hunger.
“Patients benefit because it both decreases the
desire to start eating and, when you do eat, you
stop sooner because you feel full,” says Thomas
Wadden at the University of Pennsylvania.
Following these hints that semaglutide
might also be useful for those with weight
issues, new trials took place with an increased
dose to boost weight loss, and the results were
dramatic. Almost 2000 people who were obese
were given weekly injections of 2.4 milligrams
of the drug – more than twice what the
participants in the diabetes trial received – or
a placebo, and they also undertook lifestyleNOSY
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/GETTY^ IMAGES>including pancreatic, colorectal and lung.
Despite this chequered past, with obesity
rising globally – coupled with the fact that
when people do lose weight, they normally
put it back on again within a few years – there
is still a thirst for medicines that could help.
This is where a hormone called GLP-1 comes
in. As food moves from the oesophagus to the
gastrointestinal tract, it activates a system of
hormones that help control the digestion of
food. GLP-1, which is released from the small
intestine, is of particular importance. It signals
to the pancreas to release insulin, a hormone
that allows cells to take up and use additional
glucose from the foods we eat, while cutting
the amount of the hormone glucagon – also
produced in the pancreas – which boosts blood
sugar levels. Together, this means fewer sugars
are left in the body.
People with type 2 diabetes tend to produce
insufficient amounts of GLP-1, which can result
in too much glucose in the bloodstream.
Semaglutide, however, increases the amount
of the hormone circulating the body, helping
to bring blood sugar levels under control.
Given these effects on the pancreas,
semaglutide was originally approved for
diabetes in 2019. But during the diabetes trials,
participants also saw significant weight loss.
That is because GLP-1 slows gastric emptying,
and keeping food in the stomach for longer
creates a greater feeling of fullness. The