UBC Reports | Vol.
51 | No. 1 | Jan.
Do You Really Want That Bite?
Resistance to signals from the "obesity hormone"
may feed drive to eat, and contribute to the onset of diabetes
By Hilary Thomson
How many of us have resolved to lose weight in the New Year?
Quick, put down that hamburger and raise your hand.
Obesity, along with its debilitating partner, diabetes,
is becoming recognized as one of North America’s major
health concerns. Scientists and clinicians know the two conditions
are linked -- but how?
Timothy Kieffer aims to find out. A diabetes researcher
and associate professor in the departments of cellular and
physiological sciences and surgery, Kieffer has recently received
almost $300,000 over three years from the Canadian Institutes
of Health Research to explore the connection between a hormone
called leptin and the development of obesity and diabetes.
“We’ve learned that the mechanisms of obesity
are complex -- it’s not a matter of gluttony,”
says Kieffer. “We also know that maintaining weight
loss is difficult because people are fighting powerful hormonal
effects, including the fall in leptin levels.”
Leptin -- also known as the obesity hormone -- is normally
produced by fat cells. It tells the part of the brain that
controls eating how much fat you have, information that helps
the body minimize changes in body weight. When an individual
loses fat, leptin levels fall. The brain interprets the drop
as a message that the body is starving and must eat more and
conserve energy so body weight and leptin levels can return
Obese people produce lots of leptin, but are somehow resistant
to its signals. Because it can’t “hear”
the signal, the brain thinks there is insufficient leptin
and the stimulus to eat more and conserve energy gets activated.
Kieffer believes that leptin resistance may contribute to
the development of diabetes associated with obesity.
One of only a few researchers world wide looking at the
connection, Kieffer’s work could lead to new ways to
control body weight and reduce the risk of diabetes.
In the new study, he will look at leptin’s powerful
effects on regulating blood sugar levels and how to reverse
leptin resistance. Research on the leptin connection may lead
to medications that could help people maintain a healthy weight
and reduce the risk of diabetes.
“But medication to regulate leptin won’t be
a magic bullet,” says Kieffer. “Fat isn’t
just a matter of genetics -- diet and exercise do play an
important role. How the body regulates weight is just a lot
more complex than we’d earlier believed. Ultimately
we hope to eliminate Type 2 diabetes by developing an approach
that can be combined with diet and exercise to maintain a
health body weight.”
Diabetes could Double in 20 Years
According to the World Health Organization, 177 million
people were suffering from diabetes in 2000. By 2025, that
number is expected to jump to 300 million. The U.S. Centers
for Disease Control estimate that one-third of American children
born in 2000 will develop the disease.
A huge drain on health budgets, diabetes care costs Canadians
about $13 billion annually. The U.S. spent $132 billion to
manage the disease in 2002.
About 80 per cent of patients with Type 2 diabetes (formerly
known as adult onset diabetes) are obese. With more children
becoming overweight, there has also been a steady rise in
the number of kids with Type 2 diabetes.
Kieffer’s study is also supported by the Michael Smith
Foundation for Health Research.
For more information on diabetes, visit the Canadian Diabetes
Association website at www.diabetes.ca
and click on About Diabetes.