Source: University of British Columbia
UBC Researchers Find Food-free Route to Obesity
October 19, 2006
people get fat -- and risk debilitating diabetes -- without overeating?
The answer may be yes, according to Timothy Kieffer, a University of British
Columbia researcher, who has found that imbalance in the action of a hormone
called leptin produces obesity and major disturbance in blood sugar levels,
even when food intake is at normal levels.
The findings were published this month in Cell Metabolism.
"Obesity is a complex condition -- not simply a matter of food intake. We
now have some new directions for understanding the connection between
obesity, hormones, and diabetes," says Kieffer, a diabetes researcher and
associate professor in the departments of cellular and physiological
sciences and surgery. "By targeting defects in the connection, we may
discover new therapies to inhibit obesity and its frequent complication,
Type 2 diabetes."
The hormone leptin is produced by fat and helps regulate insulin secreted by
pancreatic beta cells. Kieffer and colleagues found that weakening leptin
signaling to beta cells caused them to malfunction, leading to obesity and
disrupted blood sugar levels, even in the absence of overeating.
"We think a defect in the communication between leptin and beta cells can
cause over-production of insulin, leading to excessive accumulation of fat
in the body," he says. "This process appears to contribute to obesity --
quite independent of eating -- while also harming control of blood sugar
levels. Hormones alone arenít the sole cause of obesity but they might be a
factor that links obesity to diabetes."
Diet and exercise will always play an important role in preventing obesity
and the risk of diabetes, he adds.
"Dr. Kiefferís work is helpful because it expands what we know about an
important hormone involved in the development of obesity," says Dr. Diane
Finegood, Scientific Director of the Canadian Institutes of Health Research
Institute of Nutrition, Metabolism and Diabetes. "Obese people have a four-
to five-fold increased risk of developing Type 2 diabetes. This work helps
improve our understanding of why the two conditions are linked. The more we
understand the complex relationships between conditions and their underlying
mechanisms, the better our chances of developing safe and effective
About 80 per cent of patients with Type 2 diabetes (formerly known as adult
onset diabetes) are obese. Diabetes care costs Canadians about $13 billion
Diabetes is caused by the inability of specialized cells of the pancreas,
called beta cells, to produce sufficient amounts of insulin, a hormone
critical for regulating blood sugar levels.
Support for this project has been provided by the Canadian Institutes of
Health Research and the Michael Smith Foundation for Health Research.
The Canadian Institutes of Health Research (CIHR) is the Government of
Canadaís agency for health research. CIHRís mission is to create new
scientific knowledge and to catalyze its translation into improved health,
more effective health services and products, and a strengthened Canadian
health care system. Composed of 13 Institutes, CIHR provides leadership and
support to more than 10,000 health researchers and trainees across Canada.
More information can be found at www.cihr-irsc.gc.ca.
The Michael Smith Foundation for Health Research leads, partners and serves
as a catalyst to build British Columbiaís capacity for excellence in
clinical, biomedical, health services and population health research. More
information can be found at www.msfhr.org.
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