Metabolic Syndrome Triggered by Overeating, Not Obesity

(HealthDay News) -- Overeating, not the obesity
it causes, is the actual cause of metabolic syndrome, suggests a study
with mice by researchers at the University of Texas Southwestern Medical
Center at Dallas.

Metabolic syndrome is a collection of health factors that increase the
risk of developing insulin resistance, fatty liver, heart disease and type
2 diabetes.

This study was among the first to propose that weight gain is an early
symptom, not a direct cause, of metabolic syndrome, the researchers
said.

"Most people today think that obesity itself causes metabolic
syndrome," senior author Dr. Roger Unger, professor of internal medicine,
said in a prepared statement. "We're ingrained to think obesity is the
cause of all health problems, when, in fact, it is the spillover of fat
into organs other than fat cells that damages these organs, such as the
heart and the liver. Depositing fatty molecules in fat cells where they
belong actually delays that harmful spillover."

In this study, Under and his colleagues compared normal mice to mice
that were genetically altered to prevent their fat cells from expanding.
Both groups of mice were overfed.

The normal mice got fat but didn't develop signs of metabolic syndrome
until after about seven weeks of overeating. The genetically altered mice
stayed slim but became seriously ill within a few weeks and displayed
evidence of severe heart problems and major increases in blood sugar
levels eight weeks before minimal heart problems developed in the normal
mice, the researchers said.

The genetically altered mice showed significant damage to heart cells
and to the insulin-secreting cells in the pancreas. They also got sick
quicker, because the extra calories they consumed weren't stored in fat
cells, but rather in other tissues, the researchers said.

The study was published online in the journal Proceedings of the
National Academy of Sciences.