The high levels of adiponectin, however, made the mice physiologically skinny, Dr. Scherer said.
The continual firing of adiponectin generated a starvation signal from fat that says it is ready to store more energy, he said. The mice became what may be the worlds fattest mice, but they have normal fasting glucose levels and glucose tolerance.
This indicates that the inability to appropriately expand fat mass in times of overeating may be an underlying cause of insulin resistance, diabetes and cardiovascular disease.
This discovery also suggests that in people who have low adiponectin levels fat cells dont send the signal that theyre ready to accept fat, Dr. Scherer said. Instead, the fat is stored in dangerous places liver, heart and muscle tissues where it can cause inflammation and pave the way for disease.
More than 66 percent of American adults are overweight or obese, so most people have excess caloric intake. We need to find ways to deposit these calories in the least harmful places, because the fat has to go somewhere, he said. For instance, people with excess weight around their abdomen run a higher risk of heart disease and diabetes than those who have excess weight in the thighs.
Dr. Scherers next goal is to investigate how to manipulate individual areas of fat to find ways to maximize the good fat areas and shrink the bad areas. Researchers also could try to develop new disease treatments that dont require shedding fat.
Until then, exercise and reduction of food intake are the best ways to stay healthy, Dr. Scherer said.
|Contact: Amanda Siegfried|
UT Southwestern Medical Center