Individuals with congenital generalized lipodystrophy a genetic condition in which people are born with no fat cells in which to store fat develop metabolic syndrome at an earlier age than people who are obese. They also develop more severe cases of metabolic syndrome earlier than their obese counterparts.
The goal of this study was to determine whether an individuals capacity to store fat in fat cells plays a role in whether they develop metabolic syndrome and type 2 diabetes and at what point that occurs.
For the study, the researchers compared mice genetically altered to prevent their fat cells from expanding when overfed to mice with no such protections against becoming obese. The normal mice got fat when overfed, but didnt develop signs of metabolic syndrome until about 7 weeks into the experiment, at about 12 weeks of age.
The mice engineered to remain slim, however, enjoyed no such pre-diabetic honeymoon period, the study authors said. Some became seriously ill at 4 to 5 weeks of age and displayed evidence of severe heart problems and marked hyperglycemia by 10 weeks of age, a full 8 weeks before the normal mice displayed even minimal heart problems. The genetically altered mice also suffered devastating damage to heart cells and to the insulin-secreting cells in their pancreas.
The genetically altered animals were perfectly normal as long as they were on a normal diet and not overfed. But as soon as we put them on a high-calorie diet, they got terribly sick very fast, said Dr. May-yun Wang, assistant professor of internal medicine at and lead author of the study.
She said the mice engineered to stay slim got sick quicker because the extra calories were not stored in the fat cells, the one place in the body equipped to store fat. Instead, fat was stored in other tissues, mimicking what happens in people with congenital generalized lipodystrophy.
Recognition of this should encourage physici
|Contact: Kristen Holland Shear|
UT Southwestern Medical Center