WEDNESDAY, Aug. 27 (HealthDay News) -- Fat cells in obese people are "sick" compared to those in lean people, a new study shows.

Published in the September issue of Diabetes, a group of researchers from the Temple University School of Medicine analyzed fat samples from the upper thighs of six lean and six obese people.

They found significant differences in the fat cells of the obese participants compared with the lean participants.

"The fat cells we found in our obese patients were deficient in several areas," study author Guenther Boden, the Laura H. Carnell Professor of Medicine and chief of endocrinology, said in Temple press release.

Boden said that the obese people's fat cells showed stress on the endoplasmic reticulum (ER), which helps cells synthesize proteins and monitor how they are folded. When the ER is stressed, Boden explained, it produces several proteins that ultimately lead to insulin resistance. Insulin resistance, in turn, plays a major role in the development of obesity-related conditions.

The differences in the fat cells between obese and lean people may help explain the link between obesity and a higher risk of diabetes, heart disease, and stroke, Boden theorized.

More information

The National Heart, Lung, and Blood Institute has more about overweight and obesity.