Finicky Fat

A groundbreaking medical study from members of the SWHR-Isis Fund Network on Sex Differences and Metabolism sponsored by the Society for Women’s Health Research (SWHR), the nation’s leading advocate for the study of sex differences, uncovers new truths about fat deposition in male and female mice.

“Given the difference in gene expression profiles, a female fat tissue won't behave anything like a male fat tissue and vice versa,” said Deborah Clegg, Ph.D., assistant professor of internal medicine at UT Southwestern Medical Center. “The notion that fat cells between males and females are alike is inconsistent with our findings.”

Mice store their fat similar to humans in a sexually dimorphic pattern. Just like human males, male mice store their fat in the belly and midsection area while females store fat in their hips, thighs and buttocks. Fat around your central organs (also known as central adiposity) is the type that is most dangerous for subsequent development of chronic diseases.

Dr. Clegg, the senior author of the study appearing in the International Journal of Obesity, was surprised by the findings. “We found that out of about 40,000 mouse genes, only 138 are commonly found in both male and female fat cells,” said Dr. Clegg. “This was completely unexpected. We expected the exact opposite – that 138 would be different and the rest would be the same between the sexes.”

This news is especially helpful in determining the underlying causes of obesity-related diseases. Since men are more likely to carry extra weight around their bellies, they are at higher risk for numerous obesity-related diseases including diabetes and heart disease. Women, on the other hand, are usually protected from these disorders until menopause, when their ovarian hormone levels drop and fat storage tends to shift from their buttocks to their waists.

“The research being performed by Dr. Clegg and colleagues underscores the importance of understanding the differences in fat deposition in men and women,” said Viviana Simon, Ph.D., SWHR vice president of scientific affairs. “The ability to manipulate how and where in the body fat is deposited holds the promise of helping researchers develop strategies to prevent or delay the development of chronic conditions such as diabetes and cardiovascular disease.”

For more information on the Society for Women’s Health Research please contact Rachel Griffith at 202-496-5001 or Rachel@swhr.org.

The Society for Women’s Health Research (SWHR), a national non-profit organization based in Washington D.C., is widely recognized as the thought leader in women’s health research, particularly how sex differences impact health. SWHR’s mission is to improve the health of all women through advocacy, education and research. Visit SWHR’s website at swhr.org for more information.