Big Hips or Big Belly - It's in your Genes -- MEDICA - World Forum for Medicine

Big Hips or Big Belly - It's in your Genes

Building up fat reserves? Your
genetics tell them where to go

According to the new study led by researchers at Joslin Diabetes Center in Boston, both obesity and body shape seem to be controlled by important genes that are part of the mechanisms regulating normal development. Lead researcher C. Ronald Kahn, M.D., President of Joslin at Harvard Medical School and post-doctoral fellow Stephane Gesta, Ph.D., used for the first time gene chips as a tool to understand what genes might control the development of fat inside the abdomen versus fat under the skin.

The researchers examined the genetic makeup of fat samples from around internal organs and under the skin of both mice and almost 200 human subjects ranging from normal to very obese, and including people with mostly abdominal obesity and people with subcutaneous and intra-abdominal obesity. Theorising that fat distribution patterns may originate in the genes involved in control of development, the researchers found that as many as twelve developmental genes may play a role in different fat depots and that at least three of these seemed to be especially important in obesity.

The researchers compared levels of activity for these three genes - Tbx15, Gpc4, and HoxA5 - in intra-abdominal and subcutaneous fat taken from individuals of normal weight versus overweight or obese individuals. "The differences we found in gene expression were so distinct," said Dr. Gesta, "that we could identify the body mass index (BMI) and the waist/hip ratio in the overweight population by the expression level of these genes. This finding suggests that the expression of these genes could be related to the pathogenesis of obesity."

Can people outsmart their fat genes to alter the outcome? "Now that's the big question," said Dr. Kahn. "While we now can predict the fat pattern, we have no magic bullet to alter the outcome. But with these new findings, we have identified potential targets for perhaps one day changing body shape. We don't have drugs to alter the pattern now, but perhaps in the future we will."; Source: Joslin Diabetes Center