Study to uncover genetic basis of obesity

June 15, 2017

Studies have shown that fat stored in the abdomen increases the risk of type 2 diabetes and heart disease, even after adjusting for obesity. In contrast, fat stored in the hips and thighs may actually protect against diabetes and high blood pressure. The investigators examined the genetic determinants of waist-to-hip ratio, a measure of fat distribution, analyzing data from 77,000 participants in 32 studies. The regions identified in this analysis were then checked against data from another 29 studies including over 113,500 individuals. This revealed 14 gene regions associated with waist-to-hip ratio, adding 13 new regions and confirming the one previously known association.

Seven of the identified genetic variations have much stronger effects in women than in men, suggesting they may underlie some of the normal difference in fat distribution between the sexes. Although these identified gene regions explain only about 1 percent of the general variation in waist-to-hip ratios, the authors note, the findings point towards specific biological mechanisms involved in regulating where the body stores fat. The regions affecting fat distribution implicate genes involved in regulating cholesterol, triglyceride levels, insulin and insulin resistance, which may improve understanding of how fat deposits in certain body locations are even more tightly linked to metabolic disorders than to obesity.

"By finding genes that have an important role in influencing fat distribution and the ways in which that differs between men and women, we hope to home in on the crucial underlying biological processes," says Cecilia Lindgren, PhD, of the Wellcome Trust Centre for Human Genetics at Oxford University, senior researcher on the waist-to-hip ratio study, who was involved in both papers.

Source: Massachusetts General Hospital