Gene discovery shows even low body weight won't stop diabetes
Individuals with low body fat may not be protected from diabetes and heart disease, finds a new study that researchers say is "intriguing". In an analysis from the Institute for Aging Research of Hebrew SeniorLife, an affiliate of Harvard Medical School (HMS), scientists found a gene, called IRS1, that is linked to lower body fat. However, the gene is also associated with higher glucose and cholesterol levels, putting individuals with low body weight at risk for type 2 diabetes and cardiovascular disease.
Men especially at risk for diabetes from IRS1 gene
Douglas P. Kiel, M.D., M.P.H., a senior scientist at the Institute for Aging Research and a professor of medicine at Harvard Medical School said,. "People, particularly men, with a specific form of the gene are both more likely to have lower percent body fat, but also to develop heart disease and type 2 diabetes. In simple terms, it is not only overweight individuals who can be predisposed for these metabolic diseases."
Kiel adds, "We've uncovered a truly fascinating genetic story and, when we found the effect of this gene, we were very intrigued by the unexpected finding."
Kiel, and David Karasik, Ph.D., who are working with the Framingham Heart Study, examined the genomes of more than 75,000 people to find genes associated with body fat percentage, finding the unhealthy IRS1 gene.
The scientists explain IRS1 leads to the kind of fat that collects around organs instead of under the skin. The gene keeps people's waistlines slim, but for those with the variant, fat ends up in more dangerous places. Kiel says the result of fat around the organs is higher risk of type 2 diabetes and heart disease.
He says genes not only determine total body fat, but they also determine ..."what kind of fat you have. Some collections of fat, such as the kind located just under the skin, may actually be less harmful than the type located in the abdominal cavity, which may increase the risk of developing metabolic disease."
Since men store less fat than women, they may be more sensitive to the way fat is distributed, making them more susceptible to type 2 diabetes and cardiovascular disease.
The study, which appears online, June 26,2011, in the journal Nature Genetics, shows being thin doesn't mean lower risk of type 2 diabetes and heart disease. The IRS1 gene boosts cholesterol and glucose levels and may lead to dangerous fat around the organs, increasing the chances of developing diabetes and cardiovascular problems.
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