Genetic variant is linked to obesity and insulin resistance

June 26, 2012

A large study in people at risk of diabetes has found a direct association between the presence of a small genetic alteration in a hormone receptor and increased body fat and insulin resistance. The results, to be presented Tuesday at The Endocrine Society's 94th Annual Meeting in Houston, suggest an adverse role for a previously described genetic variant, the BclI polymorphism.

"Our findings support the idea that even small variations in hormone receptor sensitivity can have metabolic implications, such as obesity or diabetes," said co-author Bastiaan Havekes, MD, PhD, of Maastricht University Medical Center, Maastricht, the Netherlands.

"Endocrinologists should not just focus on hormone levels themselves. Taking into account hormone receptor sensitivity could help in better understanding hormone-mediated effects on metabolism," he said.

The inherited BclI polymorphism occurs in the gene encoding for the , which controls the actions of glucocorticoids, that affect every system in the body. This small variant makes the receptor more sensitive to glucocorticoids, resulting in greater effects with similar hormone levels, Havekes said.

The effects of this change appear to be similar to, although much smaller than, the excessive glucocorticoid exposure that can occur from certain medications or diseases, Havekes said. Such excess exposure can result in weight gain, especially around the abdomen, as well as in disturbed blood . This exposure most often occurs from long-term use of prednisone or other glucocorticoid medications, which are widely used to treat or to suppress the immune system. It also can result from endocrine diseases such as Cushing's syndrome. Cushing's causes overproduction in the body of the glucocorticoid cortisol, often called the "stress hormone."

Patients in this study, however, did not have known excess exposure to glucocorticoids, according to Havekes. He and his co-investigators studied 1,228 adults who participated in one of two Dutch studies focusing on diabetes in the general population. More than half of the study participants had either prediabetes (23 percent) or Type 2 diabetes (33 percent). All subjects underwent genetic testing for the BclI polymorphism.

The researchers found that 519 subjects did not carry the alternative form of the gene, or G-allele, for the BclI polymorphism on either chromosome. Another 540 subjects were heterozygous carriers, meaning the G-allele was present on one of the two chromosomes. The remaining 169 subjects were homozygous carriers and therefore carried the G-allele on both chromosomes.

Those who had the BclI polymorphism on each chromosome had a significantly higher body mass index and larger waist and hip circumferences than did noncarriers or heterozygous carriers, the authors reported. This was reflected by greater , meaning that insulin is less effective at lowering blood glucose (blood sugar).

"Determining an individual's genetic risk profile for metabolic disease is of paramount importance to prevent development of cardiovascular diseases," he said. "Future studies concerning cardiovascular risk profiling should perhaps consider the BclI polymorphism."

Explore further: Fungicide used on farm crops linked to insulin resistance

Related Stories

Fungicide used on farm crops linked to insulin resistance

June 25, 2012
A fungicide used on farm crops can induce insulin resistance, a new tissue-culture study finds, providing another piece of evidence linking environmental pollutants to diabetes. The results will be presented at The Endocrine ...

Why resist insulin? Finding genes associated with insulin resistance

June 11, 2012
(Medical Xpress) -- Researchers have uncovered six genetic regions that appear to affect resistance to the effects of insulin, which is important in many cases of type 2 diabetes. Previously, only two regions had been described.

Recommended for you

New gene editing approach for alpha-1 antitrypsin deficiency shows promise

October 20, 2017
A new study by scientists at UMass Medical School shows that using a technique called "nuclease-free" gene editing to correct cells with the mutation that causes a rare liver disease leads to repopulation of the diseased ...

Maternal diet may program child for disease risk, but better nutrition later can change that

October 20, 2017
Research has shown that a mother's diet during pregnancy, particularly one that is high-fat, may program her baby for future risk of certain diseases such as diabetes. A new study from nutrition researchers at the University ...

Researchers find evidence of DNA damage in veterans with Gulf War illness

October 19, 2017
Researchers say they have found the "first direct biological evidence" of damage in veterans with Gulf War illness to DNA within cellular structures that produce energy in the body.

Researchers drill down into gene behind frontotemporal lobar degeneration

October 19, 2017
Seven years ago, Penn Medicine researchers showed that mutations in the TMEM106B gene significantly increased a person's risk of frontotemporal lobar degeneration (FTLD), the second most common cause of dementia in those ...

New clues to treat Alagille syndrome from zebrafish

October 18, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) identifies potential new therapeutic avenues for patients with Alagille syndrome. The discovery, published in Nature Communications, ...

Genetic variants associated with obsessive-compulsive disorder identified

October 18, 2017
(Medical Xpress)—An international team of researchers has found evidence of four genes that can be linked to obsessive-compulsive disorder (OCD). In their paper published in the journal Nature Communications, the group ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.