Science & Research

Gene mutations, diet linked with lower diabetes risk

Researchers use study of genetic risk factors in women of color to inform diabetes knowledge

By
Senior Staff Writer
Thursday, January 22, 2015

University researchers have found a unique interplay among race, genes and diet that may influence a person’s risk for diabetes. In their recently published study, Simin Liu, professor of epidemiology and medicine, and Kei Hang Katie Chan, a postdoctoral research associate, identify multiple genes whose effects on the body’s metabolism may influence a person’s risk for the disease.

In a previous study, the research team found that the genes for TRPM6 and TRPM7 ­— ion channels involved in magnesium regulation — were linked with risk for type 2 diabetes, Liu said.

Magnesium “is an essential mineral that is involved in hundreds of biochemical processes,” Liu said. It is involved in the secretion of insulin and the bodies’ response to insulin,” the impairment of which is the hallmark feature of type 2 diabetes, he added.

In this follow-up study, which will appear in the March edition of the Journal of Nutrition and is currently available online, they continued their research by looking at all metabolic pathways related to magnesium. Results were divided into separate groups based on participants’ levels of magnesium intake because of its important role in insulin metabolism. The researchers found that those with high magnesium intake are at a lower risk for diabetes, Chan said.

The researchers obtained the data from the Women’s Health Initiative, which included the genomes of thousands of women and allowed for much more comprehensive analysis. Using this large dataset, the scientists examined about 600 different genetic variations, Liu said.

Sixty or so mutations have already been linked to the risk of late onset diabetes, but the mutations vary for different races, Liu said.

They chose to limit their study’s population to older Hispanic and black women because women of color are studied less frequently than white women, and they wanted to fill this knowledge gap, Liu said. But it is important to study these factors in other populations as well, he added.

Samir Malkani, director of the Adult Diabetes Clinic at the University of Massachusetts Memorial Medical Center, echoed that this study was a good start, but further studies are needed to look at the results of more inclusive populations, such as young adults, different races and males and females.

A single human genetic makeup can affect different ethnicities in different ways, which could explain the disparities observed between various ethnicities, Liu said.

For example, Hispanic women with a specific variation of the NIPA2 gene had a 35 percent lower risk of type 2 diabetes. But that correlation does not hold for all of the groups of Hispanic women. “In the lower magnesium group, we didn’t see that association for this gene,” Chan said.

The results of this study and similar ones in the future could eventually be used for personalized medicine, Chan said. “Everyone carries a particular arrangement of genes, which gives (certain people) a unique susceptibility to type 2 diabetes.” With further research in lifestyle and dietary factors, nutrition therapy could be suggested, she added.

The thought to look at the genes was very innovative, Malkani said. Though it has been shown in the literature that there is a strong genetic component to type 2 diabetes, most past studies have focused on dietary and weight factors, he said.

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