Recently, a group of scientists from the Department of Obstetrics and Gynecology at Stanford University collaborated with experts and fellow researchers in Taiwan and Texas A&M University to further explore genes and associated metabolic factors within the human body that may cause diabetes and obesity among humans.
The study showed three variations of the gene that code for the protein GIP (gastric inhibitory polypeptide) cause differences in glucose metabolism among humans. These three variations of the gene were translated into proteins at lower rates than the normal GIP gene.
Since GIP helps to control blood glucose levels by stimulating the pancreas to secrete insulin, individuals who have the variations of the gene are more likely to have lower levels of the gene in their blood, leading to higher blood glucose levels.
In particular, the results proved especially relevant to women who were pregnant in the Eurasian population that had early roots in agriculture. In an effort to match these GIP variants to a specific trait, the scientists hypothesized that perhaps the variants were associated with a genetic adaptation at a life stage that is vulnerable to environmental changes.
Because pregnancy represents a critical life stage that exposes individuals to excessive metabolic pressures, and because its success has a major impact on reproductive fitness, the researchers explored the link of the GIP variants to pregnancy.
Findings showed that pregnant women of Eurasian descent had a higher likelihood of possessing two copies of the low-activity form of the GIP gene.
In other words, women who have the variation of the gene were more at risk of having higher blood glucose levels than women who have the normal gene.
In today’s society this may be a significant risk factor for gestational diabetes, or diabetes present during pregnancy.
Interestingly, the variant genes with lower activity than the original one arose somewhere in Eurasia approximately 8,100 years ago. Scientists theorize that the same trait that causes this gene to keep blood glucose levels higher for pregnant women may have been a survival mechanism for women who were pregnant during famines or times when food supplies were inadequate.
The principal investigator of this study, Sheau Yu Teddy Hsu of Stanford University, and his colleagues speculated that because people in Europe and Asia at this time were transitioning from a hunter-gatherer lifestyle to one based on agriculture, the switch may have selected for genes that helped people adapt themselves to this new way of life.
Future studies will aim to test women from other populations to see if the gene acts the same way in everyone and if it might help predict who is likely to develop gestational diabetes.
Diabetes affects nearly 10 percent of individuals in the United States alone; this constitutes over 28 million children and adults.
In 2010, 1.9 million new cases of diabetes was diagnosed in people over 20 years of age. As a factor of mortality, diabetes contributed to a total of over 200,000 deaths per year, and can lead to complications including heart disease, stroke, high blood pressure, blindness, kidney disease, nervous system disease and amputations. In 2007, diabetes cost the US over $170 billion.
Diabetes is a group of diseases characterized by high blood glucose levels that result from defects in the body’s ability to produce or use insulin that would help decrease the blood glucose level by absorbing the glucose out of the blood and into the cells.
Research on the early diagnosis of diabetes has been a cutting-edge field of research for scientists since the illness first surfaced decades ago. Researchers are now focusing on the genetics of diabetes in search of some answers.
