Discovery links unusual protein to diabetes

From M, spring 2007

A tiny variation in a protein that transports cholesterol in the blood may predispose many people of American Indian and Mexican descent to diabetes, University biochemistry professor Gary Nelsestuen and his colleagues have found.

The researchers detected the variant form only in people of American Indian or Mexican descent and those who carry it are more likely to be overweight or obese and to have parents with diabetes. It is the first genetic variation ever found in the protein, which is called apolipoprotein C1 and is found in all human beings.

"Obesity and diabetes are serious health problems for Americans and especially for those with American Indian or Mexican ancestry," Nelsestuen says. "This protein may contribute to the elevated rates of diabetes in relevant ethnic groups and might be more common in isolated populations."

The variant form of C1 may have survived because it conferred an advantage that has been masked or even turned into a disadvantage by changes in diet and lifestyle.

"An important future goal [of our research] is to identify an adult population of New World descent who have the variant trait but no diabetes or increases in BMI (body mass index)" says Nelsestuen. "Such a population may reveal dietary and lifestyle [habits] that would benefit all individuals with the trait."