Diabetes Risk May Be Associated With Elevated Iron Levels

Source: USA Today, February 11, 2004
Author: Kathleen Fackelmann

Diabetes Risk May Be Associated With Elevated Iron Levels But some experts say more study is needed

High levels of iron in the blood may foreshadow the development of type 2 diabetes, a study suggests today.

Research has shown that people with a genetic condition that causes huge elevations of iron in the blood are known to be at risk for type 2 diabetes. This study aimed to determine whether the diabetes link would hold true for healthy people with just mildly elevated levels of iron.

Frank Hu and colleagues at the Harvard School of Public Health measured the blood levels of ferritin, a protein that stores iron in the body, in more than 32,000 women who provided blood samples to the Nurses’ Health Study from 1989 to 1990. At that time, the women did not have any sign of diabetes, Hu says.

The team kept track of the women for a decade and found that 698 developed type 2 diabetes over the course of the study.

When the researchers examined iron levels at the end of the study, they found that women who would go on to develop diabetes had significantly higher ferritin levels than women who remained free of the disease.

Women with the highest blood levels of ferritin had a threefold risk of developing type 2 diabetes compared with women with the lowest levels, Hu says. That risk remained even when the researchers controlled for other factors like a family history of diabetes or obesity.

The findings are published in today’s Journal of the American Medical Association.

Other small studies had found a link between body-iron stores and diabetes risk, but this is the largest study to find this association, Hu says. Hu and his colleagues believe that iron stored in the body may be an independent risk factor for diabetes.

The body needs iron to work properly, but too much iron can be dangerous, Hu says. And research suggests that even mildly elevated levels might boost the body’s production of free radicals, molecules that can damage cells, including cells that make insulin, the hormone the body uses to process sugar. Over time, that damage might lead to type 2 diabetes, Hu speculates.

But “this is not a well-established association,” says David Nathan, a diabetes expert at the Massachusetts General Hospital in Boston. It could take years to confirm or dispel the iron theory, he and other experts say.

Meanwhile, people concerned about diabetes, especially those with a proven risk factor such as obesity, should ask their doctor about getting a blood sugar test, says Nathaniel Clark, a vice president at the American Diabetes Association. In many cases, people at risk of developing diabetes can ward off the disease with exercise and weight loss, he says.