Health: Why So Many Of Us Are Getting Diabetes

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Any scientist who can figure out why Type 2 diabetics are insulin resistant will probably be a candidate for a Nobel Prize. It's not a simple consequence of being overweight. Many obese people are not insulin resistant, and not everyone who is insulin resistant is overweight. Researchers at the Salk Institute in La Jolla, Calif., believe that at least part of the answer lies not in the pancreas but in the liver. In a study of mice published in the Nov. 13 issue of Nature, scientists identified a protein that tells the liver to favor the metabolism of fat over that of glucose. The result is a buildup of glucose levels in the blood, a hallmark of insulin resistance.

Evolutionary biologists suspect that a predisposition toward diabetes developed among certain ethnic groups--such as Pima Indians or Americans of African descent--as a result of repeated, perhaps even recent, bouts of starvation. Those individuals who were better able to decrease energy expenditures during a famine survived and passed on the trait to their offspring. Unfortunately, that ability seems to cause insulin resistance when food is plentiful. In other words, says Dr. Peter Nathanielsz, director of the Center for Women's Health Research at New York University, "you come out into the world--at least the developed world--and there is no shortage of cheap, fast food. Your thrifty metabolism has prepared you for the wrong future."

THE SUGAR BLUES

What's so bad about being insulin resistant and having too much glucose in your blood? For reasons that researchers are still trying to figure out, having diabetes greatly increases your risk of suffering a heart attack or a stroke. A man with diabetes appears to have the same risk of cardiovascular problems as a nondiabetic who has had a heart attack. A woman who develops diabetes loses the cardioprotective benefits of being female. And kids with Type 2 diabetes are more likely to develop heart disease in their 20s and 30s.

The condition also damages small blood vessels throughout the body--particularly those in the eyes and kidneys. As many as 24,000 diabetics in the U.S. become blind each year, more than 100,000 require dialysis or kidney transplantation, and 82,000 need to have a toe, foot or leg amputated. Diabetics are twice as likely as nondiabetics to suffer from depression.

It doesn't have to be this way. Back in 1993 doctors proved that Type 1 diabetics could greatly reduce their risk of complications by intensively managing their glucose levels to keep them as close to normal as possible (using a glucometer to measure the level of sugar in a pinprick of blood and an insulin shot when necessary to bring the level down). Similar results have since been seen with Type 2 diabetics.