/ 19 July 2005

Double diabetes: Harder to detect, harder to treat

Having one type of diabetes is bad enough, but two? Doctors are seeing a new phenomenon dubbed double diabetes that makes it harder to diagnose and treat patients — especially children.

The mix can strike at any age, and comes in various forms: Children who depend on insulin injections because of type one diabetes gain weight and then get the type two form in which their bodies become insulin resistant, for example.

Or someone with classic type two symptoms isn’t responding to therapy, and tests reveal they also are developing the insulin-dependent form of the disease. Or they may not fall clearly into either category.

The labels are important — different forms require different treatments.

Yet ”there are many people in which it’s very blurred as to what kind of diabetes they have,” says Dr Francine Kaufman, a University of Southern California paediatric endocrinologist and past president of the American Diabetes Association.

There are no good statistics on this complex disease-mixing.

But the Children’s Hospital of Pittsburgh counts about 25% of child patients with type one diabetes who also are overweight and have other type two features, says Dr Dorothy Becker, a paediatric endocrinologist and leading double-diabetes researcher.

And an ongoing study to determine the best treatment for child type two diabetics is uncovering many participants who harbour antibodies that signal they have or are developing the type one form, too, says Kaufman.

Those findings echo a handful of recent research reports raising concern about the phenomenon, which some call atypical diabetes or ”diabetes one-and-a-half or even type three diabetes.

Diabetes occurs when the body can’t turn blood sugar, or glucose, into energy, either because it doesn’t produce enough insulin or doesn’t use it correctly.

With the type one form, the patient’s own immune system attacks the insulin-producing islet cells in the pancreas. Once thought to strike only in childhood, it also can develop in adults. Symptoms usually appear suddenly and can quickly become life-threatening.

Insulin, given by shots or a pump, is required to survive.

With the type two form, the body loses its ability to use insulin properly, even though the pancreas pumps out extra and drugs often are given to rev up that production even more. Type two usually develops slowly, and once was thought to hit only the middle-aged but now is striking even overweight children.

Both forms can lead to heart and kidney disease, blindness and amputations, and will kill if not properly treated. But type two has gotten more attention recently because it’s an epidemic fuelled by increasing obesity.

Yet specialists knew type one was quietly increasing, too — and then they began spotting double diabetics.

The theory: overweight people need more insulin to process glucose regardless of whether they’re insulin-resistant yet. So, perhaps obesity overworks the pancreas until it wears out, Pittsburgh’s Becker suggests. Or perhaps obesity accelerates the

autoimmune destruction — meaning someone genetically predisposed to type one diabetes might not have gotten it had they stayed thin.

”You’ve not just exceeded what you can make but perhaps accelerated the destruction,” and then insulin-resistance sets in, agrees Kaufman, who just authored a book called Diabesity exploring the overall obesity-diabetes threat.

Whatever you call that mix, it complicates treatment.

Consider Martha Larkin of Pittsburgh, diagnosed with type one diabetes at age three. For years, her mother would wake up in the middle of the night to test Martha’s blood sugar and administer insulin. Set mealtimes and off-limit foods became the family’s norm.

Then early puberty hit at 10, and Martha began gaining weight, says her mother, Cindy Stevans. Now almost 12, Martha’s daily insulin requirement grew to that of grown man, signaling developing insulin resistance. And, in a vicious cycle, the more insulin she gets, the hungrier she feels.

A recently implanted insulin pump is helping, and the family joined a pool in hopes that physical activity will help Martha stave off double diabetes — and that her twin brother will stay diabetes-free. But weight is a problem for this whole family of bookworms who hate exercise so much that Stevans calls it ”torture”.

”It’s painfully hard,” she says of her daughter’s co-battles with diabetes and weight.

Scientists don’t yet know if double diabetics will need special treatments. For now, the emphasis is on prevention. For type two, that means weight loss. For type one, scientists are enrolling pregnant women from diabetes-prone families into a major study to hunt what might protect their babies from the illness later in life. – Sapa-AP