Childhood Diabetes Boosts Risk for Kidney Problems

As more and more American children are diagnosed with type 2 diabetes, another serious problem is threatening their health. Children and teens diagnosed with type 2 diabetes are five times more likely to develop kidney disease later in life than those who develop diabetes as adults, a recent study found.

The findings underscore the importance of preventing-or at least delaying—the onset of type 2 diabetes, doctors say.

"Since the development of diabetic kidney disease is strongly dependent on the duration of diabetes, developing diabetes in youth leads to a high risk of kidney disease in early to mid-adulthood," said study author Robert G. Nelson, MD, PhD, a staff clinician with the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

"For example," he said, "a 15-year-old person with 10 years of type 2 diabetes has the same risk of kidney disease as a 55-year-old with 10 years of type 2 diabetes."

Background

Diabetes is becoming increasingly prevalent among children and teens, largely due to the obesity epidemic. The Centers for Disease Control and Prevention (CDC) estimates that among new cases of childhood diabetes, up to 43% are type 2 disease.

While type 2 diabetes can affect children of any race or ethnic group, it's more common among non-white individuals, the CDC reports. The Pima Indians of Arizona currently have the highest recorded rates of diabetes in the world, at 509 per 1,000 individuals ages 15 to 19, according to the CDC.

Diabetes is the most common cause of kidney failure. Initially, small amounts of albumin, a blood protein, begin to leak into the urine. The filtering function of the kidneys begins to decline as the amount of albumin in the urine increases. It may take 15 to 25 years for kidney failure to occur. Native Americans, blacks and Hispanics have higher rates of kidney failure from diabetes, the NIDDK said.

The Study

Dr. Nelson and his colleagues examined the relationship between a person's age at the onset of diabetes and the likelihood that they would have "end-stage renal disease," or kidney failure. The study, published recently in the Journal of the American Medical Association, was based on data collected over four decades from more than 1,800 members of the Pima and closely related Papago Indian tribes. The researchers compared people who were diagnosed with type 2 diabetes before the age of 20 with those who developed the disease between ages 25 and 55.

Results

Breaking down the numbers by age range, people who developed type 2 diabetes before age 20 were eight times more likely to experience kidney failure between ages 25 and 34 than those diagnosed after 20. And the younger diabetics were four times more likely to experience kidney failure between the ages of 45 and 54 than those diagnosed at an older age.

Expert Recommendations

Pascale H. Lane, MD, is a diabetic neuropathy specialist and associate chairwoman for research at the University of Nebraska Medical Center's Department of Pediatrics. She believes that patients and parents of children with diabetes need to be aware of the potential complications of type 2 diabetes and ways to minimize the risk.

"Nephropathy [kidney failure) may be prevented by strict control of blood sugar levels and by not smoking," Dr. Lane said. "Diagnosing and treating high blood pressure early and aggressively may also prevent or slow the development of this kidney disease."

Efforts also need to focus on preventing type 2 diabetes in children through lifestyle changes that emphasize weight loss and increased exercise, Dr. Nelson added.

"The explosion of obesity in children and adolescents is a cause for great concern and must be reversed," he said. "Calorie-dense fast foods must be replaced by healthy alternatives provided in reasonable portions, and hours of TV watching must be replaced by activities that require exercise."

Diabetes Increases Stroke Risk

Type 1 (insulin-dependent) diabetes and type 2 (non-insulin-dependent) diabetes increase risk of ischemic stroke, triggered by a blood clot that blocks a blood vessel in the brain. Type 1 also is linked to hemorrhagic stroke, triggered by a vessel bleeding into the brain.

Self-defense: If you have either type, ask your doctor about controlling stroke risk factors.