What’s behind the dramatic decline of diabetes-related deaths

Death rates among individuals with diabetes are decreasing, especially deaths related to heart disease and stroke, says a study in the June issue of Diabetes Care.

Researchers examined 16,274 people with diabetes and 226,109 people without the metabolic disease in two-year segments from 1997 to 2004. They found that deaths due to cardiovascular disease among people with diabetes dropped 40% from 1997-98 to 2003-04. Overall deaths among people with the disease dropped 23% during the same period, the study said (link).

“This is very good news,” said Vivian Fonseca, MD, president of medicine and science for the American Diabetes Assn. “What this tells us is that we have turned the corner in the bad outcomes associated with diabetes, and this has happened over about a 10-year period.”

Researchers attribute the decline to multiple factors, including treatment advances made in the 1990s. Patients also are learning to better manage the disease. Cholesterol levels are improving, and smoking rates have declined, said lead study author Edward W. Gregg, PhD, of the Centers for Disease Control and Prevention’s National Center for Chronic Disease Prevention and Health Promotion.

Three key studies have led to better care, Dr. Fonseca said. Conducted from 1983 to 1993, the Diabetes Control and Complications Trial followed 1,441 individuals ages 13 to 39 with type 1 diabetes. The research showed that controlling blood glucose levels slows the onset and progression of diabetes-related eye, kidney and nerve damage.

The Epidemiology of Diabetes Interventions and Complications was a follow-up study showing that controlling blood glucose levels also reduces patients’ risk of cardiovascular disease or having a nonfatal heart attack, stroke or cardiovascular-related death.

The United Kingdom Prospective Diabetes Study found similar benefits from controlling blood glucose levels in people with type 2 diabetes, said Dr. Fonseca, a professor of medicine at Tulane University School of Medicine in New Orleans.

Physicians know how to help patients better manage their diabetes, with better medications, improved methods of assessing patients and strong evidence for standards of care. “What we are seeing here is a translation of all of that research into clinical practice,” Dr. Fonseca said.

For the Diabetes Care study, researchers used the CDC’s National Health Interview Surveys. Individuals were studied in two-year segments. For example, researchers studied 3,825 diabetes patients and 61,141 people without diabetes from 1997 to 1998, and then studied a separate group of 3,762 diabetes patients and 55,905 individuals without the disease from 1999 to 2000.

Though researchers suspected that death rates had gone down, they were surprised by how much they had fallen. “The magnitude of the decline was really more encouraging than we expected,” Gregg said.

Some prior studies indicated that men with diabetes tend to live longer than women, but no significant difference in life expectancies between the two sexes was found in the latest study, he said.

Though deaths have dropped, the number of people diagnosed with diabetes is increasing, Dr. Fonseca said. As a result, the risks of complications related to the disease remain high.

“We’re going to continue to see more and more people with diabetes-related complications,” Gregg said.