According to the World Health Organization, there were at least 170 million people with diabetes around the world in the year 2000. Seven and a half million people with diabetes died that year but deaths directly caused by diabetes were estimated to be 2.9 million, or 5.2% of total deaths.

Since most mortality statistics are based on an underlying cause of death on a death certificate, researchers were looking to provide a more realistic estimate of the number of deaths directly attributable to diabetes. The study, recently published in Diabetes Care, suggests that the number of global deaths due to diabetes is underestimated.

Gojka Roglic, MD, stated that, “Mortality attributable to diabetes is grossly underestimated in routine sources of health statistics.” Roglic is a technical officer in the Department of Chronic Diseases and Health Promotion at the WHO.

“The available data do not allow us to speculate on the trend. The data do not give insight into the rate at which diabetes might be moving upward in the cause-of-death ranks. This study simply shows that diabetes is a frequent cause of death,” Roglic said.

Researchers conducted the study using a generic formal disease model software program called DisMod II, a multistate life model used to evaluate disease burden. It was developed for the Global Burden of Disease 2000 study.

Information from a previous WHO study that included population-based age and sex-specific diabetes prevalence from 40 countries was applied to United Nations estimates to determine the number of people with diabetes in the year 2000.

DisMod II used four age-specific transition hazards: incidence, remission, case fatality and an “all other mortality” hazard. The analysis examined patients in different age groups and either healthy, diseased or dead. Deaths were categorized into two causes, either from the actual disease or from all other causes. Six disease-specific input variables were examined, including incidence, remission, case fatality/relative risk for total mortality, prevalence, duration and mortality.

Deaths worldwide due to diabetes were estimated to be 1 million in developed countries and 1.9 million in developing countries. By gender, there were 1.5 million women and 1.4 million men who died. The percentage of excess deaths due to diabetes was lowest in the poorest African countries and in several Asian countries. The numbers were highest in North America and in the Middle East.

“It is interesting to find that in low-income regions, where diabetes is often not perceived as being a public health problem, the mortality attributable to diabetes is nevertheless considerable,” Roglic said.

In developing countries, approximately one in 10 deaths in individuals aged 35 to 64 years can be attributed to diabetes. In the poorest countries, that number is at least one in 20.

Seventy-five percent of deaths in patients with diabetes under the age of 35, 59% in patients aged 35 to 64 and 29% in patients over the age of 64 were attributable to the disease.