Annual Diabetes Mortality Rate Significantly Underestimated

Findings from a new study suggest that diabetes accounts for 12% of annual deaths in the United States, which is significantly higher than previously estimated.

These findings make diabetes the third-leading cause of death in the United States, according to a study published by PLOS ONE. The mortality rate of diabetes is still outpaced by deaths related to heart disease and cancer.

"Another way of saying that is, if diabetes were eliminated as a disease process, the number of deaths would decline by 12%," said researcher Samuel Preston, PhD. "There has been only 1 similar, earlier research effort, and it was based on data from the 1980s and early '90s. It showed deaths attributable to diabetes amounted to roughly 4% of total deaths."

The investigators determined diabetes-related mortality through examining the National Health and Nutrition Examination Survey (NHANES) and the National Health Interview Survey (NHIS).

"These are the 2 major health surveys in the United States," said researcher Andrew Stokes, PhD. "We can follow people into death records and compare those who have diabetes to those without diabetes."

The investigators observed 282,000 patients who self-reported diabetes status from the NHIS, and 21,800 patients from the NHANES, which included hemoglobin A1c measures. These measurements helped identify those who have diabetes, even if they are unaware of their condition.

The investigators found that patients with diabetes have a 90% higher mortality rate compared with patients who do not have diabetes, according to the study.

Since diabetes is significantly underreported as the underlying cause of death, the disease’s contribution to mortality has not been as high as it should have been.

"When we monitor trends in the health of populations," Dr Stokes said, "and we look at the mortality statistics, some major threats to US mortality and life expectancy stand out, like drug and alcohol poisonings and suicide. Diabetes didn't."

The US government releases annual mortality estimates for multiple disease states. Patients with diabetes typically have comorbidities, such as cardiovascular and kidney disease, therefore, it can be difficult to precisely conclude the cause of death, according to the study. This uncertainty can lead to an inaccurate death certificate, which causes mortality rate estimates to be incorrect.

"There is only one underlying cause of death on a death certificate," Dr Preston said. "Diabetes is not listed as frequently as it is involved in the death of individuals."

Given the rapid increases in diabetes prevalence, a more accurate view of the disease is critical. The CDC estimated that 5.53 million people had diabetes in 1980, with that number skyrocketing to 21.95 million in 2014, according to the study.

"American life expectancy has been growing at a very slow rate for the past decade or so, even decreasing slightly in 2015," Dr Preston said. "It hasn't yet been established statistically, but it's fairly likely that obesity and diabetes together are an important factor in this slowdown. We believe that these estimates will prove useful in helping to more precisely identify their roles."

The authors believe that these findings show the overwhelming need for large public health initiatives to prevent diabetes prevalence from increasing further.

"What our results point to is the need for strategies at the population level to combat the epidemics of obesity and diabetes,” Dr Stokes concluded. “We need something on a population scale because it's a major issue. It's not an issue that's confined to certain subsets of the population."