About 29 million Americans have diabetes, according to the Centers for Disease Control and Prevention. (Reuters)

Nearly four times as many Americans may die of diabetes as indicated on death certificates, a rate that would bump the disease up from the seventh-leading cause of death to No. 3, according to estimates in a recent study.

Researchers and advocates say that more-precise figures are important as they strengthen the argument that more should be done to prevent and treat diabetes, which affects the way sugar is metabolized in the body.

“We argue diabetes is responsible for 12 percent of deaths in the U.S., rather than 3.3 percent that death certificates indicate,” lead study author Andrew Stokes of the Boston University School of Public Health said in an interview.

About 29 million Americans have diabetes, according to the Centers for Disease Control and Prevention. There are two forms of the disease: Type 1, in which the pancreas makes insufficient insulin, and the more common Type 2, in which the body has difficulty producing and using insulin.

Using findings from two large national surveys, the study looked mainly at A1C levels (average blood sugar over two to three months) and patient-reported diabetes. In the latest study, researchers compared death rates of diabetics who had participated in these surveys to information on their death certificates.

(Centers for Disease Control and Prevention)

The authors also found that diabetics had a 90 percent higher mortality rate over a five-year period than nondiabetics. This held true when controlling for age, smoking, race and other factors.

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“These findings point to an urgent need for strategies to prevent diabetes in the general population. For those already affected, they highlight the importance of timely diagnosis and aggressive management to prevent complications, such as coronary heart disease, stroke and lower-extremity amputations,” Stokes said.

“We hope a fuller understanding of the burden of disease associated with diabetes will influence public authorities in their messaging, funding and policy decisions, such as taxation of sugar-sweetened beverages and use of subsidies to make healthy foods more accessible,” he said.

When they embarked on the study, the investigators were curious about two findings from earlier research. The first was a higher obesity rate and shorter life expectancy among Americans than Europeans. (The researchers already knew that obesity and diabetes were related.) The second revelation was a rise in deaths by any cause among middle-aged white Americans.

“We tried to piece together causes of mortality in the U.S., looking closer at diabetes, which we knew was underreported,” Stokes said.

Mortality rates attributed to diabetes are imprecise largely because death results from both immediate and underlying causes, and not every one of them gets recorded. For example, cardiovascular disease might be recorded as the cause of a person’s death even though that disease may have been caused by diabetes.

Further challenging the task of identifying cause of death is that diabetics have a long history of problems before serious complications occur.

“When diabetes started 10 to 30 or more years before a patient died, the disease may not be in the forefront of the attending physician at time of death,” explains Catherine Cowie, an epidemiologist at the National Institute of Diabetes and Digestive and Kidney Diseases. And there are no clear guidelines about which conditions should be cited as cause of death.

Detailed electronic medical records may help pinpoint the primary cause. “But still, it’s hard [to get the full picture] in this day and age when health care for diabetics is divided between different practitioners,” she said.

She advises patients to report their diabetes to all their health providers, whether they are having complications at the time or not.

“We’ve been trying to promote healthy lifestyle to prevent diabetes and complications for a long time. This includes paying attention to ‘the ABCs,’ which are to bring down A1C, blood pressure and cholesterol. But I think this [study] is new evidence that it’s important to focus on these things. It’s more data to show what diabetes can lead to,” Cowie says.

In 2016, diabetes accounted for about $1.04 billion in National Institutes of Health funding, compared with about $5.65 billion spent on cancer research. Having a better gauge on the mortality figures could have an effect on research dollars, said Matt Petersen, managing director of medical information for the American Diabetes Association.

But the true death rate means only so much.

“What’s most important is why it is and what we can do about it. The goal of research is prevention and, if possible, cure. Short of uncovering a cure, key is figuring out how do we best treat it and reduce complications,” Petersen said.

For Type 2 diabetes, new drugs that work in combination and in different ways to address differing patient cases have rolled out in just the past two years. Healthy lifestyle choices can also affect outcomes.

“So I think the public should hear [that] yes, diabetes can be deadly, but that we have the ability to reduce the chance for this disease,” Petersen says. “And for those who have diabetes, we can treat it well and reduce the risk for debilitating and deadly complications.”

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