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 number three, according to estimates in a recent study, reports The Washington Post.
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 metabolised in the body.
“We argue diabetes is responsible for 12% of deaths in the US, rather than 3.3% that death certificates indicate,” lead study author Andrew Stokes of the Boston University School of Public Health said.
About 29m Americans have diabetes, according to the Centres for Disease Control and Prevention. 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.
The authors also found that diabetics had a 90% higher mortality rate over a five-year period than non-diabetics. This held true when controlling for age, smoking, race and other factors.
“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 US, looking closer at diabetes, which we knew was under-reported,” 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 in the report.
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 $1.04bn in US National Institutes of Health funding, compared with about $5.65bn spent on cancer research. Having a better gauge on the mortality figures could have an effect on research dollars, said Matt Petersen, MD of medical information for the American Diabetes Association.
But, the report says, 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.”
Abstract
Objective: The goal of this research was to identify the fraction of deaths attributable to diabetes in the United States.
Research Design and Methods: We estimated population attributable fractions (PAF) for cohorts aged 30–84 who were surveyed in the National Health Interview Survey (NHIS) between 1997 and 2009 (N = 282,322) and in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2010 (N = 21,814). Cohort members were followed prospectively for mortality through 2011. We identified diabetes status using self-reported diagnoses in both NHIS and NHANES and using HbA1c in NHANES. Hazard ratios associated with diabetes were estimated using Cox model adjusted for age, sex, race/ethnicity, educational attainment, and smoking status.
Results: We found a high degree of consistency between data sets and definitions of diabetes in the hazard ratios, estimates of diabetes prevalence, and estimates of the proportion of deaths attributable to diabetes. The proportion of deaths attributable to diabetes was estimated to be 11.5% using self-reports in NHIS, 11.7% using self-reports in NHANES, and 11.8% using HbA1c in NHANES. Among the sub-groups that we examined, the PAF was highest among obese persons at 19.4%. The proportion of deaths in which diabetes was assigned as the underlying cause of death (3.3–3.7%) severely understated the contribution of diabetes to mortality in the United States.
Conclusion: Diabetes may represent a more prominent factor in American mortality than is commonly appreciated, reinforcing the need for robust population-level interventions aimed at diabetes prevention and care.
Authors
Andrew Stokes, Samuel H Preston
[link url="https://www.washingtonpost.com/national/health-science/diabetes-is-even-deadlier-than-we-thought-study-suggests/2017/04/07/28689b94-faca-11e6-be05-1a3817ac21a5_story.html?utm_term=.2d70cc057904"]The Washington Post report[/link]
[link url="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170219"]PLOS Medicine abstract[/link]