Over the same period, spending on diabetes will almost triple, rising from $113 billion to $336 billion, even with no increase in the prevalence of obesity, researchers based at the University of Chicago report in the December issue of Diabetes Care .
The number of those with diabetes covered by Medicare will rise from 8.2 million to 14.6 million, the researchers predict. Medicare spending on diabetes will jump from $45 billion to $171 billion.
"If we don't change our diet and exercise habits or find new, more effective and less expensive ways to prevent and treat diabetes, we will find ourselves in a lot of trouble as a population," said the study's lead author Elbert Huang, MD, assistant professor of medicine at the University of Chicago.
"Without significant changes in public or private strategies," the authors wrote, "this population and cost growth are expected to add a significant strain to an overburdened health care system."
The new estimates are far more rigorous, and more troubling, than previous predictions.
A 1991 study stated that the number of Americans with diabetes would double, from 6.5 million in 1987 to 11.6 million by 2030, which, as it turns out, is less than half the number of cases in 2009. "These projections stress the importance of prevention and education," the authors declare. "The requisite change in life style, exercise, or nutrition habits will be more difficult than if a drug is developed for treatment."
A 1998 study foretold more cases sooner: 22 million US cases by 2025. "Worldwide surveillance of diabetes is a necessary first step towards its prevention and control, which is now recognized as an urgent priority."
A 2001 study predicted 29 million cases by 2050. The authors of that study warned that their projection may be "more alarming than previously believed," adding that the "economic cost of diabetes is already staggering."
A retrospective 2008 study confirmed the predicted trends, showing that the number of Americans diagnosed with diabetes rose steadily from 10 million in 1994, to 14 million in 2000, to 19 million in 2007, and the annual cost--just for drugs--for people affected by diabetes nearly doubled in six years, rising from $6.7 billion in 2001 to $12.5 billion in 2007.
The most recent and alarming prediction may even be a bit conservative. It is based on the assumption that the prevalence of the overweight and obese in the United States will remain relatively stable.
Although obesity levels have gone up steadily for many years, the authors predict that the obesity levels for the non-diabetic population will top out in the next decade, then decline slightly, from 30 percent today to about 27 percent by 2033. "Despite recent trends in obesity rates," Huang explained, "we anticipate that the population will reach an equilibrium in obesity levels, since we cannot all become obese."
The 2009 Diabetes Care study places increased emphasis on changes in demographics, advances in treatment, and the natural history of this disease, including the timing and frequency of its costly complications. Much of the increase in cases and in costs will be driven by aging "baby boomers," the 77 million Americans born between 1946 and 1957 who are approaching the age of retirement, diabetes complications, and federal health insurance.
Various characteristics of the modern natural history of diabetes and its treatments contribute to increasing the costs of diabetes for the population. People with diabetes are now being diagnosed at younger ages. Thanks to better treatments, they are living longer. This leads to a longer history of disease, opportunities for more aggressive therapies, and time to accumulate complications, which are costly to treat. Diabetes is the leading cause of blindness, end-stage kidney disease and amputations.
The study was done to help forecast the impact of alternative policy scenarios as Congress debates changes in the health care system, particularly to Medicare.
"The public policy implications are enormous," said co-author Michael O'Grady, PhD, senior fellow at the National Opinion Research Center at the University of Chicago. "This a serious challenge to Medicare and every other health plan in the country. The cost of doing nothing is the significant increase in the pain and suffering of America's population and a financial burden that will threaten the financial viability of public and private insurers alike."
"We built this model to improve the budgetary and health outcome information available to federal policymakers," the researchers explained. It provides a rigorous assessment of the future burden of diabetes and can also be used to provide estimates of the impact of alternative policy scenarios. They predict that the growth in diabetes costs will exceed current projections of total Medicare spending.
The National Changing Diabetes Program of Novo Nordisk, a maker of insulin, funded the study. The University of Chicago investigators are co-investigators of the NIDDK Diabetes Research and Training Center. Additional authors were Anirban Basu of the University of Chicago and James Capretta, now at Civic Enterprises, LLC, in Washington, DC.