(CNN) -- The number of Americans with diabetes will nearly double in the next 25 years, and the costs of treating them will triple, according to a new report.
The figures, in a University of Chicago report released Friday, add fuel to the congressional debate regarding reining in the cost of health care.
By 2034, 44.1 million Americans will be living with diabetes -- nearly twice the current number of 23.7 million, according to the report, published in the December issue of the journal Diabetes Care. About 90 percent of those with diabetes have type 2, a version of the condition that develops over time.
Accounting for inflation, the direct medical cost of treating them will rise from $113 billion annually to $336 billion, the report says.
Current health care proposals in Congress attempt to slow the growth of spending on chronic diseases such as diabetes by funding programs to prevent disease in the first place, and by offering incentives for insurers and medical providers to encourage early treatment through so-called "accountable care organizations."
In those organizations, doctors might be paid a flat fee to treat a diabetes patient for a year, with bonuses if they meet certain benchmarks of patient health.
The staggering numbers in the new paper dwarf potential savings that have lately been discussed. For example, Health and Human Services Secretary Kathleen Sebelius earlier this month released a report urging improvements in diabetes care. If the most successful statewide programs for controlling diabetes could be duplicated nationwide, it estimates, annual savings from reducing hospitalizations and treatment for various complications would total $216 million.
The numbers are disturbing, said Dr. Elbert Huang, an assistant professor of medicine at the University of Chicago and lead author of the report. But he said he considers the predictions "very conservative" because they don't account for the growing proportion of overweight children and teenagers, who are at higher risk for developing diabetes.
The estimates also don't factor in immigration, or the rising population of ethnic minorities. Latinos and African-Americans suffer diabetes at higher rates than the U.S. population as a whole.
Type 1 diabetes is a condition in which a person loses the ability to break down glucose in the blood and turn food into energy. The condition often develops when people are young.
In type 2 diabetes, the condition develops over time. The process is complex, but aside from ethnic background, risk factors include having a family history of diabetes, high blood pressure or heart disease. The most common risk factor is simply being overweight.
Even modest weight loss will reduce the chance of developing type 2 diabetes, according to the Centers for Disease Control and Prevention.
More ambitious lifestyle changes, such as diet, regular exercise and assistance through counseling lowered the risk of diabetes by 58 percent, even without medication, in a major federally funded study.
The model used by Huang and his colleagues assumes that the prevalence of diabetes in each age group will stay constant, but that the number of cases will grow as the population gets older. For the Medicare-eligible population alone, the paper predicts the diabetes caseload will rise from 8.2 million people to 14.6 million, and that the total annual cost of treatment will go from $45 billion to $171 billion.
To estimate cost, the researchers assumed that the standard progression of the disease, and mix of therapies used to treat it, will remain constant. According to a 2005 federal report, nearly three in four adults with diabetes uses oral medication to control the disease. About one in four takes insulin.
Diabetes is the leading cause of kidney failure, according to the American Diabetes Association, and nerve damage and damaged blood vessels are also common. About 15 percent of diabetics require amputation of a lower extremity at some point in their life, according to a 1998 paper in Diabetes Care.
It's certainly possible that medical breakthroughs will improve care, but it's unlikely to lead to lower costs, Huang said. "In the past, in general, medical discoveries have driven costs up, not down."
The study was funded by the company Novo Nordisk, which makes insulin delivery systems to treat diabetics. Novo Nordisk approved the final manuscript, but the authors say the company did not play a role in designing the study or collecting data.
"Without significant changes in public or private strategies, this population and cost growth are expected to add a significant strain to an overburdened health care system," the report concludes.
The new report is concerning, but doesn't change the big picture of health care spending, said Jonathan Gruber, an MIT economist who has schooled many politicians about the intricacies of health care.
"Even without this change, over the next 75 years we've made promises that exceed the revenues we have to pay for them," he said.
There's no compelling evidence that better preventive care can significantly reduce the cost of treating diabetes, Gruber said, but he believes accountable care organizations could make a big impact. He also likes the idea of allowing insurers to charge higher premiums to people who don't meet certain health benchmarks, such as losing weight if they're obese.
"The thing about diabetes, it's among the most preventable of major illnesses," Gruber said. "We need to put patient financial incentives at stake."
Huang said he won't be surprised if the surge in diabetes turns out to be even worse than he projects.
"Prior estimates have all said there would be a dramatic rise in the diabetes type 2 population," he said, but in every case "the actual [diabetic] population has ended up being larger than the estimates."