KEYSTONE, Colo. -- The number of adults with type 1 diabetes is quietly and steadily climbing--and the American health care system is utterly unprepared to handle their needs.
So asserts Dr. Irl B. Hirsch, professor of medicine and holder of the Diabetes Treatment and Teaching Chair at the University of Washington, Seattle.
"The folks at [the Centers for Medicare and Medicaid Services] are not ready for the impact of type 1 diabetes in the Medicare age group over the next 10 years. I'll say it publicly: They are clueless," Dr. Hirsch declared at the conference, sponsored by the University of Colorado at Denver and the Children's Diabetes Foundation at Denver.
Adult type 1 diabetes poses huge public health issues, in part because of physician workforce constraints. This is a disease that will of necessity be managed primarily by nonendocrinologists, he said.
The projected number of internal medicine-trained clinical endocrinologists is nowhere close to meeting the growing demand for management of type 1 diabetes in adults. Primary care physicians do not have the skill set or time to provide state-of-the-art diabetes management. Few geriatricians are trained in type 1 diabetes. So the task, by default, will fall upon the shoulders of the midlevel providers--nurse practitioners, physician assistants, diabetes educators, and registered dieticians, he predicted. And he's just fine with that.
"The DCCT [Diabetes Control and Complications Trial] was done by midlevel practitioners. That's how we run our clinic, too," he said. "The midlevels are going to be in charge, there's no doubt in my mind. And this will work."
The incidence of type 1 diabetes is doubling roughly every 2 decades in developed nations. The rising population of U.S. adults with type 1 diabetes has two sources: a steady increase in patients with new-onset type 1 disease arising in their 30s, 40s, and beyond, and improved longevity of patients with childhood-onset type 1 diabetes.
"In our clinic, the biggest surprise for our internal medicine residents and our endocrine fellows is how many of our patients are diagnosed after the age of 20. It's a lot. I can't say exactly, but it's easily over a quarter of our type 1 patients who are diagnosed after age 20," said Dr. Hirsch.
The age record at the Seattle clinic is held by a patient who presented at age 92 with newly diagnosed, autoantibody-positive type 1 diabetes and a history of Graves disease and vitiligo.
"We [don't] really understand the epidemiology and demographics of type 1 diabetes in adults .... But now with the better treatments, having patients live for 50 years with type 1 diabetes is routine. It's not a big deal anymore," he said.
A large new research grant from the Leona M. and Harry B. Helmsley Charitable Trust is going to provide badly needed data on type 1 diabetes in adults.
"You'll be hearing a lot more about this project soon. We're in the midst of planning a very large registry of patients called the Type 1 Diabetes Exchange, where we hope eventually to have data on 100,000 individuals," said Dr. Hirsch.
With regard to new-onset type 1 diabetes in adults, Dr. Hirsch highlighted a well-documented Italian study that demonstrated that the incidence in Northern Italians aged 30-49 years was similar to that in 15- to 30-year-olds. Among males there were twin peaks in incidence: one at age 10-14, and a second at age 45-49. The trend in females was similar except that the second peak wasn't as high as the first (Diabetes Care 2005;28:2,613-9).
Dr. Hirsch said that by a very conservative estimate there are 1.1 million American adults with type 1 diabetes of either the classic type or latent autoimmune diabetes of adults (LADA), a group whose absolute need for exogenous insulin is somewhere between that of classic childhood-onset type 1 diabetes and adult type 2 disease. By a recent estimate, LADA accounts for 2%-12% of all cases of diabetes (J. Clin. Endocrinol. Metab. 2009;94:4,635-44).
He does not include in his tally of adults with type 1 diabetes the very large group with what is often called "type 1.5" disease: that is, phenotypic type 2 disease with autoantibody positivity. Type 1.5 diabetes is roughly two- to threefold more common than classic childhood-onset type 1 diabetes, but there is not as yet agreement on how to classify it. He excludes them from the type 1 diabetes category because type 1.5 patients have major problems with obesity and metabolic syndrome, which are not issues in managing type 1 disease or LADA.
The forecast is that in the year 2019 there will be roughly 3,200 internal medicine-trained adult endocrinologists. Assuming that close to half of them are not seeing any new patients because they are fully booked, or are not taking new diabetic patients because the reimbursement is paltry compared with the effort required in state-of-the-art disease management, or due to pressing research or administrative responsibilities, that would work out nationwide to 636 type 1 diabetic patients per practicing endocrinologist. That's just not realistic, Dr. Hirsch said.