BERLIN – The first-ever dementia risk score designed specifically for patients with type 2 diabetes has successfully undergone external validation and is ready for everyday use by clinicians, Rachel A. Whitmer, Ph.D., said at the annual congress of the European College of Neuropsychopharmacology.
Patients with type 2 diabetes are on average twice as likely to develop dementia as are nondiabetics. But within the diabetes population, the magnitude of risk varies enormously. The Diabetes-Specific Dementia Risk Score pins down an individual’s 10-year risk more precisely. The predictive factors are easily obtained from a patient’s medical history, enabling primary care physicians, endocrinologists, psychiatrists, and neurologists to readily calculate an individualized risk score without resorting to cognitive function testing or other labor-intensive measures.
Dr. Rachel A. Whitmer
“This is a risk score that can easily be determined in a primary care setting. It can be done by self-report. It can be done using an electronic medical record. This is a way to tell someone what their risk is. Knowing your risk might encourage patients to take steps to reduce that risk. And if their risk is low you can show it to them and say it’s all the more reason to avoid getting diabetes complications – because it’s not just about your diabetes, it’s also for your brain health,” said Dr. Whitmer, a research scientist at the division of research, Kaiser Permanente Northern California, Oakland.
She and her coinvestigators harnessed the Kaiser Permanente Northern California Diabetes Registry to develop the risk score. They evaluated 45 candidate predictors in nearly 30,000 registry participants age 60 or older with type 2 diabetes, 5,173 of whom developed dementia during 10 years of follow-up. Once they’d developed the risk score, which is based upon the eight strongest predictors, they validated it in a cohort of 2,413 type 2 diabetic patients at Group Health of Puget Sound. The validation study was published last year (Lancet Diabetes Endocrinol. 2013;1:183-90).
The predictive variables are age, education, depression, microvascular disease, acute metabolic events, cerebrovascular disease, cardiovascular disease, and having a diabetic foot.
Here’s how the Diabetes-Specific Dementia Risk Score works: A patient gets 0 points for being age 60-64, 3 for being 65-69, and so on up to a maximum of 10 points for being age 85 or more. A history of an acute metabolic event is worth 2 points, as is cerebrovascular disease or depression. Microvascular disease or cardiovascular disease are 1 point each. A college education is worth minus 1 point, a high school education or less gets 0 points. The points awarded for the eight predictors are added up. In the validation study, the 10-year risk of dementia ranged from a low of 5% in patients with a net score of minus 1 to 73% in patients with a score of 12-19.
Dr. Whitmer sees the risk score as being particularly well-suited as a tool for dementia screening of type 2 diabetes patients by primary care physicians. She noted that, today, well-managed diabetic patients have a podiatrist, dietician, and dentist, as well as a physician, all working to prevent the physical complications of diabetes. But there’s not typically anyone looking out for the diabetes patient’s brain health.
“I think it’s time now when we’re taking care of diabetic individuals that we need to think about the brain,” she said.
Numerous earlier studies conducted using the Kaiser Permanente Northern California Diabetes Registry have been instrumental in helping to establish vascular complications, depression, and hypoglycemic episodes as events that markedly elevate the risk of dementia among people with type 2 diabetes.
“The question is, if we can treat depression more effectively and manage glycemic control and prevent vascular complications, can we lower the risk of dementia in these people who are at particularly high risk? That’s where the field is right now. There are trials ongoing in people with diabetes and prediabetes looking at this question,” Dr. Whitmer noted.
The question takes on some urgency, she continued, because the intersection of type 2 diabetes and dementia looms ahead as an enormous public health problem. The International Diabetes Federation estimates that there are now 392 million people worldwide with diabetes, and that by 2035 this figure will climb to 592 million. Meanwhile, other projections are that the worldwide population of individuals with dementia will jump from just under 50 million today to more than 125 million by 2050, with most of the growth coming from low- and middle-income countries where the average lifespan is increasing.
The risk score project was supported by Kaiser Permanente and the National Institutes of Health. Dr. Whitmer reported having no financial conflicts.