Patients with type 2 diabetes are twice as likely to develop dementia as those without the disease, but predicting who has the highest future risk is difficult. Now researchers at Kaiser Permanente and the University Medical Centre Utrecht have created the first risk score that can provide an estimate of the 10-year individualized dementia risk for individuals with type 2 diabetes, as reported in the inaugural issue of Lancet Diabetes & Endocrinology.
“While a few dementia risk scores exist, this is the first one that has been developed specifically for individuals with type 2 diabetes and encompasses diabetes-specific characteristics,” said Rachel Whitmer, PhD, epidemiologist at the Kaiser Permanente Northern California Division of Research,who led the study. “This risk score is crucial for the care of patients with diabetes since they are particularly susceptible to dementia. It provides clinicians with an easy and efficient tool to know their patients’ chances of developing dementia over the next 10 years.”
Using data from two longitudinal cohorts of almost 30,000 patients with type 2 diabetes aged 60 and older, with 10 years of follow-up, the researchers developed and validated a diabetes-specific dementia risk score. The predictive test uses information about metabolic events, cerebrovascular disease, depression, education, age, cardiovascular disease, microvascular disease and diabetic foot, and assigns each a value related to their association with dementia. Combining these, an overall score can be assigned to the patient, indicating the 10-year probability of developing dementia.
Individuals in the lowest category of the 20-point risk score had a 5.3 percent chance of developing dementia over the next 10 years, while those in the highest category had a 73 percent chance. Compared to those in the lowest category, those in the highest were 37 times more likely to get dementia.
All predictors included in the Diabetes-Specific Dementia Risk Score are easy to obtain and based primarily on medical history, so the risk score can be easily calculated during a routine medical visit or with electronic health records. No labor-intensive or expensive tests, such as cognitive function or brain imaging, are required.
“Unfortunately, there is an epidemic of both type 2 diabetes and dementia,” said Whitmer. “Early detection of diabetes patients who are at increased future risk of dementia could help to develop and target preventive treatment.”
“The risk score could be useful in the selection of high-risk patients for early intervention studies and for many applications of personalized medicine,” said Geert Jan Biessels, MD, professor of neurology at the University Medical Centre Utrecht and co-author of the study. “Clinicians can use it to guide their decisions in terms of clinical attention to incipient cognitive impairment which makes people vulnerable to dangerous side-effects of diabetes treatment. The risk score will also help us to understand the causes of diabetes associated increased dementia risk, because we can examine those at high risk in early stages of the dementia process.”
Additional authors on the study include Lieza G. Exalto, MD, of the Department of Neurology, University Medical Centre Utrecht, the Netherlands; Andrew J. Karter, PhD, of the Kaiser Permanente Division of Research, Oakland, CA; Elbert S. Huang, MD, of the Department of Internal Medicine, University of Chicago; Wayne J. Katon, MD, of the Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine; and Jerome R. Minkoff, MD, of the Kaiser Permanente Department of Endocrinology, Santa Rosa, CA .
The study was funded by grants from Kaiser Permanente Community Benefits, United Sates National Institute of Health, Utrecht University High Potential Grant, the Netherlands Organization for Health Research and Development, and a Fulbright fellowship.