New Score Predicts Dementia Risk for Type 2 Diabetics: How Useful Might This Be?

Michael Gordon MD, MSc, FRCPC is a geriatrician working at Baycrest Health Science System. He is medical program director of the palliative care program, co-head of the clinical ethics program and a professor of Medicine at the University of Toronto. He is the author of Late Stage Dementia, Promoting Compassion, Comfort and Care; Moments that Matter: Cases in Ethical Eldercare, Brooklyn Beginnings: A Geriatrician's Odyssey, and Parenting Your Parents.

One of the tenets of modern medicine that is tied up to its cultural values is the benefit of prediction. The question for trying to anticipate the future is not limited to medicine but many other aspects of life. It is also not limited to the current era. Throughout human history, people have sought to try and find out “what will be” whether they are world rulers, religious leaders, or just ordinary folks. The many rituals and rites of humanity that have developed over the millennia are often attempts to foretell the future or try and influence through planning or prayer—whichever belief systems works for that individual or within that culture. In the world of high finance, for example, economic “modelling” is the computer-based input of all the known or presumed parameters that might be available which presumably increases one’s chances of making the correct and most valuable economic decisions. From our knowledge of human history, including our own contemporary times, most of us realize that these projections often fall completely flat for reasons that the pundits then are asked to explain through the use of post-hoc analysis.

What do physicians and healthcare planners do with a study that shows that one can look at wide range of factors that one can measure in those with type 2 diabetes that presumably can increase the predictive value of who might develop cognitive impairment or full-blown dementia? This research may supplement or complement the recent study that suggested that one’s ambient levels of glucose control over many years may be a factor in predicting dementia. In essence this most recent study may just be an extension of previous work in the field.

The study itself, reported recently in The Lancet Diabetes and Endocrinology in the August, 20 2013 issue is the outcome an analysis of “longitudinal data from the Kaiser Permanente Northern California Diabetes Registry, including almost 30,000 diabetics age 60 and older, to create a prediction model for development of dementia over 10 years. The model was then validated in a separate cohort of more than 2,000 similar patients from Washington State.”

The risk score that the researchers developed was based on the well-known complication sof diabetes and are those that indicate blood vessel disease, which is congruent with the current understanding in general of underlying risk factors for dementia beyond the amyloid theory or supplementing the risk factors for the development of amyloid in those individuals at risk for whatever other reasons such as genetic factors that may have already been or will be identified in the future. These diabetic complications and indicators of vascular disease included from the study: “micro vascular disease, diabetic foot, cerebrovascular disease, cardiovascular disease, acute metabolic events, depression, older age and less education. Point values were assigned to each factor, and patients were stratified into 14 risk categories, to create what the researchers called the type 2 diabetes-specific dementia risk score (DSDRS).”

The article demonstrates the predictive value of the scores. They are probably valid in that they determine the burden of vascular disease which if our understanding is correct must increase the risk of dementia development. With two concurrent diseases of high prevalence--both diabetes and dementia--seen in increasing age, it is not surprising that there would be a correlation. The question and perhaps challenge for physicians, especially those who care for the middle-aged adult, the young adult, and the more advanced elderly population is: What can we do with this enhancement of our knowledge about “cause and effect”. We have all been through the experience of trying to encourage our patients to change their lifestyles avoid smoking-related illness, with some benefit, but most of the benefit has come from public policy including making smoking more difficult in public places, social gathering places and by increasing the cost of buying tobacco products. The so-called obesity epidemic is another example of how knowledge does not necessarily get translated into actions which for many human beings are not easy when faced with myriad food choices and an industry that promotes eating especially eating large quantities as was entertainingly demonstrated by that 2004 film Supersize Me.

Physicians can only try and provide their patients with the most potent and cogent information and inducements to change their lifestyle in an attempt to improve control of type 2 diabetes with the most potent effect resulting from eating habits and exercise—much more difficult for physicians to affect than provision of medications—but these, too, may be of value. Whether individuals will respond more positively when told that what they are doing is bad for their brains, than they do when told it is bad for their heart remains to be seen. But more understanding is always better than less, as medical and other healthcare professionals do whatever we can to decrease the risk of developing a terribly disabling condition that affects individuals and their families in a way that few other illnesses do.