In people with diabetes, does controlling blood glucose levels counteract the risk of dementia? Decoded Science asked Dr. Crane, who responded,
“We don’t know because we were not an interventional study / randomized controlled trial. What we do show is that among people who have diabetes (just as among those who did not have diabetes) higher average glucose levels were associated with higher risk of dementia.
There are a lot of reasons people with diabetes should aim for good control of their blood sugar. We do not KNOW that tighter control equals lower personal risk of dementia (that would take a different study design), but our data were consistent with that. (Note that the bottom part of the U shape in Figure 1b went away when we removed the three people with very atypical natural histories of diabetes.)”
Dr. Crane also told Decoded Science that those with high blood sugar should,
“…Work closely with their healthcare provider, this may provide additional impetus to aim for good blood sugar control. This was an observational study, and the main implications are for how researchers think about brain risk. If people needed additional push to begin an exercise program, that might be an appropriate thing. But again, we don’t KNOW from this study that interventions within a person to change glucose levels would be associated with personal reduced risk for dementia.”
We asked Dr. Crane if he had any final thoughts or comments for our readers, and he replied,
“One of the things that I think is really exciting about this study is that the exposure data come from routine clinical care. We had permission from our study participants to use anything from their medical records that would be useful to us. We used computerized clinical data for careful epidemiological research, solving the problem of how to take data collected at varying intervals from people and transform them into a nice exposure for analyses. This is a very efficient and exciting way of doing scientific research, and I think people should be excited at the prospect that data generated from routine clinical care may be useful to lead to new insights about human health.”
Dementia Risk and High Glucose
The risk of dementia increased as the glucose levels increased, even in the participants that didn’t have diabetes. Dr. Crane cautioned people not to try crazy diets because this study doesn’t show that changes in behavior can lower your blood glucose levels or decrease your chance of developing dementia. However, adopting a healthy lifestyle of eating the right foods and exercising won’t hurt either. Talk to your doctor to see what changes are right for you.
Alzheimer’s Association. Latest Facts and Figures Report. (2013). Accessed August 11, 2013.
Crane, P., Walker, R., Hubbard, R., et al. Glucose Levels and the Risk of Dementia. (2013). The New England Journal of Medicine. Accessed August 11, 2013.
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