Having either previously known or newly diagnosed diabetes was linked to an increased risk for dementia over just a few years, according to a new study published in the journal Diabetes Care.
In just the last couple of years, a number of studies have looked at the relationship between diabetes, blood glucose levels, and dementia. In particular, an earlier diagnosis of type 2 diabetes and poorly controlled type 2 diabetes have been linked to a higher dementia risk, and both high and low glucose have been linked to a higher dementia risk in people with type 1 diabetes. In addition to keeping blood glucose levels controlled as well as possible, there is evidence that the type 2 diabetes drug metformin, in particular, may help reduce the risk for dementia. Healthy lifestyle measures in general have also been tied to a lower dementia risk.
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For the latest study, researchers in South Korea looked at data from about 8.4 million people ages 40 and older who had a health examination in 2009 or 2010. Participants were followed for just a few years, until 2016, to see if they received a new diagnosis of dementia (any type of dementia). The researchers were particularly interested in how diabetes status, and blood glucose status in people without diabetes (normal glucose or impaired fasting glucose) affected the risk for dementia.
Established and new diabetes linked to increased dementia risk
The researchers found that both diabetes known at the beginning of the study and newly diagnosed diabetes were linked to an increased risk for dementia. Participants who received a diabetes diagnosis during the follow-up period were 45% more likely to also receive a dementia diagnosis during that period, compared with those without diabetes and with normal glucose levels. Participants with known diabetes that was diagnosed less than five years before the beginning of the study 32% more likely to develop dementia, and participants with known diabetes that was diagnosed five years or longer before the beginning of the study were 62% more likely to develop dementia. Participants with impaired fasting glucose were only 1% more likely to develop dementia, compared with those without diabetes and with normal glucose levels.
The researchers concluded that both previously diagnosed and newly diagnosed diabetes increased the short-term risk for a dementia diagnosis, while impaired fasting glucose barely had any impact on this risk. These results indicate that to help prevent dementia, it may be especially important to identify people with impaired fasting glucose and intervene — through lifestyle programs or by prescribing drugs, as appropriate — to help prevent the condition from progressing to diabetes.
Want to learn more about maintaining cognitive health with diabetes? Read “Nine Tips to Keep Your Memory With Diabetes,” “Staying Sharp: Seven Ways to Keep Your Brain Healthy With Diabetes,” “Keeping Your Brain Strong With Diabetes” and “Memory Fitness: How to Get It, How to Keep It.”
