Oral Diabetes Drug May Protect Elderly From Dementia

Prescription of an older class of type 2 diabetes drugs called glitazones, also known as thiazolidinediones or TZDs, is associated with a 22% reduced risk of dementia, according to a long-term study published in the journal BMJ Open Diabetes Research & Care.  

These drugs may effectively prevent dementia in vulnerable patients with mild or moderate type 2 diabetes, and thus are highly potential to be repurposed, suggest the researchers.

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The Association Between Diabetes and Dementia

Diabetes is a known risk factor for dementia, although the mechanism is not fully understood. Nevertheless, it is believed that diabetes can increase the risk of developing vascular dementia and Alzheimer’s disease by as much as two times. 

This might be related to the deposition of abnormally folded proteins, as well as metabolic and vascular changes in the brain of dementia patients, as diabetes is known to damage blood vessels throughout the body, especially the small vessels.

In this study, researchers drew on the electronic health records of 559,106 people diagnosed with type 2 diabetes from the national Veteran Affairs (VA) Health System, spanning the period from January 2000 to December 2019. Only patients aged at least 60 and given the first prescription of metformin, or sulfonylurea, or a TZD between January 2001 and December 2017 were included in the study, and their health was tracked for an average of nearly 8 years.

Those who took thiazolidinedione showed an 11% lower risk of Alzheimer’s disease and a 57% lower risk of vascular dementia, as revealed in the result. In contrast, the risk of dementia from any cause was 12% higher among folks who used a sulfonylurea drug alone for their diabetes.  

Patients under age 75 seem to gain more benefits from thiazolidinedione than the older population, and surprisingly, these drugs seemed to be more protective in people who were overweight or obese.

More Studies Needed for the Highly Potential Repurposing Target  

However, as this is an observational study, there is no causal relationship to be identified. And the researchers acknowledge that certain potentially influential information wasn’t available, including kidney function and genetic factors, and those study participants were predominantly male and White.

Another drawback of this approach is that thiazolidinediones can have side effects including weight gain, liver problems, and vision problems, while some may be severe. One drug in this class, rosiglitazone, has been removed from the market in several countries due to serious heart risks. 

Thus, it is concluded to be too early to recommend the widespread use of anti-diabetic agents of any class for the prevention of dementia, but undoubtedly TZD will become the focus of scientists.

Author

Nai Ye Yeat